Tube Amp Archive

I am trying to find a schematic for the 17-11 board that uses the FET tremolo. The only schematic I can find uses the LDR tremolo and it is very different. I have troulbe with some distortion at lower levels on that channel I want to be able to accurately trace the signal.
Thanks,
Fred

I don't typicaly spend the time to build and amp smaller than 30 watts because I have many memories as a kid in a band with a sucky amp asking the drummer and other guitar player to play quieter so I could hear it. I also don't want to haul my gear out to a jam or a gig and be frustrated because I c...

I did find I need a cap to keep ossilation down, I think I'm kinda close to the phase invertor tube. I ended up creating one out of a 1/2" conduit connector with a freeze plug pressed on to the top. I followed up by drizzling epoxy inside to help glue the cap on and I also smeared the inside with a ...

That would have been great if in stock. I think I may have come up with a piece fabricated from a conduit adaptor. Ill post a pic if it works out

I totaly need to go look at my stove!!

Thanks for the replies. I saw all the ceramic stuff, like said I am hoping to find the totaly obsolete sheild (-: . The metal exterior of the tube is grounded so I think it possible that the cap would make connection to it. I have made metal sheilds like shown in the picture and that is not off the ...

I am wondering if anyone knows a source for the metel cap/sheild that snaps to the top of a 6j7 type tube (has grid connection on top). Im am building an amp using this tube and I would like to track one down. I can't seem to find a source. Nothing I can see on ebay or on the rest of the net. Thanks...

Today I measured the new chip amp from pin 5 to the ground pin and pin 7 to the ground pin. In both situations I got a measurement of several kohms. I removed the old chip amp. I then rechecked the inputs and outputs on the board. All checked okay so I installed the chip and it worked correctly. Tha...

Another way is to use a zener on the center tap of the heater coil. (or artificial CT) I did this to drop B+ on an old amp. But I am not sure if there is a zener rated low enough voltage for this purpose. If there are, then get a stud mount zener. If noisy, hang a .01uF cap across it to ground. Cor...

Turns out as Jazz Guitar suggested, pin 4 was not even set up for use. Thanks a lot for the explaination relating to that pin and how to understand the data sheet in referance to it. I pulled pins 5 and 7 out of the board and measured them to ground. I found 11 ohms from one of them to ground and 68...

Thanks for your help so far, I feel like I have a direction to go now. I am going to get after this tonight.

Thanks! I have not yet replaced the chip amp. i generally like to have some evidence prompting me to replace something, not that substituting a known good part offends me in any way, more because I want to learn the most in situations like these. when you said to remeasure pin 6, did you mean pin 4?...

Hey guys, I may have bit off more than I can chew with out some help. I know this is a tube amp forum but hoping someone here has some wisdom to help me along. I am attempting to repair a radio shack PA amplifier using the tda7396 chip amp with no output. I do not have a schematic or currently a mod...