10K RIAA - If you can believe it.....

John Chapman · « **on:** 22 Apr 2004, 03:32 pm »

Hello!

This was a post I'd began thinking I'd never make... 10K RIAA's are availiable now. There - I said it.

A long time back S&B made a 600 Ohm RIAA and announced a 10K RIAA. The 600 ohm version has been built into some really great phono stages by a few folks but quite a few guys were hanging and waiting for the 10K version - which was always just a few weeks away from being done. The 10K opens up many more options for input and output tube choices. I had thought S&B gave up. The stuggle was repeatable winding of the much larger inductors needed for the 10K version so that they could be built and they'd match specs from unit to unit. Once again he stuck with it and now can ship 10K RIAA's.

Price is the same as the 600 Ohm version - $400 a pair. Note that this is not a phono stage! It is only one part of a stage and is meant for hardcore diy types scratch building phono stages. I hope someone will do a kit/pre-built version of it before long. I want one myself and I can see that I won't get to it anytime soon!

Many Thansk!

John Chapman
www.bentaudio.com

capo · « **Reply #1 on:** 22 Apr 2004, 06:12 pm »

John,

I am happy for ya that your long awaited product is shipping.

What are the advantages over this S&B approach versus a more standard resistor/capacitor RIAA circuit?

Thanks

Doc Jr 8156 · « **Reply #2 on:** 22 Apr 2004, 07:11 pm »

This is very interesting to me. I am looking hard for my next phonostage to match my NOH. If someone can come up with a kit using this then I'll be very interested. Hpe sooner than later.

rodneyAB · « **Reply #3 on:** 24 Apr 2004, 07:50 pm »

Hi Capo
Whats the output on your cartridge? I've set up the Seduction with the TX 103 for low output cart 0.25. Maybe we could plan a future meet? This 10K tranny module sounds like fun, but I dont think I'm hardcore enough to do it myself...yet
Rodney

capo · « **Reply #4 on:** 25 Apr 2004, 04:34 pm »

Rodney,

I've got a Shelter 501 at 0.4 mv, now into a K&K Phono Stage Kit.

Where do you live?

rodneyAB · « **Reply #5 on:** 25 Apr 2004, 05:11 pm »

Hi Capo
I'm about an hour+ north of the GG bridge. I't be interesting to hear the TX103/Seduction in your system...I'd like to compare Horns too!
Rodney

capo · « **Reply #6 on:** 25 Apr 2004, 05:48 pm »

Rodney,

That sounds fun. I'll PM you with my email address.

Bill

grantg · « **Reply #7 on:** 4 May 2004, 01:04 am »

Congratulations, John! Are there any reasons not to choose the 10k version over the 600R version? Is there greater signal loss through the 10k version at 1kHz? I would think that the larger value chokes would have alot more DCR. Otherwise, a 10k version seems like just the ticket so that you can drive it from the plate of many triodes without resorting to cathode followers or large step-down ratio transformers (killing alot of the gain).

Grant Gassman
Lazy lightning NOS Tubes

John Chapman · « **Reply #8 on:** 4 May 2004, 02:02 am »

Hello!

I don't think there is a downside to the 10K version but I am not that deep into it yet so maybe someone else may have a reason!

As you mention the goal of the 10K was to open up a lot of possible tubes to drive it with. I know the inductors are a lot bigger so I don't expect DCR to be hugely different - not enough to kill a bunch of gain or anything like that. The 10K RIAA has the inductors in one can and then other parts sepearate.

Thansk!

John