Figured I’d make a thread for Pass First Watt amps since they are pretty unique and pretty worthwhile too. I myself have only owned a J2, F8, and SIT-3, but I’ve heard a few others as well. They all generally sound pretty different, but all carry one common trait: they prioritize listening enjoyment over everything else. Sure they might not pull the most detail for the money or won’t be the most pinpoint out there, but they have wonderful voicings/tunings, overall great balance, reasonable technicalities without being the focus, and a focus on both organicness and fun
While I’m here I might as well give a few thoughts on moving from the J2 to F8. So far it basically feels like it’s taken what I like about the J2, but cleaned and tightened it up, improved treble air and extension, better control overall with more tightness, and a pretty deep stage with organic presentation. Overall technical ability took a mild step up mainly when it came to resolution, macrodynamics, speed, and control vs the J2. The J2 does have a bit more tonal density, a bit more perceived impact, a bit more stage width, and a bit more warmth as well, but the F8 took most of its characteristics and created something more technically able and more balanced and refined and I personally felt it was worth the trade off.
If I do a quick comparison to the SIT-3, the SIT offered a more midrange focus with a much more rich, organic, and smooth midrange that is more pleasing than the f8, but it can also sometimes tilt too far, the SIT is also more lively and forward than the more slightly relaxed f8, I guess I’d say the SIT is more vivid and involving overall. Bigger stage and more grand presentation than the F8, but not as accurate. Timbre wise I do feel the SIT is better in the midrange but not elsewhere. The SIT is more rounded and meaty in impact, but lacks some control that the F8 offers. I do think the F8 offered more resolution as well. Generally I think different goals where the F8 is slightly relaxed neutral, refinement, and balanced where the SIT-3 goes for a more rich, forward, and involved but colored signature. Both are worth considering on what you prefer
Nice concise comparison. I hope to try one or all (lol) of these in the future. The SIT-3 in particular sounds like it could be a nice option for me to have and iirc that guy is the lowest in power in the First Watt fam? Or one of anyways. Which is good to mention I guess that these amps won’t power everything. Top out at 30 wpc ish.
So I’m not qualified to speak on the design but I know these amps are unique due to parts used, low parts count, no negative feedback and just overall design and goals of the amp. Distortion is used and ultra low THD etc is not what the amps are all about. They’re more about pure enjoyment. Makes sense to me. There are a few interviews with Nelson Pass on the Audiophiliac Youtube channel that are pretty interesting and informative.
I have the F7 and I haven’t heard others to compare it to so I’ll do my best. The stage is huge and tonally it’s rich and dense. Big textured rounded bass that isn’t the fastest but is incredibly enjoyable and doesn’t muddy up the mids at all which is very good. Good mids. Really good mids. I feel like the tuning is masterfully done. Mids and Highs are just sweet and feel just right to me and detailed enough. Excellent timbre all around too.
LTA MZ3 is an excellent pre amp pairing and I’d hazard a guess it elevates the technicalities of the F7 a bit. Amber 3 is an excellent dac pairing allowing the timbre and big stage do its thing.
For sure. Although it’s hard to know lol since all the amps sound reasonably different from each other. For example the F8 and F7 are pretty different with the F8 being more like a J2 while the F7 is a bit more like the SIT in sound imo
Yes, and are also picky about synergy, they aren’t good all rounder amps for many different types of speakers, a bit more specialist. But when you find the special pairing it’s very special
Only in some, the late F series and J2 all have feedback, SIT no feedback, early F series no feedback
I was going to hazard a guess that they are picky. Sounds like Nelson tries to voice them all differently (as you also mentioned) so that would make sense. Resale stays reasonably consistent so I probably would consider any of them tbh. Just to try them out.
My bad, that’s what I meant. No or a variety of feedbacks used depending on the model. The F7 for example has some positive and negative feedback.
Nelson Pass is incredibly pragmatic about feedback, I think he discusses it in on of his interviews with Steve Guttenberg. His response was it’s a tool, it won’t fix a bad design, but it can help control some aspects in a good one.
I do recall that but also don’t fully understand how feedback can impact a design. I bet you get much more out of those interviews than myself. His passion comes through and I appreciate how he doesn’t shy away from his business side either. He strikes a good balance and comes across as a pretty honest likeable guy.
Feedback is exactly what it says it is you take a portion of the output and feed it (negated) back into the input of a gain stage, that reduces the “Noise” in the system and the systems output impedance.
But it can smear time.
So fundamentally If I say need a gain of 2x, I can have a stage that is 2x with no feedback or a stage with a gain of 100x and feeds back 98% of the signal. And generally the 2 schools of though are low base gain low feedback, or very high base gain with a lot of feedback, the latter is how all the high measurement amps achieve their measurements, and arguably why they generally suffer in quality.
Feedback can be a for a single gain stage or across stages or both.
The noise thing rings true for me. The two tube amps I’ve used with no feedback as a design trait I honestly couldn’t completely enjoy if I’m being honest. So I think I appreciate a little being used.
I know there’s negatives and positives to no feedback but I think for myself the former outweighs the latter in my experience so far.
In a Zero feedback design, the design is critical, and the choice of components becomes far more important. You can get 0 feedback designs with very black backgrounds (The DNA amps are like this), but every part of that design/implementation is critical.
Feedback isn’t inherently bad, but too much can have an adverse impact.
Eyeballing an F7 and was surprised that they’re not crazy costly. Given the comments on this thread I think the F7 might be a good fit for me, my tastes, just not my current speakers. Well the Zu DW would probably pair well.
If you’re cost conscious and handy with a soldering iron look at DIY. All the FW amp schematics and BOMs are freely available (from Nelson) and some are even sold in kits with plenty of documentation and help available. You can easily put together an F5 or F6 for a grand.
If you want to spend a few hundred dollars more, you can still find the no longer produced output devices used in the FW originals.
And if you want more power, build the F5 Turbo versions for a monstrous 100 watts of class A per monoblock.
Been reading about First Watt amps a bit over the past week and have enjoyed the Nelson Pass and Steve Guttenberg interviews. The models that interest me are J2 and F8, the J2 because it has balanced inputs and the F8 because it looks like a successor to the J2 and is still available new. Have some questions about these amps:
How do the balanced inputs work on the J2. My understanding is that it is a single ended design so does it convert the balanced inputs with a transformer or does it just ignore a pin or something else?
Do these amps work well with headphones? That would be my main use case for now which I understand is not what these amps are made for but I’ve seen people doing that with these amps before or the lower power pass amps. Any experience driving planars specifically or any other headphones?
I’m not sure I want to get into DIY at the moment but if someone could link a First Watt kit that was mentioned that would be helpful.
I think the input stage is actually balanced but it will actively convert to single ended internally, it will work well with dacs that sound better balanced from my experience so you don’t have to have a single ended dac
I think they can, depending on your priorities and your headphones of course. My favorite headphone pairing with the j2 and f8 was either the 1266 or d8000 pro, both of which it improved midrange organicness, mellowed them out a bit and gave them a bit more roundness, and have more general warmth and richness, great tonal density as well. It’s not the most technical amp and does prioritize organicness over technicality, but if you are looking for something more sweet, rich, and a more relaxed organic presentation without being overdone, then I think the first watt stuff is great for headphones, assuming decent preamp. I did try others like the susvara which while decent isn’t really my preference in sound for those headphones, felt too relaxed and dulled imo. Trying something like a utopia didn’t do much for me either. Mysphere 3.2 surprisingly decent though. Depending on the headphones noise floor isn’t dead silent but that can be removed with a headphone attenuation box if needed
Cool I have the Bricasti MC1 which sounds better our of the xlr outputs IMO so should be fine and the rcas work well too if I need a single ended output.
Sounds good. I was thinking more of an amp for susvara but would definitely try 1266 if I end up going the speaker amp route.
The reason for the interest in a speaker amp is I see myself getting speakers at some point ( in 1-2 years ) so having gear that works for speakers too not just headphones would save me some money although I suppose it’s also a bit of a compromise getting an amp for headphones and speakers instead of one for each that does the headphone or speaker driving well.
Perhaps a DIY First Watt is the most sensible option here just to try it out and not spend 4k for a new model.
Thanks for the info! Will be checking out the DIY pages more today
I picked up an F8 and am really enjoying it. Here are some impressions I wrote up vs the Schiit Tyrs that I was using before:
Setup is Bricasti MC1 → LTA microZOTL level 2 preamp → Firstwatt F8 / Tyrs. Tubes in the pre are rolled to Philips 7062 in place of the National 12AT7 and Tung Sol 6SN7 GTB in place of the RCA 12SN7.
Some usability notes of the two amps. The Tyrs are a bit heavier and you need 2, the fins are a bit sharp so careful when lifting them. Tyrs have a bit of mechanical hum but it’s not noticable when listening. Tyrs run fairly cold, about the same temperature of my Bricasti dac. F8 runs hot even after being on for 15 minutes. It’s build is similar but feels a bit nicer even though the gaps in the panels are large in spots. The F8 is slightly larger but both will fit in a stardard rack. I’m using a monoprice xl rack.
Both amps sound great. The F8 is warmer, has a more full bottom end, vocals are full and rich, top end is extended and airy. It’s a very easy amp to listen to and seems to work better with bad recordings compared to the Tyrs. The Tyrs have a wider and taller stage and there’s more detail. They slam a bit more but lack some of the bass bloom I’m getting with the F8. The Tyrs sound airier and are less sweet in the mid range. The Tyrs might be a better amp if you want more detail and information or value slam and speed over warmth and bloom. But the F8 is just pleasant to listen to. It sounds a little slower at times but everything just sounds nice and natural. They both layer and image well and even though the F8 is missing a bit of detail I don’t find myself missing the detail I heard with the Tyrs.
Also I’m doing this test with headphones so I’m sure things would change a bit with speakers. Headphones for this comparison were the DCA Expanse.
I’m really happy with it. I did some tube rolling earlier to get to the tubes I have now and that helped too. The stock sounded a bit more analytical I guess. It just felt like the sound was too separated and not as cohesive in terms of imaging and sound stage. The rolled tubes filled out the bass a bit, added some soundstage width, and are a bit warmer overall.
I think they might pair well because LTA is so neutral and Pass is warmer and more tube-like (which is kind of funny if you think about it).
Glad you’re enjoying and I look forward to impressions with the Expanse.
On a side, I always kind of thought that the Expanse (and Stealth) should probably be treated in a similar regard as the Susvara regarding amplification. They seem they require similar levels of power to really sound their best.
