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July 05, 2022, 03:50:16 PM

Author Topic: beepre 2 connection [resolved]  (Read 912 times)

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Offline rover

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beepre 2 connection [resolved]
« on: August 21, 2021, 01:58:34 PM »
Enjoying the build but not sure about DC filament connect
As there are 2 x DC +/- on right side of filament board
Have cut 203mm green wire, only the manual pic seems shorter (end to 27L and 29L)
Is my connection correct?
Photo attached
Thanks
« Last Edit: August 28, 2021, 04:48:39 AM by Paul Birkeland »

Offline Paul Birkeland

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Re: beepre 2 connection
« Reply #1 on: August 21, 2021, 04:32:33 PM »
Your connections are not correct.

On page 39, we provide instructions to test the outputs of the board, which are not the terminals on the front of the board.

On the following two pages, the instructions are to connect the green twisted wires to +reg and -reg on each side of the board.

The "DC" connections on the front of the board are used when this board is installed as an upgrade in the Stereomour II. 

Thank you for taking the time to stop by and ask about this, as you have it wired now, both 300B filaments would be loading down one side of that regulator board and one transformer winding.  Something would get really hot eventually and fail!
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline rover

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Re: beepre 2 connection
« Reply #2 on: August 21, 2021, 04:54:57 PM »
Thanks Paul
I did the glow test with this wrong connection
Is there a test to go back on that the filament or transformer is not damaged?

Offline Paul Birkeland

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Re: beepre 2 connection
« Reply #3 on: August 21, 2021, 05:10:35 PM »
I would suggest correcting the wiring error, then checking the DC voltage between pins 1 and 4 on each of the 4 pin sockets with no 300Bs installed.  You should see about 6.3V there.

Generally when you damage a transformer, it smells horrible and you really know something went wrong, kind of like falling asleep with something cooking in the oven...
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline rover

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Re: beepre 2 connection
« Reply #4 on: August 21, 2021, 05:26:45 PM »
Yes 6.3V across DC board
Will power transformer secondary test provide any feedback if damaged?
Sorry to say there was some smoke when glow testing and switch off asap

Offline Paul Birkeland

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Re: beepre 2 connection
« Reply #5 on: August 21, 2021, 05:28:58 PM »
If the DC voltages coming out of the board are OK, I wouldn't be too worried.  You may have started to overheat parts on the PC board, but they are tough little buggers and are likely OK if the DC voltages coming out of the board are OK.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline rover

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Re: beepre 2 connection
« Reply #6 on: August 25, 2021, 12:14:42 AM »
Completed build and was getting one channel only
Swapped tube positions and both channels worked
I switched off after 1 hr running
I switched on later and was back to one channel only
Volt checked DC board and 6.3 read across L/R
Page 55, 10VDC and 100VDC check varied and not stable now, readings where on point thru build
Any idea?
Thanks


 


Offline Paul Birkeland

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Re: beepre 2 connection
« Reply #7 on: August 25, 2021, 05:03:47 AM »
Completed build and was getting one channel only
Swapped tube positions and both channels worked
This is what I would expect if you have a loose connection.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline rover

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Re: beepre 2 connection
« Reply #8 on: August 27, 2021, 03:34:50 PM »
Yes, I missed 2 solder points on inline resistor
All good to go now
Thank you for the guidance Paul