	CUSTOMER COMMENTS

Here are some comments you have made. We only publish comments with the author's permission.

Hello Brian

I built a Line amplifier with Sowter transformers 9335 and 9041.

Attenuator transformer is a dream, compared with even the best potentiometer.

In the attached image the detail of volume control.

Complete description of the amplifier on my website, at:
http://www.giannicornara.net/pages/page_lineamp.htm

From: Jan Erling Veiset [mailto:]
Sent: 13 December 2007 09:44
To: Brian Sowter
Subject: Re: FW: 1036 Jan Veiset

I'm now testing the unity amplifier and the trifilar transformer performs very well. The amps are basically built from the attached revision of the schematic and the front end is a common cathode + split load phase inverter based on E80CC.

Working conditions are 260V B+, 190V Bg2 (regulated) and –90V for the negative rail. The amp runs near to class B, biased with 4 x 10mA in the output stage. Max power output was estimated to be about 30W and I measure the onset of clipping at ~15Vrms into 8.2R (~28W)

Global feedback is kept low, about 10dB, but there are no problems to apply more feedback to get even better technical results. Personally I am not a big supporter of global NFB, but used in proper amounts it does good things.

With feedback there was no major peaks or dips in the frequency response. There was a small, low Q peak at ~100kHz (+0.8dB) but with 24pF in parallel with the feedback resistor the response turned out to be straight as an arrow up to 100kHz.

All in all, this project ended up with the best frequency response I ever have seen in a tube amp with output transformer. Thank you for superb transformers!

Just to let you know I installed the TVC today and the results are superb. This is like changing a major component in the system! The most obvious difference is the ease of the sound, the complete lack of hardness, grain, and edge, even on CD. I was already using a high quality Grayhill attenuator with Holco resistors, in a shunt arrangement in my passive, but your transformers have transformed the sound (sorry! but it's true...). The naturalness, dynamics and liquidity (not just in the midrange!) of the sound are staggering. And when things get loud, the sound does not harden or change, it just gets loud...

In my opinion every serious audiophile should hear and buy these TVC's, because a resistive volume control adds so many deleterious artefacts and subtracts so much subtle information, this is so blatantly obvious now. I am overwhelmed by the change. I expected a subtle improvement, not a transformation and huge improvement in sound in an already very high end system.

Mike Kontor
NotePerfect Loudspeakers
158 Galatea Road
Scarsdale
Vic 3351
Australia
tel (03) 53428866
www.noteperfect.com.au

Date: 3 September 2007 13:07:00 BDT
To: Brian Sowter <brian@sowter.co.uk>
Subject: 6AS7/6080 push pull output transformers

Just a note to say I installed the push-pull output transformers on Friday. They provide the perfect finishing touch to the retro 50s style 6AS7 amplifier I have been working on for the past couple of months.
There are a total of 5 pieces of Sowter ironware in this amp. A size P custom mains transformer, a pair of 3575 isolator/balancers on phase splitting duties and the pair of custom output transformers

What can I say? The output transformers have replaced a pair of Hammond 125Ds and have taken the performance of this amp to another level entirely! To talk about veils being lifted and instruments appearing from nowhere would be to fill this email with cliches. But it's perfectly true. Most people would be satisfied with this but even better is the full-bodied, clean, dynamic and effortless presentation these transformers give. No congestion at higher levels and zero listening fatigue.

From: Luca Sfarzo [mailto:luca.sfarzo@fastwebnet.it]
Sent: 31 March 2007 21:49
To: 'Brian Sowter'
Subject: R: info about Sowter 8055 and Benz ACE cartridge

I am writing you this email after having bought some time ago (about 2months) a par of 9570 and after having put them to play for about 80 hours in a World Audio Desing Phono II DIY pre-phono.

I have to say that it has been a very very fine choice buying and playing your amps; They are stepping-up a Benz ACE/SME3009S2 (rewired)/TD160 LP machine and the sound is really detailed, clear and, above all, they allow the system to give that ?live? sensation of being just in front of an orchestra playing the Beethoven 9th Symphony..

Least but not last they are very quiet; they add no hum at all and I find that it is a very remarkable feature.

Next step could be trying some sowter transformers in my wad kat6550 power amplifier...not so far in the future.

I just installed the new transformer in the RCA BA6A and the unit is working excellently now. I was able to get a perfect balance out of the vari-mu tubes.

Thanks for all your help. I tried to get the original out of the can but gave up on all that black wax goo holding it in there. I ended up using washers to clamp the new one to the edge of the empty hole in the chassis where the original was.

Tech It Out Inc.
70 Upperhook Rd.
Rhinebeck, NY 12572
845-876-2653 ext.6
845-594-6171

From: Lukasz Fikus [mailto:lukasz.fikus@wp.pl]
Sent: 26 December 2006 00:16
To: brian last; Brian Sowter
Subject: Re: Sowter DAC transformers

I hate you for what you have done to me. Your transformers are so addictive
that I can't imagine any listening without them. The musical effect is mind blowing.
I use them to connect the DAC chip directly to a high-end tube output.
I tried them in Copland 289 (parallelled BB PCM63K), Shanling T200 (balanced
BB PCM1738), Grundig 9009 (paralelled TDA1541S) and Kenwood 7090 (8 BB
PCM1702 in balanced mode). In all cases the result is phenomenal. Never mind the DC R
differences.

I completed all tests on my guitar amplifier which utilizes a U072 OPT.
I am very very satisfied!! Thanks. The description is on my website

I want to say how pleased I am with the two Sowter 9545 DAC Interface Transformers you supplied me with.
I have fitted them to a Denon DVD-2900 player with the following modifications.

c) Added an extra Burr Brown DSD1792 DAC to convert the main two channel digital audio signals.

d) Used the two Sowter 9545 transformers to provide a new two channel audio output from the new DAC. The circuit is basically that of the DAC Passive Output Stage described at www.raleighaudio.com. I have added some circuitry to reduce the DC through the transformer primaries.

e) Added a new analogue analogue power supply with Walt Jung super regulators to feed the analogue supply pins of the new DAC and the DC reduction circuitry. The DAC design described at www.tentlabs.com was useful here.

The sound from the modified player has improved dramatically. So dramatically in fact that I have had to change my ideas about the audio sound quality available from digital sound sources, especially penny plain CD. Vinyl disc replay now seems a poor relic from the past.

Hello Ruth,

Just to inform you that the parcel has been delivered.
Thank you very much indeed for your immense cooperation on this rather small order.

Its been a great experience dealing with SOWTER.Very few companies can manage good quality andbang on time delivery these days.

From: y.mahe [mailto:yannig.mahe@gmail.com]
Sent: 07 September 2005 12:14
To: Brian Sowter
Subject: message from Yannick Mahé about 9395 attenuator

Hello Brian,

I tested the 9395 "step up" attenuator connected directly on a AD1853
convertor. ( on the +12dB tap ).
I  connect it on a biamp high sensivity system ( the Grégoire Marlot
system, a very audiophile friend ).
A 38cm Supravox field coil bass speaker with a hybrid amp, and a Beyma
CP850nd 115dB mid/high horn on a 45 triode SE amp.

It sounds really good !  The transparency seems perfect.

So,  the idea is very nice....

best regards

y.

I ordered a custom mains transformer and a pair of plate chokes to my Quad amps.

Your build quality exceeded my expectations and everything was professionally packed!

Quite a bit more of an improvement than expected - missing bass octaves have appeared, previously unintelligible lyrics can now be heard clearly, and my cat no longer feels the need to leave the room when I turn up the volume... Many thanks for an excellent product

I don' t know if you did the transformers all by yourself because they are 200% perfect.

You was talking about decreasing the Freq. characteristic by making the ratio to big. I can tell you, with this quality of transformers there is enough room thanks very much,

Regards to Brain Last (but not least) and Ruth who had so much patience. I have no problem at all if you use the email I sent you, perhaps it has sense to add to it that it was very difficult for us to find someone who has still the knowledge to make this special transformers for pro vintage limiter / compressor because it is very critical.

Just to thank you for the transformers, received bang on the time
advised. They sound good with a few days "running in" and should
improve further with more use I suspect. Better than the James
transformers I've been using for the last couple of months by a
country mile.

I have completed installation of the 8983 and find them to be everything I was looking for. Powerful peaks remain perfectly clean (and very powerful). Bass is remarkable. Following is a note I posted on the SET portion of audioasylum.com. www.audioasylum.com/forums/set/bbs.html

I continue to find the transformer's performance impressive. It facilitates the full dynamic capability of my 2A3 SET amp, making possible playback of orchestral and rock selections that sounded compressed with other transformers.

"It's a little hard to find reviews of the Sowter parafeed transformers, so I'll add to the small list.

I installed a Sowter 8983 in a 2A3 SET. I was able to purchase the 8983 (5KOhm primary) with a single 8Ohm output. I prefer a higher primary impedance than the 2.5KOhm that seems to be prefered by many for the 2A3. Until now I've been using Magnequest parafeed transformers.

I originally had a cobalt Magnequest (2.5KOhm in, 8Ohm out), but never really liked it. The variations in speaker impedance of my RF-7s and Chorus-IIs caused frequency peaks and gaps. I purchased a 5KOhm primary

(1.5Watt) Magnequest and the sound completely smoothed out. Great for quiet stuff, but some compression at higher volumes.

I selected the Sowter because it has plenty of power capacity (about 10 Watts) and the I/O impedances I found so successful with the smaller Magnequest.

The Sowter does indeed handle power peaks much better than the under-sized Magnequest. Extension is very good top and bottom, and detail is fine. I recommend the Sowter to anyone looking for a little more headroom than the 1.5 or 3 Watt Magnequests.

I've kept the Magnequests in the amp for quieter selections and can select either transformer with a switch (speaker cables have to be moved to alternate posts)."

Sent: 14 September 2004 16:53
To: 'Brian Sowter'
Subject: RE: U066 Size
Brian, I thought you would be interested, received the U066(M) and connected it to the tube electronics (2 X KT88) in UL mode with cathode feedback and some overall feedback. After adjusting roll-off and feedback parameters I was able to achieve at 40W +/- 1dB 10Hz to 75KHz and <0.01% distortion at 1KHz with excellent phase margin for stability, we will reduce the overall FB for 0.05% as an added precaution. The square wave response at 1KHz is excellent with minimum ringing and zero overshoot. The transformer is excellent with a smooth rising response out of band. The amplifier is differential end-to-end and each stage was carefully adjusted for distortion.

I just received the 8920 (first I will try with the stereo to mono conversion). I just connected the 8920 to my SRPP 45 SE amplifier . Now I'am listening Turandot with Shutterland and Pavarotti from my turntable, I'm impressed. There are subtle details from the vinyl that where lost. Now I switch to Gould on CD (playing Orlando Gibbons),my words are lost. Another change, to Blandine Verlet plying Froberger, a CD named "Froberger ou l'intranquilite'. Well, my english is not sufficient to express how the sound change, to express how I feel the music. The harpshicord seems to be in my room. Thank you very much for your fast an reliable service. Now it's time to try the 9335. Soon I will order it,

thanks for the help with the info about the transformers! last week i was working on a film set in Belgium and the monitor from the lighting director made a 50Hz hum on the sound lines even after two days he did not want to believe it was his monitor causing a lot of trouble for the sound crew ! with al the transformers i found in the dump and earth lift and battery power and al the tricks ,we end up the week of working day and night it was a hell!!!! and that's why i want to thank you for your quick answer..... this is proffesional! and i apreciate this after a week of..f........ i am happy to see somewhere people take there job seriously!! thank you!! bertje@belgacom.net location sound assistant

Thanks for the mains tx and chokes, received Friday. I got the preamp finished over the weekend but only got as far as electrical checks on Sunday evening; anyway, last night I listened and wow, this beauty is *good* ... very, very good and musical. I know that power supplies are absolutely crucial in valve hifi. This preamp uses two stage pi filtering with the second stage split left/right channels .... hence my somewhat specialised needs, which you met; thank you! Rectification is by television damper diodes (6CJ3) which have *massive* voltage and current ratings, with extremely low voltage drop and 'clean' performance. I'm sure I'll be coming to you for more things in due course.

-----Original Message-----
From: Aristidis Coumpas [mailto:arco@otenet.gr]
Sent: 31 March 2002 19:00
To: Brian Sowter
Subject: Re: AC-ACPWR-110302 MAINS TRANS SPECIFICATION

Dear Brian,

I know it took some time, but here is the result and I tend to believe that your "iron" (as the Americans say...) has a lot to do with the wonderful sound heard through my horns!

I finished my preamplifier using pair 9335s and 3575s and it sounds fantastic! I wanted to share some photos with you. One is attached below and more you can find at:

.........Let me tell you also that I find your 'Neve transformers' absolutely amazing. I built a 1272 and I compared with the original. I did 24 tracks with both of them (2 songs, same one). When it was time to mix these songs, I found that the tracks I did with your transformers were adding to each other really better than the ones with the original Neve. The mix had punch and no 'fog'. Really nice !

From: "Julian" <julian@cactusorchard.freeserve.co.uk>
To: <sales@sowter.co.uk>
Subject: Re: Order quote
Date sent: Sat, 2 Feb 2002 18:33:11 -0000

Dear Mr. Sowter.

The transformers below were used to make my phono amp (you
probably guessed this as I ordered two 8055's!). After some
months of assembly and testing (and the rearrangement of some earths
to minimise output hum) the amp is now complete. There is virtually
no hum at all at the output (about 7 mV peak to peak!). Not bad
as the amplifier will produce 4 volts peak to peak from a 1 mV input
at 1 kHz.

Both the four transformers and the two chokes (choke input power
supply ones at that) are absolutely silent as the grave - not a
vestige of hum can I detect at all. Of course all four transformers
perform exactly as per specification as well.

A very big "thank you" to you, the rest of the sales staff, and
particularly, to the person or persons who actually wound and
assembled the devices. They are truly superb. Without them the
amplifier would not have been as it is. Indeed it may not ever have
come into existence. It is good to know such skill exists.

When next I need some high performance transformers (and I will) I
shall come back to Sowter Transformers.

Your service is excellent and your products without equal.

Yours sincerely.

Julian Cooke - an extremely satisfied customer.

Last week I enquired about the possibility of you supplying some transformer and choke shrouds in order that I might smarten up my old valve amplifier. The shrouds have now arrived, they're a perfect fit and exactly what I wanted. I have been so impressed with the friendliness and good service during my dealings with Sowter that I feel I must write to say thanks. I was beginning to wonder if I would ever find a source for the shrouds as I had drawn blanks with the sheet metal pressers that I had approached, and the response from certain other transformer manufacturers was a curt "We do shrouds for our own transformers only. Goodbye". Your service is all the more impressive given that my order was so tiny and almost irrelevant to your manufacturing. Even your protective packaging for transit in the mail was done very thoroughly. Please pass my compliments to all involved in my little order. You are a great company.

Dear Brian,

I have now installed the 2 8940 output transformers, that I got from you....and I must say that I´m more than very pleased with the sound of them.....I´m so glad, that I desided to buy these trannies from you, and they are as good as you said they would be....thanks so much Brian...

I`m looking forward to buy more of these wonderfull output transformers from you...

What I will do right now is to take my little mic-preamp and do a lot of beta-testing with different engineers, and in different studio`s..here in Denmark....so far It has been tested by Søren Mikkelsen ..one of the top engineers here in Denmark...He has been booked for the next 3 weeks recording one of Dk. top selling pop/rock artists...He will not return the beta ver. of this preamp before He`s done with this gig.....*S*....a lot of the sound comes from your output tranni...I have tryed Jensen, Lundahl trannies, and the 8940 beat`s both...

Thanks so much again Brian....

Best regards

Peter Simonsen. Dk.....

Date: Sun, 19 Dec 1999 19:38:44 +0100
From: "D.J. van de Merwe"
To: sales@sowter.co.uk
Subject: email from Dick van de Merwe

Dear people at Sowter I build 2 Sowter 8347 transformers into my Denon 1000 minidisc-recorder which I also use as digital to analog converter. I am very pleased with the results. It sounds are so much better then with the build-in opamp analog output. My friend didn't believe his ears. What have you done, what have you done?............ Congratulations with such fine product. I will certainly use more Sowter transformers in the future! I am an enthusiastic Tube-amp builder myself.

From: "J. Claessens" <j.claessens@chello.nl>
To: <support@sowter.co.uk>
Subject: Fairchild transformer question
Date sent: Mon, 14 Jun 1999 16:04:26 +0200

...........I also tested the Neve preamp I made with your transformers.
Though we didn't have time to do really good listening tests yet,
we can say we like it so far. I'm very happy there are still companies like yours,
with good old fashioned quality and modern specs.

From: "Graham Tricker" <gt.audio@tesco.net>
To: "Sowter Transformers" <sales@sowter.co.uk>
Subject: For the attention of Brian Last
Date: Fri, 19 Feb 1999 17:06:31 -0000

Dear Brian

This is just a note to say thanks for the transformers. I am very pleased with them. Its really great to deal with a company that's able to provide exactly what I need, taking into account my specific requirements.

Many thanks again. Kind regards

Graham Tricker

From: "Noble, Jonathan, Mr" <013NOJ@cosmos.wits.ac.za>
Organization: University of the Witwatersrand
To: support@sowter.co.uk
Date sent: Tue, 9 Feb 1999 17:58:06 GMT + 2:00
Subject: Greetings from interstage-triode fan, J. Noble, South Africa.
Dear Brian Sowter
Greetings from sunny South Africa.
See how nice your sowter interstage transformer looks on my pp6A3 amp, "Brave Ulysees", at: www.vt52.com, see under the diy section, there are photos and a schematic of my amp. (OPT is from a trashed classic Leak point one) 42 kg to give only 8 stereo watts!!

Your IT is doing a great job! With Brave Ulysees and the Ariel loudspeakers (92 db sensitivity) I get a huge 3D sound. On some recordings I get a height illusion, with sounds that seem to eminate from above the ceiling.

P.S. My friend wants me to build him a pp300B, so I will send that order through to you, hopefully some time this year.

Best Regards
Jonathan Noble
Africa's Biggest Triode Fan
email: 013noj@cosmos.wits.ac.za

From: "Bruno Dal" <brunodal@mail.bip.net>
To: <support@sowter.co.uk>
Subject: 845 Amplifier

Your trannies and chokes work excellent! The big 30H choke works very
well. And the sound from this single ended 845 DIY amplifier is really
fantastic!

From: "MAFRAND" <Dominique.Mafrand@wanadoo.fr>
To: <support@sowter.co.uk>
Subject: 8230 transformer
Date sent: Mon, 24 May 1999 19:01:58 +0200

Hi Brian,
I recently bought a 8230 transformer from your factory.
I am using it as a line input transformer in my power amp instead of a 100
k pot, that is i modified my amp the way i did with my preamp i.e a 8920
transformer instead of a passive stereo-mono converter.
Just great ! The tranny feeds the grid of a 5687 triode direct coupled to
the grid of a 10 DHT itself anode loaded with a 45% permalloy core Tango SE
OPT. The sound is very natural, very transparent, 3-D soundstage, a kind of
a mix of both best aspects of tube and transistor features. Superb. Note I
did my evaluations with a budget CD player, I can guess what it could be
with a high end source...
Bravo for this level of quality ! Keep this good work going on !
Next try will be your 30% permalloy core OPT ...
Best regards,
Dominique Mafrand

CUSTOMER COMMENTS