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D&R 4000 mkii PSU

PostPosted: Thu Nov 24, 2011 2:55 pm
by siegfriedmeier
Hey guys,

I just acquired a 4000 series near Toronto and upon firing up the PSU (not connected to the console, just in case) I noticed a resistor caught on fire and the +18 side went out, as shown from the front panel. The PSU overall looks pretty rough, and someone's been in there to do some work after a major fire burned a massive hole into the circuit board. I was assured that it worked, but I'm not surprised that it doesn't. However, I have manuals and documents but no schematics or anything on the PSU.

Does anyone have anything for me? And, I'm curious if anyone rebuilds these from scratch. We had our TAC Magnum PSU rebuilt this year from GRS Systems in LA and it was probably the best thing we could have done for that console - all the hum and strangeness issues that happened totally disappeared!

Thanks for any help guys, much appreciated!
Sig

Re: D&R 4000 mkii PSU

PostPosted: Thu Nov 24, 2011 3:17 pm
by siegfriedmeier
I just found a document that lists all the parts in the PSU. However, the PCB is not labelled in any way whatsoever, and looks rather homemade. I've attached a pic that shows which resistor burned out on what I believe is the +18 side, but I can't tell what value it is:

Image

It seems that the chips installed are newer than the ones listed in this pic - is it possible that these "newer" chips caused the resistor to fry?

Any help appreciated,
Sig

Re: D&R 4000 mkii PSU

PostPosted: Fri Nov 25, 2011 2:34 am
by siegfriedmeier
I found a cool resistor calculator Widget and iPhone app - I've always been really bad at seeing the colours, but fortunately the previous owner sent me this large image. The burnt out resistor appears to be a 470 ohm, from what I can tell. I'll stick a new one in and put the original IC's in there as well, just in case those are the reason it blew in the first place.

If anyone else is interested in the app, it's free, and here's the link:

http://www.zambetti.com/projects/resistulator/

Re: D&R 4000 mkii PSU

PostPosted: Tue Dec 25, 2012 5:10 pm
by AnalogStudio7
Hi, I know this is a really old post, but was just wondering why you didn't have GRS repair your PSU? You said they rebuilt your other PSU. I know they work on D&R consoles and PSU's, having seen a few in their shop the past few months.

Just a suggestion.

Cheers & Merry Christmas

Greg.

Re: D&R 4000 mkii PSU

PostPosted: Wed Dec 26, 2012 12:55 pm
by Jim Williams
The stock supplies can sound weak, just like most brit consoles. I set up a fellow in Phoenix with an Orion and used a pair of Power One 12 amp/24 volt supplies trimmed down to + - 18 volts.

Now it sounds huge, 24 amps will do that. They ran $200 each and I added a small 1/2 amp 48 volt supply for phantom.

Re: D&R 4000 mkii PSU

PostPosted: Mon Nov 11, 2013 9:19 am
by siegfriedmeier
So, an ongoing project this clearly is. We're looking at putting this little guy into a new room, and I'm now back to rebuilding it. GRS will do a full premium rebuild for $360 on the PSU. My concern is, could it still be underpowered? If we're spending that much money, should we just get another larger/better PSU? What would be the best option here?

Thanks!
Sig

Re: D&R 4000 mkii PSU

PostPosted: Thu Nov 14, 2013 5:17 am
by AnalogStudio7
Man, I would just buy a new PSU with more current output! Just looking at your PSU makes me nervous and why pump that much cash into that PSU.! LOL! Sorry.

GRS had a flyer out last mont on a bunch of used rebuilt power supply systems they were selling. They had some larger 10, 12 and 16 Amp systems for sale that were pretty reasonable. I believe these were trade in systems.

Cheers,

Greg
AnalogStudio7
Lake Forest, CA

Re: D&R 4000 mkii PSU

PostPosted: Sat Nov 30, 2013 11:53 am
by Goldfain
[quote="siegfriedmeier"
Image
[/quote]

Hi Sig,

what is this yellow guy in the lower left corner? My PS definitively doesn't have it - there's a straight connection between PCB and chassis. I assume, the yellow guy is some kind of mod to prevent hum. Could you tell me his specs?

Thank you an greets from Berlin

Simon

Re: D&R 4000 mkii PSU

PostPosted: Wed Dec 11, 2013 7:36 pm
by siegfriedmeier
My PSU is back up, and seems to be doing ok. The 2N3055's get hot when the entire console is running, but I'm not sure if that's normal...had a couple channels that were killing things, and those are now disconnected. Ya, I'd def not put any money into this PSU - beyond the couple bucks I've spent in parts fixing it. I've emailed GRS about a new PSU, but what's the deal with that place? One day you'll get emails, then they ignore you forever. Maybe they just don't have enough staff to answer emails or something, but jeez, it's really weird.

I have no idea what that little yellow guy is - some kinda grounding scheme of some sort. I wish I could tell you more...

Re: D&R 4000 mkii PSU

PostPosted: Tue Dec 17, 2013 11:11 pm
by AnalogStudio7
Ha, ha, ha. End of the year. The Sage, CA shop people are always across the pond this time of year.

Contact their other shop in Idyllwild, CA: grsproaudio@aol.com

You should get an autoresponder from their main email addy with a redirect, but if not, use the one above.

Cheers!

Greg
AnalogStudio7
Lake Forest, CA