Passive Preamps - Transformers

[Mihalis]

I have listened to a couple of transformer based preamps to very good effect. No careful double blind listening yet. I was wondering if you could point me to any discussions, measurements and opinions that may have been posted here. Very big picture it seems that these won't beat the insane measurements of some of the recent preamps assessed here but knowing these headline figures are on full volume and that with transformers one gets consistent performance (?) I wonder if in real life use they compete. Nice to not have another power cable too.

I am aware of the hi end Ypsilon preamp which I used but was not a big fan of. But there are a few smaller and lesser known transformer makers that have tried to produce what to my ears sounds very pleasing. Trying to figure out if that is measured and whether it is distortion rather than accuracy. Thanks.

 

[SIY]

I have listened to a couple of transformer based preamps to very good effect. No careful double blind listening yet. I was wondering if you could point me to any discussions, measurements and opinions that may have been posted here. Very big picture it seems that these won't beat the insane measurements of some of the recent preamps assessed here but knowing these headline figures are on full volume and that with transformers one gets consistent performance (?) I wonder if in real life use they compete. Nice to not have another power cable too.

I am aware of the hi end Ypsilon preamp which I used but was not a big fan of. But there are a few smaller and lesser known transformer makers that have tried to produce what to my ears sounds very pleasing. Trying to figure out if that is measured and whether it is distortion rather than accuracy. Thanks.

I had one of those in house about 15 years ago. It worked... OK. Very expensive, and no better than a cheap chip and a few resistors. In the bass, significantly worse. I could see situations where the transformer system could pick up excessive noise, but I personally didn't experience it.

The attraction here is that it's exotica, not that there's any actual advantage.

 

[gwing]

Good transformers are expensive and never perfect. Why would you want one unless you need low noise/high voltage amplification such as a MC input? For signals already at line level in a pre-amp I'd imagine they would be highly undesirable.

 

[ppataki]

I have listened to a couple of transformer based preamps to very good effect. No careful double blind listening yet. I was wondering if you could point me to any discussions, measurements and opinions that may have been posted here. Very big picture it seems that these won't beat the insane measurements of some of the recent preamps assessed here but knowing these headline figures are on full volume and that with transformers one gets consistent performance (?) I wonder if in real life use they compete. Nice to not have another power cable too.

I am aware of the hi end Ypsilon preamp which I used but was not a big fan of. But there are a few smaller and lesser known transformer makers that have tried to produce what to my ears sounds very pleasing. Trying to figure out if that is measured and whether it is distortion rather than accuracy. Thanks.

Do you need this transformer preamp for actual preamplification or only to colour the sound?
If it is the latter then you can just simply use transformer hardware emulation plugins provided your source is a computer - that way you don't need to buy the actual hardware and you will be able to try many different transformer types/models to hear how they colour the sound
This is what I am doing too (tube/tape/transformer/etc. emulation)

 

[MaxwellsEq]

This seems to get people excited:

Allegri Reference - www.townshendaudio.com

It reveals enormously deep and wide sound stages, that fill the room with holographic-like sound images, whilst unveiling previously hidden fine detail. It is the ultimate, timeless, state-of-the-art, purely analogue, passive, stereo audio volume control.

www.townshendaudio.com

 

[Mikig]

I'd love to try one. I have been using a Khozmo, passive attenuator, or passive preamp (more familiar name) for some time now and I am finding it very good. When I bought it I was afraid of not having "volume" or dynamics. but everything is ok. Clearly I have read about pre transformers, which are considered the non plus ultra and I am very curious. But I don't even want to invest so many thousand euros, when a 500 euro Pre90 can fulfill the task in the best objective way.

 

[Mikig]

This seems to get people excited:

Allegri Reference - www.townshendaudio.com

It reveals enormously deep and wide sound stages, that fill the room with holographic-like sound images, whilst unveiling previously hidden fine detail. It is the ultimate, timeless, state-of-the-art, purely analogue, passive, stereo audio volume control.

www.townshendaudio.com

I add “The Bespoke Audio Company”
“it is said around” that they are the best

 

[EERecordist]

Jensen transformers, and other makers, are used in professional equipment. They are very linear if not overdriven. Usually they are used for voltage gain, as they are used in phono moving coil step-up transformers.

So as long as a designer honors impedance matching, they can be combined with an attenuator and used as a "preamp." Key is a high input impedance of the following power amplifier.

Today's op amps are very good and cheap, arguing against the passive preamp. In the early op amp mixer days, for example in the API 312, the microphone input transformer had a gain of 1:7 or 1:8, and the output transformer from 1:1 to 1:3.

The Jensens and other professional small signal, fully characterized devices, with reasonable production volume, are not cheap.

 

[DWPress]

This seems to get people excited:

It's got "FRACTAL WIRE" so must be good.

​

 

[JiiPee]

I'd say that with today's technology, smart money goes to op-amp based preamplification plus class-D power amplification.

 

[SIY]

Jensen transformers, and other makers, are used in professional equipment. They are very linear if not overdriven. Usually they are used for voltage gain, as they are used in phono moving coil step-up transformers.

So as long as a designer honors impedance matching, they can be combined with an attenuator and used as a "preamp." Key is a high input impedance of the following power amplifier.

Today's op amps are very good and cheap, arguing against the passive preamp. In the early op amp mixer days, for example in the API 312, the microphone input transformer had a gain of 1:7 or 1:8, and the output transformer from 1:1 to 1:3.

The Jensens and other professional small signal, fully characterized devices, with reasonable production volume, are not cheap.

The Jensens are fixed ratio. I think what the OP was talking about is a transformer volume control. The description of the sound is ludicrous.

It reveals enormously deep and wide sound stages that fill the room with holographic-like sound images, whilst unveiling previously hidden fine detail.

 

[EERecordist]

This seems to get people excited:

Allegri Reference - www.townshendaudio.com

It reveals enormously deep and wide sound stages, that fill the room with holographic-like sound images, whilst unveiling previously hidden fine detail. It is the ultimate, timeless, state-of-the-art, purely analogue, passive, stereo audio volume control.

www.townshendaudio.com

That website is amusing. If they can't be bothered to to run https on their website I would suspect their engineering. It is hard to imagine they can source the custom-built multi-winding/autotransformers they claim at controlled quality.

Not sure what is

subterranean bass

 

[Mihalis]

Do you need this transformer preamp for actual preamplification or only to colour the sound?
If it is the latter then you can just simply use transformer hardware emulation plugins provided your source is a computer - that way you don't need to buy the actual hardware and you will be able to try many different transformer types/models to hear how they colour the sound
This is what I am doing too (tube/tape/transformer/etc. emulation)

Just volume control.

 

[ppataki]

Just volume control.

Well, for volume control there are many other ways (and much cheaper too)
What is your source? Do you have a DAC with a volume control?
You could easily control volume either at the source or with the DAC (or even with the amp if it has volume control)

 

[Mihalis]

This would be to use with a dac/xtc filter without a usable volume control.
Sounds like I ll stick to active.

 

[mhardy6647]

It's got "FRACTAL WIRE" so must be good.

​

The best thing about fractal wire is that you don't have to buy it by unit length, 'cause it's infinite.