cps 150 failure

[5.333V]

work is done with the rectifiers! they are fitted in the chassie with newley drilled holes, lockingnutts and some good paste for heat transition.

i have no camera unfortuneatley...

they are much cooler now.



the tranfo is of course still noisy but i will live with this. been thinking about injecting some sort of glue through the winding to make it better...


it seems that only regulators are going hot. but thats the story in this box i guess....


i also resolderd the wires of con1 directly to the pins fitted on the pcb (maybe ill do this in the desk aswell some day...).


only thing i wonder before i lock it up and mount it in a rack is about the voltages.


i measured while connected to the desk and running. measured on con1 and got +48.8 +17.4 and -17.4.
my desk is a soundcraft dlx delta and fitts 12 modules + master. the desk was not working with any signals at that point...

should i regulate pr1-pr2-pr3 so i get +48 +16 -16?
and if so is their any danger to the desk while doing this? or is their an only way to do this..?


i wont be able to do an a/b but when im done with this and start to work with my own music again ill give some points on what is experienced as different in the sound.

[Matt Syson]

Hi
Those voltages should be fine.
You will lose a bit in the power cable anyway and almost all op amps are OK for plus and minus 18 Volts (36 total).
If you want to adjust the trimmers I would suggest doing it with the desk unplugged to begin with in case they are a bit 'jumpy' or you go too high.It will of course change a bit when the desk is plugged in.
Matt S

[memphisindie]

I can tell you right now that the trimmers ARE JUMPY, so disconnect while adjusting them.

Thanks Matt, for a brilliant post, again.

[Matt Syson]

Hi
In that case setting them then measure the resulting resistance would be a good idea so you can then fit ordinary resistors of the right value.
I suggest pulling the presets out and putting them on bits of wire an inch or two long. Set them and measure the voltage with desk connected.
When happy, cut the preset's wires and measure the resistance.
By series or parallel combination you should find a value to fit. Remember as long as it is within plus or minus half a volt it will be fine.
With fixed resistors you then have something less to worry about as they will not drift or get intermittant when dirty.
Matt S

[memphisindie]

My god, Matt, he'll have a CPS150 that is stable and likely not to fail till the caps give out.
He'll need to put it in a museum to preserve it's uniqueness.
"THE CPS 150".
Should he check the 48 volt regulator circuit for noise?

[5.333V]

no fighting in this thread please.

if i find some interesting mod instruction for the desk´s modules ill rip the whole stuff open again.

but for now the psu is closed and im sattisfied.


this desk is for me pretty awsome in consideration that i did pay 0:-SweKr (0:-Us$) and is the far most better sounding desk ive had in my studio.

bought a delta 200 for 300Euros some months ago just to get hold of some group modules. so i switched some modules, cleaned the desk, replaced some pots and sold it to a friend for the same price. probobly ill be opening his cps150 soon aswell!

[Jim Williams]

Originally Posted by memphisindie

My god, Matt, he'll have a CPS150 that is stable and likely not to fail till the caps give out.

Or when the power transformer fails. I have 3 failed ones here. Anyone want them?

Jim Williams
Audio Upgrades

[memphisindie]

Recycle, that copper is worth a little money these days.

[memphisindie]

Oh, one more thing that may help;
R32 on the regulator, you could also put two resistors of half the value, or, four of 1/4 the value to create a more stable voltage and you could use 4 1/4 watts, 2 1/2 watts, or, what's to stop you from using 1 watts if you can get them, as long as the value adds up to 2.7k ?better heat dissipation, more precise tolerance.
The better that circuit, which can get really hot, can dissipate heat without changing resistance/impedance, the better off you'll be, as it will be less likely to help blow your transformer and keep more accurate voltage and less likely to blow itself.

[The dman]

We hooked up the Power One HDD-15-AG to my Delta tonight and I noticed a significant improvement. The hum went way down the highs seem clearer and the bass is tighter, everything seems a little less smeared. I'll give a better listen tomorrow but so far I'm so glad I did this. I also noticed less noise in the switches.

My Cps 150 was funky and the console would wine until it warmed up which took a while ....now it fires right up.

[Matt Syson]

Hi
You could have repaired the CPS150 properly as there is no particular reason why it should not be able to provide the power needed. It is rated at 1.25 Amps for the main rails.
If it was 'whineing' then it was telling you it needed repair. This would have sorted out some or all of the 'benefits' that your power one module claims to have done.
R32 (2K7 ) has to dissipate about 0.75 watts continually so should be a 2 or 3 watt component (or equivalent rating over several resistors).
Matt S
PS Jim
Have the transformers failed from general overheating or 'spikes' having produced shorted turns?

[The dman]

Originally Posted by Matt Syson

Hi
You could have repaired the CPS150 properly as there is no particular reason why it should not be able to provide the power needed. It is rated at 1.25 Amps for the main rails.
If it was 'whineing' then it was telling you it needed repair. This would have sorted out some or all of the 'benefits' that your power one module claims to have done.
R32 (2K7 ) has to dissipate about 0.75 watts continually so should be a 2 or 3 watt component (or equivalent rating over several resistors).
Matt S
PS Jim
Have the transformers failed from general overheating or 'spikes' having produced shorted turns?

I'm putting together an 8 channel sidecar and needed the power supply anyway. I had a Soundcraft Spirit years ago and I had nothing but problems with the CPS 150 but I'm going to have my tech fix it up for the 8 channel.

[Jim Williams]

Originally Posted by Matt Syson

Hi
You could have repaired the CPS150 properly as there is no particular reason why it should not be able to provide the power needed. It is rated at 1.25 Amps for the main rails.
PS Jim
Have the transformers failed from general overheating or 'spikes' having produced shorted turns?

1.25 amps is only enough for an 8 channel console, otherwise it is stressed = all those failures. Most of them show up already fried. The power transformers have shorted turns probably due to loose wraps eventually bending out of form. All of them buzz when working, the power transformers are poorly made compared to EI transformers made here in the states. I don't know what it is about English iron, but it does seem to have that recurring problem. I've even had large console torridal power transformers get loose wraps and then they buzz too.

Retrofitting a proper transformer is messy as the original is mounted on a PCB for voltage selection. That would all need to be removed and then maybe a decent torridal transformer could be mounted, but it's still an underpowered design using a pair of TO-220 regulators.

$170 for the Power One is a very attractive alternative. I just sent off a 24 channel Delta with one, works great, as usual.

Jim Williams
Audio Upgrades

[memphisindie]

Originally Posted by Jim Williams

Or when the power transformer fails. I have 3 failed ones here. Anyone want them?

Jim Williams
Audio Upgrades

I might, what's the terms?

[Matt Syson]

Hi
The CPS150 schem from the Soundcraft site says they have LM338's.
Presumably a later version?
Matt S

[Jim Williams]

Originally Posted by Matt Syson

Hi
The CPS150 schem from the Soundcraft site says they have LM338's.
Presumably a later version?
Matt S

You're right, they are T0-3 cans.

The 3 I have are $50 each, or 3 for $100 if anyone wants them. Good for spares.

Jim Williams
Audio Upgrades

[memphisindie]

Originally Posted by Matt Syson

Hi
You could have repaired the CPS150 properly as there is no particular reason why it should not be able to provide the power needed. It is rated at 1.25 Amps for the main rails.
If it was 'whineing' then it was telling you it needed repair. This would have sorted out some or all of the 'benefits' that your power one module claims to have done.
R32 (2K7 ) has to dissipate about 0.75 watts continually so should be a 2 or 3 watt component (or equivalent rating over several resistors).
Matt S

Mine has no hum anymore, but, now that you mention heat, since my computer broke, I have a surplus of quiet fans, Maybe I could install one in there too.

[The dman]

Originally Posted by Matt Syson

Hi
You could have repaired the CPS150 properly as there is no particular reason why it should not be able to provide the power needed. It is rated at 1.25 Amps for the main rails.
If it was 'whineing' then it was telling you it needed repair. This would have sorted out some or all of the 'benefits' that your power one module claims to have done.
R32 (2K7 ) has to dissipate about 0.75 watts continually so should be a 2 or 3 watt component (or equivalent rating over several resistors).
Matt S
PS Jim
Have the transformers failed from general overheating or 'spikes' having produced shorted turns?

I didn't mean the actual unit was whining but there was loud hum in the audio that took a few minutes to go away. Only the + 48 light would come on and the pfl solo would light and sometimes I would have to turn it on 3 times until ieverything kicked in Sorry bad choice of words

I've been using the Delta with the Power-One for about 6 hours now and wow what a difference mmmuuuccchhh quieter.

[Photolum]

hallo

talking about infamous R32 , can I replace it with 2.7kΩ 5W ? instead of 2 or 3
then come the caps , you guys said they should be replaced with 10.000µF , still 50V though ?

this thread has been very helpful to many people apparently
thanx for your contributions

Alx

[Jim Williams]

I use Nichicon 15,000 uf/35V VZ series. They fit well and work great.

Jim Williams
Audio Upgrades

[memphisindie]

Originally Posted by Photolum

hallo

talking about infamous R32 , can I replace it with 2.7kΩ 5W ? instead of 2 or 3
then come the caps , you guys said they should be replaced with 10.000µF , still 50V though ?

this thread has been very helpful to many people apparently
thanx for your contributions

Alx

Yes you can on R32 but, if you replace it with a higher wattage instead of two or three or even four lower wattage resistors, you don't get the stability of better heat dissipation, though, it probably works just fine, make sure if you use a few smaller ones they add up to the value you need, in your case, 2.7k @ 5 watts. That resistor does get very hot. The bigger the rating on the caps, the better for stable longivity, you could use 15,000 uf if you wanted, and I'd use at least 63 volts, 100v if you can get them and get them to fit in there, and if you can, replace the on off switch with a rheostat and dial it up slowly to keep the inrush surge down, it will live longer.
Don't forget to up the bridge rectifiers a TON.

[5.333V]

Originally Posted by memphisindie

Don't ya hate having to keep reopening this thing?

guess what!?


its open again!!!


im stuck in another town for 7 months with a jobb that sucks. so i thought about having something to make time go faster.

when i had this psu open some year ago i only worked with r32, bridge rectifiers and the two 4700uf caps. i was to lasy for the rest so now alot is getting swaped.

when refere to the service note with schematics, i see some difference from my cps150.

the 2k7 is going straight to ground while the 48v led is getting the 48v through a (i think) 4k7.

and also there is a rc filter thing across the ac leads before the bridge rectifiers whitch isnt included in my cps150.

so i was thinking about re make mine after the service note.

the pcb states iss. p8 27-10-89.



what do you boys and girls say?

[Jim Williams]

Buy a Power One HDD-15-5AG and stop playing around with that toy.

Unless you are self abusive.

[5.333V]

are you feeling that you have seen to many broken cps150s in your life time perhaps?


this is just for a 8-4-2 desk so i think it´ll do the jobb for me for some time.


but if i get rich some day. ill get a house outside of town, seting up a workshop and studio, buying a big desk with that nice psu for it. maybe even grow some vegtables on my own..!

so for now. ill go with what i have.

i was just wondering if remaking thoose small details would have any good effect?

[memphisindie]

If it ain't acting up and ain't broke... don't fix it.

[Jazz Noise]

Originally Posted by memphisindie

If it ain't acting up and ain't broke... don't fix it.

Agreed. There's plenty of DIY audio electronics projects that are both more constructive and less constructive. Order a kit for a guitar pedal or a mic pre or something!

[mjrippe]

I have two used Power One HDD15-5-A power supplies available. If anyone is interested send me a PM.

[Jim Williams]

Originally Posted by 5.333V

are you feeling that you have seen to many broken cps150s in your life time perhaps?
this is just for a 8-4-2 desk so i think it´ll do the jobb for me for some time.

I have 3 or 4 broken ones here if you need any parts. Yes, it will do the job, until it breaks, again.