Yaqin MC-10L no bass response

[Nichicon]

Hello,

I dont know what I did but before I did test with bass box with sub 4 ohms, maybe it f... my amp. So I have disconnected all speakers and connect sub for one channel, i did 1 minute test it was really deep bass. After that i connect old spearkers back, and proper bass...

So if I`m using one channel, no matter L (4 or 8 ohms) or R (4 or 8 ohms) bass response is fine, but if I am using 2 channels, than less bass and bass slightly disstorted but not to much... There is no stock china bulbs, EL34b SVETLANA, and preamp bulbs made in russia as well. I am using these bulbs more than 2 years and no probs at at all. Bias 0.34V

Could somebody help me?

 

[scopeboy]

Maybe one of your speakers is connected with the wrong polarity? Check the + terminal on the amp goes to the + on the speaker.

 

[Nichicon]

solved!!!
thank`s mate!!!!
But how It could makes so huge difference? because one speaker was connected proper, second one was connected reverse? but no bass was for 2 channels. really strange.. I know about speaker phases but seems for valve amp its very important! thanks again and have good weekend! From me beer for you!

 

[DF96]

Nothing to do with valve amp. Wrong speaker phase in one channel gets rid of bass whatever amp you have. The reason is simple: bass is nearly the same on both channels so if one is antiphase it cancels acoustically. Treble does not cancel in the same way because it differs more between channels and because the shorter wavelength means you would have to be in exactly the right spot to get cancellation.

 

[chip647]

With stereo (multiple) speakers the bass frequencies will cancel in your room if they are out of phase. Higher frequencies will get phasy and you loose any imaging. Tube or solid state it does not matter. It is an acoustical issue.

 

[Nichicon]

thanks guys anyway!