SPL Goldmike 9844 preamp - WHAT power transformer? New
« on: November 24, 2019, 11:07:20 AM »
Hello,
I've obtained an old GoldMike where I recon the power transformer may have gone broken. The warmup light just keeps glowing and no signal is coming through the unit. I've been in contact with SPL and they suggest that either the tube/tubes are broken or the transformer. And the tubes SEEM to be working because they are glowing and there's connectivity where it should be connectivity. I've unsoldered the PCB power transformer from Talema and as far as I know, the "pairs" of nodes on the transformer should have connectivity, and all pairs but one is linked when I check with the multimeter. Maybe this is where it all goes wrong?

Either way, I'm having a really hard time finding a new transformer because I think the one used is a custom order from Talema.
It has, as I can see, 2x115V input "pairs"/nodes and 2x15V out and yet another 250V output i think (where there's no connectivity between the nodes).  Which I guess goes to the tube unit? SPL product info says only Toroidal transformer 20VA.

First of all, can anyone confirm my theory is right, that this is where the problem is?
And secondary, does anyone know where to find a new transformer that can supply this 250V output as well, if this is the case?

I'll add some photos below of the transformer and which nodes that have connectivity.
« Last Edit: November 25, 2019, 05:29:57 PM by baslarsa »


Re: SPL Goldmike 9844 - WHAT power transformer?
« Reply #1 on: November 24, 2019, 11:14:26 AM »
This is the instructions that I can find on the PCB.

3nity

Re: SPL Goldmike 9844 - WHAT power transformer?
« Reply #2 on: November 24, 2019, 12:39:01 PM »
Did you measure any HV before removing transformer? DC?
Life is a path, death the destination.

Re: SPL Goldmike 9844 - WHAT power transformer? New
« Reply #3 on: November 24, 2019, 12:50:48 PM »
Did you measure any HV before removing transformer? DC?


Unfortunatley not, I thought it was probably going to be easier to test it taken off the board. (I'm kind of a rookie).
I can re-mount it though and test it. Is it just to measure from the 250V-out pins on the back of the board?

EDIT: Have mounted it back to the board and tested the outputs. everything seems as expected to be working except the 250V side of the transformer. There's nothing coming out of those pins.
« Last Edit: November 24, 2019, 02:27:29 PM by baslarsa »


 

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