A15mk2 Ch2 Boost Switch problem!

billymj23

Hello to all,
I 've just finished building the A15mk2 model ... I'm glad everything went according to plan and it's working like a charm ... well, except one small problem ... the gain boost switch, at (++) position I can't get any sound at all ... I've tripled checked the layout in every detail and verified all connections according to the schematic ... but in vain ... the problem persists.
I kindly ask you for your help and any advice on solving this issue.
Thank you in advance.

oksuper

Hello,

Have you check with a multimeter if the switch is working normaly ?
It may have been overheated when you did the soldering.

billymj23

Hello oksuper,
thank you for your suggestion, I've checked the switch with a DMM and it's working properly. Although, I've to say that I do get a very subtle sound, barely audible, at (++) position but only when I turn the gain and volume pots all the way to the max. Did you come across with a similar situation with your build ?
Thanks again for your time and your help.

oksuper

I didn't had this problem, no.

Everything worked fine the first time. I am still in test period with mine and I'm just looking to reduce the buzz at the minimum, by adding a metal sheet to separate the power plate from the rest. I'll also close the enclosure with a matching sheet of aluminium.

I'm sorry but I don't know what could cause your problem if it's not a faulty component (if you're sure that there is no assembling error)... Maybe check that the shielded cables are ok and be sure there is no connection between the shield and the signal.

billymj23

I did a another thoroughly check and verified every single connection.
Then I thought I might trying swapping the tubes with each other. When I replaced the V3 (gain channel) tube with the one from V1 (clean channel) the boost switch at (++) position finally worked. The bad news is that the clean channel is gone ... no sound at all. So I guess it was a faulty tube all along.

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