Author Topic: Power supply mod.  (Read 1119 times)

Offline 2wice

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Power supply mod.
« on: January 14, 2018, 12:07:03 AM »
I'm building a TPA3255 amp and needed power for it, I need about 40v for the amp and some 12v and 5v for the mesmerize preamp, 2 x Amanero units and 2 DAC's.

I had some Harris rack mount power supplies but they did not have the right mix for me.

So I pulled the 60vac presupply in a 12v unit and replaced it with a 48vdc unit.

I stripped these boxes about 3 years ago and cannot remember what the 0v ISO and +v ISO was for so I just routed the 48v there. They were from a Siemens rack .

So now I get 41v, 12v, -12v and 5v of very clean power out of one box. They can also adjust about 5% up and down.

Offline chrisc

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Re: Power supply mod.
« Reply #1 on: January 14, 2018, 09:10:19 AM »
Is that the PSU in the top left?  What components and regulators are being used?

Offline 2wice

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Re: Power supply mod.
« Reply #2 on: January 14, 2018, 09:58:28 AM »
Is that the PSU in the top left?  What components and regulators are being used?

That is the TPA amp.

In the steel box, on the right top is the 48VDC PS, that feeds the input on 12v, -12v, 5v PS on the bottom right.
Those DC unit are made by https://www.ccipowersupplies.com/.

I suspect custom made for Siemens/Harris because the model numbers don't show on the site.
They seem rocksteady.

The amp and other components are going in another PSU box I've stripped.

Busy with that now. I'll try and get the amp working on it's own before wiring up the preamp and DACs.


Offline 2wice

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Re: Power supply mod.
« Reply #3 on: January 28, 2018, 05:48:19 PM »
This is the amp the PS supplies.
Got my first sound out now, sounds awesome.

2 Amanero boards to feed the Sabre and Twisted Pear Opus DACs , that way I can change DAC on the fly in Windows.

There's a B1 Mezmerize  preamp but not connected atm, forgot it's got a shunt on board and I need 12vac and the PS is all DC.

Still need to rewire once B1 is sorted.

Nearly finished.



Offline itscraig

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Re: Power supply mod.
« Reply #4 on: January 28, 2018, 05:56:20 PM »
looks awesome, hope to see the finished pics soon

Offline 2wice

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Re: Power supply mod.
« Reply #5 on: January 28, 2018, 07:06:48 PM »
Thanks

Offline John.Perry

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Re: Power supply mod.
« Reply #6 on: February 25, 2018, 04:00:48 PM »
Looks very very nice! But dammit man it's been a month, where is the update with pics please  :rubhands:
I was also looking at the TPA3255. Where can I get one?

Offline 2wice

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Re: Power supply mod.
« Reply #7 on: February 25, 2018, 04:16:20 PM »
Looks very very nice! But dammit man it's been a month, where is the update with pics please  :rubhands:
I was also looking at the TPA3255. Where can I get one?
I'm waiting for a differential dac to get here.
I'm also changing the power to split the ground from the Amanero with LDOs from a chap in Germany. Then to shoehorn 2 x B1 buffers to handle the balanced volume.
I got the amp from TI and it's awesome.
The DAC is also from TI but I've rolled my own, Pcm5242 with on-board minidsp. Also ordered some i2s isolators.

I'll have some left over DAC PCBs if anyone is keen.

Offline John.Perry

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Re: Power supply mod.
« Reply #8 on: February 25, 2018, 05:37:26 PM »
Nice, we need to talk haha ;D


Offline John.Perry

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Re: Power supply mod.
« Reply #10 on: February 25, 2018, 07:58:38 PM »
Where can I get the TPA3255EVM locally (Gauteng)? Directly from TI website? I saw a clone advertised on BidorBuy.

Offline 2wice

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Re: Power supply mod.
« Reply #11 on: February 25, 2018, 07:59:59 PM »
No idea locally.

Offline John.Perry

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Re: Power supply mod.
« Reply #12 on: February 28, 2018, 02:15:30 PM »
2wice, if you don't mind me asking/hijacking your post quickly, can I ask your (or for that matter the forum) advice?
The only PSU I that I can get for my TPA3255EVM is a Siemens Gleichrichter GR90 1500W Rectifier(getting it for free).
Sticker says the output stage is: 48(54) VDC, 16(14)/31(28)A.
I know that sounds overkill for my light(bookshelf) use, but would this PSU work well sonically with the TPA3255EVM?
« Last Edit: February 28, 2018, 02:19:54 PM by John.Perry »

Offline 2wice

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Re: Power supply mod.
« Reply #13 on: February 28, 2018, 02:17:19 PM »
Meanwell LRS-350-48 works well.

Offline John.Perry

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Re: Power supply mod.
« Reply #14 on: February 28, 2018, 02:21:41 PM »
Apologies, I fixed my previous post. I mean I can get the Siemens rectifier for free, so just want to know your thoughts if it will work nicely or not?