#40 - #124 PT help

[oatz]

Anyone have any good recommendations for a PT for a dumble #124 or #40? I think Ive read HAD likes the fender twin PT's.

Thanks for any help..ima noob and am just learning the basics of tube amp building. Built several small SS amps and circuits but nothing this powerful, so I'm still a little shakey about all the PT specs such as milliamps on the secondary main leads.

It looks to me that most twin PT's are at about 640v at 500ma, so for now that's what Im kinda aiming for I guess.. or atleast till I understand what the diff in milliamps adds upto..

Thanks in advance

[David Root]

I would suggest you read the Dumble Files before you buy anything, and in particular everything about lead dress in Dumbles. Use the Search function.

These amps are very complex, especially #124, and because they are in relatively small chassis they are highly susceptible to oscillations from poor lead dress. Ask me how I know this.

Magnetic Components iron is very good and very well priced.

[oatz]

Thanks for the input. I'll start studying in the dressing area.

And, i just finished looking at Magnetic Components PT that wasn't to pricey.

Thanks again

[Structo]

You might want to attempt a less complex amp as your first tube amp.

Though many have built a D'Lite or ODS as their first.
I built the D'Lite kit as my first tube amp, but I have quite a few years tinkering with electronics before that.

If you have a good understanding of electronic theory and component operations, you should be able to transition to tube theory fairly easy.

Some people can learn easier than others by reading.
If you are that type there is a book list in the Garage section for good reading.
Some need the hands on type training.
Whatever your method be sure to read up on tube amp safety techniques as there is usually 400 Vdc + inside a tube amp that can bite you hard.

[crbowman]

I used a Magnetic Components JTM45 PT in my 70's style 40ish build. Works great! Used the 5v tap for the relays. Voltage's were a little high at first so you might have to play with the dropping string a little bit, but otherwise worked just fine for 50 watt amp. Wouldn't use it for a #124 though.

[oatz]

Ya my aim is a 50 watt 40ish d amp. But with the way things are looking money wise, I may have to aim a little lower. I just reeeeaaallly like the smooth over drive.