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Matrix 6R Power Supply Voltage Regulator Replacement

Matrix 6R Power Supply Voltage Regulator Replacement

2019-04-13 by t_tangent2003@...

Hi all,

I am recapping my Matrix 6R power supply, and also replacing the voltage regulators, so I just wanted to ask whether the following parts are compatible equivalents.





The reason I ask is that the datasheet for these show an Output current up to 1.5 and I just wanted to make sure this isn't a problem.

Thanks in advance for any advice on this.

Re: Matrix 6R Power Supply Voltage Regulator Replacement

2019-04-16 by t_tangent2003@...

Thanks very much for the confirmation on those voltage regulators.

For the caps, yes I have read good things about the Nichicon PW series
so will replace with the following

6800uF 16v 18x35.5mm

4700uF 25v 18x35.5mm

2200uF 25v 16x25mm

2200uF 16v 12.5x25mm

10uF 16v 5x11mm


Thanks again and I will report back when finished.

Re: Matrix 6R Power Supply Voltage Regulator Replacement

2019-04-16 by t_tangent2003@...

All done and working. Actually it was working before, but seeing as I had to open the Matrix 6R to replace the old battery that had died, I figured it was worth replacing the PSU caps and voltage regulators as well.

Readings from the PSU board 15 pin output connector J03 are as follows.

Pin No. Schematic (Volts) Before Replacement (Volts) After Replacement (Volts)
1 & 2 -5 -5.05 -5.04
3 & 4 +5 B 5.11 5.10
5 & 6 +5 A 5.06 5.09
7 & 8 +12 12.02 12.31
9 & 10 -12 -12.30 -12.14
11 to 15 GROUND

So only minor differences in these readings, perhaps with the exception of the +12 Volt pins 7 & 8, but I guess this may be due to fluctuations in the Mains supply and/or tolerances in the voltage regulators and capacitors, as specified in their datasheets. I would be interested to hear from others with more experience in electronics, particularly if anything here looks out of spec. But so long as the Matrix keeps working for many years to come, then this was worth doing, I hope. :)

Next job is to replace the tact switches for the front panel buttons, as several of those are playing up.

Cheers.


Re: Matrix 6R Power Supply Voltage Regulator Replacement

2019-04-17 by Christian Lortie

Hi,

Thank you for the update after the changes.
Many people never follow-up, so that's very much appreciated.

Thanks for the measurements too! Very useful as reference to others.

Now my question is: *******
Is the Power Supply in the Matrix-6R the same or similar to the one in the Matrix-1000 ? ******

I have the latter but not the former and would like to revamp it for longevity, and to make sure I also protect those fragile Narrow-body CEM chips.

So those voltages and the pinout distribution could help me in that process.

Thanks.

Re: Matrix 6R Power Supply Voltage Regulator Replacement

2019-04-17 by t_tangent2003@...

Hi Christian,

Yes, I find it useful when people post their results as well and wish others did it more often, so hopefully my update will be of use to someone.

Regarding your Matrix 1000, looking at some info on the internet, I think the Matrix 6R & Matrix 1000 have different power supplies. But sadly I am not really experienced enough with electronics to recommend whether you update your PSU or not, so perhaps some fellow readers with more knowledge can advise you.

I know the Matrix 1000 came out several years later than the Matrix 6R and according to the following website was produced between 1987-94, see http://www.vintagesynth.com/oberheim/mat1000.php
Whereas Matrix 6 & 6R were produced from 1986 - 1988. So if your Matrix 1000 is from the later end of production, it may still be ok for some time before worrying about PSU upgrade.

However I did find an interesting link that might be of use, and certainly worth a read.


But if you do decide to upgrade, make sure you have all the information before hand. I learned a valuable lesson today about exactly that, regarding my attempt to update the front panel tact switches on my Matrix 6R, which I posted about on this group earlier and now need to update as well.

Best of luck with your Matrix 1000. I have been trying to get hold of one of those for a while, but I always seem to just miss out, same like the Xpander which I have wanted for years, haha. Oh well, one day I hope. :)

Re: [oberheim] Re: Matrix 6R Power Supply Voltage Regulator Replacement

2019-04-17 by Bob Grieb

The tolerance on 78 and 79-series regulators is something like 5%.
I usually buy the A part when replacing them, as the tolerance is 2%.
So 7805A, with a few other letters after that sometimes, depending on the 
mfr.

Bob

--------------------------------------------
On Tue, 4/16/19, t_tangent2003@yahoo.co.uk [oberheim] <oberheim@yahoogroups.com> wrote:

 Subject: [oberheim] Re: Matrix 6R Power Supply Voltage Regulator Replacement
 To: oberheim@yahoogroups.com
 Date: Tuesday, April 16, 2019, 7:09 PM
 
 
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