Dreaming of a DIY power amp

Ideally I'd like solid state on the low end and tubes on the mid-high but dunno if my L220 crossovers can be used in biamp.

It seems possible that you could modify the L220 crossover so that the LF section was one input and the MID/HF is another. Here is the schematic (from audioheritage.org)

l220ts.gif

You could start with one Firstwatt (Aleph J, F4, F5, M2, F6... etc) and build a second Firstwatt later and have biamp mono-blocks.
 
Regarding your shopping list: It's unclear if you noticed, that amplifier boards do come in pairs, so you only need to order one "item" from the shop.
You are missing jfets in your list I think. Either buy LSK one's from DiyAudio shop, or use one of the proven sources -don't buy blindly on the internet.

You are right, thank you to pointing that out

Grazie
 
It seems possible that you could modify the L220 crossover so that the LF section was one input and the MID/HF is another. Here is the schematic (from audioheritage.org)

View attachment 927809

You could start with one Firstwatt (Aleph J, F4, F5, M2, F6... etc) and build a second Firstwatt later and have biamp mono-blocks.

I think so too, the crossover are very old fashioned, you can see from the attached pic (I had the electrolytic caps upgraded with new film ones), it won't be bad to use the tubes on the mid-high section and solid states at the bottom

 
Beauty of a First Watt amp is once you have a case / power supply, you can just swap in amplifier boards to find out what you really like with your ears, room, equipment, source material, etc... F5? Aleph J? M2X? Just swap it in... (I obviously like the F4 and then just roll preamps of different flavors..)

So, say I pick the right case and big enough transformer/caps it would be just (...) swap the power boards?

It gets more and more interesting, I am gonna enjoy sum sun by the gardens with my dog as a retired one would and once back I will read something about the F4 while listening to some music.

Told you by the way, build it or not it's such a pleasure to interact with you, we are very well covered from the other side of the wall till the west coast :cool:
 
F4 would allow full potential of your SP9 to shine, simply because F4 is not having voltage gain ....... that means that for full blast , preamp must deliver that on input of F4

that also means that F4 is not having much character of its own, resulting that preamp is dominant in amplification chain, sound wise

read pdf
 
F4 would allow full potential of your SP9 to shine, simply because F4 is not having voltage gain ....... that means that for full blast , preamp must deliver that on input of F4

that also means that F4 is not having much character of its own, resulting that preamp is dominant in amplification chain, sound wise

read pdf

Just did a couple hours ago and then called my friend in Napoli (pizza?) who confirmed being available to help and about FW being worth.

Peppe, would you help me arrange a shopping list so I can figure where would I end?

Grazie