Troubleshooting: amplifier Musical Fidelity A1

[Sala Massimo]

Damir, thanks for your answer.

Unfortunately Musical Fidelity didn't reply to my letter, and in Italy
service shops don't have ***double*** pots.

I think in Italy, as in many other European countries, electronics is going
far from do-it-yourself-guys, because the devices are going more complex
(micro, ASIC, FPGA, ...) and the service labs don't repair the single
component: they substitute the entire cards.

I remember well my trip to Russia in 1991: I can found tubes in the shops!
See http://web.tiscali.it/no-redirect-tiscali/massimosala/tubes/

In my city (150000 people) some shops had discontinued many parts, also
circuits boards !

How is electronics for DIYers going on in Croatia?


About Musical Fidelity troubleshooting, see the threads I open on
uk.rec.audio
rec.audio.tech

ciao, Massimo

 

[Stephen Sank]

It's been a number of years since working on any A-1's for me, but I recall pretty clearly that
it used bipolar output transistors, that were quite successfully replaceable with Motorola
MJ15003/15004 pairs or the higher voltage/current versions of these. The biggest problem with
these was that MF used 1/4w resistors in places where they should have used at least 1/2w, so
spent most of the time replacing resistors on these, and the occassional TL074 quad opamp
IC(pref. with AD713 Analog Devices version). The funky thing about the volume pot was that it
was actually a gain control, instead of an input voltage divider, so each section of the pot
was used as a two-terminal VR. As I recall, the pot was a very conventional 2 x 50k Alps or
Noble "base grade" part, with no unusual mounting or shaft, so should be quite easy to replace
if necessary.

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Sala Massimo" <saltlakeCHIOCCIOLA@tiscaliPUNTO.it> wrote in message
news:brkopc$3oo$3@lacerta.tiscalinet.it...

Damir, thanks for your answer.

Unfortunately Musical Fidelity didn't reply to my letter, and in Italy
service shops don't have ***double*** pots.

I think in Italy, as in many other European countries, electronics is going
far from do-it-yourself-guys, because the devices are going more complex
(micro, ASIC, FPGA, ...) and the service labs don't repair the single
component: they substitute the entire cards.

I remember well my trip to Russia in 1991: I can found tubes in the shops!
See http://web.tiscali.it/no-redirect-tiscali/massimosala/tubes/

In my city (150000 people) some shops had discontinued many parts, also
circuits boards !

How is electronics for DIYers going on in Croatia?


About Musical Fidelity troubleshooting, see the threads I open on
uk.rec.audio
rec.audio.tech

ciao, Massimo