AC/DC & POWERSTATION KIT BUILD THREAD

[Joe Malone]

Thanks Joe. After i reread my post I figured that was the case. Not sure why it didn't sink in the first time! I remember your old AC/DC boards only having two connections, and I left the center tap unconnected, so I think I was just confused with the newer version boards, with the two AC and 0V connections.

Anyways, thanks again!

OLD AC/DC PCB had AC in, AC in, 0v like powerstation kit

NEW AC/DC PCB has AC in, 0v, 0v, AC in. So lineup with dual secondary transformers.

[mikeyb]

Hi Joe - just come across a version 2 powerstation kit which i thought i had already used!
Is the copper heavy enough for me to wire a 6A bridge off board so that i can get the full 1.5A from the 4 rails - i want to make a bench supply.
Oe should i strap wires onto tracks on the underside of the board to beef up the copper?
Cheers in advance
Mike

[Joe Malone]

Hi Joe - just come across a version 2 powerstation kit which i thought i had already used!
Is the copper heavy enough for me to wire a 6A bridge off board so that i can get the full 1.5A from the 4 rails - i want to make a bench supply.
Oe should i strap wires onto tracks on the underside of the board to beef up the copper?
Cheers in advance
Mike

Yes that will work fine.

[jdirolf]

I purchased a partially completed pre amp kit and made the mistake of testing the supply that someone else assembled without doing more research into how it should be wired. Long story short, I ended up with a few experiences of magic smoke from the supply (AC/DC).
The transformer is a digikey amveco 62075. It is wired to the supply as-per your webpage. However, I am using this for a neve clone so I don't need -24v. Should I leave the brown and red wires from the transformer wired together but off of the 0v pad on the AC/DC input? Am I correct to have the voltage doubler jumpered and shorted capacitor on the -24v? (the previous owner installed all of the -v components for some reason)
I've already made the mistake of regulators touching the case (so I replaced the fried 10ohm resistor and installed separate heatsinks). I also unfortunately jumpered the voltage tripler at one point, so I replaced the 48v filter caps that received too much voltage. Should any other components be replaced from these stupid mistakes? Should I just rebuild the whole board?
Any help is greatly appreciated.
Thanks,
Jared

[Joe Malone]

I purchased a partially completed pre amp kit and made the mistake of testing the supply that someone else assembled without doing more research into how it should be wired. Long story short, I ended up with a few experiences of magic smoke from the supply (AC/DC).
The transformer is a digikey amveco 62075. It is wired to the supply as-per your webpage. However, I am using this for a neve clone so I don't need -24v. Should I leave the brown and red wires from the transformer wired together but off of the 0v pad on the AC/DC input? Am I correct to have the voltage doubler jumpered and shorted capacitor on the -24v? (the previous owner installed all of the -v components for some reason)
I've already made the mistake of regulators touching the case (so I replaced the fried 10ohm resistor and installed separate heatsinks). I also unfortunately jumpered the voltage tripler at one point, so I replaced the 48v filter caps that received too much voltage. Should any other components be replaced from these stupid mistakes? Should I just rebuild the whole board?
Any help is greatly appreciated.
Thanks,
Jared

All the above is wrong.

Remove all 3 regs and replace +V reg and +48v reg and any caps that are bulging.
Check none of the 8 x 1N4007 in the center of the PCB have gone short.
That should fix your AC/DC if none of the trim pots were burnt by being wound down with blown regs.
Separate small heatsinks will be enough for only one or maybe 2 neve clone only usually.
Check you have the correct current value mains fuse fitted for the mains transformer.

OK the Amveco 62075 has 2 x 22vac windings so I would use the AC/DC normally (without the Neve Mod no shorted cap on -24v) but both ways can work as shown below.

NO NEVE MOD wiring
Wire red and Brown to 0v terminals.
Wire Green to one AC in and Blue to other AC in.
Negative rail parts or reg can be left on or off doesn't matter.
Set to doubler and set +24v and +48v.
Turn off and connect to mic pres.

Neve MOD wiring
Do Neve Mod to PCB (Short out C8 with wire link.)
Wire Green and Brown to one AC in.
Wire Red and Blue to other AC in.
Nothing to 0v on transformer side.
Negative rail parts or reg can be left on or off doesn't matter.
Set to tripler and set +24v and +48v.
Turn off and connect to mic pres.

[jdirolf]

Many thanks, Joe!

[evilcat]

Hi everyone,

I need a new power supply for a Soundcraft E8 desk, with +/-15V and +48V.
I have build an AC/DC, with this secondary dual 9V transformer: http://docs-europe.electrocomponents.co ... 07fe8b.pdf
But I'm not able to go beyond +/-12V and +38V.
I thought that a dual 9V would gave me a single 18V but maybe I'm wrong... I wired it like shown on the 1st page. Is my Xfrm suitable for my need? Is my wiring wrong for that case? Maybe I need to put in serie 2 leads? I don't know, I prefer to ask before making any mistake...
Thanks guys,

Ben

[Joe Malone]

Hi everyone,

I need a new power supply for a Soundcraft E8 desk, with +/-15V and +48V.
I have build an AC/DC, with this secondary dual 9V transformer: http://docs-europe.electrocomponents.co ... 07fe8b.pdf
But I'm not able to go beyond +/-12V and +38V.
I thought that a dual 9V would gave me a single 18V but maybe I'm wrong... I wired it like shown on the 1st page. Is my Xfrm suitable for my need? Is my wiring wrong for that case? Maybe I need to put in serie 2 leads? I don't know, I prefer to ask before making any mistake...
Thanks guys,

Ben

HI Ben
For +/-15v you should use a 2 x 15vac or 2 x 18vac transformer and jumper set to tripler on AC/DC.

You can wire the 2 x 9vac. Remove the 2 wires going to 0v and join them together and to nothing else. Then move one of the AC in wires to 0v and you will have 1 x 18vac running the AC/DC. But this is only good for light current draw but worth a try and see if it works quietly or not.

Since your running a whole desk a 2 x 15vac transformer of the correct VA would be the best for quiet power supply.

[evilcat]

Hi Joe,

Thanks a lot for your reply. It worked obviously!!!
But now I have another problem with another PSU, the Powerstation. My -V2 rail doesn't works anymore. The components seem ok, visually...
Where should I start looking at? (It was connected to a diode who burned, it was for an 1176, running the -10V rail)

Best,

Ben

[Joe Malone]

Hi Joe,

Thanks a lot for your reply. It worked obviously!!!
But now I have another problem with another PSU, the Powerstation. My -V2 rail doesn't works anymore. The components seem ok, visually...
Where should I start looking at? (It was connected to a diode who burned, it was for an 1176, running the -10V rail)

Best,

Ben

If you remove the load off -V2 and it doesn't come back to -10v or goes to full -Vunreg then you just need to replace the LM337 reg.

If you have not adjusted the trim pot at all it should return back to -10v with a new reg.

[evilcat]

Ok, got it. Thanks a lot!

Ben

[evilcat]

Hi!
Just to report: issue wasn't the powerstation but the other circuit. Thanjs again for your help Joe.
Best,
Ben

[cromwell]

Hi Joe,

a stupid question:
I used a 30VA transfomer with dual 33v output unregulated, 31v regulated.
Everything works fine but the phantom power is 60v at the lowest trim pot level (Doubler jumpered).
When I cut the jumper (neither/nor T/D) I get 25v phantom power on the highest trim pot level.

Do you have any suggestions how I could get closer to 48v?
If there is no solution: All my condenser mics are 48v, do you think I would hurt them with 60v phantom or should I stay then with the 25v?

Cheers and thanks in advance

Eric

[Joe Malone]

Hi Joe,

a stupid question:
I used a 30VA transfomer with dual 33v output unregulated, 31v regulated.
Everything works fine but the phantom power is 60v at the lowest trim pot level (Doubler jumpered).
When I cut the jumper (neither/nor T/D) I get 25v phantom power on the highest trim pot level.

Do you have any suggestions how I could get closer to 48v?
If there is no solution: All my condenser mics are 48v, do you think I would hurt them with 60v phantom or should I stay then with the 25v?

Cheers and thanks in advance

Eric

HI Eric
2 x 33vac transformer is to high and should not be used really. It is just pushing everything to the limits and making lots of heat. So large heatsink will be needed. Not sure what you mean 31vac regulated as a AC transformer has no regulation? Or do you mean loaded? What power rails are you trying to get besides 48v? +/-V?

33vac x 1.414 x 2 = 93v unreg into +48 regulators. The 48v reg overvolts protection will cut in with more than 40v across the reg. So 93v - 40v = 53v lowest setting. So your 33vac must be more like 35 to 36vac to get the 60v you have. If you really want to stay with this transformer you could change the 48v reg to a special LM317HV which allows 60v across it before protection. But best is to change the transformer to the correct one for the +/-V rails.

33vac x 1.414 = 46.67v unreg into +/-V regulators which is ok but will make a lot of heat.

[cromwell]

Hi Joe,

thanks for your quick reply.
Yes I ment loaded.
Thanks for that clarification, I´m going to buy a new transformer;-)

Have a nice weekend!

Cheers

Eric