u/Accomplished_Stay127

I'm using Tayda's UV printing service and they have very specific instructions but unfortunately they are not terribly clear for my purposes, because I am printing only in black on a silver enclosure. They mention very clearly that you must use CMYK printing and not RGB but it's not clear what will happen if you try to print white in CMYK.

I have tried to go and turn all the white bits as see-through, so that there is no fill color where the white is if that makes sense. Like, there's just a checkered background thing in hopes that the printer will treat it like there's just nothing there to be printed but I've never done this before so I'm worried that I'm not doing it how they want you to do it.

Or would it make more sense to print onto an all-black enclosure? Come to think of it, I feel like that will look better so if that seems like a better idea lmk.

If anyone who has more experience with this can give me feedback I would very grateful.

I started out with the idea of wanting a pedal that can be an actual pre-amp pedal with a clean channel as well as distortion so clean tones don't sound all flat and dark into a power amp but I also wanted to be able to use it as a regular distortion pedal that can be fully bypassed and this is the final result.

I started out with the pre-amp section of a Randall RG100SC which coincidentally uses a very similar topology to some of the solid-state Fender Frontmans from the '90s. However, I ended up modifying it to the point where it isn't really the same circuit anymore because i wanted the gain pot to be more responsive and the clipping structure to feel smoother. The topology remains similar but not exactly the same.

For the EQ section I basically just stole the exact configuration from the Wampler Triple Wreck, which is a Mesa Boogie Triple Rectifier clone because I like the EQ of Mesa amplifiers and Brian emulated its response quite well.

The other stuff like the switching system and suchlike are evident in the schematic attached. I have the potentiometers, toggle switch, and indicator LED are on the "back" of the board, facing up. Everything that you see in the 3D render is what you would see if you took the back off the pedal. The footswitch and power jack will be jumper-ed since otherwise they'd take up a lot of extra room on the PCB.

Once I order the PCBs and get it built I might record a demo of it. Also, if anyone would like me to make one custom for them I would be delighted and I wouldn't charge much. Maybe I could set up a posting on Reverb. Alternately, you could just build it for yourself since I have attached the schematic.

Also if anyone can figure out what inspired me to name the pedal Buford I will make one for you FOR FREE but I will be very impressed if anyone can figure out my circuitous (pun intended) "logic" behind the name.

For me its undoubtedly The Stand, although i havent read all of his horror stuff. The Shining is a close second, maybe even tied, but theres something disturbingly grim and heavy about The Stand. The Shining is almost purely a story of indescribable evil, but The Stand feels more real, at least the first half. The idea of everyone you know and love dropping dead around you seems so terrifying in a visceral way that evil supernatural beings like Pennywise dont have. I also think Randall Flag is uniquely terrifying because he seems almost human, almost real, like a particularly violent and cruel psychopath, but with an unnatural ability to travel great distances unreasonably fast, and seemingly impossible to outrun, which is all the more terrifying.

Edit: I logic-ed my way through the switching system and it looks like it's just turn on or off different transistors which close one FET while opening the other, so in theory, moving R132 to control Q4 and R133 to control Q3 should do exactly what I want it to do but I'd still appreciate confirmation that this theory is correct.

I have been modifying a Randall RG100SC (not a pedal but pre-amps and pedals are very similar in most aspects) and I've mainly been modding the two different gain channels.

Originally, the rhythm channel was indicated by LED6, which is green, and the lead channel was indicated by LED5, which is red. However, I want the red channel to be rhythm and the green channel to be lead due to the mods I've done. On the footswitch, the 'gain select' switch connects to an LED which turns on when the red channel is engaged and is off when the green channel is engaged. Since green is the lead now, I want to have it configured so that the footswitch LED turns on when the green channel is on, and off when the red channel is on.

At first I thought I could basically just "bridge" R132 and R133 so that R132 connects to the GAIN 1 OFF net and R133 connects to the GAIN 2 ON net. However, I don't understand enough about this kind of switching system to be sure that it won't cause problems and because it's part of a larger amplifier I'm worried that messing with this could damage the power amp and/or the pre-amp.

If anyone has a better understanding of these FET/BJT switching systems work and can explain if my theory works, or if not, how I could make this work or if it not realistically feasible and I should just embrace the jank.

TL;DR: amp pops loudly when turned on, works fine otherwise. Likely due to a repair, replacing two transistors in the power amp because it was not an issue previously. What is the most likely cause and how do I fix it?

While modding my amplifier I accidentally burnt out a resistor in the power amp section which subsequently destroyed the adjacent transistor, an A970. I replaced both the resistor and the A970, along with a C2240 that I broke while figuring out what the issue was (the shorted A970 had made the fuse blow) with the same models. The amplifier works as intended once turned on, as far as I can tell, but makes a loud popping noise when turned on which is a new development - it did not used to do this.

I have some more information about this amp which I think will be helpful. It is a stereo amp, designed with two separate 50 watt power amplifiers that run to the right and left speaker outputs for both 8 ohms and 4 ohms. I'm currently running two 50w 8 ohm speakers, although you can also use two 75w 4 ohm speakers. Because the replacement of the resistor and transistors was only on the right half of the power amp, I have noticed that the popping is louder when a speaker is plugged into the corresponding output. However, there is still an audible, if quieter, pop when just the left speaker is plugged in.

I have done a little bit of research into why this might be and the most likely cause seems to be voltage stabilization issue, which seems to be a common issue with solid state amplifiers. I'm wondering if it has to do with a parameter mismatch between the replaced transistors and the original transistors. I believe this amp was made in the 90s. My main concern is that mismatched components could cause more damage over time, especially if I push the amp harder. So far I've only tested it at bedroom levels but it can get really fucking loud.

I have attached a schematic which is very similar but not identical to my exact amp. Most notably, this only accounts for one half of the dual power amp that I have. I also think this is a 200 watt power amp as opposed to the 50 watts I have, but the structure is basically identical. The transistors in question are Q5 and Q1, the resistor is R9. Notable differences between the schematic and my own amp:

1. 1N4148 parallel C6 with the cathode (-) touching the base of Q5.
2. Q5 is an A970, not a 2N5401.
3. R9 is a 47 ohm 1/4 watt resistor, not 330 ohm 1/2 watt (probably irrelevant).
4. C6 is 68pF, not 100pF (almost certainly irrelevant).

I could provide a picture of the actual amp but I don't think that would be very helpful.

Additional information: this is the on/off switch on a Randall RG100SC guitar amplifier. I have included the schematic on the last slide. I dont see why it would matter which way it was hooked up since its just a simple switch and a capacitor that isnt polarized but I wanted to double check because I dont want to fuck anything up.

Can someone explain to me exactly what this jack is doing when it is or isn't plugged in? I get that jacks can have contacts that touch or don't touch stuff if the cable inserted but I've never dealt this with a jack that has so many pins and I just want to understand what's going on with each individual pin. This technically isn't a pedal but the pre-amp of a Randall RG100SC but I'm having some issues with it and I want to eliminate potential causes. I've also attached the full schematic if that helps.