Yeah, the ACA Minis went fast, pretty simple and everything's there. The Aleph was quite challenging on several fronts not the least was not having stuff that I needed and accumulated a lot of stuff $$$ LOL. All the tools and supplies created its own set of issues, and the skipping around in the build while I waited for parts, Oye!My main frustration currently with the F5M is that I keep missing things to finish
It's all fun. I have that experience of just losing full track of time messing around with this stuff. I do feel that eventually, I will hit the critical mass of components (Chassis, transformers, and FETS), tools, and everything else. The real factor only being the time to mess around with this stuff.The Aleph was quite challenging on several fronts not the least was not having stuff that I needed and accumulated a lot of stuff $$$ LOL. All the tools and supplies created its own set of issues, and the skipping around in the build while I waited for parts, Oye!
I do fret sometimes about the end of life and NOS Transistors, either not being available, or those that are available being overpriced, like FQA36P15. I called a company here in Florida to ask for pricing, and they told me that they were 50 dollars each.

It does feel that I got into this hobby at the wrong time, or maybe it has always been that way... who knows!
Kits and group buys will probably continue to be a thing on this site, probably need to be patient and keep working on the projects on hand.
Break....
to not get completely off-topic with this thread. I do think that several of the popular FW clones on this site have a great variety in terms of different Class A topologies to explore and listen to. The M2 gets mentioned a lot around here but also does the F4, F5, F6, and the Aleph J (everyone should build one OBVIOUSLY, which you did

You did mention that you have other projects, which ones??
Best,
Jose
I was literally just thinking that! I am close to completion on a Tubes4HiFi Sp14, this forum has spoiled me, the instructions and support for the SP14 are not the best. I am in process of a P3, that got put on a back burner for the SP14 which in turn got put on the back burner for the AlephIt does feel that I got into this hobby at the wrong time, or maybe it has always been that way... who knows!

That's really clever! Really clever!Mark has used a nifty board layout
@6L6 in the original post you commented that the input stage might be subtle due to how it is used, wondering if you still feel that way. I often find that earlier in the chain can be significant.
Nah.... I use my F4 with a variety of pre-amps. I have maybe 2 that will output 20Vp or more. Heck, I ran one of my DACs directly into an F4 with no pre-amp. It was delightful.The only one that seems to need something special is the F4, which requires a pre-amp that can drive it.
Certainly not calling you out specifically...
IMO, too many people may miss out on an incredible amp b/c they've been given the idea that their pre-amp must be capable of outputting enough voltage to result in the F4 clipping.
"Will it drive an F4?" ...

^ So many amps, so little time. Now I see why you use quick connects in your builds, for me the expense of the chassis is second to how much space the stuff takes!
😱 $50 WHOA!I do fret sometimes about the end of life and NOS Transistors, either not being available, or those that are available being overpriced, like FQA36P15. I called a company here in Florida to ask for pricing, and they told me that they were 50 dollars each.![]()
I agree, and I worry about the same things... but not too much.
The good news is that if you have a project ready to go that lacks a set of transistors, the kind folks in the forum will usually help you out. Someone may even reach out via PM, so they're not advertising to the world that they have those parts.
If you go so far as to show that the project is REALLY ready to go (you're not just looking to hoard transistors yourself or have them sit unused on a shelf) then it's likely you'll find what you need very, very quickly unless you're looking for something truly exotic. Don't go looking for 2SK77Bs, but ... if you find some for less than a kidney, let me know. 😉
Ah I see. Its certainly on my radar as something I want to try, and I stand corrected. I did get the DIY FE anyways, just to have more options. I got the boards for the warbler amp, and the FE might work nice with that amp.Certainly not calling you out specifically...
IMO, too many people may miss out on an incredible amp b/c they've been given the idea that their pre-amp must be capable of outputting enough voltage to result in the F4 clipping.
"Will it drive an F4?" ...![]()
I built som Pass amplifiers from Zen to Aleph 100w, easy topology and nice sound class A. The best sound I have from Dartzeel clon amplifier with tripple pair bipolar transistors without negative feedback. Its my saint grail for speakers with normal hifi drivers. Another way is speakers with proffesional drivers with 100dB sensitivity and easy tube amplifiers, se or PP like Audionote with EL84 or another diy tube amp optimal with little feedback.
told me that they were 50 dollars each.
concept sings the most, then difference (if any) in parts sings some too
clever way of having proper fun - always take in account what cheapest parts options are, build as that, then investigate what more xpensive option can bring, if your time/wallet/energy approves
in short - if amp is possible with plain ol' IRFP parts, you probably have them enough laying around, try with them
if you like what you hear, chase Kosher options
Kind of where I’m at with the M2X as well. For comparison, it’s going up against a pair of PS Audio BHK 300 monoblocks and I find myself leaving the M2X in. No other amps have accomplished that.M2x is the one that always seems to make it back into my system and is the hardest to remove when I need to try something new…
This may sound like sacrilege for pass forum, but affter most first watt classA amps are exhausted, i suggest wolverine.
why sacrilege?
fun is everywhere, and god amp is good amp, whatever way been made
don't forget that at least half of tube amps, ppl are raving about, are not A Class at all
fun is everywhere, and god amp is good amp, whatever way been made
don't forget that at least half of tube amps, ppl are raving about, are not A Class at all
Hi Ed, as you probably saw I referenced the Wolverine earlier in this post. Would you give some of your impressions as to what the Wolverine does well?i suggest wolverine.
Being a greedy boy i obviously want it all but assuming a pleasing tonality, I love systems that have holographic imaging. Coming at it from a purely subjective approach I intuit that that requires a very low noise floor.
If by top end you mean around 10KHz I might be able to hear thatExtremely clean top end no other amp can match.

All frequencies are important for sure, good low end gives realism, midrange is where we live, where music happens, but the top end is the cherry on the cake. If its rotten, all is lost.
I enjoy those chimes, triangles, bells and whistles as clean as possible. Not mushy soft, not metallic sharp. As clean as possible.
Many first watt amps do it well, but wolverine excells.
I enjoy those chimes, triangles, bells and whistles as clean as possible. Not mushy soft, not metallic sharp. As clean as possible.
Many first watt amps do it well, but wolverine excells.
You have to bear in mind, the commercial First Watt M2, AlephJ, etc were 3-4 thousand dollar amps......It's all fun. I have that experience of just losing full track of time messing around with this stuff. I do feel that eventually, I will hit the critical mass of components (Chassis, transformers, and FETS), tools, and everything else. The real factor only being the time to mess around with this stuff.
I do fret sometimes about the end of life and NOS Transistors, either not being available, or those that are available being overpriced, like FQA36P15. I called a company here in Florida to ask for pricing, and they told me that they were 50 dollars each.So it looks like the search will continue with that particular part. A friend called another company in Texas and they told him the same thing. That is not a great proposition, since you have to get several to get a good match.
It does feel that I got into this hobby at the wrong time, or maybe it has always been that way... who knows!
Kits and group buys will probably continue to be a thing on this site, probably need to be patient and keep working on the projects on hand.
Break....
to not get completely off-topic with this thread. I do think that several of the popular FW clones on this site have a great variety in terms of different Class A topologies to explore and listen to. The M2 gets mentioned a lot around here but also does the F4, F5, F6, and the Aleph J (everyone should build one OBVIOUSLY, which you did). Each one is a different take and probably has its strengths and weaknesses. The only one that seems to need something special is the F4, which requires a pre-amp that can drive it. The store has the DIY 2022 FE that fits that bill and it's cheap. In the end, you will probably end up reusing the big-ticket items like Trafos and Chassis for other things, if it's not your cup of tea.
You did mention that you have other projects, which ones??
Best,
Jose
That is always a solid option. IRFP are everywhere, and the store has harris version which seem to be the best of the bunch.in short - if amp is possible with plain ol' IRFP parts, you probably have them enough laying around, try with them
if you like what you hear, chase Kosher options
I had the $$$ to start sourcing parts for the wolverine, mainly a 63v secondary trafo… then the F5M dropped and I spend saved money for it. Sometimes I find myself chasing the new shiny object instead of focusing on what I have on hand.This may sound like sacrilege for pass forum, but affter most first watt classA amps are exhausted, i suggest wolverine.
I am definitely aware that the commercial FW are way more expensive, and out of any range that I could afford.You have to bear in mind, the commercial First Watt M2, AlephJ, etc were 3-4 thousand dollar amps......
Price will probably dictate many of my decisions on what to build. FQA36P15 is pricey compared to the N channel part. Plus need to source several to match them, which is the annoying part. For that I could spend the dollars and get a matched set of THF-51S.
Either way, I will adapt and overcome. I sourced some FQA28N15 from @Toys4Boys, and I could use those to build a F6. No real loss.
- Home
- Amplifiers
- Pass Labs
- What's Next Amplifiers