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

Dear all,

I encountered an issue. After replacing the Svetlana with a Tung-sol 6550 Black Plate I experienced sometimes a moment without sound. After some time the sound came back (black-out?). Now my REF3 is dead. I replaced the Tung-sol with the original Svetlana and still no music! I checked everything including connections etc. What can have happened?

Dear all,

I became curious. I acquired 2 NOS Tung Sols Black Plate 1957. Can I exchange without any other "thing to take care off"?
Keep you posted.

Cheers,

Broederen

Hi Guidocorona,

The details of the Tungs are as follows:

Pair of 1957 Tung-Sol 6550 tubes. The tubes were " MADE IN U.S.A." by Tung-Sol and the matching production code is 3225711-3 . The construction is superb with smooth black plates, triple top mount rectangular getters, copper grid posts (killer) and tight metal bases with strong guide shafts. They were tested for gas, leakage and merit on my Eico 667 tester where the 60-80 range is somewhat acceptable. The tubes tested 136 and 136, very strong on the life test and matched.

Cheers,

Broederen

Thanks Guidocorona

I have replaced the Svetlana 6550 with a 1957 Tung Sol. I'm surprised by the difference in sound. I'm not so good in describing but its seems tighter bass, increased resolution and more "punch". And the system is now playing only for a couple of hours.......................

I can imagine that for a company like ARC it is not possible to put these type of 6550's in simply because of costs and even more constraining: availability!

Cheers,

Broederen

Dear all,

After one day (no power on) the unit is now functioning normal again with the original swetlana 6550C. Anyone any thoughts?

Cheers,

Broederen

Hi Elberoth,

You were spot on. Problem was related with the combination of ARC socket and pins of 1957 6550. Issue is now solved.

Cheers Broederen.