ARC sp10 joy and concern...

I finally went and purchased an ARC sp10 via Ebay! It arrived damaged (which happens far too often), but was insured. After repair, my tech is recommending retubing (the tubes test strong, but are original). Thanks to all of you who have shared such good posts on the 'Gon and Audio Asylum (newbie, jafox, bambi, et al)! Have decided to start with new ARC tubes and will work from there overtime.

My problem now is a buzzing (similar to a noisy flourscent lite) coming from the Power Source. I've tried removing the binding post link on the back of the pre, but the buzz persists. It is not heard over the speakers. I think it might be noisy tubes, but am open to other thoughts.

BTW was quite pleasantly surprised to find the 10 is a Mark II (Leonard at ARC was his usual helpful self)! I was also shocked at how great the pre sounded right away - despite the buzz. I'm replacing an ARC sp11 with upgraded phono (Seimens gold pin 6dj8s) and line stage (Bugle Boy 6922s) tubes. Even with its original tubes, the improvement of the 10 over the 11 really shocked me. That's one reason I'm hoping the buzz isn't because of the old tubes!

Am undecided on the fate of the sp11. Until all of the kinks are worked out of the 10, it will be a fabulous back up.

My overall system consists of two ARC D115 Mk IIs (passive bi-amping) with a VPI Scout (Grado Sonata) and Oskar Heil Kithara speakers. ICs are XLO with Cardas on the phono. The speaker cables are Xindak FS1 with which I just replaced my XLO Type 5s. I don't listen to CDs.

Comments welcome!

Hi Dave- If the buzz is from the power supply and isn't heard through your speakers, its probably a mechanical bzz from the transformer. Notoriously difficult to get rid of. Try tightening all bolts holding it down, try putting it on a different circuit, sometimes reversing polarity on AC plug helps. Sometimes nothing helps. Good luck.
Swampwalker is right on - I have a transformer buzz that has come and gone over the years. I think it has something to do with the quality of the power. Right now I have it on a dedicated line and its quiet - here's hoping it stays that way. Anyway, its not the tubes! By the way, if the tubes aren't noisy, and if you like the sound, why change them? The Sovteks you'll get from ARC will be expensive and tonally cold (but dead quiet). Welcome to the antiquarian audiophile group. :-)
From what you describe, I'd say Swampwalker is right. Very difficult to get rid of transformer buzzing--you can try what he suggests but nothing is a sure cure for it. You might ask Leonard at ARC if he has any suggestions. Too bad you probably can't switch the power supplies for the SP-10 and 11!
Yes, It definately sounds like the laminations comprising the transformer which can be heard as an audible hum. Definately worth giving Leonard a call at ARC for his suggestions. The 10 is a very nice pre amp and although not as neutral as some of the SOTA pre amps of today, is not a bad sounding unit. I debated going with an older SP-15 ( 2 chassis affair) last year and asked for some advice. Many,like Jafox, were very helpful and could speak from previous experience with the ARC line. Best of luck with your 10!
HI Dave, I have a D250 that has a slight hum as well. I found repositioning the amp made it go away. my floor was a bit uneven and the amp being a monster needs REALLY solid level surface to sit on.
With the amp on try slightly lifting the handles a bit, the noise may change.
Hope this helps!
Hi Dave, where did you purchase your Kithara speakers and are you happy with them?