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The "$250" Amp? - 6LU8 Compactron SE, UL

I think the circuit could be adapted to work with KT88s, as well. But with a KT88, I'd be leaning seriously to Tubelabs SimpleSE boards that are available.
 
Been watching this project for a while now, and I'm in.. I've looked at many SE Amps for my first jump into Self Execution, and while checking out Tom McNally's "Darling" Amps I saw the 6T9 which had more a sensible Wattage and led me here. I've used 6U10's in my modified ST70 for 25 or so years now, so the Compactrons also caught my eye.
So now it's time to get on with the basics, and I want to start a Power Supply.. My question now is the Power Transformer. I've already decided on going with a Tube Rectifier, which I've narrowed down to either a 5U4G @ 3A, 5V4 @ 2A or a 5AR4 @ 1.9A. These now narrow down my PT choices...Which would be the best for this Amp, and also future SE Projects?
Either a Hammond P-T272BX with 300V/ 100ma/ 5V 2A, 6.3V 3A ..
Or a P-T270FX w/ 275V/ 150ma/ 5V 3A/ 6.3V 5A. The costs are close enough not to make a difference at this point..
I can only Listen to one Amp at a time, so I would like to be able to use this Iron in more than just one Shocker Project...
...Thanks for your Input...
 
I've done a little Homework and came up with this PS. It seems close, with easy to get components...(Cheap)...Hammond Choke $11, and Motor Run Cap. $8. It can be tweaked closer with a different choke if need be.
Have I overlooked any Major Issues with this?
 
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That would work, but it may be a bit noisy. :(

2 things I'd suggest, up the second cap value to 200uf (maybe parallel another 100uf)
and I would use the choke from Radiodaze (or similar) with it's larger 8H cleaning value.

The scond PT you mentioned would be my choice as well, which looks like that is what
you are modeling. And the use of the 5V4G rectifier is always good in my book as well!

Here's a link to the radiodaze page. (which is listed on the first page of this thread)
http://www.radiodaze.com/RD-transformer01.htm
 
Sure that would work fine, not sure why your having problems with 8H choke an 200uf cap though.

Works just fine for me here. :)
 

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The load is real close to 108ma for a whole stereo amp.

I wouldn't worry about trying to get your voltage exact in the sim, as it's usually a bit
different once you get the real transformer and other parts in the supply, then you can
tweek the first cap value so you end up between say 295 and 305 volts of "clean" DC.

And yes those be the outputs we are using.
 
Anyone looking for speakers to use with this amp and may want to build some there is
the Econowave project in the speaker forum that does very well with this amp, just get
a decent bass cabinet with sensitivity on your woofer in the 90-99db range an your set!
 
Here's another way to use Compactrons...ST70, JJ KT77s & RCA 6U10s....
 

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I've got some of the sockets necessary to make these. I bought a small group of them when the thread started.
 
Well, lets see when they get this all sorted out...For now I'm looking for a 5V4G...Just got 4 RCA 6lU8s from VacuumTubes for a Buck a Pop... They still have 3 RCAs left..With any luck they'll be nice...
 
Hey, Tom.. Thanks for the Heads Up on the Sockets.....
Wheee...This is a Fun Ride on the Compactron Learning Curve....
 
Man I have been itching to see the completed version:thmbsp: Great work guys, I just can't fathom desinging such a thing. And if you end up doing a group buy for parts and such you can most definiantly count me in!!
 
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