Obviously everything is not fine, or you would not hear the incessant humming. I'll take that amp off your hands. MSG me with the details.
Bad filter cap(s) and/or solder joints? Is it still under warranty?
I'd place the power transformer and switch near the IEC connector.
You don't need to worry about anything. The amp isn't going to fall apart or stop working due to a little rust. Short of completely resurfacing, there is not much you can do. Dab some light household oil (LPS, WD-40, etc) on a cloth, and carefully rub it into the rusted areas. Don't get any on the tubes!
I would think pretty much like you described. Probably have to drill new mounting holes for the chassis to migrate it to the bottom. You might want to fill the open leftover holes in the top and sides of the cab. Measure twice (or thrice), cut once!
Not to hijack this thread or anything, but I've never heard of anyone trying to attenuate the post phase inverter signals with a single pot. Are there examples of this? Also, I haven't personally compared, but what would the advantages be of a post phase inverter volume over a pre phase inverter volume? I've read the hype, but all I can discern is that you would be employing more triode overdrive, and less output tube overdrive from which most "desirable" distortion is derived. In other words, you would obtain more triode clipping from the phase inverter, and less output tube compression by attenuating the phases driving the output tubes. I can understand the advantage of utilizing both, but not exclusively post phase inverter.
You could try connecting those speakers in series with each other, and then the two in parallel with the cube speaker. It probably won't damage the amp, since the final impedance will be ~ 5.3 ohms. Just be careful. Doing this will void your warranty, and may damage your amp. If you hear any strangeness, discontinue.
You can wire the output of your smaller amp into the input of your larger amp, but MUST use a resistor (probably ~ 470K) in between the two.

Another (and better, IMO) option would be to connect a microphone to the 30W amp, and place the mic in front of the 10W. I've achieved interesting results doing this with my shitty generic mixer amp. It sounds much better if I use a mic pointed at the speaker of my guitar amp and connect it to the input of a channel of the mixer than connecting the guitar and effects directly to the mixer. The microphone pics up the sounds of the amp's speaker and cabinet, which comprise part of the nice tone you love about the 10W amp. Yes, the bass speaker is not designed to reproduce guitar tones, but experiment and find out what you achieve. Adam Jones of Tool is known to use guitar heads with bass cabinets, and I think his tone is sick.
Searching Google, it sounds like that model has chronic power tube issues. You could try replacing the power tubes (I love the sound of EL84s!

If you feel like taking your life into your own hands (literally), open the chassis and visually inspect the interior... don't touch anything at this time. Looking at the schematic ( I see a 100uF, 500 volt capacitor. A discharge from that through your body would knock you on your ass, if not kill you. If you see anything that doesn't look "right", respond here with what you see. Take some pictures and post them, if you can. You're looking for burn marks, shitty-looking solder joints, blown components, disconnected wires, etc. If you take one look and feel overwhelmed, stop, and call your friendly neighborhood tech. I'm serious about keeping your fingers out of this thing. If you can't discern anything amiss, don't screw around... take it to a tech.
Do you mean no guitar sound, or no sound, period? Do you hear any hiss when you crank up the gain and volume? If not, first and foremost, make sure the wires connecting the amp to the speaker are actually connected to the speaker terminals. If so, sit tight and wait for step-by step instructions from one of us. I have to leave for work, presently.
TS: What do you have in mind, and what is your budget?
I skimmed over this, and think the author did a fine job explaining electronics to people who have little or no experience. I'm not affiliated with this person at all. It's too large to attach, so you'll have to download it:
I can't find the LED in your circuit. SYK is right; a part of the circuit including and below Q1 and Q2 is faulty.
I'm looking for a limited edition flamed maple top charcoal burst Schecter Gryphon in mint/extremely good condition. Willing to pay $400 shipped or trade mint condition Schecter Damien FR with custom stainless rear covers, Tremol-no, and RoadRunner soft case. Email me:
I absolutely HATE the Floyd Rose copy on my Schecter Damien. Henceforth, I will only buy string-throughs or hard-tails. That being said, yeah, it's a balance. I just spent (literally) over an hour replacing the strings on the Damien. I went with slightly heavier than I had on there, but I wanted to tune to drop Bb. Even though the three low strings are thicker, the claw screws required loosening because of the tuning change. The method that works the best for me is: twist the fine tuners to be at mid position. Tune the strings with the head tuners to the desired tuning. Look at the bridge. If it is angling toward the body, loosen the claw screws. Do the opposite if it is angling away from the body. Turn the screws only a half turn at a time. Re-tune the strings. Check the bridge again and adjust the claw screws as necessary. Tune the strings. Repeat until the bridge is parallel with the surface of the body. Tune using the head tuners so that the strings are slightly flat. Lock the nut clamps. Fine tune with the bridge tuners.

A huge PITA, IMO. I use a Tremol-no to lock the bridge into position, since I hardly ever use the bar. If anyone has a charcoal burst Gryphon they're willing to trade or sell, let me know.

The Damien plays great, otherwise, just a PITA to set up.
Fantastic tutorial, blandguitar!
The following tests should be performed while the circuit is powered up.

First, set the meter to read volts DC. Check at each place where the voltage is labeled on the schematic to make sure you have the correct voltage supplies where they should be.

One question... Where is the 4.5 volts coming from? Looks to me like the junction between R4 and R5, but without component values, it's hard to tell. The schematic isn't entirely clear. Do you have a link to the original, or anything?

If all the voltage sources are correct, check to make sure all of the transistors are biased, or turned on. Leave the meter set for DC volts, connect the + lead to the base, and the - lead to the emitter. A properly biased BJT will drop approximately 0.7 volts across the base and emitter.
The 47pF cap is to attenuate the highest "harsh" frequencies. 100pF would essentially cut the attenuated frequency in half, thereby cutting lower frequencies of the top end.
Make sure the bridge is connected to the sleeve of the jack. There should be a wire that goes through the body and is either sandwiched between the bridge and body, or soldered to it somehow.
Troubleshooting by using a screwdriver to induce hum is like a blind person using a stick to find their way to the park.

Make sure the transistor pins are connected properly. If you don't have any other means to test this circuit, build the audio probe, connect it to a speaker, and use it to probe spots in the circuit as you strum your guitar while it's connected to the input and the circuit is powered up. Start at the emitter of TR3 to ensure you have the signal there. If so, move to the base of TR5. If no signal, move to the volume pot wiper. If you have a signal there, that tells you that something is wrong with the lower half of the circuit (the FETs). If you don't, there's something wrong with the clipping part of the circuit. Cut that circuit in half by testing at R20. If there's a signal there, you know the problem is with the tone circuit. Keep on with this method until you find the spot where your signal is missing.

Q1 and Q2, and the circuit below them, are used to switch the effect circuit. If that part of the circuit isn't working, you won't hear anything at TR5.

If you can afford to build something like this, you can afford to buy a cheap digital multi-meter. Check the electrical section of your local hardware store. Most places will have a basic meter for around $10. Being able to measure voltages at different points of your circuit will help immensely.

Edit: I just thought of something while crushing cans With the audio probe, use a high-impedance piezoelectric element earphone. A speaker's impedance is going to be too low to hear anything at certain parts of the circuit.
Pine would resonate more, but given the same dimensions, the difference in sound would be negligible. The selection of speakers will make a bigger difference.
Sounds like a bad connection. #1 culprit: the input jack of the amp. You mentioned that it was loose, and you tightened it. It is almost a guarantee that the connections to the jack broke or became tangled, causing an intermittent connection. This would cause a "popping problem". The only way to repair this would be to gain access to the interior of the chassis, and re-connect in a professional manner (strip wires, solder, etc). Another thing you could try, though less likely, is to completely remove all the tubes and re-install them, making sure they are seated properly. If a tube isn't making proper connection to its socket, it could produce the symptoms you are experiencing. I put my money on a shitty input connection, though.
Trying another guitar through your amp will tell you definitively whether it is your amp or your guitar. If you achieve the same sound with a different guitar, it's the amp. If the different guitar sounds good, it's the wiring job of your guitar. Adhere to SYK's advice. The most likely thing that became screwed up is the last thing that you changed. If your next question is, "How do I fix it?" capture some pictures and post them here.
[quote="And also, how might you wire a 2-tube preamp to run on only one tube?[/QUOTE"]

Disconnect the first tube from the second tube (usually, in a preamp, the second stage from the third stage... two stages per tube). Disconnect the second tube from the third tube or output section. Use an adequately rated capacitor (depending on circuit) to connect the output of the second stage to the grid of the fourth stage or phase inverter or output tube.

Go here:

... and read your eyes out.
Quote by blandguitar
digital delay might be a little hard to do without smd or anything, but i don't really mess with digital myself.

dual triode? op amps?

Okay, so my question is on triode emulation, reading through this i was wondering if putting a large capacitor with possibly a higher voltage rating would somewhat slew a SS clipping stage to make it a little softer since the plates need to charge, or would this only affect the first period(taking from pre-calc last year with sine waves) of the wave?

No. Connecting a "large capacitor" in parallel with clipping negative feedback diodes will look like a conductor to AC (sound) and attenuate the signal. The same thing will occur with post-stage clipping.
If you have low skin resistance, an 85 volt jolt from a capacitor can kill you just as easily as a 450 volt discharge.
Sounds fun! I understand "two valves in a row", but what do you mean by adding a fuzz and booster?
I don't have experience with this amp, but I will tell you that replacing the speaker and preamp tubes will not SIGNIFICANTLY improve the amp. You will hear some subtle changes, especially in frequency response, and perhaps heightened touch sensitivity. I also suggest replacing the EL84s as well. Most commercial amps set the cathode currents conservatively to prolong output tube life, so you shouldn't have a problem. However, if you change the brand of output tube, have it checked by someone who knows what they're doing, just in case.
Technically, if you were to somehow power an effect circuit by transforming and rectifying string vibration, hand motion, etc. (which is a pipe dream), the circuit stops being passive and becomes active. Here's an example of a truly passive reverb effect: play your guitar through a loud amp in a gymnasium. ;-)
IMHO, space-charge tubes sound better than tubes designed for high voltage at lower plate voltages. These schematics are a start, not a complete solution.
Remove the saddle and immerse it in WD-40 or Liquid Wrench. Let it soak overnight. If that doesn't work, you'll have to drill it out with a small drill bit, and clean up the threads with a tap. Fun!
Quote by DLrocket89

TS: tube amp operate at lethal voltage/currents, SS amps operate at the same as your car careful, but it *shouldn't*kill you.

Not entirely correct. SS amps, especially higher power ones, may utilize +-50 volt power rails or more, and might use large capacitors that could be potentially lethal.

Your Fender 15G, on the other hand, is probably fairly safe.
Quote by Les Paul Ell
Are you saying that if I took the LED out of all my pedals and replaced them with either jumpers or diodes (I don't know which), I could improve my battery life?

Don't replace them with anything. The LED is just an indicator. And yes, it would increase battery life.
A 1000mAh coin battery? Go Lithium! Your idea should work, Blackie08. You're right, Kurtlives91, the Ah rating will not increase in series; it would in parallel.

mAh rating stuff:
I doubt it. My V18's chips aren't socketed. Almost nobody sockets chips. It adds cost, and isn't generally advantageous to a manufacturer. Break out the solder wick!
Thanks... and good ideas! I haven't spent much time in the crypt lately. It's been so frickin' cold down there.

On a side note, Hammond makes a lot of small audio transformers. I use a 146N with the 12K5's.

The data sheet link is on the page as well.