First watt f2. Next in line is my F7.

First watt f2. Is a 250va 18-0-18 toroidal transformer undersized for a mono bloc for these amp types? What would be the ideal VA rating? Thank you! -David May 5, 2018 · Here are my pics for the Firstwatt F6. The place where audiophiles talk. MOSFETs Jul 4, 2016 · As many of you may know, First Watt is dedicated to exploring the performance quality of small, simple power amplifiers. It has been about 9 months since the introduction of the First Watt F1, and I have been very surprised to see everything going more or less according to plan. 75” H Mar 25, 2006 · Hi Guys, I am a complete newcomer to this hobby but would desperately like to build a First Watt F1 for my AKG K1000 headphones. Test #1: F1, F2 and Decware Zen Taboo on 12-ohm 101dB Zu Cable Druids: The F1 and F2 have an unfair advantage. Small See competitors, used pricing, and more. Each channel has only one gain stage and draws a constant 100 watts. 1% Matched online on Etsy India. It’s also the First Watt amp with the lowest part A community dedicated to helping everyone learn the art of audio. I am Apr 13, 2011 · Hi All I would like to bild a first Watt F2 or F3 for my Fostex fullrange horns, reading through a few threads it seems the F3 may be a more versitle amp so I am looking to get the circuit boards. Today, I tried hooking up a pair of REL subs in stereo configuration to my First Watt F2-J via the high level Speakon connection. Great condition. Find top brands, exclusive offers, and unbeatable prices on eBay. Are they very different to an Aleph amp ? Thanks thomasheisig 11-23-2005 10:52am 7 responses Add your response Lower Distortion. Small The F1 is a 10 watt per channel stereo amplifier operating in balanced single-ended Class A without feedback. Made only in small numbers by Nelson Pass, with no possibility of any further production, these amps are the holy grail for those looking for a solid-state solution for their high-efficiency single driver speakers. Today I compare both amps with 12BH7A Mar 1, 2021 · First Watt F2J with Karlsonator 0. 1 FREE download site for High End, HiFi, Pro & Vintage audio schematics & service manuals But like all the other First Watt amps so far – this one is different. However, in man places I read that First Watt are current amps (in opposed to voltage amps) and thus they can only be used with single drivers speakers. But the F5 is the product of numerous decisions that set it apart. First-Watt F2 [J] is the ony Single Ended PURE Class-A TRANSCONDUCTANCE Solid State Amplifier Design In Existence hyeah: Explore a wide range of our First Watt J2 selection. Jan 12, 2024 · Rare First Watt F2 Stereo Amp. with the right speakers -- even very good valve amps find themselves on the short end of one particular stick. MOSFETs May 7, 2023 · The First Watt Amplifier Thread Discussion in ' Audio Hardware ' started by avanti1960, May 7, 2023. The F1 and F2 are both current source (as opposed to voltage source) amplifiers with no feedback. That said, its the very best sounding Nov 28, 2012 · Re: First Watt F2 di Pass Da Contenuto sponsorizzato Contenuto sponsorizzato Argomenti simili » Nelson Pass A40, 40 Watt Class A amplifier » [VENDUTO] Sub attivo Polk Audio PSW111 150 WATT RMS - 300 WATT PICCO COLORE NERO € 150 » Biografia di Nelson Pass (Pass Labs) » Perchè 80 watt di un ampli non sono uguali ad 80 watt di un altro ampli? Dick Olsher famously remarked that “The first watt is the most important watt. Of all my First Watt amps, it has the best imaging, the largest soundstage and the deepest bass, thanks to it’s high(ish) Now that Nelson Pass published the details of the JFET upgrade to First Watt F2 and that Newark sells power JFETs from Semisouth, there was no excuse not to upgrade my Zen V4 with the new active device. It has no feedback and no voltage gain, only current gain. It's based Test #2: F1, F2 and Decware Zen Taboo on 16-ohm Lowther DX4 in Medallion III cabinet: My first up close & personal encounter with a Lowther in my own system came by way of the Second and Third Rethm. Check out our first watt f2 selection for the very best in unique or custom, handmade pieces from our shops. . I will be reading Dec 26, 2020 · Today, I tried hooking up a pair of REL subs in stereo configuration to my First Watt F2-J via the high level Speakon connection. That way, people can make comparisons to the amps already reviewed. It’s also the First Watt amp with the lowest part Dec 26, 2020 · Today, I tried hooking up a pair of REL subs in stereo configuration to my First Watt F2-J via the high level Speakon connection. Over the past four years, five such amplifiers have been designed as concept pieces and produced in limited quantities. Sounds great and guaranteed to work upon shipping. I didn't used pcb, is all hard wire point to point. Materials: IRFP240, MOSFET, IRFP9240 I have kitted up Matched IRFP240 & IRFP9240 MOSFETSs for your First Watt F2 Clone, F5 Clone, or M2X amplifier project. First Watt F2 6 16 2005 It has been about 9 months since the introduction of the First Watt F1 and I have been very surprised to see everything going more F2 Manual - First Watt F2 Manual - First Watt SHOW MORE ePAPER READ DOWNLOAD ePAPER firstwatt. Manual Library / First Watt First Watt F1 Stereo Power Amplifier (2004) add a review Aug 12, 2015 · Lager en liten tråd om First Watt F2, en av konstruksjonene til Nelson Pass. Projects by fanatics, for fanatics! Apr 12, 2017 · Official Court Jester Joined 2003 2017-04-12 1:25 pm #4 first - amp is made for enhanced type of devices , which means biasing voltage at gate of mosfet is positive ref. Don't wurry, be 'appy. Search ResultsNewsletter Subscribe to win a $90 OFF on NAKTO e-bikes! " The First Watt M2 is a two channel audio power amplifier delivering 25 watts per channel. Nov 5, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. These are short-run specialty products designed for extreme performance into limited-use applications. Use Hifi Shark to monitor pricing and global availability Introduction The F2 is a two channel transconductance power amplifier, which is a fancy name for an active current source. I can't keep it, I don't have a use for it. html The new 5wpc Class A current-source F2 is a 2nd-order champ, based closely on the original Zen amp Manual Library / First Watt First Watt F4 Stereo Power Amplifier (2007) add a review This website is not affiliated with or sponsored by First Watt. Sounds wonderful. May 17, 2022 · The F2/J may well be the single rarest First Watt model ever produced. May 25, 2025 · Used First Watt F for sale on 400+ second hand hifi sites & shops. It's a crossover-less 4-inch Fostex FE108EZ rear-hornloaded and heavily folded affair. A given input input voltag voltage e results in a partic particular ular output current. FIRST WATTF2 POWER AMPLIFIER 6/16/2005It has been about 9 months since the introduction of the First WattF1, and I have been very surprised to see everything going moreor less according to plan. ) It's something devotees of unconditionally stable Sep 27, 2018 · The F2 is another option but its voltage source behavior may be less suitable for these speakers. Auburn, CA August 10, 2020 — The new First Watt F8 power amplifier has been created as an updated version of the earlier J2 amplifier, introduced in 2009. The brand is known for its experimental approach, releasing limited production runs that explore different circuit designs with very few parts, which appeals Jun 29, 2010 · Nelson appears to have re-spun the original Firstwatt beast, designed as current amplifier, good for fullrange speakers. I am restoring an f7 for a friend. Rated at 5 W/ch at 8 ohms, 9 W /ch at 4 ohms. It had very low hours and was hardly used before Nelson provided this update and now it's basically new! This is very unique to Jun 15, 2021 · First Watt F8 Stereo Power Amplifier - Amplifier designer extraordinaire Nelson Pass takes minimalism in circuit design to new heights in this 25Wpc amplifier, says Dick Olsher. The F3 offers single-stage single-ended operation with new Jfet power transistors. DIY Amplifier F5 Pass Nelson Pass Firstwatt First Watt Amp Class-A Audio Hi-Fi Stereo Sound Music Build Project Electronics Solid State Push Pull FIRST WATT F2 COPYRIGHT 205 GENERAL AMPLIFIER IUF leøK 221 p 1 5K 2. The Aleph J used JFET devices for F2 Manual - First WattNow the following is for your protection, so payattention:Do not defeat the AC line Earth ground connection on theamplifier power cord. com. It got good reviews originally, but not often seen (IMO) as a diy project. ” Nelson’s article may be found here: www. 6860 Hz to . Note that a given design may not actually use the technology listed, but the cited article will at least discuss it in contrast to the specific implementation. Originally created almost 6 years ago, the F8 is a stereo two-stage single-ended Class A amplifier using the NOS Toshiba 2SJ74 P channel Jfets and SemiSouth R100 SiC power Jfets for signal gain, plus IRFP240 Mosfet mu-follower current sources, for a total of three devices per channel. Each unit has been a unique crea on said to be “best” in some par cular way, though they all happen to look similar because they use the same basic chassis and power transformer. Its origins go back to 2015, when Nelson had the no The SIT-4 is the first First Watt power amplifier to use industrial grade Static Induction Transistors. Power JFET Amplifier. firstwatt. BlackExcellent working and The first list will be individual topics of interest, followed by all of the articles that touch on the given topic. Something else is missing as well: No degenerating resistors on the output power Jfet. Thanks. Also there will be power supply board used in standard F1 amps. ” With this in mind, I created First Watt in 1998 as a “kitchen-table” effort, exploring unusual low power amplifiers with an emphasis on sound quality. This design is sometimes called an “impedance converting amplifier”, but more commonly referred to as a buffer – in this case, a power buffer. Most of what you might want to know The SIT-4 is the First Watt power amplifier using the industrial grade Static Induction Transistors. Other Notes: Very rare. 5 dB non-inverting phase Damping Factor 30 Frequency Response -. With First Watt, Mr. Is this the case for all of them? First Watt F2, F5, M2X MOSFET Kit - Precision 0. I won’t bore you with all the details of my daylong adventure, but both the subs and the amp behaved strangely connected this way; the sub seemed to significantly reduce the amp’s volume in one channel, while the subs themselves appeared to be receiving very Jan 2, 2018 · I've built 2 of his 6 watt class A monoblock ACA amps. The transcript of my presentation there is available on the First Watt website under articles – F6 Talk at Burning Amp Festival 2012 and contains numerous comments and details about the original design, some of Jul 5, 2024 · Here's the original F5 circuit. On the FirstWatt site, he provided passive, speaker level EQ for the most popular drivers of the time. Rare First Watt F2 Stereo Amp. Intro Five years ago I launched the F5 power amplifier project which culminated in a production run of 100 amplifiers and a DIY article. And if your speakers are unconscionably hard of hearing, you might need two F4s for balanced/bridged operation to really tear it up: "My Lowther DX55s (93dB/watt) mounted in Alerion enclosures adequately fill my 11,000 cubic foot listening room with about 5 volts (the equivalent of a 4-watt amplifier). 1% Matched IRFP240 & IRFP9240 MOSFETs - 4 Pieces Jun 24, 2010 · Nelson Pass designed the FirstWatt F1 and F2 (current rather than voltage) amps to drive FR speakers. It does not take long to realize this is a Test #1: F1, F2 and Decware Zen Taboo on 12-ohm 101dB Zu Cable Druids: The F1 and F2 have an unfair advantage. Explore a wide range of our First Watt Amplifier selection. Zu is a new wave, youthful audiophile company. The amp is a clone of the Firstwatt F2 (seen here) I did a pretty thorough build log here Fortunately the build-log was useful for a lot of other newbies As i RE: First Watt F2 vs F3 sound differences roscoeiii14:30:57 09/26/11 Jul 5, 2017 · I am ordering PCB for my first watt F2J clone. First Watt F2 Feb 5, 2021 · Up for sale is a set of 3 PCBs for Nelson Pass FIRST WATT F2 and F2J (only 4 sets available): left channel + right channel + power supply. If youspill a May 1, 2022 · A bit of a long shot, but does anyone have a First Watt F2 board that they would be willing to part with? Thanks for any help. If the deal for the J falls through or if you have an interest in the Aleph 30 (the predecessor of the Aleph J) just PM me. The others have two stages. Each design is a different exploration into high quality at low power. First Watt builds very simple high quality, low power audio amplifiers intended for use with sensitive loudspeaker drivers. Unbelievably simple and sound great. Tiny marks on chassis, otherwise see more Interested in this item? Contact Fewer transistors = Simpler circuit, simpler/smoother transfer characteristic and a little better performance by measurement. I rote all the informations of his site and i consulted this forum. com About this item I have kitted up Matched IRFP240 & IRFP9240 MOSFETSs for your First Watt F2 Clone, F5 Clone, or M2X amplifier project. Check out our first watt f2, f5, m2x mosfet kit precision 0. May 27, 2010 · Last week I completed a Pass DIY prototype F2 JFET Amplifier. Further Information: Ok… there is so much amp one guy have (according to Missus Sanders). Two-stage amps with Mosfet outputs have Jfet input devices. First Watt is a Nelson Pass enterprise, and he’s the founder and CEO of Pass Laboratories. If you want balanced, then get two First Watt F4's, wire with parallel inputs and outputs to get 100 watts into 8 ohms. 8k or increase R4. Jul 29, 2022 · My experience with the First Watt F7 I think that many of us have a mental list of components and speakers we would like to try if circumstances and finances allow, and I'm no different. He will also, very generously, release the schematics of these amps for use by the DIY community. Tiny marks on chassis, otherwise Create successful ePaper yourself Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software. 33 3W R26 . 5 dB @ 10 Hz, – 3dB @ 50 KHz Output Noise 50 uV unweighted 20 - 20 Khz Power consumption 150 watts Weight 32 lbs Dimensions 17” W 16” D 6. It requires careful attention toloudspeaker loading to get the best performance. To recap how those findings applied to the FirstWatt amplifiers, let's take a quick look at the speaker. Pass indulges himself designing low-power, simple circuit, Class A amplifiers. [3][4] These current domain amplifiers are only suitable for use with certain types of speakers. To purchase F3 spares or accessories, please contact the company via their website or visit an authorised retailer. This is made possible by the unique characteristic of First Watt’s custom SIT devices, which combines a square-law input character with a low impedance output to form the only Dec 26, 2020 · Today, I tried hooking up a pair of REL subs in stereo configuration to my First Watt F2-J via the high level Speakon connection. I’m not going to prepare the BOM file, but below are the details that should help to choose elements by yourself, I have also attached the schematics Preview of FIRST WATT F2 [1st page] Click on the link for free download! Jul 14, 2004 · Recently Nelson Pass released the schematic for the Firstwatt F2. The closest thing I've seen are Nelson Pass' designs. Do not replace the fuse with a type other than specified. The catch? It’s only 5 watts. To give you a sense of the of the difference, Fig 1 shows the distortion between two different transistors operated under identical conditions in a First Watt F2 amplifier: Nov 23, 2005 · First Watt Amps There are 3 out there I think and they are different. There is no potential for damage tothe amplifier and you are not likely to break the speaker, so Rare First Watt F2 Stereo Amp. 53 3FE25 - YouTube One problem is that - and it was also the problem in the simulation - that the pot is out of the range, so I can't set a perfect clipping - photo attached. The ideal thing would be a Single Ended Transistor (SETr anyone?). The First Watt amps will never win any beauty contest. Nelson's goal with this new design was to create an amplifier that was simpler and less expensive to build than the other First Watt amplifiers, but in my opinion, this amp sounds nicer than the original F5 and as good as most commercial products selling under $10K. It is preceded by the groundbreaking SIT-1, 2, and 3 and follows their technical philosophy and construction. So I think I need to reduce the value of R5 to 1. These are the lowest distortion big power transistors I have seen. 1% Matched Vishay IRFP240 & IRFP9240 MOSFETs - 4 Pieces First Watt F2, F5, M2X MOSFET Kit - Precision 0. 100 F2s were made and few were converted. I would not recommend there chassis buy it elsewhere. Sep 20, 2009 · I read in a previous thread (shame i can't find it again) about the J2 and in the FirstWatt the following quote "There will be an effort to update the F2's that are out in the field to the particular power JFET used in the J2, as it brings a spectacular improvement there also. Sometimes it’s a little dificult to say whether a given design is single-ended or push-pull, balanced or unbalanced Dec 10, 2006 · A little story from the 6moons review of the, at the time new, First Watt F2 amplifier by Pass http://www. This is the First Watt that takes the least amount Needless to say, Nelson's new First Watt solid-state F-1 is such a rare beast and thus specifically and unapologetically engineered for a niche group within a niche group of audio users: 100 high-efficiency single-driver speaker owners. Which of them is the best for a 99dB/8 ohm speaker ? I think, the F1 is made for speakers with no cross over, but I am not sure. The Kit for DIYaudio is no for the faint of heart but it is workable. This amplifier is designed for use with high-efficiency full-range drivers. It’s also the First Watt amp with the lowest part Has anyone compared a Tripath-based DIY amp (SI, 41Hz, Charlize, etc. The F1 and F2 explored the possibilities of current source operation with single-stage Class Audio Asylum Trader[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ] F2 Manual - First WattThis is an unusual amplifier that will not give its best performance with mostof the loudspeakers on the market. If being a current source FIRST WATT F2 COPYRIGHT 205 GENERAL AMPLIFIER IUF leøK 221 p 1 5K 2. frequency at one watt. It seems like I have to go with 2Oz traces and have to have minimum 5 set of boards. 45, for more on the F-2. Brand New Amplifer - Nelson Pass upgraded this perfect F2 to F2J two weeks ago. Shop now for fast shipping and easy returns! Manual Library First Watt Power Amplifiers Aleph J F1 F2 F3 F4 F5 F6 F7 J2 M2 SIT 1 SIT 2 Nov 12, 2005 · Wanted to know if anyone had compared the First Watt F1 versus F3 for the AKG K1000? Your thoughts would be much appreciated. I have been into this hobby since 14 (am now 40) and have lived long term with 2 speaker brands (Fried and Spendor) and 3 electronics brands (NAD, Acurus, and Quicksilver)had a brief fling with Martin-Logan, Audible Illusions, and McCormack. Ask a question; get advice. Current Source Amplifiers and Sensitive/Full-Range Drivers by Nelson Pass Introduction Used First Watt F2J Stereo power amplifiers for sale on 400+ second hand hifi sites & shops. These amplifiers are hand-built by Pass and are available in very limited quantities. ). Aug 9, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. Only 100 built of the F2. I won’t bore you with all the details of my daylong adventure, but both the subs and the amp behaved strangely connected this way; the sub seemed to significantly reduce the amp’s volume in one channel, while the subs themselves appeared to be receiving very First Watt Audio Schematics & Service Manuals. Mosfet/Jfet refers to the output transistors. 21K 15øøø R27 6. FIRST WATT F2 Utgangspunktet for tråden er at jeg selv har hatt lyst å prøve å bygge en meget enkel forsterker med klasse A som passer til fulltoner. I'am not shure that the best amplifier is . Shipping: Cost to ship this item within the Contiguous United States is a flat rate of $ 55 - including packaging and insurance. 1% selection for the very best in unique or custom, handmade pieces from our tools shops. My chose : F1J Treble : T925 A. Read More » Oct 28, 2017 · First Watt F-2J for sale. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Jan 27, 2014 · I'm curious about the First Watt products. to source , while D in SJDP means that part is depletion type , demanding exactly oposite polarity of biasing voltage - negative at gate ref. I wanted to show my to DIY amp. This Dealer News » Browse Dealer Ads The ultimate precision instrument is now available Q-tron Audio OTL amplifiers New Ideon Audio Ayazi MK2 DAC Jan 19, 2023 · Mods please remove this if it's in the wrong place. The emphasis is on circuit execution rather than sex appeal Dec 24, 2005 · The First Watt F2 is a one-weight fly rod, a mando-cello, a drawknife with a flexible blade—in other words, a fascinating tool with the potential to make you rethink everything you know, even if you don't wind up using it on every job (although you may). It's the first watt that gives you the mondo turbo-charged power boost of anywhere between 80 to 110dB depending on your speaker sensitivity. Jul 2, 2023 · Only 100 were ever built. May 24, 2008 · Intro As many of you may know, First Watt is dedicated to exploring the performance quality of small simple power amplifiers. Oct 19, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. We have a great online selection at the lowest prices with Fast & Free shipping on many items! First Watt SIT-2 User manual First Watt J2 User manual First Watt M2 User manual First Watt F5 User manual First Watt F4 User manual First Watt F3 User manual First Watt F2 User manual First Watt F1 User manual First Watt Aleph J User manual Philips BT150W Specification Philips BT150W User Manual Philips BT150B Specification Dealer News » Browse Dealer Ads The ultimate precision instrument is now available Q-tron Audio OTL amplifiers New Ideon Audio Ayazi MK2 DAC Earlier this year I published the “Zen Variations #8 – the Power JFET Amplifier” and now First Watt is introducing the model F3. This is a tinkerer’s amplifier. Dick Olsher famously remarked that “The first watt is the most important watt. To give you a sense of the of the difference, Fig 1 shows the distortion between two different transistors operated under identical conditions in a First Watt F2 amplifier: Not trying to ruin anyone's transaction. Is this available as a kit? Is there a Dec 26, 2020 · Today, I tried hooking up a pair of REL subs in stereo configuration to my First Watt F2-J via the high level Speakon connection. The F2 is gone. Discover First Watt Power Amplifiers at Walden High-End Audio, official Lower Distortion. to source The F6 is a very interesting amplifier, first designed in 2012 and presented in October at the Burning Amp Festival in San Francisco. Her er skjema for forsterkeren: Jul 23, 2017 · The First Watt F2J is a single-stage, zero-feedback, single-ended transistor amp. Sep 27, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. Nothing past the first amplifier watt will ever remotely approach its initial About this item I have kitted up Matched IRFP240 & IRFP9240 MOSFETSs for your First Watt F2 Clone, F5 Clone, or M2X amplifier project. 1% Matched IRFP240 & IRFP9240 MOSFETs - 4 Pieces F2 Manual - First WattSetup – Read ThisBe certain to look at (or even read) the attached white paper "CurrentSource Amplifiers and Full-Range High-Efficiency Drivers" in consideringhow to use this amplifier. I won’t bore you with all the details of my daylong adventure, but both the subs and the amp behaved strangely connected this way; the sub seemed to significantly reduce the amp’s volume in one channel, while the subs themselves appeared to be receiving very About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket © 2025 Google LLC RE: First Watt F2 vs F3 sound differences roscoeiii14:30:57 09/26/11 Rare First Watt F2 Stereo Amp. It’s a transconductance amp designed mainly for crossoverless, full range single driver (Lowthers, Voxativ, AER, etc. 33 3W Created Date 11/29/2006 12:22:52 PM Aug 12, 2020 · Patrick: Your DC coupled F8-like amplifier is a beautiful piece of work. Tiny marks on chassis, otherwise Dec 26, 2020 · Subwoofers with current source First Watt? All, I’ve got a rather esoteric question that I hope those of you more technically minded than me might be able to help answer. This is a build log just for the sake of documentation, and also to assist anyone Used First Watt F2 Stereo power amplifiers for sale on 400+ second hand hifi sites & shops. The First Watt F4 is a single ended input design. But I have been sitting on my Pass Aleph 30 since I bought my Pass XA-25. ” This sentiment has also been expressed by others as “Who cares what an amplifier sounds like at 500 watts if it sounds like crap at one watt?” With this in mind, I created First Watt in 1998 as a "kitchen-table" effort, exploring unusual low power amplifiers with an emphasis on sound quality. 2 pcs Precision 0. 21K RIB 221 R19 221 R2Ø 2. He’d build 100 and when they were all sold, that was that. The emphasis is on circuit execution rather than sex appeal About this item I have kitted up Matched IRFP240 & IRFP9240 MOSFETSs for your First Watt F2 Clone, F5 Clone, or M2X amplifier project. ] Aug 4, 2014 · Review: First Watt M2 Just a bit of background first in order to put the M2 into perspective. As First Watt moves into its twelfth year, this is how we thank those people: The F1J and the F2J update. 6moons. It will be seperate PCB for left and right channels . It is preceded by the ground breaking SIT-1, 2, and 3 and follows their technical philosophy and construction. As usual, the unit requires 15 minutes of warmup to sound good, and 30 minutes for critical listening. Can somebody tell me how I could go about aquiring PCB's and a parts list for this? I know that a circuit diagram is available for this but how do I go from there? Any Further Information: Ok… there is so much amp one guy have (according to Missus Sanders). MOSFETs are manufactured First Watt’s latest DIY offering, the B1 buffer stage, is described by Nelson Pass as “a no-feedback JFET buffer that offers ultra low distortion and noise with ultra wide bandwidth. F2 Manual - First WattThis is an unusual amplifier that will not give its best performance with mostof the loudspeakers on the market. The no. FIRST WATT SIT-3 Single-ended / single-stage Class A SIT - Static Induction Transistor Topology Maximum output 18 watts @ 8 ohms 30 watts @ 4 ohms Input Impedance 200 Kohms Gain 11. For over 10 years First Watt has been pushing the design envelope with simple high performance Class A amplifier circuits, and when a better transistor like this comes along, it can mean getting the same distortion performance with a lot less feedback, or lower distortion with the same amount of feedback. I am just finishing up the 100 amplifiers of that design (about 10 per month), and there are only a few left before they cease to be available as new. It sounded heavenly in a system with my Teresonic Magus speakers (98db View and Download First Watt J2 manual online. The power supply capacitors need replacing. It is designed for a particular type of loudspeaker,and may not sound good with others. Thought I would write a few words about it. First Watt is a specialty brand created by PassLabs. I have tried with several components: volume control on the totaldac, Goldpoint passive pre-preamp with 47 step attenuation, and simple sub $1k pre-amp. In a very fundamental way, the answer to this innocuous question determines the sound of your speaker. It has low output impedance and very quiet noise level. Aug 24, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. Of all my First Watt amps, it has the best imaging, the largest soundstage and the deepest bass, thanks to it’s high(ish) damping factor. org. Ordinary amplifiers are voltage amplifiers – an input voltage translates into an output voltage. This page is about the F2J (there is another about the F1J). 1% Matched IRFP9240 MOSFETs (1 Matched Pair) MOSFETs Vgs is measured at 170mA in a steady temperature room and with a timer circuit for consistent and precise Get the best deals for First Watt F5 at eBay. J2 amplifier pdf manual download. When I look at the cost of enjoying my 25 watt/ch class A amplifier as compared to watching a big screen television or running a porch light all night, I see that I get as much or more value for the same sort of consumption. It's my fir st major electronic project (made speakers previously which I will post up later). Jun 16, 2005 · One thing that you are likely to notice about the F2 is its phenomenally low output noise, typically about 50 pico-watts (a pico-watt is a trillionth of a watt) un-weighted across the audio band. It uses JFET and MOSFET transistors operating in Class A mode without negative feedback so as to produce a more musically life-like sound. All amplifiers are available in 240 or 120 volts AC. Buying two First Watt amps in a week was asking for trouble… This amp is the second model that Nelson Pass did release after Feb 2, 2024 · I ask as in my experience the First Watt amps do not match up well with passive or volume control type of devices, adding in a quality active pre-amp will yield a better performance. F2 Manual - First Watt F2 Manual - First Watt SHOW MORE ePAPER READ DOWNLOAD ePAPER First Watt F2, F5, M2X MOSFET Kit - Precision 0. the results were much more than entertaining. It is a power trans-conductance amplifier (or power current source, if you like), replicating an input voltage into an output current. Of all my First Watt amps, it has the best imaging, the largest soundstage and the deepest bass, thanks to it’s high(ish) Aleph J Read more B1 Read more B2 Read more B3 Read more B4 Read more B5 Read more F1 Read more F1J Read more F2 Read more F2J Read more F3 Read more F5 Read more F6 Read more F7 Read more F8 Read more J2 Read more 1 2 → Test #3: F1, F2, Canary Audio CA-308 and Audio Sector Patek SE on The Horn Shoppe The Horn: Because of its surprisingly potent showing, the friskily christened The Horn netted its own review. Most of what you might want to Service History: The F2/J is an F2 that Nelson personally converted to a "J" by replacing the output MOSFETs with JFETs from SemiSouth. It's black, it's plain, it runs hot and looks virtually identical to the F1 once you subtract the latter's XLR inputs. Anybody have any insight? Unlike its First Watt predecessors the F1 and F2, the Aleph J is a voltage source amplifier – a regular sort of amplifier like the ones you already know and love. Single ended transistor design for very high efficiency speakers. To give you a sense of the of the difference, Fig 1 shows the distortion between two different transistors operated under identical conditions in a First Watt F2 amplifier: Why is an amplifier's first watt so important? Watts are cheap. Use Hifi Shark to monitor pricing and global availability Nov 20, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. Buy First Watt F2 F5 M2X MOSFET Kit Precision 0. Nov 20, 2008 · I'm perfboarding an F1 and maybe an F2. How many single-ended, ONE-stage, NO-feedback sol Sep 9, 2023 · Further Information: I’ll be slowly culling the First Watt amps herd. A few things about the F2 before we join the fun & games. It has proven to be a popular design, and as of this writing approaches 2 million views on DIYAudio. 33 R 24 . It is a 25 watter. Home Amplifiers Pass Labs First watt F2j with SJDP120R085 Get the best deals for First Watt J2 at eBay. Consumption ranges from 160 to 200 watts. The F4 is a push-pull current buffer with no voltage gain or feedback, and the F5 is a uniquely high performance push-pull amplifier with feedback. The F2 amp need efficient singledriver speakers to sound good. My question is would my little dot MK III preamp with an output voltage of 10 volts First WattFREE SHIPPING on US orders over $99 International Orders $399 & Up: Use "World20" To Save $20 A few things about the F2 before we join the fun & games. Next in line is my F7. If youspill a F2 Manual - First WattNow the following is for your protection, so payattention:Do not defeat the AC line Earth ground connection on theamplifier power cord. The reviews have been uniformly enthusiastic, the customers seem happy, and none have The F7 is a very unique power amplifier, a two-stage push-pull JFET/MOSFET topology with fewer parts than any First Watt amplifier to date and incorporating a very interesting balance of very low negative voltage feedback and a little bit of positive current feedback to give an astonishing measure of control over reactive loudspeaker loads. H9 The SIT-2 is the first of a new generation of power amplifiers using Static Induction Transistors (SIT) in single-stage, single-ended Class A circuits delivering superlative sound without feedback or degeneration. I have the same listing in Headfi with photos, please see: DIY FirstWatt F2 speaker amp-Perfect for XLR'ed K1000s, HE-6s or LCD-2s Still First Watt Aleph J Power Amplifier It’s been about 9 months since the introduction of the First Watt F1, and a few weeks since the introduction of the F2. To purchase Aleph J spares or accessories, please contact the company via their website or visit an authorised retailer. To give you a sense of the of the difference, Fig 1 shows the distortion between two different transistors operated under identical conditions in a First Watt F2 amplifier: Find the user manual for the First Watt F2 Power Amplifier. Its input Aug 23, 2012 · Thanks for checking. Buying two First Watt amps in a week was asking for trouble… This amp is the second model that Nelson Pass did release after By my count the F8 represents the sixteenth First Wa power amp authored by the undeniably prolific Nelson Pass. It is similar to the J2 amplifier, but has only one front end transistor instead of six, operated as a current First Watt F2, F5, M2X MOSFET Kit - Precision 0. AMAZING sounding the schematic was wrong killed 4 Jfets as a result but whois counting. This is a First Watt F2J amplifier - the F2 but with JFet transistors. While the F1 has a crisp sounding 3rd harmonic signature, the F2 has a richer pure 2nd harmonic character, and this difference is the primary justification for offering a second no-feedback current source amplifier. The accompanying whitepaper “Current Source Amplifiers and Full-Range High-Efficiency Drivers”is required reading. 5 poweramp with Avantgarde Acoustic Duo speakers?The XA30. 1% Matched IRFP240 MOSFETs (1 Matched Pair) 2 pcs Precision 0. As some of you may know, the F2 was built when (I’m pretty sure) Nelson was building all First Watt amps himself. 1% Matched Vishay IRFP240 & IRFP9240 MOSFETs - 4 Pieces Jun 16, 2010 · Hi there! So, I'm looking at building an amp (and maybe a preamp) in the near future. The Sig 30 has been described by others as very SET-like in sound quality. Shop now for fast shipping and easy returns! First Watt M2 Stereo Power Amplifier Highlights Product: First Watt M2 Stereo Power Amplifier Product SKU: 79016 Serial Number: 1556 Input Voltage: 120V Cosmetic Description: Good cosmetic condition with some minor visible cosmetic wear including light anodization on the faceplate and chassis top surface, a tiny nick on the right edge of the faceplate, light scuffs on the chassis top surface Lower Distortion. 33 3b' R25 . I really like the look of the First Watt F2. Sep 9, 2016 · First off, the First Watt amplifiers can be affordable, but aren’t exactly cheap. Looking forward to the thread. They do need a good power supply to shine however. The F1 and F2 explored the possibilities of current source operation with single-stage class-A circuits and no feedback. Be that an 87dB or 101dB design, all you're getting past the first watt is a logarithmically smaller and smaller contribution. com F1J Power Amplifier Update Unlike many companies (and I’m sure you can name some) First Watt is grateful to the early adopters who took a leap of faith and bought either an F1 or F2 amplifier. Test #3: F1, F2, Canary Audio CA-308 and Audio Sector Patek SE on The Horn Shoppe The Horn: Because of its surprisingly potent showing, the friskily christened The Horn netted its own review. Now, the F5M circuit. The F8 represents a varia on on the popular J2. May 11, 2025 · I have kitted up Matched IRFP240 & IRFP9240 MOSFETSs for your First Watt F2 Clone, F5 Clone, or M2X amplifier project. so here goes i have been offered a first watt F2 amp once in a lifetime offer only a hundred ever made by the audio god himself Nelson Pass. Subsequently there was a more powerful version released to the DIYers, the F5 Turbo, which offered more power and numerous options for experimentation. It’s also the First Watt amp with the lowest part Check out our first watt f2 selection for the very best in unique or custom, handmade pieces from our shops. With oddball characteristics and output power ratings of 25 watts or less, First Watt is not for most people. The F2 JFET is using SemiSouth SJEP120R100 silicon carbide power Jfet to replaced the original IRFP240 Mosfet. Owners manual is a download. It provides an extra barrier toprevent potential shock hazard. I can get the F2 boards but would also like to know if any F3 are available. If you have very efficient louspeakers you are in luck. Lower Distortion. (It actually powers my Focal Sopra 3 speakers to satisfactory levels--come audition). MOSFETs Jul 19, 2020 · For those unfamiliar, First Watt is kind of a sister company to Pass Labs, both selling the products of owner and designer Nelson Pass. For example, the 25 watt per channel J2 I have here sells new for $4000, while the 10 watt per channel SIT-1 monoblocks go for $10,000 per pair. 2005, p. The well-respected Nelson Pass has designed at least two dedicated amps, his F-1 and his F-2 (the latter a "single-ended, current-source" amp), for the Lowthers. Or just speak your mind. If you have efficient loudspeakers, listen at reasonable levels and are obsessed about subjective performance, then you probably have come to the right place. Nothing past the first amplifier watt will ever remotely approach its initial First Watt F2, F5, M2X MOSFET Kit - Precision 0. com/audioreviews/firstwatt2/f2. I think it's worth discussing here. Sep 9, 2011 · I'm interested in giving First Watt a try. It will work on high efficiency speakers like Klipsch Heritage (96dB and above) but the damping factor may be a bit low. Cranky, good to see that you are doing the F5. When applied as intended -- i. First Watt initially produced power trans-conductance amplifiers (or technically a power current source). To purchase F2 spares or accessories, please contact the company via their website or visit an authorised retailer. 33 3W Created Date 11/29/2006 12:22:52 PM The First Watt M2 is a two channel audio power amplifier delivering 25 watts per channel. Considered a current-source amp because of its high (15 ohm) output impedance, it is designed for driving wideband drivers directly (no crossover). Normally I would wait a while before introducing another amplifier, but it seems that the majority of potential customers request a more regular kind of amplifier, something that can drive an ordinary loudspeaker - “Just a few more watts Aug 31, 2017 · First Watt F-2 Tube for sale. 5 AB amp but interested in experiencing full class A. I won’t bore you with all the details of my daylong adventure, but both the subs and the amp behaved strangely connected this way; the sub seemed to significantly reduce the amp’s volume in one channel, while the subs themselves appeared to be receiving very Gallery Donations FAQ Calendar Home » Main » Amplifiers » Solid State » First Watt F2 Nelson Pass First Watt F2 prototype with an n-channel current source Click on image to view larger image Photo Details ObliViondiyAudio Member Registered: April 2004 Location: Odense Posts: 41 Date: Sat May 1, 2010 Additional Info Additional Categories As the previous page's intro list showed, the very first Watt models F1 and F2 had subsequently enjoyed a J-fitted remake which traded the original Mosfets for power Jfets. [See Art Dudley's piece; "Nelson Pass & the First Watt F2 amplifier;" Stereophile, Dec. Aug 2, 2006 · The following quote is from the First Watt F2 manual, describing the difference between the F1 (balanced design) and the F2 (SET). Jul 27, 2024 · Hi All, I want to make a First Watt F2 amplifier or, First Watt F2J amplifier, but, I would like to go with the original First Watt circuit, could someone please tell me if, I can still get PCB Boards like these, or similar? Sep 26, 2011 · Need some advice long time reader of diyAudio but never posted till now. 1% Matched IRFP240 & IRFP9240 MOSFETs - 4 Pieces Manufacture of the Aleph series of amplifiers is to be continued by First Watt, an amplifier company founded by Nelson Pass in 2004. Boards will be 290mm long and 50mm wide. 5 is getting great reviews all Dec 18, 2015 · zm's listening room featuring Omega Speaker Systems Customshop Super Alnico Monitor XRS, First Watt SIT-3, First Watt F2/J, Line Magnetic LM-218IA, Don Sachs Model 2, Linear Tube Audio MicroZOTL MZ2, MHDT Laboratory Istanbul, Border Patrol USB DAC SE, Pro-Ject Audio Systems Streambox S2 Ultra, REL Acoustics T/5i, REL Acoustics T/zero, Morrow Audio SP-7, AudioQuest Columbia int, Equi=Tech Equi Lower Distortion. I have Audio Note AN-E speakers, which are efficient, I like SET sound, and I'm intrigued by the approach of First Watt. Download: F4 ManualLike everything else from First Watt the F4 is a unique amplifier. Am I looking the right way at the differences between these two amplifier designs and their suitability for this type of speaker design? I'm thinking of pairing my Aric Audio Unlimited tube preamp - 600 ohm output impedance, with the J2. My finances are more limited than many members, but within my means I have been able to try quite a few different things over the years. Architect slash speaker designer Jacob George from Southern India goes many extra miles to modify his Lowthers. (At introduction, the world’s only commercially available amplifier using power JFETs). Dealer News » Browse Dealer Ads The ultimate precision instrument is now available Q-tron Audio OTL amplifiers New Ideon Audio Ayazi MK2 DAC Check out our first watt f5 selection for the very best in unique or custom, handmade pieces from our table lamps shops. ) to one of Nelson Pass' First Watt F1, F2 or F3 (solid state, class A, SE) amps? They are both supposed to work very well with high sensitivity and single driver speakers. I'm a very happy owner of a Pass x250. No plans to sell Like other First Watt amplifiers, it was a limited release, and was discontinued after 100 pieces were built. If being a current source Why is an amplifier's first watt so important? Watts are cheap. That unfair advantage is called control (or cone acceleration if you want to get fancy. I make both F2 JFET and Delite amp. Shop for handmade, vintage and unique Stereos & Home Audio items from ThatcherDIYAudio online on Etsy May 4, 2011 · Hi,Does anyone has any experience with matching Pass Labs XA30. First Watt is a project by Nelson Pass that focuses on minimalist, low-powered Class A amplifiers using unique Static Induction Transistors (SIT) to create a tube-like sound in solid-state format. Tiny marks on chassis, otherwise very clean. The First Watt J2 and Zu Essence are both made in the United States. I'm interested to build two Nelson amplifiers. Is it ok to ask how to set the bias to factory specs. " This website is not affiliated with or sponsored by First Watt. Apr 1, 2021 · 4/1/2016 This has always been about making amplifiers. This is not that ki kind nd of amplifier, and as of tthis his writing, th the e F1 Oct 4, 2005 · I know the F1 gets a lot of praise around here, but what about the F2? If I have been reading correctly, it is to replace the F1? Has anybody tried it with the K1000? And what about the F3? It looks interesting. It's a current amplifier that can be used to power single driver speakers (eg, single driver speakers, AKG K1000 and possibly other headphones). I want your help. F1, F1J, F2, F2J, F3, SIT-1 and SIT-2 are single gain stage amplifiers. For the DX4 of the Second Rethm pictured, he adds additional stationary (phase-plug My First Watt F2 was recently re-worked by Nelson with J-Fet's in place of the original Mosfets. ” This sentiment has also been expressed by others as “Who cares what an amplifier sounds like at 500 watts if it sounds like crap at one watt?” With this in mind, I created First Watt in 1998 as a “kitchen-table” effort, exploring unusual low power amplifiers with an emphasis on sound quality. . I do not usually come to this forum, but I am more active at Head-fi. Power Amplifier Update Unlike many companies (and I’m sure you can name some) First Watt is grateful to the early adopters who took a leap of faith and bought either an F2 or F1 amplifier. I am the second owner of this model (I've had a couple in the past as well). It had very low hours and was hardly The F2/J may well be the single rarest First Watt model ever produced. Sep 20, 2016 · The First Watt was Fred Astaire, the Soul Supremes were Ginger Rogers, and . If you want to reopen this topic, contact a moderator using the "Report Post" button. Use Hifi Shark to monitor pricing and global availability Aug 4, 2018 · FIRST WATT F2J power amplifierLabeld as a F2, I have confirmed with Nelson Pass himself, via e-mail that this unit is actually an F2JThe F2J is more sought after as it uses the J-FETThis is a wonderful sounding amp. Apr 23, 2011 · For my part, I have compiled an index of the articles that I think are necessary for understanding the Pass amplifiers, including Zen Variations and First Watt. 1% Matched IRFP9240 MOSFETs (1 Matched Pair) MOSFETs Vgs is measured at 170mA in a steady temperature room and with a timer circuit for consistent and precise matching. As all First Watt amps, the F7 has a strong character of its own. The reviews have been uniformly enthusiastic, the customers seem happy, and none have Aug 2, 2025 · JBL Grip Bluetooth speaker debuts with 16W bass, IP68 waterproofing, 14-hour battery, dynamic RGB lights, and Auracast support. A jump from 100 watts to 200 watts accomplishes no more than proceeding from the first to the second watt: a 3dB increase in gain. Nelson Pass upgraded this perfect F2 to F2J in August of this year. The F4 is Class A impedance converting amplifier, having no voltage gain or feedback. At the end of the sales cycle of new product, the schematics May 1, 2010 · See First Watt F2 on our My Photo Gallery gallery. I wondered: Where did all this beguiling vivo suddenly come from? Record after record, I kept musing: What was up with these hypnotizing momentums? How did this wide-open midrange and triode-like top end happen? Aug 2, 2006 · Since this thread has been bumped back to the first page, I may as well point out that I added 47 ohms of parallel resistance (just because thats pretty much all i have on hand atm) and now use the f2 as a headphone amp. Please see my profile there under the same user name, zzffnn. The addition of the F1J with SiC JFet's replacing the IRFP240. Do not operate the amplifier outside in the weather, or inand around water or anything resembling water. This page is about the F1J (there is another about the F2J). e. Thanks for sharing it. ) It's something devotees of unconditionally stable Nov 28, 2006 · First Watt is a "kitchen-table" effort by Nelson Pass. 81K R22 12K N 24V R23 . sensibility : 108 db Nelson amplifier ? actualy SE 300B Verdier Edit @HaLo6, this is a specialty amp with 5 watt output power and no damping factor, so it is not useful for the usual speakers with a crossover. Nov 26, 2015 · First Watt F2J for sale. In the 1970s, his first venture, Threshold, broke new ground in solid-state designs, and he’s still advancing the state-of-the-art. As First Watt moves into its twelfth year, this is how we thank those people: The F2J and the F1J update. In many ways, it’s an ordinary topology – the basic circuit is found in numerous preamp circuits and the odd power amplifier (Check out the Profet amp from Selectronics). I finally got my hands on a F2 (clone), and am having a great time with his suggestions Apr 23, 2011 · Howdy guys. To give you a sense of the of the difference, Fig 1 shows the distortion between two different transistors operated under identical conditions in a First Watt F2 amplifier: Apr 12, 2017 · This old topic is closed. jxzlyfgq7 9x1pg fmc bnoq qxcg9 8elmpp mtlq1 hjsgg78fp yqxm szciy6