The Amp Garage

rj - Fake pi - using only half of a normal phase inverter (long tailed pair), using half of a preamp tube. When implemented in a single ended amp, this replaces the normal pi of a push pull amp and acts as a slight gain stage. This works well with a preamp like the express which uses only three gain...

I don't know zambo... That its pretty refined... And sounds off the hook! I have seen quite a few of your projects and I'm always impressed with your innovation. Come on man... Who else could put a speaker in a flower pot and make every one forget that fact when the sound hits? Your projects and pla...

Almost forgot... I will build a full blown rocket before too long. This is just one of those things that is just screaming for my attention right now. It won't be my only rocket. Just a little one!
Tony.

Finally got time to check it out... I checked the electrolytics with my esr meter and they look very bad. Not surprised. Not even going to put power to it. It will be parts. Still worth the $5 though. I see what you guys are saying... and I understand. I would never expect this thing to have authent...

I bought something I think is pretty cool this last weekend... A Crescent TR-673 reel-to-reel tape recorder. I'm pretty sure there is a part missing in the pinch roller mechanism (56)... Don't know if this is really worth a restoration or not. I haven't even plugged it in yet... There is no fuse to ...

Glad to inspire, if at all possible. I have been experimenting with some express preamps with the fake pi. I have had a log of complements on how it works outside of the normal push-pull configuration. BTW... the sozo mustard caps (the regular ones... not the hand-made type) sound great in the ones ...

Very nice looking amp... I have been mulling over a big-bottle SE Express. Very interested in how you warm it up... Could you possibly take some before and after clips. Just curious... what brand of caps did you use?
Tony

Could you give us an idea of the pricing for the cab... I mean drawer?
Tony

Manamp,
Steve had stated earlier in the thread that it was a failed experiment that he had left on the board but not really attached to anything.
Tony

Zippy, To answer your question... I don't know exactly how much gain there is to a Rocket PI... but I do know there is some there. The example I'm typing of is a Trainwreck Express... Since you don't need the PI for a single ended amp, you can use just one half (the top half in this instance) of the...

The first clip has that clean sound that I've been looking for.... Makes me salivate just a bit. I am seriously considering building something similar... like an express with a fake pi mated to a 6L6 single ended pa. This thread has got me thinking that the rocket may be a better candidate. I love t...

Just out of curiosity, how would this amp sound if it had a Rocket pre with the fake pi? Just wondering if you might have tried this already. If so, what is that like. If not, is there any reason why it wouldn't?

Thanks G... I don't mind getting off topic a little, if you want to drop some knowledge on us... Even though the pre is not like the one I want to use, I am still interested in the why and how of the NFB... Btw... Is it also being used as a grid stopper? I think it could be for both. The circuit wor...

Rob - That is odd... wouldn't the 470k resistor and the 4.7k cathode resister combine for a series resistance as a grid stopper for stage 3 input... Maybe there is some sort of feedback being used here. I was more concerned with the power amp and supply sections. It is a great question though... Has...

Thanks for the response. Ok... How about this schematic... [IMG:1024:680]http://i946.photobucket.com/albums/ad304/dorrisant/QWxsZW4gQ2xhc3MgQWN0LmpwZw.jpg[/img] Can anyone try the power supply with Duncan PSU II? When I try this one in particular, I end up with low HT for the preamp section. Too low...