[brach]

Thanks for taking those tests.
It looks like you need a new fuse. You can get one from us, but you’d probably be better off finding one locally…it’s a pretty generic part. You need to get a 1A, 250V fast-acting (not slo-blo) fuse. I think 15mm is the length, but you can measure that yourself.
Next, your pcb needs some help. But before we get to that let me ask…when you measured the 122V (am i correct to assume AC voltage?) on the switch, when was that? Was it before or after the fireworks? Was it plugged in to the wall when you measured that? It would be helpful to know this before we proceed with the pcb repair
In the meantime you can check out the switch to make sure it is still working correctly. With your meter still on the continuity setting measure between the switch’s middle pin and both the outside pins (one at a time). It should beep while touching one outside pin, but not beep while touching the other. Flip the switch and test again. It should now be just the opposite…it should beep on the other pin now and not beep on the pin it beeped on originally. Let me know what you find (or if this is too confusing).
Good luck.
-brach

[brach]

The wedding isn’t happening until later this afternoon so I have a bit of time right now to help figure this out…
First of all, sorry for the trouble. Secondly, don’t worry…we’ll get this fixed real soon and you’ll have a nice amp to play through. I’m out of state right now so i don’t have an amp in front of me, but we can get started with what i remember.
Thanks so much for the photos. That really helps. The voltages you read seem correct when the amp is plugged in to the wall and the switch is on, but from now on keep it unplugged until we get some more measurements done.
With the meter on the continuity setting (it’s the one that makes a beep when the two probes touch…not the voltage setting) test weather you have continuity between the round pad of P4 and the middle pin on the switch (it should beep if there is continuity). Also check weather you have continuity between either of these points and ground.
Also, check for continuity across the fuse to see if the fuse blew when you saw the fireworks.
Do these tests and let me know what you find.
Good luck.
-brach

[brach]

Thanks for your question.
If the speaker can handle the proper wattage, there is no drawback at to trying it out. How it will sound might be a different issue, and that all depends on the type of 12″ speaker you use. Generally it’s going to sound good if you use a speaker designed for guitar and has a wattage rating of at least 10 watts (or so). 12″ Speakers generally have the potential to sound louder and somewhat “bigger” in the lower frequencies than a 8″ speaker (but that depends on a lot of other factors). Also, something to be mindful of when selecting a speaker is it’s sensitivity. For the Percolator, (it’s my opinion that) the more sensitive it is the better. The speaker is only being pushed by 2 watts, and it’s sensitivity has a lot to do with how many subtle harmonics you will hear. I wouldn’t suggest using a “hifi” type speaker, or any type of speaker with a “whizzer” cone. These types of speakers are designed for low distortion and a much different frequency response than what you’d typically want from a guitar speaker.
Guitar tone is so subjective and it’s always fun to explore new tone territory with other speakers, so i encourage you to try out as many different speakers as you can get your hands on (as long as they are 8 ohm). You’ll find one that really resonates with you!

• This reply was modified 9 years, 8 months ago by brach.
• This reply was modified 9 years, 8 months ago by brach.

[brach]

Thanks for asking…The Percolator has a fairly typical input impedance for an amp (~1M ohm), so interfacing with most pedals is not a problem. Modulation effects (flanger, tremolo, chorus, etc…) sound great, as well as delay effects (reverb, echo, etc…). In fact, one of my favorite things to do with the Percolator is run tremolo and reverb into it (in that order) and crank up the volume to where it just starts breaking up nicely. I could listen to that sound all day. I’m still amazed at the kind of tone this amp can put out at such low volumes. Honestly, I’ve never played the Percolator through an overdrive or distortion pedal…it already breaks up enough for my taste. With the volume at around noon it starts getting a really nice warm overdrive (that only comes from tubes) and that’s better than any overdrive or distortion box that i own. At close to full volume it’s got a good high-gain sound (think Marshall stack) and i don’t feel the need to add any distortion to it…but that’s just my personal preference.

[brach]

The P8R is a great little speaker, but a bit over-priced in my opinion. A very nice sounding 8″ alnico that you might want to try is Weber’s “alnico Signature 8” (not the 8S…it’s harder for the 8S to break up under the Percolator’s output wattage). At nearly half the price of the P8R, i think it sounds as good or better in some cases…https://taweber.powweb.com/weber/asig8.htm

[brach]

We are using the 6AF11…it’s a Compactron with two triodes and one sharp cutoff pentode. It’s definitely not a common tube to use in audio amplification. It was originally designed for video amplification in TV circuits, but we’ve found it sounds great in a guitar amp. I love using obscure tubes in guitar amps because of the unique tone you can get with them, and it’s fun to repurpose something that probably would never be used anyway…there’s not many working tube TV’s around anymore, but there are are plenty of these tubes left.

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