proton am200

[diymax62]

Hi to all, I recently bought a Proton AM-200 and I'd like to put my hands on it, but first of all, I must try to remove the 1,5V continue voltage at the speaker output (TOO high...).

I suspect some old electrolytic out of range, but I can't manage to find the schematics, even if I searched it a lot.

Is there any good soul that want to help me?

 

[destroyer X]

I have found the owners manual, it has not schematic

The offset you inform seems to me damage, not something you will adjust..if you are very lucky you may find oxide inot the offset adjustment trimpot....but only if you are very lucky.

Watching your Proton AM200 owner manual, i felt it looks alike the NAD3020, and this factory, Proton, used to copy the schematics from NAD, to produce under license, or is an associated factory....even the schematic was made alike the NAD.

Into Jan Dupont"s schematic site, i have found the model 520... and really, maybe has something alike your model 200, because even the ouput power and other specifications are the same.

If you want to take a look, them download the 520 schematic here:

http://www.audio-circuit.dk/Schematics/Proton-520-int-sm.pdf

regards,

Carlos

 

[destroyer X]

Here you have the user manual link

http://www.hobbyelectronics.it/hosting/640312/Proton_AM-200_instructions.pdf

If you want to pay for the service manual, you can use this link:

http://www.audiocircuit.com/index.php?c=PSH&m=AM-200#

When we type Proton AM200, sometimes appear into google search AM520....so....they seems to have something alike.

Capiche fratello?

arrivederci

Carlo

 

[diymax62]

Thank you Carlos, yes, maybe there can be a damage, but nothing so serious if I can put my hands on a schematics. I already have the Proton 520 (and I already modded a Proton 520... what a fine amplifier!), it seems to me that they are quite different.

Maybe something similar, but... you must have a precise referring when you are in searching of something specific.

It seems that Proton AM200 is a hard-to-find schematic like the Rotel RA-820. I spent about one month to understand where to put my hands on without destroy it (but I achieved a very good result, at least... )

I know the audiocircuit link, but it's quite strange to pay for a schematic of an obsolete amplifier. Serious company give the schematics for free... Maybe I'll try with Proton directly... will they be serious?

Ciao

Max

 

[destroyer X]

I also hate people asking money for schematics

But.... people use all they can/have to earn money.

When we need a lot, also we use to be ready to pay a lot...and there they are... alike Sharks waiting for us.

regards,

Carlos

 

[diymax62]

I think that, for schematics without copyright like these, we all audiophile friends should begin a service to share them, eventually with a dedicated and categorized thread. I would be happy to share all my documentation.

I know, it's a database duplicate, but it should be VERY useful, just to have a secure place to find, and just to left the sharks a little bit fasting...

regards Carlos, if I understood who you are, I like your way to "feel" audio world.

Max

 

[diymax62]

WOW!WOW!WOW!

You were right, Carlos, am-200 and 520 are practically the same, with few changes (it seems to me only output and driver transistors...) so...
what a strange damage: VR5 and VR6 was broken, totally broken!

They are used to adjust the output DC offset (... ...), probably thay manage an amount of current that they can't support. I've changed them with a stronger ones, made the regulation (0mV DC output at the speakers, just let's be maniac...) so... let's start to dance, with silver-mica, cerafine, metal resistors and so on...

Thank you a lot for your inputs, Carlos!