Soundcraftsman MA5002 Bias

[Depaj]

Yes I know but that's one piece of equipment I still have to buy and they aren't cheap.
Thank you, I will set it at this, leave it for a while, see if it drifts, how heat sinks feel and check scope for crossover although that's probably not very accurate.
Thanks for your help

 

[epicyclic]

Sounds like a good plan to me . Glad to have helped

 

[Depaj]

Bias stays nice around 15mV (+/- 0.5mV), heat sinks are slightly warm and I don't see any crossover notch.
The only thing left to do now is check out that power meter and see what's wrong with it.
I did already verify and they do get the same voltage across their terminals.

 

[Depaj]

Last problem has been solved, I disassembled the power meter that was weak and completely cleaned it : the back spring got stuck to the back of the casing. They now track pretty closely.

 

[HutchAmpMan]

Service manual for Soundcraftsmen A5002

Does anyone have a readable service manual for the Soundcraftsmen A5002 (the one with the LEDs)?

The manual I have is a very low res scan and hard to read.

Thanks!
Tom

 

[crooner2264]

The SWR Bias procedure says to connect the amp to a 2 ohm load, inject a signal and turn it up to clip, then adjust bias to remove the crossover notch! Never seen it done that way before!

75ma seems low to me??? i thought my PCR-800's ran closer to 400ma bias....I will have to dig out my schematics aagin, maybe im confused. But im pretty sure the calculation was 100ma of bias for each of the 4 mosfet output devices or something like that....

hello, Zero cool: i know this is an old post but i will ask any ways. do you know what resistors on the board to measure to check bias?