Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Crack-a-two-a => Topic started by: TurbOSquiD77 on February 17, 2017, 04:14:54 PM

Title: TwoQuiet Coarse Switch Volume Control Hum/Buzz/Noise
Post by: TurbOSquiD77 on February 17, 2017, 04:14:54 PM
Hello all,

On the coarse switch I get a "enhhhhhh" hum/buzz type noise on -9dB and 0dB (when no audio is playing because that would be quite loud haha!) Noise is louder on the 0dB setting. This is also present, ever so quietly on the -18dB setting but barely noticeable. Suggestions? I can post the forum on this if you wish. Solder joints are solid as can be - triple checked and re-soldered.

I believe PB mentioned RCA caps to isolate outside noise? Any other sources of this issue? Otherwise this was one hell of an upgrade - bonus points!  8)

Thanks much,

-T
Title: Re: TwoQuiet Coarse Switch Volume Control Hum/Buzz/Noise
Post by: fullheadofnothing on February 17, 2017, 05:41:25 PM
If a noise is increased by changing the volume setting, it must be sourced prior to the volume contol. Therefore it is most likely your source component. Second most likely is your cable, and the third possibility is the wiring from the jack to the source selector/volume control. Furthermore, since it is inaudible at listening levels, it is inconsequential.
Title: Re: TwoQuiet Coarse Switch Volume Control Hum/Buzz/Noise
Post by: TurbOSquiD77 on February 18, 2017, 09:38:19 AM
If a noise is increased by changing the volume setting, it must be sourced prior to the volume contol. Therefore it is most likely your source component. Second most likely is your cable, and the third possibility is the wiring from the jack to the source selector/volume control. Furthermore, since it is inaudible at listening levels, it is inconsequential.

Cool, thank you.

I disconnected my source components one at a time. Each disconnect resulted in the noise being almost gone - all the way to my PC. USB noise? I'm running a Jitterbug USB filter, Schiit Wyrd, and Modi Multibit. I get no noise (or very little) over toslink.

Next I'll reduce fan speeds in my PC and try some other stuff too. But I'm running a brand new gaming board, GTX 980ti, water cooled i7-6700k, in a Phantek's Enthoo Evolve case.

If you see this Josh, could you please take a look at my last post in the Tube Rolling thread - Crackatwoa section.

Thank you,

-T
Title: Re: TwoQuiet Coarse Switch Volume Control Hum/Buzz/Noise
Post by: TurbOSquiD77 on February 19, 2017, 09:09:57 AM
Update on Crackatwoa - noise/other - noticed something different today.

Setup:
HD6XX
TwoQuiet volume at -45dB coarse, 0dB fine.
PC -> Jitterbug USB -> Wyrd USB -> Modi MB USB -> RCA out -> center RCA terminals C2A (input #2).

Issue:
Sounds great, but when I set the selector switch to input #3 on the C2A I can still hear audio, but at a very low volume.
Switch selector input #2 - all sounds well and has normal volume.
Switch selector input #1 - I can still hear audio, but now at an even lower volume than selector input #3.
Inputs #1 and #3 show an increase in volume (still very quiet) when I turn up and down the coarse and fine settings respectively.
This is all done with the RCA's on the center terminals (input #2) on the C2A with TwoQuiet (not that the TwoQuiet is the issue).

Same issue occurs when RCA's are physically on the left most terminals (#3) - I can hear audio from input selector #2, and more quiet on input selector #1.
Same issue occurs when RCA's are physically on the right most terminals (#1) - Audio from input selector #2 and #3 are now the most quiet out of all tests. I need to turn up the coarse switch to -36dB or higher to hear. Audio also shifts towards the left ever so slightly on input #3 during this section of the test.

I've braided the signal wiring. I am not running RCA shorting caps yet - picking some up soon.I enjoy fixing issues, which is why I'd like to pursue fixing the noise/audio from non-connected terminals, even if the issue isn't bad for the amplifier.

Is this something that should be fixed or is it just something to work on without urgency?

Thank you
 ::)
Title: Re: TwoQuiet Coarse Switch Volume Control Hum/Buzz/Noise
Post by: Paul Birkeland on February 19, 2017, 12:34:01 PM
A little bit of signal bleed isn't all that abnormal.  If you have the amp cranked up all the way, it will simply exaggerate this effect.
Title: Re: TwoQuiet Coarse Switch Volume Control Hum/Buzz/Noise
Post by: TurbOSquiD77 on February 19, 2017, 07:37:02 PM
A little bit of signal bleed isn't all that abnormal.  If you have the amp cranked up all the way, it will simply exaggerate this effect.

Cools, thank you.