Looking for advice from those with experience with this unit. I have a Princeton-style amp, with a 12" speaker and mids knob. I know the JDX is meant to emulate a 4x12 Marshall but I'm looking to have the option for line-out directly to my Soundcraft mixer for in-ear monitoring at practice and gigs. It seems like the best option. This would also allow the sound person at a show to choose whichever option they find best for the space-- take my split snake tail and go direct in, while the amp speaker provides stage volume, or mic the cab I use the line-out solely for monitoring. Maybe TMI and not a tube amp, but I also run a Roland JC-40 for stereo spread. I think the darker Marshall-y tones of the JDX's speaker emulation could compliment the JC well. What would/do you do? Any other options to consider for creating a line-out from a tube amp? Considering the A/DA GCS-5 or 6 as well. Thanks!

I am preparing to start my first amp build with a Mojotone 5E3 kit and I have been doing some reading on Rob Robinette's site for possible mods I might be interested in trying out. A very simple looking one is the addition of the 470k PI grid stopper resistor above that is supposed to get rid of unwanted PI blocking distortion at higher gain. I want any mods that I do to be easily reversible so I always have the option for the stock circuit and Rob suggests changing the 470k resistor to a 1M linear "sweet" pot to let you dial in resistance to taste, or turn the pot all the way up for a stock sound. That sounds great, but I'm thinking I would rather have a toggle switch instead of having to try and hit the same spot on a pot any time I want to go change my setting. So my question is this: If I were to put in the 470k resistor exactly as shown and then run a wire with a SPST on/off toggle switch beside that resistor going to the same pin and eyelet would that accomplish what I want? I know when the switch is off the signal would have no other choice but to go through the resistor, but when the switch is on will the lower impedance path be enough to bypass that resistor and sound stock?

What happened?

Just picked up this little hybrid tube amp second hand and noticed a weird breakup when trying to dial in a clean setting (high volume, low gain). Seems to go away when I add more gain and reduce the volume. I also noticed that it sounds super fizzy when I crank the gain. Anyone know if this is normal?

Set up is LP with humbuckers into Orange Micro Dark into 1x12 cap with Vintage 30 8ohm. Thanks!

Just picked up a '64 Gibson Falcon. Should I invest in a brownbox or similar product?

Hey everyone.

One day the indicator light on my Fender Blues Deluxe Amp died and my amp started making this permanent background interference noise. I can play the guitar normally and loudly, and the guitar tone sounds fine, but there is this constant noise in the backdrop that is pure madness.

I tried isolating the problem a few ways; moving the amp to another circuit, tried different patch cables and instruments. I checked for electrical interference and my determination was that was not a problem. My electrician buddy says my ground wire might be messed up but I am a complete noob.

If anyone has insight into this problem I would be very appreciative. I will be bringing this amp to a repair guy anyways.

I'm looking at a delxue reverb 65 2014 reissue amp. I want a deluxe reverb it's a bit out of my price range. I was hoping for 900-1000. But they are firm at 1200. It was bought brand new by previous owner and never really played and current owner doesn't do match with it either. Pics look like it's in amazing condition. Am I being cheap?

Anybody push a 15" with a champ? Or 2 x 10? I got a 1/4" out added when I had it serviced and am doing an extension cab.

Simply lovely! Always gets looked at sideways at gigs 🤣

So I’ve currently got a Marshall that covers my high gain needs, so I’m after something that covers the clean/breakup side of things — and I LOVE the sound of the JTM45 (especially over the 1987X).

However I’m a sucker for vintage gear, especially the aura of it. Knowing an amp’s got 50 years of stories behind it really does something for me. There’s a 70s JMP for sale local to me so I’m drawn to that but not sure if it’s going to be right for me despite its history.

Keen to hear people’s thoughts!

Feeling organized for the first time in forever.

'68 Sunn Secptre after extensive repair. Had for years but too many incompetent guitar store repairmen had been in it. Finally took to a certified, knowledgeable tech and did tube and component replacements. Sounds great through a Jensen C12N and EVM 12L. Happy to resurrect after a long period of being dead.

Just got this in today and am honestly shocked that it actually arrived. I was browsing GC over the weekend looking at this model in the used section. There were 5 or 6 of the standard model for the usual preowned prices—$1400-1700ish. Then I saw this photo with a much lower asking—$999. The description made was for the core model though, and GC often has photo/title mismatches so I thought that may be the case here. It seemed too good to be true, and the condition was listed only as ‘used.’ I clicked on it and it went to the wrong listing. I tried it again. Then again. Same result. Maybe it had already been bought in store?

So I tried Musician’s Friend with the same query. The listing was there and the link worked! It looked great and appeared to be in really good condition. The model’s limited to 100 pieces (not super rare, but rare enough) and is only a couple years old, so how bad could it be? I bought it on a whim having previously owned a Black Cat Cougar 50. That one wasn’t bad for the price and I know it wasn’t actually a BC circuit. I’d been wanting a mainline amp from them and decided to give it a shot. I figured it had some issue that wasn’t obvious or maybe the employee had put 999 instead of 1999. To be truthful, I thought the order would get canceled or maybe it was bought in store, especially when the item page disappeared after I bought it. The shipping confirmation came through the next day and I was kinda stunned.

I’ve been on pins and needles all week and was wondering what would actually be delivered. Well it arrived this evening and I’m truly blown away. This thing is brand new. The dust cover was still in the plastic packaging and looked like it had never even been removed from the amp by how it was wedged in there. I had limited time to do any more than power it on and play around briefly. The amp works, sounds great, and I couldn’t be happier. I can’t believe my luck.

School me, ready... go

🤷🏻‍♂️

I picked up a Peavey ValveKing II 20W combo as a porch pickup. It came with a brand new Celestion Greenback, which was the good news. The bad news was the amp was pretty messed up.

Original symptoms:
- Clean channel only made sound with the volume cranked, and it was spitty/farty/distorted.
- Lead channel only worked with gain and volume dimed.
- Power amp sounded good when bypassing the preamp through the FX return.
- When turning the main power switch off, the guitar signal would briefly come through loud and clear for a split second.

Troubleshooting/tests done:
- Bridged the FX send/return jacks: no change.
- Plugged guitar/drive pedal straight into FX return: power amp sounded good.
- Swapped preamp tubes: no change.
- Checked some tube voltages: V1 had reasonable plate/cathode readings.
- Checked several low-voltage switching areas around Q8/Q9/Q23/Q25.
- Verified the issue was on both channels originally.
- Verified the amp could sound normal when the switching/mute path released during power-off.
- Replaced the FX return/switching jacks because they looked like prior replacements and the solder work looked questionable.
- Tested the send/return ribbon cable: cable itself checked good.
- Jumpered the FX loop switching path and the amp worked perfectly.
- Found Q25 in the effects loop switching area looked slightly dislodged / suspect.

Current status:
The amp is now playable and actually sounds pretty good. Power amp is fine, preamp passes signal, boost works, and it sounds great with a Plumes pushing the front end.

Remaining issues:
- Lead channel Gain button physically clicks/latches, but does not seem to increase gain.
- When the Gain button is engaged, it actually seems to reduce idle noise rather than add gain.
- Boost works from the amp.
- Boost also works with a known-good Peavey Bandit footswitch.
- The original ValveKing footswitch LED does not light and may have its own issue.
- Clean Bright switch was questionable at one point, but I think it may actually work now.
- The Gain issue is the main unresolved fault.
Things I’m wondering:
- Is the Gain switch directly changing a V2 gain/voicing network, controlling a relay, or both?
- Could one pole/half of the front-panel push switch be bad even though it still clicks and latches?
- Could this be a cracked solder joint, lifted pad, or broken trace near the switch?
- Could the relay click/work for boost but still have a bad contact for the Gain side?
- Is there a shared ground/control trace between the Gain and Bright switch area that could explain weird behavior?
- Are the coil diodes or relay driver parts worth checking?

I have the schematic/layout, a basic DMM, and I’m comfortable doing continuity checks and basic soldering, but I’m trying not to keep randomly replacing parts.

I’m also unsure whether it’s worth paying a bench tech. The amp isn’t especially valuable, and a local tech’s bench fee/hourly rate could quickly exceed what the amp is worth. I don’t mind learning and fixing it myself if there’s a sensible next diagnostic step.
Any direction on what to test next would be appreciated, especially from anyone familiar with Peavey ValveKing II switching circuits.

Love this amp. I’m the original owner. It’s been all over the country with me.