Musical Fidelity A220 Schematics?

[ckng]

Hi,

Does anyone has the schematics or service manual for the Musical Fidelity A220? I searched around here and in google but cannot seem to locate one. Thanks!

Regards
CK

[lt cdr data]

hi try here, identical apart from output stage, which has more transistors

http://www.rspu.ryazan.ru/~foboss/pl...il.ru/mfa2.htm

[davidsrsb]

Hmmm.... Negative rail at the top of the schematic to confuse, why can't people stick to drawing conventions.

The bias setting pot goes to maximum current if the wiper goes open too.

[ckng]

Thanks. The page appears to have only the pre-amp section tho, the power section is not shown. I can't read russian but are they trying to bypass the op-amps for some reason?

I am also wondering (assuming the circuitry is similar, at least for the pre-amp stage) is it feasible to take the ouput from the op-amps (pin 1/7) after the 100ohm resistor and use it as a volume-controllable preamp output?

Regards
CK

[dimitri]

reverse engineering:
http://www.rspu.ryazan.ru/~foboss/pl...2/MFA2MAIN.jpg

how it should be - from Paul Skritek
Handbuch der Audio-Schaltungstechnik
http://www.rspu.ryazan.ru/~foboss/pl...MFA2/AMPSK.jpg

[t.ruppenthal]

Hi guys,

i have a wonderful A220 which just gave up in a puff of smoke. As i love this sweet sounding amp i would love to get it fixed again but for that i need a circuit diagram. Can anybody help please.
I already had a look at previous posts but the links are dead.

Thanks guys
T.ruppenthal

[Hans2983]

Hi,

Does anyone has the schematics for the Musical Fidelity A220? I searched around here and in google but cannot seem to locate one. I am interested in the differences with the MF A2.

Regards
Hans

[cpitts]

*BACK FROM THE DEAD!!!!*

So to help people out, I'm doing a refresh/fix-up on my amp to make a really nice amp, a lot better. Won't divulge where I got this info, but here's a link to my site that's documenting my work (currently underway).

Doodads galore! We just luv em.

Have also completely rebuilt my speakers as well which is worth a read (jump to the link via the menu at the top ). And no, I'm not selling stuff, pushing product or anything, I'm just wanting to share as much of this as possible.

[ckng]

Originally Posted by cpitts

*BACK FROM THE DEAD!!!!*

So to help people out, I'm doing a refresh/fix-up on my amp to make a really nice amp, a lot better. Won't divulge where I got this info, but here's a link to my site that's documenting my work (currently underway).

Doodads galore! We just luv em.

Have also completely rebuilt my speakers as well which is worth a read (jump to the link via the menu at the top ). And no, I'm not selling stuff, pushing product or anything, I'm just wanting to share as much of this as possible.

Wow, can't believe this thread was revived after 5 years! Thanks for all the information that you've put up.

However, sadly, my A220 literally went up in smoke a few days ago after an hour of playing + 1 hour idling after that. White smoke came out from the vents until I powered it off and unplugged everything.

Suspecting maybe a blown electrolytic cap I wanted to open up the case but it's secured with security Torx screws. The next day I searched high and low in the nearest hardware store for a suitable driver and had to buy the whole set as they don't sell singles.

Anyway, after it's open, I found nothing that appears to be obviously burnt. One of the 1W(?) resistors in the right power stage had some chipping. I am not about to plug this in again to see what is actually burning up though.

Any idea how I can troubleshoot this safely or will it be better to get a certified pro to check it out/repair it?

Thanks!

Regards
CK

[ckng]

Originally Posted by cpitts

*BACK FROM THE DEAD!!!!*

So to help people out, I'm doing a refresh/fix-up on my amp to make a really nice amp, a lot better. Won't divulge where I got this info, but here's a link to my site that's documenting my work (currently underway).

Doodads galore! We just luv em.

Have also completely rebuilt my speakers as well which is worth a read (jump to the link via the menu at the top ). And no, I'm not selling stuff, pushing product or anything, I'm just wanting to share as much of this as possible.

And interestingly, your A220 has a pre-out, mine doesn't. Hmm...

Regards
CK