R-core transformers in UK

[uncle_leon]

I have been looking for a source of R-Core transformers in UK, without much success - I wanted transformers made specifically for audio use, with extra inter-winding shield and outer magnetic shielding. As I have been unable to find any source that would be able to supply custom units, I decided got in touch with a manufacturer in China and after exchanging a few polite emails, they agreed to make a small run of custom transformers for me.

The prices currently work out at:
- 50VA, Pri 230V, Sec 12-0-12V (2.1A x2) = £40
- 50VA, Pri 230V, Sec 9-0-9V (2.8A x2) = £41
- 300VA, Pri 230V, Sec1 22-0-22V, Sec2 22-0-22 (3.5A x2) = £85 [ie. for a Gainclone]

These are rough estimates as the exchange rate may change and also making a payment may entail some bank fees (I'm investigating this);
the prices do include delivery from China, but if you don't live in Lancashire, please allow for some UK postage.

If there is more people interested, the price will go down as postage is murderous for single units. Well, it's still murderous for multiple trafos, but quite a bit less so 😉

Anyone who is interested, or has a suggestion of a different trafo, please leave me a message in this thread, and I will get back to you asap.

 

[Marra]

I was going to suggest Selectronique in France but there R cores have dual secondaries but aren't centre tapped. Here's the link anyway.

SELECTRONIC ::: L'univers électronique :::

 

[uncle_leon]

Yes, I know of seletronic, they would work out cheaper, but the specification of their transformers doesn't mention any shielding, so I'm assuming it's not included. In my opinion inter-winding shield is an absolute requirement in a transformer meant for audio use because inter-winding capacitance is where a lot of noise gets into the audio system.

Centre - tapped is not a problem actually as you could join two 0-9V windings into one 9-0-9V.

If I don't hear from anyone by the end of the week I will order on my own.

 

[tinitus]

hey, those 300VA are dual mono trafos
each 'only' 150VA

and quite expencive

if you want special 'audio quality', try contact Toroidy.pl
seems very reliable

or if you can find a local firm who builds old style UI-core
those can be very good too

 

[uncle_leon]

Thanks tinitus, I am already using toroids custom made for me by Mr Lachowski from toroidy.pl 😉

While I believe they will be hard to beat in powering a solid-state amplifier, I am not so sure about my CD player and DAC. Toroids have inherently (relatively) high inter-winding capacitance, and even with a shield between windings I suspect they may be letting in a bit too much mains noise for a digital component.

So I decided to try the R-cores and while I was at it, I thought I might as well ask if someone wants to join the order 😉

 

[TheShaman]

I think the Selectronic ones feature a shield.
That's what the yellow wire on the primary side is supposed to be.

 

[uncle_leon]

That's actually well spotted... Now that I looked at the pdf again, it does say "Ecran" on one of the drawings...

The trafos in Selectronic are a lot more expensive than the actual prices I got from the manufacturer (approx 13$ for a 50VA trafo), but the postage is likely to be a lot less, so in the end it may work out cheaper. I'll check it.

 

[h_a]

of their transformers doesn't mention any shielding

They do have or at least used to have one interwinding shield. Pretty well build units IMHO, I liked them!

Hannes

 

[jacco vermeulen]

the yellow wire on the primary side

.

 

[superhkm]

Is this thing over already ? I would like to try two of those 12-0-12, shipped to Norway...

 

[uncle_leon]

Hi, superhkm, my attention got diverted to other things, and I still haven't placed an order (although I'm planning to do so soon), so I could order them for you. Postage to Norway will cost extra - although this may partly balance itself out, because with your transformers included the order will be larger and the price per unit will work out less expensive. Let me know if you want me to go ahead.

 

[syklab]

Hi Uncle_leon,
How's luck with the custom make R-core transformer ?
I also interested in this one,
- 300VA, Pri 230V, Sec1 22-0-22V, Sec2 22-0-22 (3.5A x2) = £85 [ie. for a Gainclone] but with 350-400VA for dual mono.

I also try to look for R-core for CD and GC (just like you).

 

[uncle_leon]

Hi syklab, sorry about late reply, I was away on holiday. I have placed an order for 3 transformers of each type, slightly revised. I am currently waiting for a reply from the manufacturer.

 

[syklab]

Hi uncle_leon,
Hope you have a nice holiday. I am going to order 1 R-Core transformer with 9V+12V for the singaclone from ebay and see how it will perform. I also have been sourcing for the BG in HK. I also took out a few 4.7u 50V from my old tube pre-amp. The difficult one will be the enclosure and a nice CD puck.

Best regards

 

[42001]

Ok, this thread is a bit old, but still: Anyone try the R-Cores allready? What's the verdict?

I see a 500VA can be bought for about €100,00 excl. shipping. That is not bad at all if they are really as good as suggested on different fora.

 

[uncle_leon]

I tried them in my Shigaclone, with excellent results. Audibly better (clearer, more precise sound) than the best toroids. I will try them in an amp soon.