trinityamps.com

Just finish the build, and a couple of problems have popped up:

The Top Boost channel is about half the volume of the Normal Channel... and ideas on what I should look for ???

Also the Bass control "drops" out when it is on full when using the Top Boost channel, work right up till it hits around 8-9 and then its gone, sound still comes out of the amp... just missing bass, but has mids.

I am a bit tired, and the brains are not working as well this evening so any help to get me going the right direction would be great !!!

Thanks.......

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Life is to short to drink American Beer

To start, check the cathode voltage on the pre-amp tube on the quiet channel.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thank you for the suggestion, but it turned out to be the 100p MICA cap on the Volume pot. Cold solder maybe... I traced the signal with a audio generator and that is where the sound got soft, unsolder it and it got loud, put it back and all was well.

That is what I get for working when I am tired.

Thanks again for the help

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Life is to short to drink American Beer

Good job. That can be a tough one to find. Does your AC30 Top Boost build have tremolo or reverb? or is it straight up AC30?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

It's the Hoffman... so it is straight up... Now I just need to find out why the Bass pot cuts out when it is all the way up

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Life is to short to drink American Beer

Hi

I have the same issue with the bass control on the amp i recently built myself. From about '7' up to '10' (max) on the bass setting, the bass seems to roll off rather than keep increasing. I haven't had time to get back to it as i seem to be flat out working on everybody else's amps at the moment.

In my case, i have wondered whether it it the cap values i used, as i have used 2 x 0.033's instead of the usual pair of 0.022's, but it sounds like that may not be the problem. (I have now got a nice pair of Sprague Vitamin Q's 0.022's to put in there but just haven't had the time to get to it).

Let us know if you get any results, and i'll get back to you as soon as i can do more work on my amp. I am interested to know whether anyone else has had this problem, hope you get some more responses here,

cheers, neil.

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Lumbering dinosaur....what's a master volume?

Where is the treble control set? AC30 controls are interactive & it's possible for this to happen. I posted some tone stack curves for the TC-15 and this would be similar.

Try backing off the treble to middle& see if the bass comes back.


Thought this would be of interest to some. These are frequency response simulations of the Trinity15 Tone Stack.

Trinity 15 Tone Stack - all controls set to middle position



Trinity 15 Tone Stack - Sweep Bass; Treble in middle position




Trinity 15 Tone Stack - Sweep Treble; Bass in middle position

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Ok, after being able to really "open" the amp up... the volume on the Top Boost Channel was still not as loud as the Normal channel...

So it was back to the tone generator and more tracing... Turns out the wire from the input jacks of the Top Boost channel was grounding... not enough to kill the signal or for it to beep when checking for continuity. Just enough to rob it of some signal.

It's always the simple ones that get us ....

Thanks for the help guys... some times you just need some fresh input

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Life is to short to drink American Beer

Excellent news & good advice!!

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Well I took out the amp to use at a local JAM, really got to open it up... sounded really good and was very pedal friendly. Even had a couple of guys ask how much to build them one. Feels good !!!

Guess you can call me a proud papa now

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Life is to short to drink American Beer

Now that must have been fun. No recordings of the jam eh?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps