Forums - Occasional static in Right Channel on Taboo...

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Posts: 6

Occasional static in Right Channel on Taboo...
11/02/24 at 23:18:24

Hello all,

Recently, my Taboo started making an occasional static noise in the right channel. It usually starts after the amp is fully warmed up, usually 30+ minutes into listening. It will make a static sound, similar to the sound when playing a dirty album, for about 2-3 seconds, then it goes away.

It comes and goes about every minute or so. Sometimes it will persist for several seconds at a time.

I have tried the following:
Replaced all 3 tubes back to the original Decware tubes.
(I was running a vintage Telefunken ECC83 and a new set of "Preferred" EL84's from TheTubeStore.)
Unplugged my Schiit Saga preamp from the Taboo
Adjusted the gain knob on the Taboo
Adjusted the Lucid knob
Swapped out the speaker cabling
Checked all connections

Any other ideas?

Thank You for the help!

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CAJames

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Re: Occasional static in Right Channel on Taboo...
Reply #1 - 11/03/24 at 00:48:04

Quote:

Posted by: paradisecom Posted on: Today at 15:18:24

...I have tried the following:
Replaced all 3 tubes back to the original Decware tubes.

You say you replaced 3 tubes, but the Taboo has 4. Have you tried a new rectifier? Also, just for completeness have you tried swapping the left and right power tube? I'm sure that is something you're going to be asked to do, even if you put in good tubes.

Quote:

...I was running a vintage Telefunken ECC83...

You really mean a ECC83 aka 12AX7? That's an interesting choice for an input tube.

Given your symptoms I would have bet a lot on a bad tube. If the noise persists with 4 good tubes and no input connection IMO it is time to talk to Steve. Good luck regardless.

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[FOOBAR2000 | Jay's CDT2 MRK3] -> Denafrips Terminator 2 + Gaia
Sumiko Pearwood -> Mapleknoll Athena -> Luxman SUT -> Mapletree Phono 3E
STR-1002 -> Woo WA22 -> 2x UFO25s, balanced monos
Omega SAM , Hifiman Arya, Audeze LCD-XC

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paradisecom

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Posts: 6

Re: Occasional static in Right Channel on Taboo...
Reply #2 - 11/03/24 at 17:29:06

Perhaps I should have clarified, this is an older Taboo, from about 2008, I believe. It runs a 12AX7/ ECC83 input tube.

I haven't swapped out the rectifier tube since I don't have any extras and I figured since the amp works, it's doing its job and not affecting 1 of the channels. I could be wrong, though.

I swapped in another set of EL84's today to see if any issues persist. I see what it does today.

Thanks for the reply.

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mrchipster

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Posts: 79

Re: Occasional static in Right Channel on Taboo...
Reply #3 - 11/03/24 at 17:30:31

I agree with CAJames that these symptoms are usually the result of a bad (or going bad) tube.

I recently had a similar issue with the input tube in my UFO25. I had received a full set of NOS tubes to replace the tubes in all my equipment so I could use the original Decware tubes as backups. 2 to 3 months later I noticed the static/hissing sound coming from the left speaker. After putting all the original tubes back in as a starting point (and not hearing any static) I systematically replaced the tubes and found the culprit to be the input tube in the UFO. I sent the tube back and I'm awaiting a replacement.

However, here's a kicker and maybe something else to try if you haven't already.
Every once in a while, I turn all the knobs and pots and switches on all my equipment just to exercise them. I then just set them back where they were when I'm done.
I did this the other day and then turned on my equipment. I heard a similar static/hissing faintly coming from both speakers. I said damn, not another tube! Something was different about it and it was coming from both channels now instead of just the left. My first instinct was to flip the bias switch on the front of the UFO and then back again. I heard the usual pop (which is not a problem) and to my surprise the static noise went away. Not sure why, but it seems the circuit needed to be exercised during operation to set it completely right again.

If you haven't already, you could try exercising the front hi/lo switches and speaker hi/lo switches on the back a few times. You could do this with the amp off first and then with the amp on.

Just wanted to throw out my two cents and hope it helps.
Good luck.

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CAJames

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Posts: 2279

Re: Occasional static in Right Channel on Taboo...
Reply #4 - 11/03/24 at 18:08:52

Quote:

Posted by: paradisecom Posted on: Today at 09:29:06

Perhaps I should have clarified, this is an older Taboo, from about 2008, I believe. It runs a 12AX7/ ECC83 input tube.

That makes sense.

Quote:

I haven't swapped out the rectifier tube since I don't have any extras and I figured since the amp works, it's doing its job and not affecting 1 of the channels. I could be wrong, though.

My experience is with tubes pretty much anything (bad) is possible. I agree a bad rectifier is not likely but the only way to rule it out is to try another one.

Quote:

I swapped in another set of EL84's today to see if any issues persist. I see what it does today.

To me, the input tube is at least as likely than the output tube, but that certainly is worth trying. Have you tried tapping on the tubes? That can lead you to the noisy tube.

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[FOOBAR2000 | Jay's CDT2 MRK3] -> Denafrips Terminator 2 + Gaia
Sumiko Pearwood -> Mapleknoll Athena -> Luxman SUT -> Mapletree Phono 3E
STR-1002 -> Woo WA22 -> 2x UFO25s, balanced monos
Omega SAM , Hifiman Arya, Audeze LCD-XC

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paradisecom Verified Member Posts: 6	Re: Occasional static in Right Channel on Taboo... Reply #5 - 11/04/24 at 01:14:13 Today I ran a set of vintage Valvo EL84's all day. It seems to be working properly now. I guess I didn't think that 2 newer tubes in a row could be failing. If anything changes, I'll circle back here. Thanks for all the suggestions!
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