gtfields13
Well-known member
- Build Rating
I have finished my build of a revised Terrier Review, ProCo Rat copy built on the PedalPCB Muroidea Distortion (2025 update).
Mods
I may have learned a few things since my first build, in which I strictly painted-by-numbers. I breadboarded the circuit before I built it to evaluate alternative Op Amps, and generally see if I wanted to make any more adjustments to the circuit. I did make a few:
1. I built using an OP07DNZ. I tried a bunch of different Op Amps on my breadboard and could hear no difference between the OP07DNZ and the LM308N. I could hear differences with some other Op Amps, but they were pretty much always bad. Using the OP07DNZ also meant deleting C6 (30 pF).
2. I setup asymmetric clipping diodes with 1N914 diodes
3. On the breadboard, when I was tracing through the circuit, I found that the output JFET was too close to ground and would clip before the actually diode-clipped signal from the OpAmp arrived. My mod for this was to bias the Gate by setting a voltage divider between Vcc and Ground, with 1M to Vcc (at the Drain) and 330K to ground.
4. I switched to using SMD JFET, to accomodate #3, and this means replacing the 2N5458. I used a 2N5457 (MMBF5457, actually) with no problems.
Build
After tackling some higher count and density boards, the Rat is a very friendly build with no real opportunity to make mistakes (hello, properly polarized electrolytics). The new PCB with the SMD alternative for JFET was perfect for my bias mod, as I was able to take advantage of the through hole pins to mount my new exta resistor. On the whole pairing up the asymmetric diodes and biasing the JFET went super easy. I also used excessive quantities of flux and my Pinecil iron was up to the task of mounting the SMD JFET without it looking too horrible.
I think this is as clean a build as I've managed, with better grounding, and cleaner wiring. I still have to decide where I want to lift connectors so I can cut some out, while still being able to disconnect from the case. I did hit the connector/wire crimps with a touch of solder for robustness (see below for why).
Design
After my first iteration, which I dropped into the Players Haters Ball, I made a number of changes to the case design. Mostly successful, as the scale changes generally work. I've posted Rev 2 side by side with the original for comparison. I like all of the changes and think it works a lot better, although I still goofed the color fill on text (I think I filled with the RGB of the RDG_MATTE before I set it as a spot color) and this suffers from poor use of fill and stroke in Affinity Design 2.
New Poem
I also re-wrote the bottom poem text. In some ways, I tried to simplify the style to be more doggerel. Having written another 5 or 6 IU have a better feel for the cadence and length I need (plus I was in a hurry the first time to get the case printed so I could see how print settingds looked). I hope you like my update.
Sound
Although I couldn't hear any difference on the breadboard, when I put this pedal side-by-side with the TR-01 I can hear a difference. I suspect that this may be related to my breadboard using the 2N5458, vs. the MMBF5457 in the final build. The changes are all for the better; this version has more range in its tonal variations and is a bit louder (TR-01 needs to go about 10% higher for the same level) - it now goes from completely silent to a mild boost. If I understand the JFET choices correctly, this is a consequence of the MMBF5457 swap.
I have posted real-guitar playing demo with the new pedal. My playing is really bad so maybe "playing" is overstated - I am working to recruit a friend who actually can play guitar competently to help me out with future demos. The setup details are in the link, but this is Fender Strat with Lace Gold single coil on the middle position - all going straight from the pedal into a MOTU 828. I didn't bother trying to cross fade or indicate what controls are changing around, I just chunked some chords and sour-picking to show some of the range from jangly-bright to woofy-chug, but deleted most of the video of my hand turning knobs.
Phido Sound Milestone
I pushed to get this built and put together because this pedal is leaving Colorado after Thanksgiving. Going off to the hands of guitar-playing classmate of one of my boys, I want to start getting builds out and working to see how they perform, how they break, and just get some feedback. My goal is to generate enough interest that I can maybe recover the component costs by making lower-cost versions of mainstream pedals as I fill out the crazy brand idea that's in my headl
As always, thanks for reading through. I appreciate the support from this community!
Mods
I may have learned a few things since my first build, in which I strictly painted-by-numbers. I breadboarded the circuit before I built it to evaluate alternative Op Amps, and generally see if I wanted to make any more adjustments to the circuit. I did make a few:
1. I built using an OP07DNZ. I tried a bunch of different Op Amps on my breadboard and could hear no difference between the OP07DNZ and the LM308N. I could hear differences with some other Op Amps, but they were pretty much always bad. Using the OP07DNZ also meant deleting C6 (30 pF).
2. I setup asymmetric clipping diodes with 1N914 diodes
3. On the breadboard, when I was tracing through the circuit, I found that the output JFET was too close to ground and would clip before the actually diode-clipped signal from the OpAmp arrived. My mod for this was to bias the Gate by setting a voltage divider between Vcc and Ground, with 1M to Vcc (at the Drain) and 330K to ground.
4. I switched to using SMD JFET, to accomodate #3, and this means replacing the 2N5458. I used a 2N5457 (MMBF5457, actually) with no problems.
Build
After tackling some higher count and density boards, the Rat is a very friendly build with no real opportunity to make mistakes (hello, properly polarized electrolytics). The new PCB with the SMD alternative for JFET was perfect for my bias mod, as I was able to take advantage of the through hole pins to mount my new exta resistor. On the whole pairing up the asymmetric diodes and biasing the JFET went super easy. I also used excessive quantities of flux and my Pinecil iron was up to the task of mounting the SMD JFET without it looking too horrible.
I think this is as clean a build as I've managed, with better grounding, and cleaner wiring. I still have to decide where I want to lift connectors so I can cut some out, while still being able to disconnect from the case. I did hit the connector/wire crimps with a touch of solder for robustness (see below for why).
Design
After my first iteration, which I dropped into the Players Haters Ball, I made a number of changes to the case design. Mostly successful, as the scale changes generally work. I've posted Rev 2 side by side with the original for comparison. I like all of the changes and think it works a lot better, although I still goofed the color fill on text (I think I filled with the RGB of the RDG_MATTE before I set it as a spot color) and this suffers from poor use of fill and stroke in Affinity Design 2.
New Poem
I also re-wrote the bottom poem text. In some ways, I tried to simplify the style to be more doggerel. Having written another 5 or 6 IU have a better feel for the cadence and length I need (plus I was in a hurry the first time to get the case printed so I could see how print settingds looked). I hope you like my update.
Sound
Although I couldn't hear any difference on the breadboard, when I put this pedal side-by-side with the TR-01 I can hear a difference. I suspect that this may be related to my breadboard using the 2N5458, vs. the MMBF5457 in the final build. The changes are all for the better; this version has more range in its tonal variations and is a bit louder (TR-01 needs to go about 10% higher for the same level) - it now goes from completely silent to a mild boost. If I understand the JFET choices correctly, this is a consequence of the MMBF5457 swap.
I have posted real-guitar playing demo with the new pedal. My playing is really bad so maybe "playing" is overstated - I am working to recruit a friend who actually can play guitar competently to help me out with future demos. The setup details are in the link, but this is Fender Strat with Lace Gold single coil on the middle position - all going straight from the pedal into a MOTU 828. I didn't bother trying to cross fade or indicate what controls are changing around, I just chunked some chords and sour-picking to show some of the range from jangly-bright to woofy-chug, but deleted most of the video of my hand turning knobs.
Phido Sound Milestone
I pushed to get this built and put together because this pedal is leaving Colorado after Thanksgiving. Going off to the hands of guitar-playing classmate of one of my boys, I want to start getting builds out and working to see how they perform, how they break, and just get some feedback. My goal is to generate enough interest that I can maybe recover the component costs by making lower-cost versions of mainstream pedals as I fill out the crazy brand idea that's in my headl
As always, thanks for reading through. I appreciate the support from this community!