Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: theaterguy on November 10, 2019, 12:05:20 PM

Title: Ibanez TSA30 - buzzing
Post by: theaterguy on November 10, 2019, 12:05:20 PM
Hi all, my first post!

Recently I bought a used TSA30 combo, for the money it was a bargain (180€), me thinks.
Everything works fine except, amp randomly buzzes  when a cable is connected to TS/boost jack.
Twisting the cord can make it disappear and when it has been powered hour or so it rarely makes any noise.
Same buzz can be heard when touching simultaneous plugs sleeve and chassis.
Now this makes me think that signal ground and chassis is connected thru condenser and that should be replaced.
What do you think? And where would this component reside?

Let me make this one clear: It's not a bad cable issue. I tried it with several TRS cables and all those behaved as antenna. The footswitch  itself is not original but does it job perfectly, leds and all.

Thanks
Title: Re: Ibanez TSA30 - buzzing
Post by: DrGonz78 on November 10, 2019, 02:58:37 PM
Welcome to the site  :dbtu:

Well here is the schematic... Please look at the components where there is a capacitor between signal ground and chassis. Please let us know which caps on the schematic so we might have a better way of visualizing what you are thinking about that one. Also, I am confused by " amp randomly buzzes when a cable is connected to TS/boost jack" since all I can see is there is a boost switch but not a boost jack.

Anyway we know there is a random buzz occurring and that you twist some cable to make the buzz disappear. Which cable is this one? The Input cable from guitar or cable for footswitch?

Schematic>>>
https://www.ssguitar.com/index.php?action=dlattach;topic=4011.0;attach=6242
Title: Re: Ibanez TSA30 - buzzing
Post by: Jazz P Bass on November 10, 2019, 06:07:15 PM
I believe that the OP is referring to the Foot Switch jack.
Title: Re: Ibanez TSA30 - buzzing
Post by: theaterguy on November 11, 2019, 07:25:24 AM
I believe that the OP is referring to the Foot Switch jack.

Yes and thank you.
The cable connected to the Foot Switch jack causes the buzz.

Following the ground from the TS/boost jack, it goes to ground via c55 but then same trace goes direct to chassis near the input jack. hmm...?



Title: Re: Ibanez TSA30 - buzzing
Post by: phatt on November 12, 2019, 08:52:26 AM
This might help;
https://www.ssguitar.com/index.php?topic=4011.0
Read second post by Bajaman.
Cheers, Phil.
Title: Re: Ibanez TSA30 - buzzing
Post by: theaterguy on November 15, 2019, 02:24:52 PM
Thanks, I try that.
Title: Re: Ibanez TSA30 - buzzing
Post by: theaterguy on November 25, 2019, 02:58:06 PM
For those it may concern; before anything, just try a short cable between send-return jacks.
Cheap&easy but some curiosity was left...