Tube Amp Archive

I had a similar problem with mine, I have the Ceriatone with the Heyboers and upgraded caps.
Mine turned out to be a Bias issue. After the headroom dissappeared I had the Bias measured and it was at 54ma .
Had it fixed and the Head room came back

Rooster, Physically the plate structures are similar with a few small differences. The TADs look to have welded plates whereas the Saratovs have a crimped plate. The getters and fins look to be the same. In size the Saratovs are approx 1/4 inch taller (bottle) and have thicker pins. As to tone diffe...

Rooster, thanks mate...
I put a set of Philips in after the TADS, I like them a bit better. I also have a set of Saratovs on the way which I will probably use on a day to day basis and keep the TADs for backup, save the Philips for a rainy day.

Well I got her back from the tech today, with 2 replaced sockets and a fresh set of TAD's. There was some bias issues (50ma) :shock: I must say it sounds quite different now but not in a bad way. it now has more head room. It used to break up at around 10 o'clock but now its up around 12 before it "...

It's quite possible that all your tubes are on the edge of red-plating with the high local mains. But we will wait and see. 50mA is way too hot. The amp isn't very old, if there is some sort of component failure I would be surprised. Ian, you could be right the mains is hovering up to 250v at times...

Rooster, you're right. When I had it at home I only had 1 tube plating, the tech reckons there are 2 redplating...
I will reinforce that I want both sockets tested.

The tech rang me today (been busy), looks like a resistor as the bias on 2 of the tubes is around the 50ma mark.....

I had a similar experience a while back, it ended up being an EI 12ax7 that was causing the problems.....

Ian,
Thanks for the feedback.. I did try another 2 tubes and they both redplated in that socket only.
Its with my tech at the moment, he is gonna go over the soldering on that socket and give her the once over.
You're right on the Brisbane power, its all over the place.
Cheers

Cheers mate, I'm on it..........

Guys, Just fired up the Rocket this arvo for a practice and was ok for about 4 secs and the power tube furthest from the Trannys red plated...hmmm Changed the tube for another Saratov and was fine prior to taking her off standby, soon as I flipped the switch the replaced tube redplated immediately. ...

Raven, thanks for the reply.
I went ahead and grabbed it, figured I could flip it if I didnt like it.

The cab turned out to be a great option for the Rocket, kept most of the nice cleans and when driven the bottom end stayed tight.

Another vote for the Saratovs, a lot more happening on the harmonic front than the TADS I tried.
In the pre I have Tungsram, RCA (short plate) and Pre war EI in the PI. Rectifier is Sylvania Fat boy...
I found this combo sounded better with sealed cab when driven but open cab when clean...

Guys, I currently have an open back 2x12 that is ok with the Express but kinda boomy with the rocket. I have played both through a custom 2x12 closed and they sound great. Question, I have the opportunity to buy a Mesa 2x12 closed (horizontal) unloaded at a very good price. Does anyone have any nega...

Hey Mark, gave your suggestions a go.... Wow its not bad at all mate.

I found it tightened the bottom end a bit and you can dial in quite a balanced tone whereas no particular frequency seems to stand out.
Cheers