ARC Ref 3: Tung-Sol 6550 in power supply?

I thought that I would resurrect this topic perhaps with a little more pertinence to the later Ref 5SE and in particular with regard to comment made by Ethannn back in 08

" 07-13-08: Ethannnn
I would recommend the (blue label) GEC KT88 for this pre."

I would appreciate any further actual user expearience with regard to substituting 6550 with a KT88 in this circuit, given that they are very close in specification.

I did make inquiries with ARC only to received the standard

" We do not recommend , you will comply "

response .

I fully appreciate that there would be no economic incentive for this consideration by ARC , however that is not quite the same as ~

" Whilst we would not warranty support or be liable in instance of this substitution please find attached our considered opinion on a technical/circuit basis alone "

Ironic and timely that this thread has been resurrected. I am planning to replace the ARC supplied 6550 WE tube in my PH-8 phono pre. The 6550 WE has 2000 on it and its time. Not having read this thread, I went ahead and bought a "modern" Tung Sol 6550.

I realize this thread is about the Ref 3. As stated, I will be rolling the PH-8 PS tube. I'll report back with my reactions. Just thinking out loud -- I wonder if the 6550 PS tube in the PH-8 phono pre makes as much difference as tube rolling in the Ref 3.

Btw, I used to own the Ref 3 and have since swapped it for the Ref 5 and then the Ref 5 SE. I mention this because I think the Ref 3 was and is a **great** linestage. IMO, while somewhat different sounding than the Ref 5 (not SE), both are (were) great linestages. I think the SE upgrade does take the Ref 5 to another level, but I gotta tell ya -- the Ref 3 is a classic.

This OP kinda spooked me about the Tung Sol 6550, so I ordered a 6550 WE from ARC. I should get it in a couple of days. In the meantime, I'm using the TS 6550. I'll swap the TS out for the WE when the WE comes in. I'll report back with reactions.

I like the Sed 6550 Winged Cs better than the WEs in my Ref Anniversary.

Barry, I ordered a SED "Winged C" 6550 from Upscale Audio. Kevin Deal called me after the order was placed suggesting I pick another tube because he wasn't satisfied his current batch of "Winged C" 6550s were reliable. Ergo, the Tung Sol 6550.

I expect to receive the ARC 6550 WE in a day or so. I'll swap it in and report back. In the meantime, I'm using the TS 6550. It works ok.