yaqin mc10k

[inquisitive]

hi, i have a yaqin MC10K amplifier 220v 50/60 hz version.The voltage where i live is 240v is it ok to use? thankyou.

[drboyd]

...especially since that amp will only work for about three months before it pops a resistor and a tube, as the bias was mis-adjusted from the factory.

Mine was.

[EC8010]

Welcome to the forum, Inquisitive. With a bit of luck, drboyd will tell you which bits to tweak to avoid your amplifier producing a firework display.

[inquisitive]

thankyou for answering my question drboyd you replied that the bias was incorrectly set at the factory could you tell me what resistor value you used to correct this problem? do you think i need to change any other components to get this thing stable? thanks, your help would be sincerely appreciated.

[kooltubes]

Be very careful with this amp. I will recommend you bias it correctly using cheap speakers. I have seen some Yaquin amps being self-immolating over a few weeks, especially the model using the 6080 tube at the output. I guess you bought it from Cattylink

Anyway, you can always modify it, that's the beauty of tube amps.

[drboyd]

Well, I can't help you much, as mine is still waiting for someone who knows more about it than I do to fix it. If you do a google search for it, you'll find someone on a different forum that figured it out. Basically, the bias is set from underneath the chassis.

Now we find out.

[kooltubes]

Get in touch with Snowy ( he or she never says his/her gender)at
www.cattylink.com , they are the ones who OEM that amp and you must demand full support.
Hope this helps

[inquisitive]

thankyou for the replies, when i purchased the amp i intended to modify it with the help of my good friend who was a broadcast engineer from way back, unfortunately he passed away recently and his knowledge and friendship is sorely missed. kooltubes , what do you think the best path for modding this amp would be? i want to put in higher quality output trannys, and better components, what path would you take. I will find out about the bias so i can stop it self immolating and muck around with it as time permits............... WE will find out with any luck drboyd thanks any ideas would be most appreciated

[inquisitive]

well underneath this amp there are a series of holes through the chassis underneath each bank of valves .When i inspected the holes i found 2 trimpots 1 for each valve, near each trim pot there were adjacent holes , you could see the track on the board and appeared to have a dimple on the end about the size of a test probe.this configuration is repeated on the other channel, my question is would this be the place to adjust with a meter? The trimmers have hex heads so they would be easy enough to adjust.What would be the best procedure when doing the rebiasing ? by the way drboyd i couldnt find that diy forum could you direct me to it? (excuse my ignorance), well with a little help we might get this thing running properly any suggestions would be sincerely appreciated.

[drboyd]

Here's the link about the guy who fixed his Yaqin MC-10K...

http://www.stereo411.com/forum/viewt...838707c9d8e4c7