R-Core transformers

[Covenant]

Can any of you clever people tell me why an R-Core is better than a toroidal?:)

[UV101]

I'd also be interested to know the science behind it ;)

[istari_knight]

Cant claim to know the answer but this page seems to argue their case rather convincingly... http://www.custommag.com/products/r-core.shtml

Unfortunately every R-Core I have encountered has hummed & buzzed like a hornets nest.

Toroidals for me any day.

[Covenant]

Cheers James,
Good article. Some experienced designers swear by them so it's interesting to hear a negative view.

[Mr Kipling]

Looking on the 'net they appear to be better at divorcing the device employing one from mains noise and muck. Back in the late '80s/early '90s Technics started using them which was when I first heard about them.

[istari_knight]

The Bose Waveradio uses an R-Core.... Need I say more ? :lol:

http://www.myboserepair.com/images/Wave-CD-open-viewsm.jpg

I'm sure [at least I hope!] if you were to order one from a decent transformer company it would be perfect... My experience is only of commercial products mass produced in China such as Cambridge Audio A3i / Technics SU-A900 + a couple of Chinese DAC's... so they may have been fitted with inferior quality transformers.

[Covenant]

These have been recommended to me from someone who knows his stuff:
http://www.selectronic.fr/selectronic_catalogsearch/results/?q=R-Core

[Rare Bird]

Look it can be the greatest Design Transformer ever but if it aint made properly it's basically not much cop imho..

[istari_knight]

I think you've hit the nail on the head there Andre! Personally I use this company for all my transformer needs http://www.toroidy.pl/

Don't know what the prices are like now but 18 months ago a top spec 500VA potted core w/ screen was 40% cheaper than any built in the UK & the quality leaves nothing to be desired.

[Rare Bird]

Lundahl are good. For excellent priced, excellent quality toroidal trans i choose: Avel Lindberg

[istari_knight]

These have been recommended to me from someone who knows his stuff:
http://www.selectronic.fr/selectronic_catalogsearch/results/?q=R-Core

I would ask where they are manufactured, Would be nice if they are fabriqué en France.

[Mr Kipling]

The Bose Waveradio uses an R-Core.... Need I say more ? :lol:

http://www.myboserepair.com/images/Wave-CD-open-viewsm.jpg

I'm sure [at least I hope!] if you were to order one from a decent transformer company it would be perfect... My experience is only of commercial products mass produced in China such as Cambridge Audio A3i / Technics SU-A900 + a couple of Chinese DAC's... so they may have been fitted with inferior quality transformers.

Is that why they cost so much James?

[Mr Kipling]

The Bose Waveradio uses an R-Core.... Need I say more ? :lol:

http://www.myboserepair.com/images/Wave-CD-open-viewsm.jpg

I'm sure [at least I hope!] if you were to order one from a decent transformer company it would be perfect... My experience is only of commercial products mass produced in China such as Cambridge Audio A3i / Technics SU-A900 + a couple of Chinese DAC's... so they may have been fitted with inferior quality transformers.

Don't get much "gubbins" (technical term there) for your £800.

[istari_knight]

Indeed. I'd be surprised if each one cost a lot more than £20 to produce.

[Ali Tait]

That's about the usual mark up for commercial kit isn't it? :D

[istari_knight]

That's about the usual mark up for commercial kit isn't it? :D

A fool & his money are soon parted, there's a sucker born every minute etc etc....

They fill a niche, purchased by the same people who are happy to pay £4 for a cup of coffee @ Starb*cks IME...

[istari_knight]

... Sorry Jerry this has turned into a Bose bashing thread :D

I have sent a message to that French company asking where the transformers are manufactured.

[Ali Tait]

Anyhow, to get back on track, toroidals are used as they radiate less of an RF field than other types. They saturate very quickly though. R, C and EI cores are better in this respect AFAIK.

[Chris]

I bought 2 R-cores ( 120VR - 9v and 12v secondaries) from Selectronic for my Salas SSLV Shunt regulator to feed a Hagerman Piccolo head amp and they seem fine -(they´re good enough for Salas anyway). They say SHILCHAR on the brass rear mounting plate - India perhaps ?

[UV101]

When you say they are good enough for the Salas shunt regs......................

I doubt you'll find a better performing shunt reg. I have built several and its only size that puts me off them. I suspect if what they say about R cores is true and you are using decent caps in the supply, it will an exceptional power supply.

[Chris]

I was referring to the man himself as I read in the never-ending story on DIYAudio that he uses the same R-Cores.
Yes, indeed, my Piccolo/P10 combination is certainly surprising me all the time. I use a choke power supply to feed the SSHV shunt reg for the valves in the P10 MM circuit, too. I used to think my previous Linto was quiet but this is another level.
Funny you should mention the caps. I used a 10uF 400v Solens in the LV shunt and have just bypassed it with a Russian 600v teflon. How can something which is not in the signal path affect the sound so much ? I shall be looking out for some Auricaps/Black gates when my finances recover.

[6L6]

...How can something which is not in the signal path affect the sound so much?

The PSU and power supply is in the circuit path - all the grounds are tied together at some point.

[istari_knight]

I got a reply, apparently they cannot tell who the manufacturer is.... A little digging on the net shows that you are correct Chris, SHILCHAR transformers as supplied by selectronics are made in India.

http://www.shilchargroup.com/images/9.jpg
http://www.shilchargroup.com/images/12.jpg
http://www.shilchargroup.com/images/11.jpg

[Covenant]

IMHO those photo's give the impression of a quality business. Yes, I know the place would have been cleaned up for the photos but there is nothing to put you off purchasing one of there products.

[Yomanze]

Can any of you clever people tell me why an R-Core is better than a toroidal?:)

Really good post here: http://www.diyaudio.com/forums/parts/41967-r-core-vs-toroid.html#post486553