Question for EWBrown?

[CpuZapper]

First off, I'm new to the site so Hello all.
I hope to learn as I try my hand at making a ST-35 style amp. My electronics theory is weak but with some help I should be ok.

Question for EWBrown, have you had the time to use the Trafomatic toroidal transformers, if so how do they sound?
Has anyone else tried them?

Suggestions for my project?

I have been thinking a set of Trafomatic transformers might be a good way to go.

I had ordered a set of ST-35 blank boards before I found this site so I would like to use them for my first project, unless this is a bad idea? They have not arrived yet, I would like to use 9pin ceramic sockets for the El84's. What are good ones to mount in the boards?

I read it is a good idea to use a c-354 choke in place of the first resistor in the power supply (R12, 50 Ohm 5 Watt) is this the right spot?

I don't have a c-354 choke so I was wondering if it is the best choice, from what I read 1.5-1.75 Henries is not allot for a power supply filter.
Would a Hammond 193H 5H/65 Ohm/200mA be a much better choice for this job? Will I have to make changes do to the extra 15 Ohms DCR?

I hope others will suggest away as well, what do I need to look at to make my first amp a success.

Thanks, egilbert.

[Shannon Parks]

I think Ed is just in the preliminary stages of the Trafomatic project. Indeed, I've acquired a set of the same trannies from Ed. Their construction is very nice with a sharp looking finish. We'll both be using the Tubezone chassis from Ned. I may use the Russian 6L6GA tubes and a diytube ST70 board with octals wired to it. We will report on performance, but if the build quality is any indication, this looks very promising. :)

[TomMcNally]

I had ordered a set of ST-35 blank boards before I found this site so I would like to use them for my first project, unless this is a bad idea? They have not arrived yet, I would like to use 9pin ceramic sockets for the El84's. What are good ones to mount in the boards?

I read it is a good idea to use a c-354 choke in place of the first resistor in the power supply (R12, 50 Ohm 5 Watt) is this the right spot?

I don't have a c-354 choke so I was wondering if it is the best choice, from what I read 1.5-1.75 Henries is not allot for a power supply filter.
Would a Hammond 193H 5H/65 Ohm/200mA be a much better choice for this job? Will I have to make changes do to the extra 15 Ohms DCR?

The little original ST-35 boards only have a hole where the EL-84 sockets
stick through, they are oversized to allow a little airflow, so any socket
will work. Try to get a ceramic socket with the mounting ears attached,
some of them come with a ring that isn't attached, they won't work
as well.

The 5H choke would be fine, the power supply voltages aren't all that
critical in a tube amp, plus or minus 10 to 20 percent is likely OK.

Good luck with the project.

[EWBrown]

The Trafomatic project is still just in the conception stages, I probably won't get anything materially done until after Labor Day.

THese trannies are just a wild gamble on my part... I've heard good, and nothing bad about them...


I'll be using the metal plate and wood base ST35 chassis from Ned's Tube Zone, it will erquire a little bit of hole drilling to mount the three toroids and pass the leads through the top plate. After that, and some priming & painting, the rest should be pretty simple...

/ed

[CpuZapper]

Thanks guys, any info would be appreciated, I have found little info about the Trafomatic transformers but they do look good.

I will just have to take that leap and try them.