AC15 channel output difference

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plookit
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Joined: Sat Jan 28, 2023 7:38 pm

AC15 channel output difference

Post by plookit »

Hello,

I made an AC15 chassis up about 10 years ago and never got around to completing it due to being overwhelmed with my teaching job, which I just retired from. I have dug out the AC15 and fired it up. It sounds great and need to get it in a cabinet.

One thing that concerns me though is the output difference between channel 1 (vibrato channel) and channel 2. Channel 1 is quite a bit lower volume than channel 2. Is this normal on an AC15?

Thanks

Tom
sluckey
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Re: AC15 channel output difference

Post by sluckey »

That's normal.
plookit
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Re: AC15 channel output difference

Post by plookit »

sluckey wrote: Sat Mar 25, 2023 12:39 pm That's normal.
That's good to know. Thank you.
sluckey
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Re: AC15 channel output difference

Post by sluckey »

You can make it much better by swapping positions with R10 and R35. Even better if you replace R35 with a jumper wire and change R10 to 62K. Refer to linked schematic. Easier to see what's going on if you look at page 3.

http://sluckeyamps.com/VAC15/Vox_AC15.pdf
plookit
Posts: 16
Joined: Sat Jan 28, 2023 7:38 pm

Re: AC15 channel output difference

Post by plookit »

sluckey wrote: Sat Mar 25, 2023 12:52 pm You can make it much better by swapping positions with R10 and R35. Even better if you replace R35 with a jumper wire and change R10 to 62K. Refer to linked schematic. Easier to see what's going on if you look at page 3.

http://sluckeyamps.com/VAC15/Vox_AC15.pdf
That is brilliant, thanks so much. I'll let you know how I get on. What a superb set of documents.
plookit
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Joined: Sat Jan 28, 2023 7:38 pm

Re: AC15 channel output difference

Post by plookit »

I made those mods on R35 (jumper) and R10 (66 because not got 62) and channel 1 seems even quieter. Will reverse it and compare
sluckey
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Re: AC15 channel output difference

Post by sluckey »

I did not expect that.

And I should add... Looks good on paper but I have not done this to verify.
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