Thinking of using this for a mixing console rather than class A amp. The supply is +/- 22V, can the SLB work for this application. Thinking of using a chunky toroidal out of a PA power amp that runs around 50Vac. I'd like to over rate the PSU for this mixer, can the SLB deliver more than 5A.
Thanks
Thanks
Sure, as long as you don’t require regulated voltage. Isn’t +/-22v kind of high for normal opamps on a mixer console? They are at most +/-18v I think. You could drop with regulators after the SLB and have very clean supply. You need 5A? I guess consoles have hundreds of opamps. They add up.
Thanks for your reply.
It's a tube mixer so not the ordinary run of the mill stuff. The PSU has 3 rails as shown below. Sadly I bought it with an under rated supply meant for a smaller model with only 8 channels. Mine has 16 plus its master section so indeed a lot more opamps to drive. The PSU I have has a smaller transformer that can only handle 5A on the +/- 22V. My 16CH mixer definitely needs the 10A capable supply it should have come with and its no wonder why the seller let it go. The schematic below is that of the PSU that shipped with the mixer new.
The +200V and +70V rails get enough power from the existing smaller Transformer but not the +/- 22V. So with a beefy Toroidal out of a an old Wharfedale Poweramp I'm thinking of employing the SLB to do the job for the +/-22V rail. I'd fit the two toroidals, the smaller PSU sans +/-22V rails plus the SLB in the retired power Amp's rack case. In fact I'm open to advice and suggestions on cleaning up the 200V / 70V lines as well. There must be tube specific PSU projects. I could keep just the Toroidal and do away with this vanila linear supply altogether. Open to suggestions.
Also just in case anyone into tubes is reading, can I run them (12AX7s) higher than 200V. I recall hearing that can work wonders if implemented right but I need advice in this department. Irrespective I'm sure I could clean the power right up with a new PSU altogether, part based on the SLB.
We put so much effort into our playback equipment. I'd like to apply the same effort to ensuring music is recorded with the same attention to detail.
What do you guys think
It's a tube mixer so not the ordinary run of the mill stuff. The PSU has 3 rails as shown below. Sadly I bought it with an under rated supply meant for a smaller model with only 8 channels. Mine has 16 plus its master section so indeed a lot more opamps to drive. The PSU I have has a smaller transformer that can only handle 5A on the +/- 22V. My 16CH mixer definitely needs the 10A capable supply it should have come with and its no wonder why the seller let it go. The schematic below is that of the PSU that shipped with the mixer new.
The +200V and +70V rails get enough power from the existing smaller Transformer but not the +/- 22V. So with a beefy Toroidal out of a an old Wharfedale Poweramp I'm thinking of employing the SLB to do the job for the +/-22V rail. I'd fit the two toroidals, the smaller PSU sans +/-22V rails plus the SLB in the retired power Amp's rack case. In fact I'm open to advice and suggestions on cleaning up the 200V / 70V lines as well. There must be tube specific PSU projects. I could keep just the Toroidal and do away with this vanila linear supply altogether. Open to suggestions.
Also just in case anyone into tubes is reading, can I run them (12AX7s) higher than 200V. I recall hearing that can work wonders if implemented right but I need advice in this department. Irrespective I'm sure I could clean the power right up with a new PSU altogether, part based on the SLB.
We put so much effort into our playback equipment. I'd like to apply the same effort to ensuring music is recorded with the same attention to detail.
What do you guys think
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I was looking at the schematic and the Mouser parts list and didn't understand one section. I apologize if this is trivial and/or discussed many times.
Why are the MOSFETs not identical for each rail? Is this to communicate possible options where people can choose, or is there a functional reason for a different part for each rail (Q10/Q12, Q9/Q11)?
Why are the MOSFETs not identical for each rail? Is this to communicate possible options where people can choose, or is there a functional reason for a different part for each rail (Q10/Q12, Q9/Q11)?
Thank you! Sort of highlights the limits of my understanding of electronics, I suppose...
Thank you! Sort of highlights the limits of my understanding of electronics, I suppose...
It certainly does. 😀 But only by asking questions do you learn more.
Andy
Yes, I am ordering more now. Will have them in about 10 days. I didn’t realize they sold out until the last one was sold a few days ago.
Resupplies of single rail SLB’s are on their way. Green mask 2mm thick FRO, 2oz copper, ENIG boards. Blue PCBs appear to not be in vogue, so are very expensive. Hence, I have switched over to green boards lately.
The SLB SR's arrived today, I will get them back up in the shop soon. These are 2mm FRP, 2oz Cu, ENIG finish and green solder mask.
I have not seen the single rail boards in the Etsy shop yet, will they have the same concern about BD 139 mounting as the older SR boards?
Sorry for the delay. No, they are the newer version with correct heatsink orientation for BD139. I’ll put the listing up shortly.
Finally making some progress on my multiple projects. Have the 2 soft starts (H9KPXG) working. I'm planning on using 2 SLB for a dual mono Sissysit with a chassis for each side. Choose the Anteks 4222. As you can see I'm getting 31.5V unloaded. My wall voltage is 124.7V. Which might explain the higher voltage. Haven't yet checked the other SLB build but suspect it will be the same.
1. Is this ok for my use with sissysit ? Seems higher than what others have seen with the 3222's unloaded . Know that it will drop when loaded but seems like it has a way to go.
2. Haven't quite figured out if the pot on the board does much in regards to changing the voltage. A turn or two did little.
Overall things went quite smoothly once I had the parts. Thanks for the project and all the support throughout this thread! Looking forward to getting to the final part of this project.
1. Is this ok for my use with sissysit ? Seems higher than what others have seen with the 3222's unloaded . Know that it will drop when loaded but seems like it has a way to go.
2. Haven't quite figured out if the pot on the board does much in regards to changing the voltage. A turn or two did little.
Overall things went quite smoothly once I had the parts. Thanks for the project and all the support throughout this thread! Looking forward to getting to the final part of this project.
Attachments
Nice planned project. I too will try the SLB with my SissySIT.
When loaded by the amp, voltage will drop approximately 5v. The trimpot adjustment is less than 1v, its not meant to adjust voltage like a “regulated” supply.
When loaded by the amp, voltage will drop approximately 5v. The trimpot adjustment is less than 1v, its not meant to adjust voltage like a “regulated” supply.
Is there a formula with which I could calculate/predict the output voltage from an SLB with a given transformer voltage? The load will be a typical class A amp.
@Nikodemuzz
Go back to the beginning of this thread, specifically post #35, all is explained there.
Best,
Anand.
Go back to the beginning of this thread, specifically post #35, all is explained there.
Best,
Anand.