The Amp Garage

Dude! If you don't know where to find the plate resistors ask yourself if you have any business messing about inside this amp. It's not the easiest amp to work on anyway, but you risk damaging it beyond repair if you don't know exactly what you are doing. Plate resistors are not the only thing this ...

So here is where I am at so far; While the problem(s) are almost constant, the static sometimes goes away for a while, and the power tube shutdown only happens here and there, which may make finding the problem difficult. The static is not a tube problem. If it was V1 the volume control would effec...

Those are a real pain to work on, pcbs are in an odd 3d U shape, so testing things is no fun. If tube swapping doesn't work, I would suspect bad solder joints before anything. Tube sockets, jacks, pots, and jumpers between boards are a good place to start. Just reflow anything that looks remotely s...

Considering the cost of the v.6 over v.3 I'm wondering if I wouldn't be paying for something I'm unlikely to ever need in its full capacity. I think 3+ is more than adequate. I summarized my experience and recommendations a few posts up in this thread. Start reading here: https://ampgarage.com/foru...

Have you tried swapping the tubes out? Describing a hiss, rather than a hum... Swapping the tubes out is the easiest and quickest to check. Not just reseating them, you understand, but replacing them. I notice this is your first post so be sure to check out the safety advice dotted around this site....

Hiya, I'm planning to build a uTracer this year and I'm torn between version 3 and version 6. Just wondering if anyone had experience of both and if you found any real advantages with the version 6 for guitar amp work. I understand there may be some problems with oscillation in v.6 that are not pres...

Triad step-down transformer.
Mouser No:
553-F105Z

No need for fancy NOS parts in a relay transformer. Better off saving your money.

How to find information.

https://ampgarage.com/forum/viewtopic.p ... 622#p45562

The TD's power section is remarkably similar to the 5E3 and if we figure in the interpolated voltages, this is what we get.

The main job of the trimmer below the bias resistor in TD is to tune the tone of the amp. The tail of the TD cathodyne phase splitter is comprised of the 10k trimmer, a 56k fixed resistor and a 33k fixed resistor in series. These three resistive elements have their counterpart in the single 56k resi...

For the sake of completeness, here is the RDH4 entry for the cathodyne: RDH4 - cathodyne phase splitter.jpg You will notice Eq.34a is the source of Blencowe's equation for the effective output impedance. I am inclined to go with this rather than Lanterman's suggested equations. It also doesn't reall...

I found an interesting paper that offers a more accurate mathematical model of the cathode output when it is taken from bottom of the bias resistor. Rightly or not, many of the small signal models for the cathodyne out there, are predicated on the assumption that we want a more or less perfect balan...

I think once you realise the goal is not to get an equal voltage amplitude from the plate and cathode, but to trim it up to get the most differential power from the fundamental it liberates you to think about the tone of the amp in a new or at least different way. That word "differential" has gotten...

Greetings Lads and Lassies: It's been a long long time since I posted here. I've not been in a position to build anything and have been other interests taking up my time. Anyway, there was a time here when someone had access to a lazer printer and was making wooden faceplates for the trainwreck stu...

As previously mentioned then, it's impossible to get an equal voltage amplitude when the cathodyne is unbalanced with a 110k resistor on the plate. It is possible however, if you replace Ra with a 100k resistor. This changes the harmonic distribution of the signal however. Harmonics over 1kHz fundam...