Topaz Low-Capacitance Isolation Transformers - for Affordably Clean Power
Jan 7, 2021 at 3:40 PM Post #526 of 536
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Is the chart in the OP still accurate in that you need to get 2 sets of transformers? I'm currently confused as to how you're supposed to connect your system with computer/dac/amp. There's a lot of stuff said in the thread but none are summarized into one recommendation after being discussed so far.

I just have a computer/Schiit Bifrost 2/and THX 887 amp. The Bifrost 2's Unison USB claims to have electrostatic+electromagnetic isolation so I'm not sure if I need to move the PC off the Topaz or not. I see a lot of Topazs coming with two receptacles. Do you need to put every component on a strip off of 1 receptacle or can you mix and match?

(Edited for question clarifying)

DACs and PCs are known to generate "backwash" noise, polluting the power going into anything else that's plugged into the same outlet or power strip.

You've got three devices, so you will need a small, simple power strip, with a short power cord, no surge protection or pilot lights or fuses, into which you would plug your THX 887 amp, directly (i.e. Uninex PS28E).

Optionally
, go ahead and plug the Bifrost DAC and your computer - both of which might be generating backwash noise - into that same power strip shared with the THX amp. Now plug the power strip into the Topaz grounded-neutral secondary isolation transformer (rated to handle at least twice as many vA (Watts) as that consumed by all three devices when running).

Ideally, to ensure that neither your DAC or your computer can pollute the power coming into your THX 887 amp, you should purchase two more isolation transformers that will sit between the power strip and those two devices. These two isolation transformers should have a grounded faraday shield and a floating-neutral secondary (i.e. two B&K Precision 1604A).

Mike
 
Jan 7, 2021 at 3:48 PM Post #527 of 536
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Anyone know how this would compete with Topaz isolation transformers?
https://www.aliexpress.com/item/4001285233703.html
or
https://www.aliexpress.com/item/4000176601682.html

Price is much cheaper & is much more recent than used Topaz.
What should the input & output selection be for North America? Both 110v?
It's highly unlikely that those isolation transformers have the extremely low interwinding capacitance (0.0006 pF) of the Topaz -31 or -32 model series.

In other words, they can't compete. They would only be able to attenuate common-mode and normal-mode noise below 400 Hz, typically.

The Topaz -31 and -32 series transformers can attenuate commond-mode noise by 146dB, all the way up through 20,000 Hz.

Nothing like this is still manufactured, today. If you find it, please let us know. :wink:
 
Jan 7, 2021 at 7:08 PM Post #528 of 536

Thenewguy007

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It's highly unlikely that those isolation transformers have the extremely low interwinding capacitance (0.0006 pF) of the Topaz -31 or -32 model series.

In other words, they can't compete. They would only be able to attenuate common-mode and normal-mode noise below 400 Hz, typically.

The Topaz -31 and -32 series transformers can attenuate commond-mode noise by 146dB, all the way up through 20,000 Hz.

Nothing like this is still manufactured, today. If you find it, please let us know. :wink:

I think those Chinese ones are made for audiophiles. But who knows, since they don't publish their specs.
 
Jan 8, 2021 at 1:49 AM Post #529 of 536

darkfireblade25

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DACs and PCs are known to generate "backwash" noise, polluting the power going into anything else that's plugged into the same outlet or power strip.

You've got three devices, so you will need a small, simple power strip, with a short power cord, no surge protection or pilot lights or fuses, into which you would plug your THX 887 amp, directly (i.e. Uninex PS28E).

Optionally, go ahead and plug the Bifrost DAC and your computer - both of which might be generating backwash noise - into that same power strip shared with the THX amp. Now plug the power strip into the Topaz grounded-neutral secondary isolation transformer (rated to handle at least twice as many vA (Watts) as that consumed by all three devices when running).

Ideally, to ensure that neither your DAC or your computer can pollute the power coming into your THX 887 amp, you should purchase two more isolation transformers that will sit between the power strip and those two devices. These two isolation transformers should have a grounded faraday shield and a floating-neutral secondary (i.e. two B&K Precision 1604A).

Mike

Great, so if I buy the floating-neutral secondary ones, they'd be plugged into the power strip as well? And as a follow up question, if you go the power strip route, the other receptacle on the Topaz shouldn't be used for anything then?

As an addendum, I think I bought a unit with a Va that is a bit under the double load requirement. Can't tell if the B&K Precision 1604A is gonna handle 250-300W that my computer outputs from its specs sheet either.
 
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Jan 9, 2021 at 9:18 PM Post #530 of 536

darkfireblade25

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So I bought a Topaz 91095-32 and the internals look different than what was posted so far.

This is the output side.
IMG_20210109_210942.jpg


This is the input side
IMG_20210109_210630__01.jpg
 
Jan 26, 2021 at 6:37 AM Post #531 of 536

rsbrsvp

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Question for the experienced:

Should my en tire system be hooked up to the topaz or should my streamer and sotm tx-usb ultra which are on good linear power supplies but come before galvanic isolation not be attached to the topaz?
 
Jan 27, 2021 at 3:50 AM Post #532 of 536

Energy

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Question for the experienced:

Should my entire system be hooked up to the topaz or should my streamer and sotm tx-usb ultra which are on good linear power supplies but come before galvanic isolation not be attached to the topaz?

I'd say to have them all connected to one unless you can find yourself multiple TOPAZ's to ground their GND (green wire) at the output altogether via Star Grounding. By doing so reduces the AC leakage currents while keeping their 0.0005pF galvanic isolation towards specific gear. For example by doing so you could have your digital setup on one while after the USB cable to the rest of your audio system can be on another. This should reduce the high frequency hash that's dumped back into AC mains that could potentially work it's way back to your DAC/AMP if they were all tied to a single isolation transformer.
 
Jan 29, 2021 at 2:54 AM Post #533 of 536

bequietjk

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I've decided to put my 91001-31 up for sale due to space. Minimizing my workspace and having limited area makes this difficult so, gotta downsize now.

If anyone is interested, PM me.
I'll also be wiring it for unbalanced (how it came to me initially).

Unbalanced is the standard 120V in/ 120V out, right?
 
Jan 29, 2021 at 12:44 PM Post #534 of 536

bequietjk

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Good morning and good afternoon gents,

Before I fire this topaz off to sell, can someone confirm this to be properly wired?

Input:
0129210937_HDR~2.jpg


Output:
0129210920_HDR~2.jpg


I appreciate all the help over the past year from everyone here. Some day ill be able to afford having one of these in my chain again.
 
Feb 4, 2021 at 5:38 PM Post #535 of 536

darkfireblade25

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I'm trying to find a floating-secondary transformer that can go with my computer and this is what I got back from the Hammond Mfg rep when I asked about the 171 line that was mentioned in the OP:

1612478236139.png


Does this mean that the secondary is actually grounded?

Edit: Got a follow up finally after a few weeks. I'm just too paranoid and it is a floating secondary.
 
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