Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  
previous: Tom 100w Marshall PT, how do I hook it up in a humble clone -- 8/28/2000 12:34 AM View Thread

Does not Depend On Amp Desing

8/28/2000 3:42 PM
Gil Ayan
Does not Depend On Amp Desing
There is pnly one way to hook up a power transformer correctly, Tom. So, if your tranny needs a full bridge in the Marshall, it will need the full bridge rectifier in the D-clone or whatever other amp you want to build.  
Regarding the wire that goes between the two halves of the first capacitor, you can connect it or leave it unused. The former is supposedly better, but I have used a Marshall PT where I just decided to not use that extra wire and the amp was no noiser than with the thing connected.  
Regarding the center tap for the heaters, once again... use the iron the way it is supposed to be used. You can use the center tap, or use a hum balance arrangement (100 ohm resistors), or BOTH if you'd like. (Yes, I have checked that too, and all three options seem to sound the same to me in terms of hum).  
The only thing I'd say is: whether you are building a Dumble cloner or a Fender, the transformer will be fine. HOWEVER, the Dumble amps usually have "conservative" voltages on the plates of the power tubes (say 450VDC or so), whereas your Plexi iron will generate 500+VDC on the plates. So, that's going to change the sound and there is not much you can do about that. I would encourage NOT using 6L6s with that transformer too, since that voltage is just too high for 6L6s.  
Good luck,  

Tom Thanks for your reply Gil !... -- 8/28/2000 11:07 PM