Soundtracs Topaz 48V power supply issue

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Soundtracs Topaz 48V power supply issue

Post by JeffOsborne » Sat Dec 09, 2006 9:16 pm

Recently bought a Soundtracs Topaz 24/8. It's in good condition and has been well maintained. I'm very happy with the sound of it. It's my first console and I feel like I've got a tool that will take a long time to outgrow.

The first issue that's come up for me is that the power supply's 48V phantom supply is not working.

The previous owner is a serious technician and he's very familiar with this board. I've asked him for leads on solving the problem and I'll post whatever I learn.

In the interim, what would you do?

The options I'm considering are:

* Send the supply for service. If so, where?
* Open the power supply and look for black components. If so, then?
* Spend $130 on a Stewart phantom power supply box and get back to recording.

I'm not against becoming familiar with the inside of the power supply. But maybe there's something obvious that I'm overlooking. Thanks for any ideas.


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Post by nlmd311 » Sun Dec 10, 2006 7:37 am

I can't help you much with troubleshooting the powersupply. You might have better luck over in the D.I.Y. forum. There are a lot of Soundtracs owners around here so you might get more information than you think.

On the other hand...Unless it is something you figure out is fairly simple, I'd suggest getting it repaired by the US Soundtracs Tech. I was in contact with him a few tmes asking general questions to get more familiar back when I first got a Soundtracs board (sold it a few months ago... biggest mistake I've made in years.). He is a really nice and easy to talk to guy. He was in New York but moved down here to Miami a little while ago. His contact information can be found here: ... t.htm#usa2 ... upport.htm

And just incase you don't find it on that page, it is:
Victory Technologies Inc.
1780 N.E. 191st. Street
Apt 212
N. Miami, Florida 33179

Phone#: 305-944-2503
Contact: Steve Magalnick
See if you can afford to get it repaired. That would be my suggestion.
Hope that helps.
Keep us posted.

slowly panning across something kind of crappy...

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Post by syrupcore » Sun Dec 10, 2006 11:20 am

sounds like the same problem I have. I haven't sent it off to get repaired yet because life has been hectic. I did talk with the fella in florida. It's actually a little more complicated than sending the power supply. you have to open up the board and take out an internal power supply and ship that along with the external. He had given me complete instructions but I lost them when my computer was stolen. I'll see what I can dig up. I really gotta send this thing in. It's just sitting there saying 'fix me asshole' everyday.


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Post by Everybody's X » Sun Dec 10, 2006 12:54 pm

the external powers supply is just a terroidal xformer, that's it. your problem is inside the board itself, most likely.
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Soundtracs Topaz 48V power supply issue

Post by JeffOsborne » Sun Dec 10, 2006 3:27 pm

Ok, thanks for all the ideas. Very helpful.

I opened the power supply and there's really not much to troubleshoot in there. Simply remove four screws and the top panel comes off. Inside you've got a toroid with four leads on the primary and four on the secondary.

The primary is wired to the power switch and the male IEC to AC mains. The secondary leads run out of the panel to the board.

I looked for signs of damage and or loose connections. Everything is solid in mine. The transformer looks great. No discoloration or signs of overheating inside the panel box.

No suprises. So as described above the problem is in the board. Thanks syrupcore for posting what you know.

I'm going to see if the board starts talking to me too. So far it's been silent but we've only been together for a short time (and I drink less now than I used to do).

Leaning toward a third party phantom power supply box. I'd like one that can support four channels. I've seen the Stewart at one of the big online retailers. I've also seen that Samson makes a battery operable power supply and it might be a good match for microtracking. I think the Samson only offers two channels tho...

I've got a schematic for the board and I may decide to dig around. If I do I'll post some pics or whatever.


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Post by syrupcore » Sun Dec 10, 2006 5:11 pm

Hey, sorry this happened to you but thanks for posting about it. It got me off my ass and I finally took the damn thing apart today. it took <10 minutes and I was taking photos at each step thinking it was going to be a pain to put back together - it's not. Serisouly, it's like 15 screws or something.

there is a yahoo group for the topaz boards and there is some info on their from some one who rebuilt there's themselves.

here's the post I'm talking about:
I used GBPC3504 parts for the diode bridges and LM338K parts
for the regulators. The filter caps were direct replacements.
The GBPC3504s were a bit of overkill, 2502, 2504, 3502s
will work too, but they were all about the same price as I recall.

Not sure if it was necessary to change the smaller caps, but
they are cheap so I basically rebuilt the whole DC section of
the power supply while I had it out of the board. The only
part that is in the external box is a transformer.

All the necessary parts were available from Mouser.

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Post by severe » Fri Dec 15, 2006 10:05 pm

Steven Magalnick, "the fella in florida", upgraded the power supply on my 24 channel. The work was performed with the previous owner. I had a conversation several months back with Steve, he was very kind and helpful.

He described, in detail, the work he performed. He claimed it's now, more or less, pushing the same power as the 32 channel power supply, etc.

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Post by b3groover » Sun Oct 21, 2007 10:59 am

UP because I just did this rebuild myself and it is not hard to do if you know about soldering and desoldering.

I replaced all the capacitors, the recitifiers (with the "overkill" parts listed in the post above), and both LM338 regulators. Phantom power comes from the other regulator (can't recall the part right now).

My board was having an issue where it would take several minutes for it to "stabilize", during which time there was a nasty humming / buzz coming from the outputs and some of the channel LEDs would be flickering. After a few minutes the buzz would disappear and everything would function normally.

After replacing the rectifiers, regulators, and caps, that is all gone. It powers up and runs perfectly from the get go.
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