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My Hot Rod Deluxe went out on me the other night. I gave it a quick glance inside at practice, I didn't have tools on me to get any more involved. No obvious burnt components.

Symptoms:
Low Volume
Distorted signal

Tubes are good and tested. no physical damage. It was running fine, then the volume dropped.

I've got it back at my place, I'll get it cracked open and start poking. If anyone has a link to the schem, that would be awesome. All of my paperwork is still packed up from the move.

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If practice makes perfect, and nobody is perfect, then why practice?

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How were the tubes tested, and were they tested after the amp quit? One tube quitting can give the symptoms you describe, and on occasion can be hard to see any sign of failure.

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tubes are brand new JJ tubes i picked up from eurotubes. I switched out the old ones when the amp went down. Symptoms were identical.

_________________
If practice makes perfect, and nobody is perfect, then why practice?

It hurts me to say this.. but.. follow me on facebook and.. instagram

When you are trouble shooting this sort of behavior the best way is to START with the speaker and work your way backward.

Eliminate the speaker, then the speaker cable (both weak spots on stock FHR amps).

Then proceed to Power tubes and driver circuit.

After speakers and power tubes, your most likely culprit on that amp is any one of several resistors on the power tube board.

REMEMBER TO SAFELY DISCHARGE THE AMP BEFORE YOU GO MESSING AROUND INSIDE.

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Granville Guitars - Guitar & Amplifier Repairs - Custom Effects Pedals - Hand Wound Pickups
http://www.granvilleguitars.com/

cool, thanks for the tip. I'll be screwing with it tonight, i'll post what i find.

_________________
If practice makes perfect, and nobody is perfect, then why practice?

It hurts me to say this.. but.. follow me on facebook and.. instagram

I've found R57 to be dead. It is located just under V3. Is this my culprit?

http://support.fender.com/schematics/guitar_amplifiers/Hot_Rod_Deluxe_schematic.pdf

I measured it out of the circuit, it's definitely at infinite ohms.

Anyone got a half watt 82k 5% they'd first class mail me?

Another quickie, the caps were drained when I went in to drain them, is this normal? I expected them to still have a charge.

_________________
If practice makes perfect, and nobody is perfect, then why practice?

It hurts me to say this.. but.. follow me on facebook and.. instagram

That is one of the splitter resistors.

The other one should be 100k R58.

Replace that one as well.

Also, when I open these up at my shop I replace the screen grid resistors (470 ohm 1watt) with 5 watt "salt lick" resistors.

PM me your shipping info and we'll take care of it.

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Granville Guitars - Guitar & Amplifier Repairs - Custom Effects Pedals - Hand Wound Pickups
http://www.granvilleguitars.com/

Ah, how far I've come. This Hotrod went up on me and sent me down the path of my first amp build: http://www.byocelectronics.com/board/viewtopic.php?f=8&t=45874

Fast forward, this thing has been in parts ever since UPS ran it over and I couldn't find the problem. No more, today I got off my ass and figured it out. Would you believe a cold solder joint in the channel select relay?

I also fixed a Deluxe with a reverb issue this morning. Driver side of the op-amp was dead, I don't believe I've seen one half fail before. Popped in a tl072 and it was as right as rain.



I also changed out the caps in june of '13. Glad I'll finally get to see a return on that investment.

_________________
If practice makes perfect, and nobody is perfect, then why practice?

It hurts me to say this.. but.. follow me on facebook and.. instagram