Any good Output Transformers from China?

[Johan Potgieter]

Thanks,

I follow lt cdr data's basics more or less. But I use C-cores (grain-oriented), where I have been told that up to 15K.Gs is OK, but I keep lower. Only I am no longer able to measure distortion since retirement (no longer the work's grand instruments!), but am in the process to get the necessary on my PC. I used RDH p. 211 - 227 all these years with results somewhat superior to calculations. My main concern at present is how the particular C-cores will perform regarding distortion. M5 is standard, M6 is an improvement but at a price. So it is a toss-up.

But these things are getting quite bulky, and compromises appear. For 100W output my just enclosing box measures 13 x 14 cm by 11 cm high. [The core is rated 500W for mains (50 Hz) use.] This is (hopefully!) for < 1% distortion at 20 Hz. Let us hope.

Regards

Edit: Yes, I feared that toroids might give poor winding consistency. So for the time I will stay with C-cores.

 

[Rudolfs1972]

I may go a bit off topic, but I gave the issue a second thought, and, guess what -- I will not by any Chinese transformers.
I do not think many of them know what they are doing, and I do not know the good ones, so it is as good as a lottery.
Then again my salry is paid from the EU taxes -- I just cannot go around spending it on Chinese transformers if fellow Europeans make better ones.

 

[dolphin123]

Hi everyone,

Where can I buy small and cheap tube output transformer in China (5kohm / 8ohm)?
Small size and good price are priority.

 

[soundbrigade]

I bought some transformers from AliExpress. Guess there are quite some companies selling trannies as well as tubes and other stuff.
The one I got: Transformers from this shop: Shop.

Please not the very odd description of transformers - "cattle output transformer".

haven't tried them yet but they will be mated with something like 832, 6V6 or EL84 - haven't decided yet.

 

[dolphin123]

Thanks! I asked them about this.
They have no transformers I need and can not produce for me.

 

[soundbrigade]

Your flag indicates you're from Rzeczpospolita Polska. There's a Polish producer of transformers:
Ogonowski.eu - profesjonalne transformatry do wzmacniaczy lampowych
Lampyelektronowe.pl - Lampy Elektronowe On-Line. Najwi?kszy polski sklep z technika lampow?.
And next door you have Frag Jan Zuerst and a bit further away you'll find LivingInThePast.
I have used transformers from Jan and Danbury (Livinginthepast) and prices for their budget transformers are OK and so is quality.

 

[dolphin123]

Yes, you are right, but they too not offer small transformers
I need the smallest i can buy to tests. Like in Miniwatt N3.

 

[soundbrigade]

Try out Röhrentechnik - www,roherentechnik.de. I bought small SE-transformers for pensize tubes. From LivingInThePast I bought a pair of Danbury guitar transformers for Laney (Valve Transformer VT1576).
Another option are Hammonds 125 series of transformers.

 

[dolphin123]

This roherentechnik site does not work

but I found like this:
http://livinginthepast-audioweb.co.uk/index.php?p=xfrmrvt1417
http://livinginthepast-audioweb.co.uk/index.php?p=xfrmrvt1552

 

[soundbrigade]

Sorry, rohrentechnik.de ...

If the Swedish Post hadn't asked for ridicolous money for transporting a little iron across the Baltic Sea, I had offered you mine Chinese speakers.

 

[seppoa]

dolphin123 asked about good and cheap 5k/8R OPTs:
Where can I buy small and cheap tube output transformer in China (5kohm / 8ohm)?
Small size and good price are priority.
Well, in Poland, Indel has very good transformers for little money, such as
TGL 5/001 INDEL - Transformator: högtalartransformator | TME - Componenti elettronici
I have used Indel OPTs and they are really good, especially for the price. The frequency range quoted is in reality much better.

 

[dolphin123]

Thanks, but still is too big for my tests
As I wrote, I need small transformers like in miniwatt N3

or like that:

I know Indel and another similar polish company

 

[dolphin123]

I had similar transformers but I have no contact with guy who produced this :/
Lampowy PCL86 SE - dolphin123 audio

An externally hosted image should be here but it was not working when we last tested it.

 

[soundbrigade]

Check: Röhrentechnik!!!!

 

[dolphin123]

I sent mail yesterday, thanks

 

[soulmerchant]

The UK has by far the most time-served and experienced audio transformer designers around still in their winding houses. History says it. The drawback is they want too much for their product.......BUT it is good quality.

richj

One could argue that there are just as many decent winders left in Japan. The best of them can't speak more than a few words of english though. Word has it that ISO Tango closed its doors since many were simply getting on in their years and needed a rest...

Ian

 

[soulmerchant]

Of all the designs I've used, the toroid although being best on paper often comes up as one of the worst if pile wound. The winding constructions have to be very well designed by a expert winder. I'm staying with standard EI.

richj

I have made this same experience, but there is something about certain toroids designs have on push-pull...

 

[be.audiophil]

Definitely - there are some cheap Chinese amps with quite good opts (e.g. dynavox vr-70e)

I disagree, especially the Dynavox opt aren´t really good ones. Furthermore you will be able to aquire a good pair of used Dynaco EL34 OPTs or Partridge OPTs that are quite a bargain.

Maybe the Bowei OPTs should be mentioned. Many people are raving for their 2A3 amp and the OPTs used in that amp. But at the end of the day you will get what you pay for

I live in Sweden so Lundahls would normally be a 1st choice but I am rebellious and avoids stuff with too high rating, and besides they look awful and need covers.
Else in Europe cheap Xformers can be found in Germany:
Röhrentechnik
in England
Mike's
and there's an Italian place too:
Elettronica Novarria

Some years ago we did a comparism of several 3,5 k and 5 k output transformes. We tested Lundahl, Trafo Baule, Gerd Reinhöfer, Thöress, Tango and James. Best performance for your money you will get with Lundahl, Trafo Baule and Gerd Reinhöfer. The James transformer is a little bit more expensive but also a quite good product. Tango were best but quite expensive.

In addition you might go for Amplimo in NL or Trafo Ritter in Germany also and there would still be the OPTs made by Arkadi

 

[soulmerchant]

I had similar transformers but I have no contact with guy who produced this :/
Lampowy PCL86 SE - dolphin123 audio

An externally hosted image should be here but it was not working when we last tested it.

These are very small indeed. I have a few small Japan Tomiko single ended OPT's.

Approx. 6cmx6cm footprint with 5cm hight. These sound very good all things considering. Look decent once painted too. 0-1.7k-3.5k into 1-4-6-16 Ohm. They are rated for 10W...

They were quite inexpensive a few years ago when I got them at Akihabara.

Ian

 

[dolphin123]

I have some offers but they are too expensive for me and still I am looking for better price