• Hi all, the board is in read-only mode for a couple hours while we migrate to new servers :)

Tung-Sol 6550's - blown up (PIC)! Reliability thoughts?

  • Thread starter Thread starter PM33AUD
  • Start date Start date
Plate voltage pushes 500 on the MOD 50. Example is we only suggested using JJ 6v6's because they had a rating of 500 Volts, where every other 6v6 was lower. Same deal with the Tungs. Their limit is at 500 volts so unless you bias cold they will not give you reliable service.
 
parntz145":1iioe5ae said:
I have used them in many of my Marshall's and never had a problem. I really love the tone of the Tung-Sol 6550. I just ordered a matched quad of them for my 83 JCM 800 and the PV is 468. Is am going to set the bias a 52. You guys have me nervouse now. think they will be ok?
Proably not. Why risk your OT and other components in your amp?These tubes can still sound very good at lower bias levels. It really depends on how much volume you push them at. If you crank up the volume you will still have great tone as the bias goes up tremendously when pushed. It really depends on that. I push my amps when I can and I have seen average bias readings at pushed levels of 150ma per tube, maybe even a little more. The problem comes when you bias higher at idle and then push your amp. You could be driving the tubes too far over what they can handle.Even 1ma at idle can raise your bias floor at volume several ma.You have to find a good balance depending on how hard you push the tubes. If you play at lower volumes then you are safer to bias hotter at idle. If you crank your amp then bias lower. It's a misconception to some degree that the hotter you bias, the better your tone. There are a few other factors that are more important, especially how hard you push the tubes.
 
By me biasing at 52 im right at the 70% mark. I have never had any issues with the Tung Sol's by staying in the 70% range and cranking the amp.
 
Back
Top