^ well, the old adage of be careful what you wish for comes to mind…. 
Edit: I also think that @Mikerodrig27 just gave more details to what @rhthatcher mentioned in post #5
Edit: I also think that @Mikerodrig27 just gave more details to what @rhthatcher mentioned in post #5
Last edited:
And don't worry about building too many amps if that's what you enjoy doing. On this point, the Mighty Zen Mod offered his sage advice:
https://www.diyaudio.com/community/threads/official-m2-schematic.281520/page-88#post-4969758
https://www.diyaudio.com/community/threads/official-m2-schematic.281520/page-88#post-4969758
I don't think that you can go wrong with any of the amps described here. I've had fun with the M2 clone, M2x, F2J, SissySIT, ACA Mini, and now the F5m. They are all fun to build. The problem I have is not enough time to build them all.
The one amp that I have that is particular about speakers is the F2J. It's a current-source amp and because of its high (15 ohm) output impedance, it is designed for driving wideband drivers directly (no crossover), and it works very well when used that way.
The combination that I always comeback too is the ACP+ and ACA Mini for my desktop listening. It is a match made in heaven for me, and I'm only using some inexpensive Sony SSCS5 speakers.
I'm using the F5m and FY22 Front End on my main system right now.
One of the other major considerations when building a Pass DIY amp is the great support from the all the forum members. I have had issues with builds and received tremendous help with troubleshooting.
Bottomline, I could live with any of the amps on the Pass forum. They all sound great and are fun to build.
The one amp that I have that is particular about speakers is the F2J. It's a current-source amp and because of its high (15 ohm) output impedance, it is designed for driving wideband drivers directly (no crossover), and it works very well when used that way.
The combination that I always comeback too is the ACP+ and ACA Mini for my desktop listening. It is a match made in heaven for me, and I'm only using some inexpensive Sony SSCS5 speakers.
I'm using the F5m and FY22 Front End on my main system right now.
One of the other major considerations when building a Pass DIY amp is the great support from the all the forum members. I have had issues with builds and received tremendous help with troubleshooting.
Bottomline, I could live with any of the amps on the Pass forum. They all sound great and are fun to build.
Attachments
I agree they all have their charms and some do certain things better than others, with a trade-off here or there of course. Like mentioned in #100, some have a more noticeable "character" that is typically pleasing to listen to. Some are better into tougher loads. The amp in my signature is very transparent and detailed, and a good match for my speakers. I like the phrase "what's next?", rather than "what's best?", because the journey is so much fun..
I think there's something special about those autoformer amps. I added that modified Stasis front end to get the gain up on my SissySIT, the stock 11.5db was just too low for my use. That turned it into a 20db gain power amp. It remains one of the very best sounding amps I've ever built, within it's limitations...
Attachments
Can you share what modifications that you did on the Stasis FE to pair with SissySIT for more gain? Please share the schematic if you have one.
Thanks
Ha, I was afraid someone would ask about that.. 
I only have a schematic in my brain at the moment. But the concept is very similar to figure 14B in papa's diyopamp article. I shared some details about it <here>. If I went back to it I would lower the 3rd stage (the EF) current, maybe 20 to 30 mA instead, and likely use a more proper BJT there, like a KSC2690. This configuration drove the autoformer directly, bypassing the buffer on the SissySIT pcb. That said, there is absolutely nothing wrong with ZM's solution there. It was just a choice I made at the time. And a proper DIY person would just layout a new board with these changes, instead of all the hack and slash I did to the Stasis board (the back of my creation is quite ugly...). Hopefully that helps, if not shoot me a PM or whatever.
I only have a schematic in my brain at the moment. But the concept is very similar to figure 14B in papa's diyopamp article. I shared some details about it <here>. If I went back to it I would lower the 3rd stage (the EF) current, maybe 20 to 30 mA instead, and likely use a more proper BJT there, like a KSC2690. This configuration drove the autoformer directly, bypassing the buffer on the SissySIT pcb. That said, there is absolutely nothing wrong with ZM's solution there. It was just a choice I made at the time. And a proper DIY person would just layout a new board with these changes, instead of all the hack and slash I did to the Stasis board (the back of my creation is quite ugly...). Hopefully that helps, if not shoot me a PM or whatever.
Last edited:
<iframe width="743" height="418" src="
" title="The Knights Who Say "Ni!" - Monty Python and the Holy Grail" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
