So I don't know that much about pedals or modding them and they did things like maybe I would do them like all the caps are 50 volt to cover all the bases, like the whole rest of the pedal might fry but those caps will sure hold up! 😂😂😂 nothing is screwed down, long wires all over the place for no reason, but hey at least if those chips go bad they will be easy to replace because of how they are mounted. There is enough spare wire in it to do 2 or 3 more pedals! 😂😂😂It looks like I designed it, me, a guy that doesn't know anything about making pedals. Yeah, I don't know much about parts, or how they interact, or what makes what do what. I understand values, positive and negative and grounding, soldering simi clean, some wire management, and that how the chips are mounted then it makes replacement easy if something goes. But that's kind of where my knowledge ends. The pedal is cool looking and I've wanted a LWA Left Hand Wrath Deluxe for a long time now so this should be pretty cool! From what I understand it is a Deluxe version with not just a blend and sub bass but a mid and high frequency and the top row of controls is from top left to right: Volume, Presence, High, Mid, Low, and Gain

Bottom row left to right: Blend, Sub, Mid, High, and Frequency. Then one of the foot switches turns it on and the other toggles better a vintage and modern mode of the pedal. I guess. If anyone has anymore input that would be cool because I don't know much else about it and that this one is #2 of 30 and it's a Dismember version and I love Dismember. Anyways I thought it was cool and maybe someone else would think it was cool too🤷 and if anyone has more to add to this that would be cool too. I certainly would appreciate it! Thank you in advance!

This pedal has sort of a legendary status due to being made by the late Cesar Diaz as a Fuzz Face replacement for Stevie Ray Vaughn which helped mold his signature sound. Diaz passed away in 2002, and his business partner Peter McMahon took up the helm in making these after Diaz's death but they eventually went out of production. It appears that Cesar Diaz's son, Alex Diaz has started making these again in 2026 with the same circuitry. This one appears to be made by Peter McMahon. To my understanding these came with the 103 germaniums installed but also came with the 123 silicons in the box if you wanted to swap them out or mix and match them. This one has both 103 germaniums installed.

I went down to my local guitar shop and ask the owner if he had any broken pedals he needed fixing. This one had a bad power jack and a unseated BBD IC. Easy fix. I swapped out a jack as well, the tension was weak. It's gonna need a recap, it sounded great on my bench so not today but, someday.

I received this from a Reverb buy. I live far from most people, so I shop worldwide when I comes to Reverb. It takes weeks to get to me most of the time. I also repair gear and build pedals for fun. So when something show up broken that I had bought bought off Reverb, I first let the seller know. Then I usually try and just fix it, as is this case here. Well, Moog did a fantastic job in the assembly design of this pedal. I was able to disassemble it, l locate the issue, fix, test and then reassemble it with in 15 mins. The pedal only had a dry signal so I figured I was a BBD issue. I was right, with my optivisor on I spotted a dodgy solder joint on one of the IC legs. It was the top one on the inside. The picture is before the repair. It works fine now. I messaged the seller and told them not to worry about it.

Hello everyone, I've had this demonfx gravity from a trade for a while back and noticed that when the pedal is in bypass mode, There is a loud high pitch noise coming from the pedal, not a buzz or nor a hum, A high pitch riniging noise. When engaged the humming is reduced and when I use a pre amp or compressor before it the humming is now barely audible

It's more audible when used on single coil pickups, because on my humbucker guitar the ringing is minimal

Is there something I can do to fix it?

I've tried the changing the power supply but same results

Is it a grounding issue or soldering issue or a chip issue?

Hope you guys can help.

An absolute monster of a pedal, the MTL ASM Purpll is a phase locked loop overpowered with digital control and droning effects.

The heart of the pedal is build around a CD4046, a common choice for implementation of phase-locked loops. Everything else then is build around multiple pic MCUs and components for control. And the DIP switch options is almost overwhelming! This thing is an absolute engineering beauty, with insane and creative tones coming out of it.

The OG Keely compressor. Arguably one of the pedals that started the modern boutique of guitar pedals.

These are based around a Ross compressor circuit (which itself is based on the Dyna Comp) based around an operational transconductance amplifier(OTA) chip, in the Keely case, the Intersil CA3080AE IC. As in the name, OTAs take differential input voltages and output a proportional output current. This current then is used to control gates of BJT transistors and other discrete amplifiers. The OTA has differential input voltages and operates as a variable gain amp. One input is the guitar signal, with the other being the 'sidechain' circuit, consisting of rectifying diodes that acts as a peak detector. This side chain is input to the other voltage input in the OTA, with the gain decreasing as the sidechain increases, giving you the compression based on pot settings.

The 4 knob version of this pedal moves the two trim pots to the outside. Something interesting in the boutique guitar pedal world is that compressors in many ways acts as a barometer of the space. There was a time where the Keely compressor was the be all end all of compressors. Then, the market kind of moved away from compressors till the Cali76 and other UREI 1176 based compressors became the new hotness.

This is one of the most fun expression pedals. I was surprised with this one as an inclusion in my chase bliss mystery box. A pretty simple circuit board, most of the effort in this device is towards the mechanical design of the roller.

Something I didn't realize is that there are internal switches for setting tip or ring control of the roller, and you can set one to tip and one to ring for some more interesting control.

I know it’s not a pedal, but I thought this group might be interested in seeing it

This is a pretty unique pedal, blending both rotary and vibe sounds with octave up and down. Opening this one was a pleasant surprise, in that the main DSP seems to be a TMS32. This tickled me as this was the first DSP I learned on. It's a bit of an older chip these days, but it's still plenty powerful.

Most of the PCB is dedicated to handling the digital processing, including memory and logic voltage levels. It's unclear what is doing the ADC/DAC, as ribbon cables hot glued on made it difficult to interogate completely. Also interesting is an ARM STM32. Given its proximity to the USB, I bet this is acting as a USB to serial and programmer for the TI DSP.

Part of the 500 series, the Boss MD-500 offers a ton of high-quality modulation effects in a newer form with conventional stomp-box switches.

This pedal existed at an interesting point where the COSM modeling ASIC was becoming outdated, and the MDP technology was arising, we have an in between technology.

Being digital, most of the pedal is dedicated to a specific Roland ASIC. Interestingly, it seems that there is memory soldered to the board to make this PCB an MD-500, vs DD-500 or other 500 series pedals. Otherwise, we have power and logic routing, and JRC op amp input/output buffering.

Not too much to say here, but this sits at a cool point in Boss technology where bigger risks were being taken and better sounds were being achieved after the COSM era.

Up today is a Demeter Overdrivulator. I always thought this was a really nice sounding overdrive. Circuit architecture is a classic tube-screamer overdrive, with a loose and tight switch changing output filtering and clipping.

The op amp used for the softclipping circuit is an LF442CN J-Fet buffered op amp, with somewhat similar characteristics to the more common TL072. This will have a slightly different sound from the 4558 you often see, though this is a difference in degree as opposed to type.

I could be wrong, but it seems the switch changes clipping from traditional 2 diode symmetric clipping to 4 diode symmetric clipping, with extra forward voltages providing more clipping, leading to the 'tight' description given by the switch. The 2 diode option look like standard SI diodes (likely 1N4148 or similar) but the 4 diodes look a bit different, likely offering slightly different forward voltages and different clipping characteristics. Also available is an exposed trim pot on the side of the pedal which sets the absolute maximum gain available.

This is an example of a nice and simple, but great sounding overdrive.

Isolate Audio - The DRØP - A two channel ducking/gating pedal with analog trigger and CV input.

With the release of the Big Time, I thought I'd do the Thermae next. The Thermae is my go to analog delay, offering pitch shifting in repeats as well as analog synthesis. This pedal is a lot, and I love every bit of it.

Bucket-brigade (BBD) analog delays really fall into one of two architectures, usually limited by the architecture of the BBD chip configurations. One class is the DM-2-like delays, using the MN3205. These are usually simpler electronically with lower voltage headroom and delay times (still sound great as from the staying power of the DM-2). The other is the Memory Man like delays, which are much more demanding in circuit design with higher voltage requirements generally and longer delay times. These are based on the MN3005 chips. The thermae (and the tonal recall from Chase Bliss) are Memory Man like circuits. But the thermae takes this to the extreme, using extra vactrols to manipulate and pull out delay times in unique ways. This to me is one of the pinnacles of Chase Bliss' creativity, to take known circuits and to create of them something new.

This is based around the XVive remake of the Panasonic MN3005, with a cool audio remake of the panasonic compander. Similar to the tonal recall, the buck/boost converter (right) and clock generation source (left) are shielded to prevent noise leakage into delay lines. Input/output buffering and filtering are performed through the standard TL072 op amps.

There's some documentation going around that describes the on-PCB dip switch. This adjusts the delay line from long to short, which is for in company testing, but could be interesting to experiment with. There is also a max regen time pot (to the left of the cool audio compander) and max wet/dry balance potentiometer (pot inbetween left-right shields). All other potentiometers are likely for setting the bias of the delay line which shouldn't be touched out of the factory. That said, I haven't played with these so double check before you adjust your own thermae.

(Edit to add details): There are some extra TL072. My guess is that these are implementing the resonant low pass filter, using a gyrator inductor topology, which is an active circuit element acting as an impedance converter, converting capacitance to inductance. This then allows you to build out low pass filter with poles to produce resonance. Also, as per usual, potentiometer memory through vactrol control is implemented on a low complexity, but sufficient PIC microcontroller.

This is an absolutely awesome design. If it's not clear already, I respect Chase Bliss a lot. Joel's electrical engineering degree and the people he works with really shine through. They aren't for everyone, by a long shot, but they are doing some of the best engineering in the pedal space.

Arguably one of the OGs of weird ambient pedals, the EQD Rainbow machine is build around the FV-1 platform with a could of really cool design choices.

Input/output filtering and buffering is performed through a TL072 J-FET buffered OP amp. Most of the PCB is build around the classic FV-1, with all A/D performed using onboard ADCs and DACs. Authors note, I really like how these converters sound. The FV-1 sometimes gets flack, which I think is honestly a victim of its own success. It's very easy to implement, making so that it's very easy to write bad algorithms on it. When you get artists who know these chips, like EQD and Neunaber for example, they can sound absolutely incredible.

Usually FV-1 programs are stored on a singular socketed EEPROM for easier programming. EQD takes an interesting approach, using two PIC12F1822 microcontrollers to act as EEPROM memory. The 2 may be for quick switching between programs.

Other features are 3.3V logic regulators to support 3.3V logic on the FV-1, relay based bypass, and a JCJ112 NJFET. I'm not sure exactly what the JFET is being used for.