TAD tubes?

[Mark]

I was wondering what the findings were on the Tube Amp Doctor premium tubes?

I've only bought a set of 6V6's for my Fender Champ clone, these valves sound okay, but I didn't think it could take the beating a 6V6 takes from a Champ.

On to the links

Mullard style. http://www.tubeampdoctor.com/en/shop_TA ... Tubes_1749

http://www.tubeampdoctor.com/en/shop_TA ... lected_392

The Telefunken description. http://www.tubeampdoctor.com/en/shop_TA ... lected_951

The Faithful reproduction of a Mullard/Valvo GZ-34

http://www.tubeampdoctor.com/en/shop_TA ... lected_951

Okay this is pitch, what are the findings you've experienced?

[Littlewyan]

I've used their EL34s and was very impressed. Very closely matched and sound great in my Trainwreck Express. I'm definitely using them for all future Power Valves. As for Pre Amp Valves I use JJ or Tung Sol, not tried TAD.

[sepulchre]

Unless you're looking for NOS tubes, JJ's 6V6 is the toughest I've found. In fact I've seen specifications that say something like "the max ratings are (blah blah) unless you're using JJ's." Mind you, this is only for their 6V6 tubes, but I like JJ's in general.

[Stevem]

So your Champ clone is push pull class A, or parallel single ended?

Just so you know the most stress full time for a tube be it a preamp tube which are always in Class A, or a output tube run in class A will be when they are NOT passing any signal!
When they are just sitting there powered up they are dropping the full wattage the are biased for across them selves, when they are passing signal if you want to look at the case of the output tubes than they are dropping the load out to the speaker!

[Mark]

The JJ tubes are very tough and I've used the EL-84's, the ECC83 and the ECC803, I thought all of the tubes were a bit thin sounding, this was a good thing in one build, but not so good for my 18 watt amp.

The issue with the Champ is that like all 59 Champs the secondaries are 330-0330vac which means there is 380VDC at the B+ instead of a nominal 330VDC. (I've included a link to the TAD 6V6 specs which shows maximum voltages.)

In the case of my Champ the maximum plate dissipation of 14 watts was exceeded by 2 watts and the screen grid dissipation of 2.2 watts is most certainly being exceeded.

I found after several months of use the TAD 6V6 was sounding a bit rattly and dead seemed imminent, I found once I changed the bias and added a screen current limiter the rattliness went away and tube life appears to have been extended.

http://www.tubeampdoctor.com/images/Fil ... .07.11.pdf

I'm wondering if the TAD pre-amp tubes live up to the hype or they are just another current production tube?

The Telefunken tube could be a real winner in the PI stage for Dumble builders if it lives up to the hype, there are a couple of other tube which claim not to be microphonic, again a real useful tube in the V1 position to an Express or Liverpool builder.

[harleyboy2112]

As far as TAD preamp tubes go, I've used their premium 12ax7 in V1 of a fussy Bogner a customer brought in. It worked great as far as noise & microphonics go. Tone wise I'm not sure, all those high gain amps sound the same to me

[Mark]

Thanks for your reply that is good to know. I had a look at you web page it looks good.