where to buy sc947-02

drmike · « **on:** 31 May 2007, 10:26 pm »

where can i buy the sc947-02 transformer?
thanks,
drmike

tanchiro58 · « **Reply #1 on:** 1 Jun 2007, 12:08 am »

You can purchase at Scientific Conversion located in California. Be careful there are two different models one is RoSH compliance (lead free) the other is none. Call or email them to ask for a quote. Good luck.

drmike · « **Reply #2 on:** 1 Jun 2007, 10:33 am »

hey tan,
which one should i use?
thanks,
drmike

tanchiro58 · « **Reply #3 on:** 1 Jun 2007, 04:14 pm »

drmike,

Lead free one costs $16.00 and non lead free is cheaper (I do not remember how much?). Actually you can buy either one to use in US. SC said the lead free is for foreign user since it has to be transported without lead.

Tan

art · « **Reply #4 on:** 4 Jun 2007, 04:52 am »

Aviod the SC SPDIF transformers. Try the Newava ones from Digi-key.

Pat

crooner · « **Reply #5 on:** 4 Jun 2007, 06:55 am »

Why avoid them?

So far they sound great on my Super SB and DAC.

Builder Brad · « **Reply #6 on:** 4 Jun 2007, 12:43 pm »

Hi Pat,

I have also heard an improvement using these SC transformers - what is wrong with them?

Brad

rajacat · « **Reply #7 on:** 4 Jun 2007, 02:33 pm »

Me too! I have the SC tranny installed in my SB3 and I have perceived an improvement in resolution, speed and transparency.

Raj

art · « **Reply #8 on:** 4 Jun 2007, 03:51 pm »

If we are talking about transformers for SPDIF.........

Their coupling is too low. They, along with the idiots at Crystal, seem to have this misguided notion that you need low coupling to prevent noise from getting coupled in.

Too bad that also kills the HF content of the signal, and that is essential to get a good, clean edge.

The other problem........low coupling means low capacitance. Which means high leakage inductance. It is hard to get rid of the effect that has on the signal. Someone like me can design networks to help compensate for it, but you guys don't have all the fancy test equipment to allow you to try.

Bottom line..........go with one that has real tight coupling. The old Schotts...........the cheap imitation one by Pulse Engineering, or the ones Newava makes. Newava may be the same thing, made by ex-employees at some new, nearby location after Schott went belly-up. They sure look like it.

BTW......Crystal are the same idiots that design receiver chips with Schmitt trigger inputs. Another rant for another time. Bottom line is: they do all the worst things that one can do to a SPDIF signal, and have no clue how wrong they are.

Pat

F-100 · « **Reply #9 on:** 4 Jun 2007, 04:21 pm »

Pat,
Do you have the Digi-Key part number for the Newava transformer? I did a search for "Newava" and 5 different models showed up.

Thanks

art · « **Reply #10 on:** 4 Jun 2007, 09:28 pm »

And now I have to look it up.......

S22083. S22160 should also work. A larger core, but not bifilar.

Actually, the best form factor is a combination of the 2. Hard to 'splain..........

This guy knew how to make transformers the right way. Hand-made, right here in good ol' Texas:

http://www.audioasylum.com/audio/cables/messages/19927.html

Probably the only guy I know who understands as much about SPDIF as I do.

(I read the follow-ups.........Jon Risch also knows what he is talking about.)

Pat

tanchiro58 · « **Reply #11 on:** 4 Jun 2007, 10:10 pm »

Quote

S22083. S22160 should also work

I talked to Keith at Newava in South Dakota. He said S22133 (non-capsulated) and S22100 (encapsulated) which are the best pulse transformers are using for audio. I will talk to Todd in Minnesota to quote the price of S22100 models. Anyone is interested let me know. There will be discounted for a large quantity.

http://rocky.digikey.com/WebLib/Newava/Web%20Data/S22133.pdf

Tan

crooner · « **Reply #12 on:** 4 Jun 2007, 10:20 pm »

So, according to Pat, the much lauded SC947-02 is not as great as we thought it was.

I know Parasound and the now defunct Sonic Frontiers used SC pulse transformers on their DACs, stock from the factory.

So, who is right and who is wrong?

Quite frankly, I don't feel like opening up my DAC and Squeezebox and replacing these things. Perhaps for my next Super Squeezebox (MKII) project...

F-100 · « **Reply #13 on:** 4 Jun 2007, 10:30 pm »

Quote from: crooner on 4 Jun 2007, 10:20 pm

So, according to Pat, the much lauded SC947-02 is not as great as we thought it was.

So, who is right and who is wrong?

I have an extra SB3 so I'll try to do an A/B comparison and will let you know my opinion.

rajacat · « **Reply #14 on:** 4 Jun 2007, 10:34 pm »

It would have been great if Pat gave us this info before the group buy and before most of us went to the trouble and risk of installing the SC tranny in our SB's.

Maybe the SB4 will already include a pulse transformer or make it's addition moot.

Raj

tanchiro58 · « **Reply #15 on:** 4 Jun 2007, 10:41 pm »

Quote

So, who is right and who is wrong?

Crooner,

Nobody is right and nobody is wrong. It all depends to your own ears. Every product has its own design. I saw a lot of old CDP and DAC having pulse transformers with a small toroidal ferrite laminate or core wounded by a single or double wire. I just ordered Promitheus SS DAC with an extra silver pulse transformer which it looks very simple. Therefore, I do not need to install another one. Let see how the Promitheus SS DAC sounds.

Tan

crooner · « **Reply #16 on:** 4 Jun 2007, 10:47 pm »

Well.. to my darned ears, the SB and DAC sound a heck of a lot better with the SC trannies installed. I have no doubt there's room for improvement, but I much rather leave them as is. Not worth the hassle. The tiny solder traces might lift after messing with them more than once!

rajacat · « **Reply #17 on:** 4 Jun 2007, 10:53 pm »

I only have the SC tranny installed in my SB3. I have one more that was going to be for the DAC but since there seems to be differing opinions on whether the SC should be installed on both the dac and the SB, I'm going to wait awhile until the dust clears and there is a clear consensus. Maybe a poll is in order.

-Raj

crooner · « **Reply #18 on:** 4 Jun 2007, 11:02 pm »

Yep. Looks like our SPDIF expert arrived a little late to the scene.

I do think the SC stuff is backed up with solid theory and made total sense to me when I read Jon Paul's papers. There's a lot of emphasis on reducing jitter which is the whole point of installing these transformers in the first place.

Even though there are differing opinions, theoretically you'd want transformers at both TX and RX ends. That's what I did and the improvement in sound quality was pretty obvious. I did tie all the grounds and shields to the system's common grounding point which goes to the AC outlet ground. This should have taken care of the noisy ground plane inside the SB, or so I hope!

JoshK · « **Reply #19 on:** 4 Jun 2007, 11:48 pm »

Well I wouldn't get your panties in a bunch over which tx. It might very well be better, but we should experiment to see. There is always something better out there, thus the fun of diy. Pat offers an alternate viewpoint, which should be tested by those who have the curious nature to test.

My opinion is that SPDIF is so terrible to begin with (particularly the transmitters) that anything done to improve it is a step in the right direction.