S800 Support Thread

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I'm not sure about the extra screw, but it may be a place for you to star ground everything...... you can hook it up to either of the yellow arrows..... I usually run my tranny's centertap to the one on the right and just run the one of the left to the chassis star ground
 
Well, I was in the test phases, but you really think that not grounding it would give the incorrect voltages??  The JLM supply needs to be grounded as well, but it still shows the correct voltage even without grounding.

I'll try it, but I don't know...

Thanks,
Sig
 
I'm not sure, haven't tried it ungrounded, and haven't had problems with these PSU's.... I've got 5 of em in various applications, and they've been great!  probably don't need to run it to your chassis right now, but I'd make sure it's grounded somewhere.
 
Sig,

There is an old adage that says "A picture says more than a thousand words"... SHOW us your PSU, maybe we can spot something that might be a miss.

Also, no the ground wouldn't make a difference, as long as you measure from the transformer CT to your reference point it should be fine.

Cheers

Matt
 
Stitch, the silkscreen is perfect... I'd use ceramics or poly's on the 100nf's, so no need to worry bout polarity (if you've got lytics for that value, you'd better trace it :))

Sig, sorry bout the confusion with grounding.... Matt's right, I was thinking in terms of the centertap being connected (was thinking back to a time when I was getting weird voltages and realized I hadn't grounded it)
 
Couldn't get any voltages from your PSU Peter, so I gave up and trashed it and used a JLM - works perfectly, as always.

Ok, a word to the wise.  USE nylon screws and nuts if you're going to mount the regulators to the case.  I tried and tried, with the insulating washers and the little round nubbin thing but I kept shorting out and blowing fuses.  Think I've got it under control now - man, are those hard to find locally - NO ONE carries those things.  Best advice I could give, build yourself an external PSU and forget about putting it into the case.  It's far too annoying and messy.  Then hook it up with a 4 pin XLR like I did my Neves.

Sig
 
I've got no time to be fu*king around with a power supply for endless hours.  If something else works, then get it done and move on.

Everything is done, tested, calibrated and sounding fantastic.  Just putting on the knobs now and I'll post some pics later.

Sig
 
Siegfried Meier said:
Couldn't get any voltages from your PSU Peter, so I gave up and trashed it and used a JLM - works perfectly, as always.

Ok, a word to the wise.  USE nylon screws and nuts if you're going to mount the regulators to the case.  I tried and tried, with the insulating washers and the little round nubbin thing but I kept shorting out and blowing fuses.  Think I've got it under control now - man, are those hard to find locally - NO ONE carries those things.  Best advice I could give, build yourself an external PSU and forget about putting it into the case.  It's far too annoying and messy.  Then hook it up with a 4 pin XLR like I did my Neves.

Sig
Click to expand...

Sig,

You did of course NOT forget to use a mica isolator ALONG with the insulating washer and screw right? And isolator kit comprises of 2 parts, a mica pad that goes between the reg and the case and then a washer that goes through the hole and is mounted with a screw.... if you didn't DO it, you may have is sitting ok NOW, but it WILL one day short... and at best take out a fuse... worse take out your EQ's...

If you use my mounting method for the PCB's there is ample room for the PSU's in the rack and even with the Torrid my 8 channel is DEAD and I mean DEAD quiet.

I hate to say this but I'm sure the problem doesn't lie with Peter'c PCB as MANY of of us have built hundred of them combined with no problems. Glad you go the JLM to work... for now... just hoped you HAVE indeed mounted it correctly.

Cheers

Matt
 
matta said:
Siegfried Meier said:
Couldn't get any voltages from your PSU Peter, so I gave up and trashed it and used a JLM - works perfectly, as always.

Ok, a word to the wise.  USE nylon screws and nuts if you're going to mount the regulators to the case.  I tried and tried, with the insulating washers and the little round nubbin thing but I kept shorting out and blowing fuses.  Think I've got it under control now - man, are those hard to find locally - NO ONE carries those things.  Best advice I could give, build yourself an external PSU and forget about putting it into the case.  It's far too annoying and messy.  Then hook it up with a 4 pin XLR like I did my Neves.

Sig
Click to expand...

Sig,

You did of course NOT forget to use a mica isolator ALONG with the insulating washer and screw right? And isolator kit comprises of 2 parts, a mica pad that goes between the reg and the case and then a washer that goes through the hole and is mounted with a screw.... if you didn't DO it, you may have is sitting ok NOW, but it WILL one day short... and at best take out a fuse... worse take out your EQ's...

If you use my mounting method for the PCB's there is ample room for the PSU's in the rack and even with the Torrid my 8 channel is DEAD and I mean DEAD quiet.

I hate to say this but I'm sure the problem doesn't lie with Peter'c PCB as MANY of of us have built hundred of them combined with no problems. Glad you go the JLM to work... for now... just hoped you HAVE indeed mounted it correctly.

Cheers

Matt
Click to expand...

A mica isolator is those little round nubbin things, or the flat insulating washer that spans the size of the regulator?  Either way, yes, I used those, along with the plastic screws.  I don't know why it kept shorting out on me.  Perhaps the regulator was touching through the back of the insulating washer.  I used all the parts that came with the JLM PSU.

And, as far as the Green PSU goes, I have no doubt that many of you have had great success with them.  If the problem doesn't lie with the bridge I used, then I don't know what.  I'm of the frame of mind that if something doesn't work, you find another solution and move on, come back to it later if need be.  The studio is really busy right now and I would likely have not gotten back to it for another 2 months if I played around trying to get that old PSU to work.  Now, I have an eq that works that I can use on the next several sessions.

Oh, and I didn't use your mounting technique because I did not have any standoffs that large sitting around, and it's STILL dead quiet on channel 8.  I may do that later on sometime, or not.  Who cares, it works, I don't give a shit what the inside looks like, and neither does anyone else.

Thanks,
Sig
 
Hey Sig,

I'm glad it works! I'm just worried as to why it kept shorting!

It may well have just been a prob with something in the PSU, it is solved great. I just hope it doesn't come back to bite you and trying to help you troubleshoot and figure out WHERE the problem lies, if it KEEPS shorting you got to ask WHY.

One thought that comes to mind is that you may have a metal 'rasp' where you drilled your chassis holes and when you tighten the screw is cause it to push the bur through the mica isolation (that is the strip that goes between the reg and the chassis)... I've seen this happen before.

An easy test would have been to try a regular heat sink that is NOT ground to the chassis/star ground and see if still shorts... if not, then the prob is the chassis... you won't damage the regs as both LM317/LM337 have a thermal shut down /protection in them.

You may have it working now, but if the reg slips or is overtightened, then it may well short again , doesn't mater WHAT PSU it is, JLM/PeterC/MNATS etc...

But hey, if you are happy then go for it! Problem solved  ;D

RE not caring what it looks like inside, well that is your approach, personally, I care... as do others.

Clean/Clear wiring can help you trace down problems that may/will occur in time... and 'guessing' which of the no less than 380+ off board wires in that unit is the problem is going to be a bitch if it looks like a dogs breakfast.

Yes it is frustrating and time consuming, but a stitch in time save nine as they say.

Matt
 
Oh, I didn't say that my wiring was messy, in fact it's impeccable, I used little pieces of heatshrink on every pair of cables to tie them together (not twisted like yours, can't seem to braid like you do - are you a hairdresser by day?) and on every pot/connection.  I'm simply referring to the fact that the 8 modules just sit there and aren't strapped together like yours, which I can easily do down the road.  Very easy to trace things down, and everything is properly colour coded so should anything go wrong, it will be very easy to figure out.

Your idea of a metal "rasp" from drilling could very well be what was making it short out.  I'll check into that.

Sig
 
Siegfried Meier said:
Oh, I didn't say that my wiring was messy, in fact it's impeccable, I used little pieces of heatshrink on every pair of cables to tie them together (not twisted like yours, can't seem to braid like you do - are you a hairdresser by day?) and on every pot/connection.  I'm simply referring to the fact that the 8 modules just sit there and aren't strapped together like yours, which I can easily do down the road.  Very easy to trace things down, and everything is properly colour coded so should anything go wrong, it will be very easy to figure out.

Your idea of a metal "rasp" from drilling could very well be what was making it short out.  I'll check into that.

Sig
Click to expand...


Hah Hah!!! Not a hairdresser, no... and that twisting takes a few seconds a foot!

I'll let you in on the trick! I use an electric drill!!!! Place the ends of the wires on one end into the drill chuck, then tighten. Use you other hand to hold the other end, then just start the drill, it twists the wires for you in no time as all.

All you need to do is make sure you slowly release the hand holding the wires as they will naturally want to twist back on themselves, let the kinks work out naturally and viola, instant twisted cables in seconds!

RE the bur, check it out and see, use a counter sink to clear away any burs and smooth the surface.

Matt
 

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