Hi, I've just received a refurbished SP-6 back from AR. I bought one used on eBay recently and immediately sent it to AR. They replaced all the power supply caps, the tubes (were original!), and replaced some resistors in the phono section that were causing excessive noise. I received it back a month later. Pretty fast for the audio world I would say! They did not replace the Electrocube coupling capacitors.
I am pleased with the job they diid.
The SP-6B has temporarily replaced the ML#38s preamp in my system. Power Amp is ML#27. I've managed to go through the changes from balanced to single ended without any noise or AC hum pickup degradation. I used a conversion cable I made myself. I tried a Rane BB22 Balance Buddy but in my system there is more noise and distortion than with the conversion cable. I really wanted the BB22 to work. Oh well.
I'm listening to phono now (SL-1200G table, Benz LP-S, homebrewed Cinemax SUT at 10X (470 ohms loading)).
Observations:
1. I had to use the 50dB gain setting (switch on back) to allow me to set the gain pot at about 12 rater than 9:30 with 60dB gain for both phono and digital inputs.
2. ARC uses the Electro Harmonix 12AX7 EH tube in all 6 positions. I asked why and they said it is a good all-arounder tube with very low noise, as needed for the first tube in the phono and line level stages.
3. The sound is....pretty neutral. It is very, very quiet. The lower midrange does have a nice bloom. In stock, I have NOS Mullards from Brent Jessee, JJ, and Gold Lion that I could swap in. I'm interested in how each type will color the sound. I'm looking for a mellow tube sound without bloat. The EH tubes seem OK, but I'm looking for a more tubey sound. I'll listen to the AR setup for a while and then start swapping. The EH tubes could age a bit since they are brand new, except for the burn-in and testing that AR did.
My questions:
1. Any problems with using the 50dB gain rather than 60dB?
2. Do you agree with AR's tube choice?
3. How will the different tube types I mentioned above alter the sound?
4. Is the #27 a good match for the SP-6? Are there better? Doesn't have to be tubes.
Thanks for your assistance!
Kevin
