The Amp Garage

I am looking at your power supply wiring. Mostly what looks like 3 wires coming off of one side of standby, and I see no power supply to the first two caps with the other wire running to the standby switch. Double check your wiring there. I might just be looking a the pic wrong or not see the prope...

I am looking at your power supply wiring. Mostly what looks like 3 wires coming off of one side of standby, and I see no power supply to the first two caps with the other wire running to the standby switch. Double check your wiring there. I might just be looking a the pic wrong or not see the proper...

I like Edcor iron---- i'm using an Edcor PT (XPWR109) in my current build (50 watt channel switcher). But this Mag comp OT is one of my favorite OT's of all time--- i've used several in builds/conversions/replacements---- it's one sweet sounding piece of iron, IMO: http://www.classictone.net/40-180...

Oh Steven, if you only knew the depth of the decision you made to start building amps, and the addiction that will soon follow. LOL. You will tweak, find a tone you like and say, wow, I am done. Then in a short period of time you will find yourself in front of the open amp chassis with a soldering i...

Steven got this thing running, and he has been emailing me his opinions of the amp. It sounds like he will need some tips to tweak it and make it his own. I suggested trying a 12AY7 in the preamp. Hoping he will come back and get some input. Thanks for all the help. Great news. Getting the amp put ...

Echosonic? Never heard of them.

+1 on using a Bandaxall TS. The FMV is not a great TS for bass as I am finding out. It is way too sensitive and the treble pot acts as a mid scoop as you adjust it. You can get a good tone out of it, but it is a challenge. You might check out the TS set-up on an old SVT pre-amp it has a neat little ...

Did ya make any progress Steve? I'm curious.

I talked to some other people about this, and the conclusion was that the diode and capacitor supply negative DC to the coil. One side tied to ground the other to -6 DC or more should work the relay. Just bypass the mute circuit, dis-connect the relay and try it again. The heaters to the tubes shou...

I agree, 12at7 for the PI. I think there is consensus on removing the 4th stage, too. And rework your NFB loop. After those are done I would revisit the Choke in place of the inductor/sag resistor. Cool, thanks guys, I have a 12at7 lying around I will give it a try. NFB loop was making the distorti...

The New Steve H wrote:I got the books! I swear! Give me a year or two to digest them!

LOL.

+1

a Blackface PI with a feedback loop and a 12AT7 would give you cleaner tone with tighter bass. You'll get no speaker damping with that open-loop power amp... The Silverface PI with 330K grid resistors and 47K plateloads would also be a good choice; even cleaner and setup better for the 12AT7... I'm...

that dumble schematic looks wrong. I would think a 15k bias resistor would not bias the stage right. Check out the dumbleator first stage: http://ampgarage.com/forum/viewtopic.php?t=12876 They are both pretty similar. The 470k or 1M grid leak won't make much difference. They difference here is coup...

The buffer would be a cathode follower, similar to a send side of an effects loop. Basically, the output impedance of a cathode follower is under 1k depending on the tube type. If you drove the cathode follower from the output of the tone stack, you wouldn't load the tone stack down. As it is you h...

Sorry, three more stupid questions. On the buffer, can I basically use the send side of an effects loop buffer? Would I break the signal from going to the PI and power tubes if the Pre is used? And if I do break the signal from feeding the PI and power tubes, do I still need a speaker load on the am...