Soundcraft Spirit 328 digital power supply

[grtstrm]

HI, I have an idea to replace the cheesy OEM PSU in these boards, looking for your feedback. I have a 350W PC power supply that has voltages that are pretty close to the specs on the OEM PSU. I believe that by replacing or tweaking the 12V rails on the PC supply to 17V, and adding a 48V supply for phantom, the PC supply could be the ticket to saving these otherwise serviceable desks! The PC supplies are cheap and reliable, the MOD is easy (he thinks). Any comments appreciated!
In the meantime, if anyone has access to the service manual for the OEM version, I have a dead one on my workbench, and am trying to figure out why all the input voltages to the second stage transformers are LOW. There is no Transformer 1, it is 2 jumpers, so I think that could be part of the problem. Any insight is appreciated, I'm trying to save the unit from an early demise. A photo of a working PSU, service manual, someone who has fixed one before... Thanks in Advance!

[Matt Syson]

Hi
PC power supplies are nothing like the ones used for audio work.
You may have 12 Volts at 5 Amps but the negative 12 volts is rated at a few milliamps.
The ripple and radiation would be horrendous. Audio rails should have a ripple in the order of half a millivolt.
If the OEM unit has jumpers it will not be a transformer that is missing.
Most supplies seem to use recognised 'chipsets' so look out the app notes for the major chips on your board.
Matt S

[mwoodall]

Hi,
I have a 328 that is now entering Boat Anchor Mode. After 10 years of flawless service, The power supply has started acting up. I replaced the two high voltage caps which brought it back to life temporarily but once it gets powered down it's a crap shoot if it will power up again. I think it has to do with one of the two multi tapped transformers but I'm just guessing. I'd love to help you in your investigation. If there is something I could do please let me know. Marshall

[evening]

I'd like a solution to this as well.
My 328 was DOA until they sent me a new PSU way back when.
(easier than shipping the whole unit back.)
After many years I'm waiting for the other shoe to drop...

Once the required voltage/current values are determined it seems a fairly easy project to replace it with an outboard - there a lot of that DIY PSU stuff going on around here anyway.

[Matt Syson]

Hi
The 'universal' answer may be to get a 'Power One' 15+15 Volt + 5 Volt' module and put it in a box. You would have to determine how much current you need but this can be at least 'guestimated' from the power rating on the existing unit (rear plate value) and working backwards.
Fit a suitable connector on the back of the 'desk' and it is done.
Matt S

[mwoodall]

That's an interesting idea Matt. Sure beats the $800 option from Soundcraft. I was fooling with the 328 PSU again last night and made a little observation. I reinstalled the Torroidal transformer that I was told to remove by way of a Tech Bulletin. It seems that the board will now power up consistently (at least it did last night). I'm not sure why they suggest to just put jumpers across those terminals because I think that Transformer actually does something. Go figure

[Matt Syson]

Hi
It's probably a bifilar choke.
No idea why it would affect startup though.
Matt S

[grtstrm]

Hi everyone, thank you very much for your suggestions, here is where I am today, unit #1 had an original version power supply. The UCC3810 power manager chip was malfunctioning due to one of the two MOSFETS failing. The MOSFET that is on pin 3 of TX2 shorted to ground during the failure. I am guessing that unbalanced the circuit popping the other MOSFET. I checked the transformer coils to be sure we didn't take those out, and replaced the Bridge. The UCC3810, and the two MOSFETS were removed and replaced. Voila! we have a working power supply.

Unit #2 had been sent back to Soundcraft for the $800 repair (ouch). They replaced the whole PSU with a new one. This has failed, and it is out of warranty. This new version is not as complex as the old version, but it is still cheesy. two resistors are burned to a crisp, and the fuse is still good. Hmmm. I am trying to locate the schematic for the new version, the part number is S-S2005A-04. I have a call in to Soundcraft to see if they will share.

We have a third console, unit #3 that has failed as well, and it just went back to the factory. when that one went, the studio was facing shut down. fortunately the parts came in on time for the first one, so down time was minimized to the swap out.

In the meantime, I have ordered up some commercial grade power supplies, switching for the logic and LED's, and motor, and a super clean linear +15V and -15V 2A balanced, .05v ripple under load for the analog section. With a box and some fit it together bits and pieces, it has come to ~$400. About half of what Soundcraft wants for theirs. Everything should be coming in today, so in a week or so, we will know if this is a viable solution. I'm not dissing Soundcraft for putting a $40 power supply in a $4500 console, but, we may have a little better solution for those that want to keep using these mixers.

Any questions, feel free to ask!

[ginozarri]

Hello everyone, I have a 328 digital without psu , I need tips to build a new psu, or if there is one compatible.

Thanks

Gino Zarri (Italy)

[TAVD]

In the meantime, I have ordered up some commercial grade power supplies, switching for the logic and LED's, and motor, and a super clean linear +15V and -15V 2A balanced, .05v ripple under load for the analog section.

Seems like the best solution. The original psu always got too hot for comfort anyway, imo. I wouldn't be surprised if the preamps sound better as well.

[grtstrm]

Hi everyone, I was extremely successful building the external power supplies. I found all the parts required at Mouser Electronics - Electronic Component Distributor execpt for the 48 volt power supply for phantom power. That came from DigiKey Corp. | Electronic Components Distributor | United States Home Page. I used an industrial metal outdoor electrical component box that has a removable mounting plate inside. The power supplies all fit inside very nicely, and the biggest improvement was the +/- 15 v supply for the audio section. The two 5 V (logic and "Analog"), 12V (motor), and 48 v are all switching power supplies, slightly overrated for the application. A power entry module for mains input fusing and filtering, a couple of barrier strips to connect it all to the mating connector of the 328, and it was done. The best part of the whole project was that once installed it gave the board a fuller, warmer, deeper, sound. I attribute that to the +/-15V non switching power supply. The studio liked it so much, they commissioned me to build a dual supply to handle both mixing consoles. Basically the same parts, I just went up on current to account for both boards and some headroom. Same box, just had to make a dual harness. The total cost for the single version with $200 of labor for me, was $800, and the dual supply was $900. They have been running for two months straight, no hassles, no hiccups, no failures. I even have a testimonial if you are interested! If you are comfortable cutting and drilling, soldering, and making wiring harnesses, this is a pretty good project for you. If you would like more information, don't hesitate to ask, I can supply the parts list and a layout diagram. Or, build one for you! The good news is that there is a reasonable solution to save these wonderful mixing consoles fro a design flaw that would have sent them to oblivion.

[ginozarri]

Great!! I am concerned I have a 328 without psu ....
I would be happy if you send me the information needed to build a psu.

Thanks in advance

Gino

[gmontano]

sigh my digital 328 power supply just went too. I am in the US. Any advice?

[Evert63]

Hi, I am not a native speker so please be forgiving.

My PSU is failing sometimes, mostly barely fulfilling the startup sequence. Does anybody know which part of the PSU generates the problem? In my case the LCD flickers just before the Pacman eats the diamond beneath the B of Booting... Is it the digital 5V that causes the problems?

Secondly: How to fool the "PWRGOOD" signal. This is used to start up the processor is'nt it?

Thanks,
Evert

[Matt Syson]

Hi
I am sorry I can't help specifically with the supply problem but would point out that it is dangerous to the desk (and maybe you) to 'experiment' with the supply in any way with the desk connected. If you are working on the supply, disconnect it from the desk supply rails and use 'dummy loads' (power resistors) while checking the supply. 6 or more volts on a 5 Volt logic rail inside the desk could well be permanent death of a considerable amount of logic.
Matt S

[Radardoug]

Just a note. One of the most common failures in switchmode supplies is the caps drying out. One is the supply cap for the driver i.c., often a XX3842. This cap dries, and the chip hasn't enough supply to start. Also drying of the output filter caps can cause no startup, as the supply thinks it is going to overvoltage. Replace all caps and see what happens.

[NickyBoy]

Does anybody know how much id be looking to pay for a used 328???? (not the 328 xd)

[Evert63]

Radardoug, thanks for the tip!

Matt S: I won't experiment in a live apparatus! thanks anyway. I can't help thinking that the real problem should be located in just ONE area. I don't think it 'll be the 48V phantom power that's causing all the problems. Maybe somebody can help me strengthen the right parts without lifting any of the voltages...

[Wavebourn]

Is it possible to find a schematic for this console?
Which popular consoles have similar problems?

The hardest part is UL certification, but if the fault is common and there are many unhappy owners, it may be worth trying...

Anatoliy Lisovskiy
MS EE, Electronics designer and technologist

[jibarosoul]

I have a 328 that is giving me issues with the faders. The faders move in an eratik way and jitter up and down. channels 1-2 are the worst as they some times drop to 0 even though the fader itself will be halfway up. seems like the automation motors are shot? is there a way to disable the motors if i dont use the automation? Is the actual level determined by the motors position? Any insight would be great thanks.

[ikstephan]

My Digital 328 was down for almost year, suspectedly because of a dead psu. Since I used it purely for my homestudio and not for work I did not really depend on it and I never got to get it fixed. When I finally found the time yesterday I contacted the Soundcraft dealer in Holland who put me through to the technical people in Belgium. They helped me on my way and it turned out quite simple to fix my unit.

I replaced just 3 capacitors on the psu board. Number C40 (10uF, 63V, 5x11mm), number C43 (47uF, 63V, 8x12mm) and number C48 (4.7uF, 50V, 5x11mm). Machine works fine now!

Could be that I just was lucky and that this won't fix the problem for everyone or that my psu will break down again in the future... Worth the try I'd say! It will not cost you more than 2 Euro.

I have the same problem with 2 of my faders by the way. They also are out of sync. Looks like they need callibration or something.

[NRG70]

Hi ikstephan,
i have sent you a PM message,
would like to know some things.

Thanks!

Originally Posted by ikstephan

My Digital 328 was down for almost year, suspectedly because of a dead psu. Since I used it purely for my homestudio and not for work I did not really depend on it and I never got to get it fixed. When I finally found the time yesterday I contacted the Soundcraft dealer in Holland who put me through to the technical people in Belgium. They helped me on my way and it turned out quite simple to fix my unit.

I replaced just 3 capacitors on the psu board. Number C40 (10uF, 63V, 5x11mm), number C43 (47uF, 63V, 8x12mm) and number C48 (4.7uF, 50V, 5x11mm). Machine works fine now!

Could be that I just was lucky and that this won't fix the problem for everyone or that my psu will break down again in the future... Worth the try I'd say! It will not cost you more than 2 Euro.

I have the same problem with 2 of my faders by the way. They also are out of sync. Looks like they need callibration or something.

[AtticaEnumbrea]

Hello,

Nice to know somebody else is using this board - unfortunate, however, that so many people are having problems with it.

I am have a similar problem in that it seems to initially turn on O.K. but Mr. Pacman gets hung up on his last little tidbit and then eventually it starts (maybe after 30 seconds).

This isn't really a problem, but it started happening at the same time that my other problems arose. When I recall a snapshot it takes about 30 seconds to load. It used to load instantly.

Also, when I try to access FX 2, it takes 30-60 seconds to access any parameters and to put them in effect. Anyone else encouter something like this?

Also, in response to buying one used, I think I payed $1200-$1400 (fuzzy memory) at a local music store. for the board and the additional preamp (giving it 32 inputs)

[MarcusJay]

Hey AtticaEnumbrea,
Unfortunately I'm brought to this forum as the power just went on my 328XD too. When I checked it out there even appears to be a chunk of graphite(?) from what I can only assume is the transformer floating around in there which is mystifying.

But your problem sounds very reminiscent of a simple fix I've had to do a number of times in the past.
Remove all the raised black screws from the top side (and a few from the bottom of the very front & a few from the back side.) Lift the blue metal casing off the top (being careful of the one clip-off power cable connected to the top.

You should see 4 vertical plug-in pcb cards (resembling RAM in a pc) on the left hand side of the base.
Carefully remove them & properly resit them in their slots. This should fix the problem as it has for me on many occasions.

Hope that helps.

[zak69]

Hi, i´m new user and from finland so sorry ´bout my very poor language

I have 324 Live desk and it has booting problem.
I have changed those 3 elko´s (sorry don´t know the english word) from the PSU, but no affect.
When the desk finally boots up, it will stay up as long as there´s power in it.
I have checked all the cables and components, not measured, but just by looking and they seems to be fine.
In the PSU there´s 2 big things, line filters??, and one of them has been hot in a way sometime.
Should i replace them, I mean can this cause perhaps the booting problems?
And what was that message above where someone was talkin´about some chips in left corner on the disk, can´t remember can I find them in this 324 Live too?

[zak69]

Little update, tryin´to put the right words, hope you understand......

Today I tried to startup the desk about 10 times, all digits flashin several minutes and no booting.
Finally it booted up and everything worked fine, then i shut down the desk about 15 times and started again.
EVERY time it started to boot immediately (right word?), digits were no flashing and the "pac-man" started to eat the symbols on the lcd.
What might be the problem, seems like when the desk have once booted up then it easily boots again, at least no long time between boots.

Hope this helps someone to detect what might be broken/cause of that random booting problem

[NRG70]

Originally Posted by ikstephan

My Digital 328 was down for almost year, suspectedly because of a dead psu. Since I used it purely for my homestudio and not for work I did not really depend on it and I never got to get it fixed. When I finally found the time yesterday I contacted the Soundcraft dealer in Holland who put me through to the technical people in Belgium. They helped me on my way and it turned out quite simple to fix my unit.

I replaced just 3 capacitors on the psu board. Number C40 (10uF, 63V, 5x11mm), number C43 (47uF, 63V, 8x12mm) and number C48 (4.7uF, 50V, 5x11mm). Machine works fine now!

Could be that I just was lucky and that this won't fix the problem for everyone or that my psu will break down again in the future... Worth the try I'd say! It will not cost you more than 2 Euro.

I have the same problem with 2 of my faders by the way. They also are out of sync. Looks like they need callibration or something.

i really wonder how long your machine has been working correctly after the repair, or any other experiences?

[zak69]

I changed also those components fot my PSU, but no really visible effect.
Except i replaced all with 100V ones, should last better? (white circles around)
Can those 2 big things (sorry don´t know english word) cause booting or other problems, one of them seems heated up sometimes a bit

#3175993 | 324live | zak69 | Kuvablogi.com

#3175992 | 324live | zak69 | Kuvablogi.com

[jose_jiminez1]

I've started having trouble with my 328 recently, just wondering if anyone has suffered a similar issue - basically after half an hour or so of operation I start to get problems with the mono input channels, where it's like the channels overload at random, all the leds light up from green to red on each channel - almost like it starts to overheat? The stereo inputs and the outputs work ok, it's just on the input channels and it will usually start with whatever channels I happen to be using. If I turn it off and leave it for a while it works again after I turn it back on, then after about half an hour or so it'll start all over again. It's probably not a great description of the problem but it'd be great if anyone could shed any light and steer me in the right direction. Thanks.

[AtticaEnumbrea]

Originally Posted by jose_jiminez1

I've started having trouble with my 328 recently, just wondering if anyone has suffered a similar issue - basically after half an hour or so of operation I start to get problems with the mono input channels, where it's like the channels overload at random, all the leds light up from green to red on each channel - almost like it starts to overheat? The stereo inputs and the outputs work ok, it's just on the input channels and it will usually start with whatever channels I happen to be using. If I turn it off and leave it for a while it works again after I turn it back on, then after about half an hour or so it'll start all over again. It's probably not a great description of the problem but it'd be great if anyone could shed any light and steer me in the right direction. Thanks.

Sorry for the late response, and thanks for the tip on fixing the booting problem. I'll see give it a shot!

As for the overload problem...shoot...I've been having a simliar issue lately as well. Every 7th or 8th time I turn it on, the Master Channel overloads with massive noise and completely maxes out in the red. I have to turn it off and then on again and it usually corrects itself. Sorry I have no answer, but just wanted to let you know...you are not alone!

Maybe our boards are staring to "go?" I bought mine used and I'm not sure what the life expectency of these things are....