Any good DAC Output/Input Transformers from China ?

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TasoTaso

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Joined 2018
#1
#2
Mine look like those in your second link, they work great and are excellent value for money. I don't use them in my DACs though as for that purpose I normally want a step-up. These work great as line input trafos such as you might want at the input to a balanced classD amp being driven from an unbalanced signal.
 
#5
I have some similar sets of transformers from China. Bought them to check out the sound quality. Also have a pair of (Cinemag?) transformers that I was told are the same type as used on some piece of high end commercial audio gear.

Personally, I don't like the sound of any of them. They are all distorted compared to the audio quality one can get without using signal transformers. So, I would say it probably depends on the situation where you want to use them.
 
#6
I would like to use trasformers in a Behringer DEQ2496 as the input to the A / D conversion (AKM 5393VS) and in a Cambridge DacMagic (azur) DAC as an output to the Wolfson WM8740a DAC.

In the DEQ2496 I enter "XLR Analogic Input" with XLR-Rca adapters (source signal unbalanced).
In the DacMagic I come out of the XLR outputs with homemade XLR-Rca adapter cables because I enter in two different amps.
On the XLR pin2 + pin1 go to one amp (50K input) + pair of speakers, pin3 + pin1 go to the other amp (47K input) + pair of speakers (reverse polarity which I then straighten by turning the speaker wires).
Both amps have unbalanced inputs.
I hope I have explained.
My English is not good.
This is my situation.

My goal is to eliminate the opamps to achieve a better sound.
 
#7
Markw4 said:
I have some similar sets of transformers from China. Bought them to check out the sound quality. Also have a pair of (Cinemag?) transformers that I was told are the same type as used on some piece of high end commercial audio gear.

Personally, I don't like the sound of any of them. They are all distorted compared to the audio quality one can get without using signal transformers. So, I would say it probably depends on the situation where you want to use them.
Click to expand...

TasoTaso said:
I would like to use trasformers in a Behringer DEQ2496 as the input to the A / D conversion (AKM 5393VS) and in a Cambridge DacMagic (azur) DAC as an output to the Wolfson WM8740a DAC.

In the DEQ2496 I enter "XLR Analogic Input" with XLR-Rca adapters (source signal unbalanced).
In the DacMagic I come out of the XLR outputs with homemade XLR-Rca adapter cables because I enter in two different amps.
On the XLR pin2 + pin1 go to one amp (50K input) + pair of speakers, pin3 + pin1 go to the other amp (47K input) + pair of speakers (reverse polarity which I then straighten by turning the speaker wires).
Both amps have unbalanced inputs.
I hope I have explained.
My English is not good.
This is my situation.

My goal is to eliminate the opamps to achieve a better sound.
Click to expand...

If you require transformers to have the lowest possible distortion there are a few criteria that need to be met.

- The transformer must have very large cores
- They must be High Nickel types and even then the best use proprietary heat treatment that they don't talk about much
- They must be low impedance windings
- They must be driven from (close to) zero ohms source Z.

So.... as an example, a high level, low impedance Jensen OP Traffo can achieve around 0.002% at 20Hz and +4dbu provided it is driven with zero
ohms. Above 20Hz the distortion will disappear. Increasing the drive Z to even 150 ohms will increase LF distortion by a factor of almost 4 x. The coils
themselves have a DC resistance of around 40 ohms and the physical size is massive. I think the Cinemag have even lower resistance coils.

Meeting all the above criteria with a totally passive approach is not really possible so you have to just choose your compromises.

Other core materials are available such as Finemet / Nanocrystaline etc that have reportedly even high performance but I've only seen them available
on ebay / Chinese sites etc and there are no decent measurements available to characterize their performance and show they have been correctly
optimized. They are also very expensive.

It really comes down to personal taste, some people love them, some don't.
For the ADC, most likely a low ratio step down would be best, for the DAC, a 1:1 should do the trick given it's a V out DAC.

TCD
 
#11
Buy cheap, buy twice.

I avoid these ultra cheap transformers like the black plague as we had very good companies here that did know how to make stuff right and those can still be found NOS/NIB. From what I hear by those that do buy ultra cheap transformers many of these tiny transformers are not capable of the signal levels in DACs and distort considerably. Not all but it is trial and error and may cost time and effort so if you have time in abundance it may well suit you. Of course it is nice to see the reincarnation of your scrap metal 🙂
 
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#18
toshiba_nz said:
I'd be interested in a 1:1 (80% nickel or better) interstage (toroidal or otherwise) that is really good for 5ma DC, with 120VDC on the primary, AC component on the primary up to 40V RMS. 25hz-30khz +/-1db
Click to expand...
Your transformer will be more like a small Single Ended OP transformer but with the 80% Ni core - should be possible. All of these SE transformers are gapped and how they do this is part of the secret sauce.
Maybe talk to an existing supplier of Toroidal SE interstage + OP Traffos such as Vanderveen or Toroidy.
It's an interesting set of requirements, a lot of voltage swing, small DC current and presumably quite high impedance. This will all point to high inductance but also low capacitance.
I still think it's probably doable. Good luck.
 
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