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August 24, 2019, 07:27:32 AM

Author Topic: 5 Seconds of Hum When Stereomour is Powered On  (Read 305 times)

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Offline ptlud

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5 Seconds of Hum When Stereomour is Powered On
« on: June 13, 2018, 08:09:58 AM »
I have a Stereomour amp running with 2A3 tubes and driving 100 dB/m speakers.

When I turn on the amp, hum is noticed from both speakers for approximately 5 seconds.  After that, dead silence.

Any suggestions on the cause of this issue and how to "fix" it?

Thanks!
Paul

Stereomour 2A3
Modded Toshiba 3950 DVD Player + Schiit Uber Bifrost DAC
JVC A40 Turntable with AT95e + Schiit Mani Preamp
Klipsch KLF-20

Online Paul Birkeland

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Re: 5 Seconds of Hum When Stereomour is Powered On
« Reply #1 on: June 13, 2018, 08:18:51 AM »
There's nothing to fix here, there will be some noise between when you power the amp on and the 2A3s start conducting.

One measure to reduce the level of the noise is to rewire the output transformers for a lower impedance setting. 
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline ptlud

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Re: 5 Seconds of Hum When Stereomour is Powered On
« Reply #2 on: June 13, 2018, 09:21:48 AM »
Great.  Thanks for the information.

I love the amp.

Paul

Stereomour 2A3
Modded Toshiba 3950 DVD Player + Schiit Uber Bifrost DAC
JVC A40 Turntable with AT95e + Schiit Mani Preamp
Klipsch KLF-20