Long cable run from my phono preamp to linestage.

Al, I've got a similar situation going. I'm running a 15 to 20 foot SE run from my phono pre to my linestage. No ground loop or hum problems that I can detect.

The output specs of my ARC Phono Pre 8 are 200 ohms unbalanced; recommended load is 50K-100K ohms and 100pF.

And the input specs of my REF 5 SE are 120K ohms Balanced; 60K ohms SE.

Tom Tutay made custom SE I/Cs for me. I recall he said the I/C capacitance is 19 pF per foot. I guess it would be better if I could shorten the run to 5 or 6 feet. Oh well.

Assuming my I/C capacitance is about 400 pF, what impact would that have on the signal??

Bifwynne.
Your output impedance of your AR P8 being 200ohm is fine to use 20ft of interconnect with, as even if the interconnect was 100pf per foot (=2000pf for 20ft) that equates to a -3db of 400khz which is bat hearing teritory.

Paraneer.
For me to calculate yours with your 5mt of interconnect, I need to know the output impedance of the Pro-ject Phono Box S pre-amp, not the load impedance you've posted. Saying that, I've done a google on this Pro-ject and being solid state, I would guess it similar to Bifwynne above.

Tube output phono stages or preamps and passives would have the big ? on them, with these long interconnect runs.

Audiobrian the OP, needs to post what his phono stage output impedance is to see if he will get 100% sound quality transfer. But it looks like he's missing in action, even though he's the one who started this thread.

Cheers George

George, just an fyi, both of my ARC units are tube. But, aside from the electrical characteristics of the SE I/C, ARC gear is designed to be extremely synergistic with other ARC gear.

Btw, just inserted a DEQX Premate in between my ARC Ref 5 SE linestage and Ref 150 amp. Was a bit concerned about impedance compatibility, but all is well. Little nervous about inserting an artifact in the line signal too. But I think the DEQX benefits greatly outweigh whatever downsides there may be.

Kim and Al are very good mates of mine and operate just around the corner, putting Deqx premate in between anything will never cause damaging trouble even if there is a impedance mismatch.

Your Ref 5 has a 300 ohms SE ouput impedance, they (AR) recommend a minimum of 20k load, and I see no impedance mismatch with the Deqx 50kohm input impedance, and the output of the Deqx being SS should be fine looking at the 300kohm input impedance of the Ref 150.

Deqx don't give an output impedance on their website propaganda sheet, I must let them know to include it, I assume it to be around 50-100ohms.

Cheers George

PS: They (Deqx) just rang me and said the output impedance of the Premate is 600ohm XLR and 74ohm SE.

Cheers George

Bruce & Paraneer, I agree with George's comments. Also, Bruce, I see that ARC indicates for the PH8 a maximum load capacitance spec of 2000 pf, in addition to the "recommended load" spec of 100 pf.

George, thanks for the info on the DEQX. I'm planning to get one also, in a few months.

Regards,
-- Al