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October 31, 2014, 06:42:42 pm

Author Topic: First voltage check Stereomour  (Read 1247 times)

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Offline bobbeanbags

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First voltage check Stereomour
« on: April 24, 2012, 06:28:38 am »
Im a little concerned that the first voltages I checked are significantly higher than specified in the manual.

1. Power supply PC board pads HV+ is 450V (should be 380V)
2. Terminal strip 1 is 450V (should be 350V)

I turned off the Stereomour because I didnt want to cook anything.  Any help would be appreciated.??

Offline Paul Joppa

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Re: First voltage check Stereomour
« Reply #1 on: April 24, 2012, 10:53:01 am »
Two checks:

Is your power line voltage really high? Like, 140vAC?

Are the 2A3 filaments lighting up? This happens in a few seconds, but they are not very bright.

And of course remember how easy it is to rotate the sockets or plug the tube in wrong. Nobody like to admit it, but we've all done that at one time or another.  :^)
Paul Joppa

Offline Grainger49

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Re: First voltage check Stereomour
« Reply #2 on: April 24, 2012, 11:28:01 am »
It is really, really easy to get the 2A3 in the wrong way.  Check the manual it should be very specific about the tube orientation.

The 2A3 pins are too evenly spaced.  That is the source of that problem.  I have to remind myself every time I put a tube in my amps.
Grainger Morrison, Audio Salesman 1966-1976

VPI HW-19/Souther Tri-Quartz (Grado Sonata-1)/Eros/FP-2/Paramours (1) with MQ Iron (upgrades to all), Blumenstein Orca/Dungeness Speakers - PS Audio Regenerator
[img width=635 height=111]http://i244.photobucket.com/albums/gg7/Grainger49/Signature/GiveLife

Offline bobbeanbags

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Re: First voltage check Stereomour
« Reply #3 on: April 24, 2012, 11:54:41 am »
Hi Paul, Thanks for the help, its been awhile - 2A3's are not glowing or getting warm.  c4s diodes are aglow.  Im actually not 100% sure how to orient the 2A3's.  Two pins on the tubes are larger in diameter and I have those facing  forward, is that correct?  The manual isnt specific about their orientation.

Offline bobbeanbags

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Re: First voltage check Stereomour
« Reply #4 on: April 24, 2012, 11:56:56 am »
@grainger.   Thanks for the reply.  How do the tubes orient?   With the Sovtek logo facing front?

Offline Doc B.

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Re: First voltage check Stereomour
« Reply #5 on: April 24, 2012, 12:06:36 pm »
Hey Bob,

Large holes go toward the back, nearest the hum balance pot.
Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.

Offline Paul Joppa

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Re: First voltage check Stereomour
« Reply #6 on: April 24, 2012, 05:28:41 pm »
Next time we re-do the manual, we should mark the sockets. F is for Filament, and for Fat Pins!
Paul Joppa

Offline chard

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Re: First voltage check Stereomour
« Reply #7 on: April 24, 2012, 05:33:19 pm »
The 2A3 Sovtek tubes I got with my kit had a number 1-4 by each pin on the underside of the tube. These numbers were pretty small but visable and they were accurate.
Clifford Hard

Offline chard

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Re: First voltage check Stereomour
« Reply #8 on: April 24, 2012, 08:17:31 pm »
Two checks:

the 2A3 filaments lighting up? This happens in a few seconds, but they are not very bright.


My aren't very bright but they have a small red light at the top of the plates and a blue gaseous light surrounding the top of the plates. They look really cool in the dark.
Clifford Hard

Offline Grainger49

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Re: First voltage check Stereomour
« Reply #9 on: April 25, 2012, 01:37:02 am »
If you get that red glow you tubes are heating and inserted in the socket properly.
Grainger Morrison, Audio Salesman 1966-1976

VPI HW-19/Souther Tri-Quartz (Grado Sonata-1)/Eros/FP-2/Paramours (1) with MQ Iron (upgrades to all), Blumenstein Orca/Dungeness Speakers - PS Audio Regenerator
[img width=635 height=111]http://i244.photobucket.com/albums/gg7/Grainger49/Signature/GiveLife