Audio Research Ref 5 preamp

say I want to tube roll the stock 6550c tube. I have a Tung Sol 6550, is it okay if I drop that in? I just want to make sure because I don't know what 6550c means in comparison to 6550. Also, there hasn't been any post, buzz or reviews on this preamp lately. Any owner impressions to add?

Compared to my old Ref 3 it has tighter bass and plays complex demanding passages more cleanly. I guess I would call it more " precise". To me it was worth it but some might prefer the Ref 3's darker character. - Jim

Kclone - I assume you mean original US-made Tung Sol 6550s, which run fine in ARC power supplies. I also think they sound better there than current Russian tubes do. The original Tung Sol puts out a bit less power than a 6550A or 6550C (35 watts as opposed to 42, I believe), but I don't think there is much question that they were the best sounding 6550's ever made.

yeah, I have the American version. I originally bought them for extra tube for a Cayin KT 88 (was using 6550s in place of the 88s). Okay, then I will drop the Tung Sol in the ARC REF 5. Thanks for the helpful response.