mark iv tweed problem

[creative]

Hi! my problem is when i swich on tweed power i notice huge drop in volume and drive,only with tung sol12ax7(new). when i put stock 12ax7 is function normal. i tried 3 pieces of tung sol in V1. when i play about 10 minutes gain and volume rise slow(only on tweed). is something wrong with my mark iv????

 

[Russ]

Sounds like it is a problem relating only to your Tung-Sol use. It could be that they need more time to completely warmup when in tweed because you said that they do eventually rise. It will be interesting to hear what others have to say.

 

[Boogiebabies]

That's a good point. Normally the plates see between 375 and 425 volts in full power. If the tweed mode cuts 30-40% of the plate voltage, you could be losing 100 to 150 volts. It could be an anmoly in the tube manufacturing. As with most current tubes the quality and quirks can vary from batch to batch. Batch A may have a lower vacuum and is prone to microphonics and Batch B may have a heater flash and higher average gain. Batch C may have lower average gain, thinner glass and the good lord knows about longevity. JJ preamps are a great examlpe. Myles at GT tested a few batches and they were all over the place. You may have found a flaw or issue with the tube. Call the Reflektor plant, speak clear Russian and tell them the problem.

 

[wads3]

I would like to know the outcome of this seeing as I'm seriously considering tung sol's..... How do they sound once they warm up?

 

[Russ]

Call the Reflektor plant, speak clear Russian and tell them the problem.

:lol: :lol: :lol: :lol: :lol: :lol:

 

[creative]

How do they sound once they warm up?[/quote]

better but never at full gain.

 

[creative]

I tried 3 of them,2 regular and 1 with gold pin. :?

 

[Russ]

Those Tung-Sol's might need full power.