Yaqin MC-10L Preamp Tubes
 

Hi,

Just got myself a yaqin MC-10L tube amplifier and after some tinkering and replacement of dodgy cathode resistors it now sounds really good.

I have purchased some svetlana 6n1p preamp tubes to replace the chinese ones that come with it as I find they seem to go microphonic quite often and trying to find them to purchase is near impossible.

So I rebiased the EL34's and changed the 6n1's for the svetlana 6n1p but after about 30 seconds there is a terrrible hum through the speakers. There is no bias pot on the preamptubes and was wondering what I need to do to get the svetlanas to work.

Any help would be appreciated

Hello,

did you have a response about your problem?
I have the same amp tube and due to microphonoic problèms , I want to change the 6n1P china tubes with svetlanas one.Isi it possible without making any bias adjustements?

Re: Yaqin MC-10L Preamp Tubes
 

Hi again,

Could you please give me how to mesure ans change the bias the MC-10L.
Thank you very much