Author Topic: Sowther Transformers  (Read 25664 times)

Offline topround

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Sowther Transformers
« on: June 22, 2010, 02:50:40 AM »
I am beginning my journey for a new preamp, one that will be custom built around the 26 tube.
The entire preamp will be transformer coupled with Tango iron. I had been trying to decide on what volume control to use, leaning to the custom made stepped attenautor with resistors.

But I was thinking of using these Sowter attenuator transformers with OCC wire , it would be like a passive TVC with a full blown gain stage of 26 tubes and tube rectified power supply.

Is anyone out there building an active pre with these types of trannies as volume controls?
Getting more resistors out of the way can only be a good thing I believe.


Mike
System consists of an amp a preamp, 2 speakers a turntable and a phono preamp, Also some cables and power cords and a really cheap cd player.

Offline bpape

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Re: Sowther Transformers
« Reply #1 on: June 22, 2010, 05:04:58 AM »
I'm still toying with the idea of a optically coupled LED based volume control.

Bryan
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Offline richidoo

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Re: Sowther Transformers
« Reply #2 on: June 22, 2010, 05:32:24 AM »
The Sowther trannies look pretty cool, good specs. 2db steps



http://www.sowter.co.uk/transformer-attenuators.php

Offline rollo

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Re: Sowther Transformers
« Reply #3 on: June 22, 2010, 06:57:56 AM »
I'm still toying with the idea of a optically coupled LED based volume control.

Bryan

  I'm with you Bryan. LED baby. Rich check out the Bartolucci trannies for the preamp. Tangos are VG but the Italian Bartoluccis are the cream of the crop. Used in the Wytech Opal.  If the LED thing is not practical. Can be tricky. A Penny and Giles attenuator is the best around. Period. Just consider that too many trannies will roll off the top and soften the transients a tad.
 Me I would keep the trannie output and use a LED for volume. P&G as a second choice.


charles
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Offline richidoo

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Re: Sowther Transformers
« Reply #4 on: June 22, 2010, 07:26:34 AM »
With magnetics, the source and load impedance determines the rolloffs. With 1k input and 100k output (to the transformer) it is only -1dB at 50kHz. Junk CDPs make about 200ohms, and Mike will have a 26 tube following the secondary, that will probably be higher than 100k.

Thanks for the other brands too rollo. I'll check them out. I did see a Sowther tranny for DAC output. I asked my friend Sol if it will work with my Buffalo2 DAC. Thanks for the tip topround.

Hey Mike, did you see this article: http://www.vt52.com/diy/myprojects/amps/26_lc/26lc.htm    Maybe some helpful tips in there for ya.

Offline topround

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Re: Sowther Transformers
« Reply #5 on: June 22, 2010, 02:50:43 PM »
Rich,
thanks for the link I will read it tonite.

The 26 tube has a very special sound, and my friend has figured out how to make it not humm.

He uses copper chassis, and oil chokes and teflon tube sockets and he knows how to implement a circuit.
The result...killer...fanatstic highs and lows....tons of air and inner details and tremendous dynamics, the best preamp I ever heard in my life! The DHT tube sound is pure magic. The small inner details are portrayed in ways that make music oh so interesting. It is liquid acid!!

Charlie I will look into the Bardolucci tranny's. Are they readily available?

Also I am ordering a Sowter tranny for my dac,. Honestly I got tranny's on the brain!!

Mike
System consists of an amp a preamp, 2 speakers a turntable and a phono preamp, Also some cables and power cords and a really cheap cd player.

Offline richidoo

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Re: Sowther Transformers
« Reply #6 on: June 22, 2010, 03:12:06 PM »
Liquid Acid, that sounds like a NJ version of Liquid Ear Sex!   :rofl:

Offline Triode Pete

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Re: Sowther Transformers
« Reply #7 on: June 22, 2010, 04:37:17 PM »
The 26 tube has a very special sound, and my friend has figured out how to make it not humm.

He uses copper chassis, and oil chokes and teflon tube sockets and he knows how to implement a circuit.
The result...killer...fanatstic highs and lows....tons of air and inner details and tremendous dynamics, the best preamp I ever heard in my life! The DHT tube sound is pure magic. The small inner details are portrayed in ways that make music oh so interesting. It is liquid acid!!

Charlie I will look into the Bardolucci tranny's. Are they readily available?


Mike

Mike,
The Bartolucci's are OK but their QC can be questionable. The highest quality transformers are from Tango & Tamura (both Japanese). Also, getting high marks are the ElectraPrints from Jack Elliano (Las Vegas, USA). They produce the ultimate "Big Tone". Check out the Magnequest (Pennsylvania USA) as well as Audio Notes (UK)...

Be careful with microphonics using DHT's in any preamp... My single-ended UX-171A preamp (on my Tannoy system) can microphonic as hell due to the nature / construction of the DHT (really intended as the last output stage of a power amp)... but they are very magical sounding!!!

Hope to see you soon,
Pete
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Offline topround

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Re: Sowther Transformers
« Reply #8 on: June 22, 2010, 05:02:31 PM »
My guru likes Tango, Tamura and Black Art

He is actually hunting for some Tango iron for me as we speak.

'He says  some of the Silk tranny's are very good for some applications.


Magnequest seems to be missing in action, but from what I understand Mike from Magnequest is sick, so getting tranny's from him might be very tough.

The Sowters I ordered are for the volume controls and for my Dac.
mike
System consists of an amp a preamp, 2 speakers a turntable and a phono preamp, Also some cables and power cords and a really cheap cd player.

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Re: Sowther Transformers
« Reply #9 on: June 22, 2010, 08:15:42 PM »
Might be worth checking with Dave Slagel as well, he can wind pretty much anything you can dream up.

http://www.intactaudio.com/atten.html


Offline topround

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Re: Sowther Transformers
« Reply #10 on: June 23, 2010, 06:50:21 PM »
Just ordered Sowther trannys for my Dac and 2 Interstage tranny's for the new input section of my amp based on the 417 tube.
4 trannys for dac (for my dac and a friends) and 2 interstage trannys in mu metal containers

$861 shipped :duh :duh

Hope this works.

Next shipment will be the Sowther tranformer attenuators with OCC copper!

I am going tranny crazy!!!!!!!!!!!

mike
System consists of an amp a preamp, 2 speakers a turntable and a phono preamp, Also some cables and power cords and a really cheap cd player.

Offline richidoo

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Re: Sowther Transformers
« Reply #11 on: June 23, 2010, 07:13:47 PM »
My engineer friend Sol Samet said I'll get 5Vrms into 47k preamp from the ESS 9018 DAC with the Sowther 1:5 DAC tranny.  :thumb:  So I'm right behind you Mike. I'd love to hear your feedback when you get them playing. I like that they can give SE or BAL output too.

Offline Face

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Re: Sowther Transformers
« Reply #12 on: June 23, 2010, 11:53:19 PM »
Did you also check out Audio Note?

Offline topround

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Re: Sowther Transformers
« Reply #13 on: June 24, 2010, 02:43:36 AM »
While Audio Note makes excellent gear and transformers, they are not a transformer company, someone else is winding their trannys to their specs.  Just like their caps are not made by them. Maybe Sowther, probably not though.
Their trans, while very good are very expensive hence the 2nd party markup.
I decided to go to a transformer company to get to the horses mouth as they say, but honestly it was still very expensive. :duh

I read some great reviews on these transformers used in the applications I am going to use them, would others have been better, I don't know, could be like caps, getting a certain flavor of transformer.
I will post my honest reviews of what all these changes do to my system. I am very excited about this new direction.

First up will be the modding of my cd player ,Lector CDP7 Mk 1.
It will have a new clock, and new diodes by next week and I will report if that was a good upgrade or not, or if it ruined my player!
Then when the Sothers come I will install the transformers and see what that does.

I will be very honest, I have no interest in tricking myself into believing something is better, it either is or it isn't.

My guru has a whole different set of mods he would like to do as well, but I want to do it in steps
He would like to change dac chips and also change the tube output to 417 tube and maybe eliminate the tube section altogether. I will see how it goes with the first set of mods and then decide later about going nuts!

System consists of an amp a preamp, 2 speakers a turntable and a phono preamp, Also some cables and power cords and a really cheap cd player.

Offline richidoo

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Re: Sowther Transformers
« Reply #14 on: July 29, 2010, 06:41:44 PM »
Hey Mike, you mispelled Sowter in the topic, so I have been spelling it wrong ever since!!   :rofl:   I finally saw the name in the picture.

Did your iron show up yet? How do they look?

Jensen and Lundahl both have mic trannys that would work for DAC. But Sowter has dual in and out windings. They cost about the same, Sowters about $130 each, Jensens $100, Lundahl somewhere in the middle. Did you ever see any comparisons about the sound quality?
Rich