1981 Inventions DRV clone.

Here’s a PedalPCB Informant. This is mostly the Rat circuit with a few changes. The biggest change is the addition of a charge pump. The charge pump provides a +9 and -9 volts power for the circuit to run off. Effectively this doubles the voltage.

I have some reservations about the power supply. The clipping section clips at a fixed point. After the clipping diodes the charge pump doesn’t make any difference. With only a 9 volt power supply the circuit would running off +4.5 and -4.5 volts and there would be plenty of headroom going into the clipping section. The clipping section uses silicon diodes which will clip the signal at 0.7 volts. Which means the signal can’t really get past +0.7 volts and -0.7 volts. After the clipping section the output buffer is unity gain so nothing is added there.

The circuit does have a buffered bypass. The PedalPCB Informant offers an option to make this true bypass. The original DRV is buffered. I went with a buffered option. Here the charge pump can offer something since the buffered output can use the entire +9/-9 volt swing.

I built this is from a PedalPCB Informant PCB. The board is a great quality and set up for an easy build with all of the pots and LED mounted to the board. I would be happier to put this in a 1590B enclosure but the board is a little too large. On the other hand using a 125B allows for all of the jacks at the top.

The cost of this project was about $25. Which is pretty reasonable and took only a couple hours. The parts are all easy to get. Nothing special or hard to source. You can get everything for this at Tayda Electronics including the charge pump.

I milled the enclosure, filled the engraving with some paint and sanded the enclosure after. there is a small hex bolt between the knobs at the top. I drilled there for an LED but realized I had some of those stomp switches with the LED ring later and decided to use one of those. I used the hex bolt to fill the hole.

Parentheses Fuzz #5

I think this is #5 I’m losing count. These are so much fun to play the world needs a couple more! I used matte black sand textured enclosure. Which give this a good industrial vibe.

This is a pretty easy build for what you get. The board is a good size and parts are comfortably spaced. All of the pots are mounted to the board making wiring easy. The switches require some work but the pads are well organized.

The only down side is finding FETs and Ge diodes. Luckily D1 and D2 can be replaced by just about any type of type. D7, D8, and D9 could also be any type but Ge will have a noticeable sound to them. Ge diodes here will have a particular sound, not better or worse. If you’re looking for “that” sound you might stick with Ge for these. Otherwise test out any type of diode and use your ears to decide what sounds good here.

The main distortion circuit is based on the LM308 op-amp which are hard to get and can cost $5 or more, that’s a lot for an op-amp. Luckily the part is not critical. You can a few replacements. I used an OP07 which was $0.50 at Tayda.

The PF5102 FETs are hard to get. I used J112 from Tayda successfully.

And, it sounds amazing! This might be for sale check my for sale page.

Parentheses Fuzz #5 was originally published on Super-Freq

Parentheses Fuzz #5

I think this is #5 I’m losing count. These are so much fun to play the world needs a couple more! I used matte black sand textured enclosure. Which give this a good industrial vibe.

This is a pretty easy build for what you get. The board is a good size and parts are comfortably spaced. All of the pots are mounted to the board making wiring easy. The switches require some work but the pads are well organized.

The only down side is finding FETs and Ge diodes. Luckily D1 and D2 can be replaced by just about any type of type. D7, D8, and D9 could also be any type but Ge will have a noticeable sound to them. Ge diodes here will have a particular sound, not better or worse. If you’re looking for “that” sound you might stick with Ge for these. Otherwise test out any type of diode and use your ears to decide what sounds good here.

The main distortion circuit is based on the LM308 op-amp which are hard to get and can cost $5 or more, that’s a lot for an op-amp. Luckily the part is not critical. You can a few replacements. I used an OP07 which was $0.50 at Tayda.

The PF5102 FETs are hard to get. I used J112 from Tayda successfully.

And, it sounds amazing! This might be for sale check my for sale page.

Parentheses Fuzz postmortem

What is it

Parentheses Fuzz is a PCB from PedalPCB that is a clone of the Earth Quaker Devices Life pedal, with some mods. Originally designed as a sort of signature pedal for the Band Sunn o))).

What does it sound like?

This thing sounds lightly. It has a distortion, boost, and a switchable octave. The distortion is great, the boost works well, and the octave sounds pretty good for an analog octave effect. The controls provide volume, distortion, tone, boost, and a switchable option for the diode clipping.

What’s in the box?

Internally the pedal is based around the ProCo Rat circuit. The Octave section is similar to the Dan Armstrong Green Ringer, and the boost uses a BS170 MOST al a the ZVex Super Hard On. Not sure how they can up with the design. I wonder if Sunn o))) plugged all of these pedals together and asked EQD to make something that sounded the same or if these were just building blocks?

Costs

This is one of the more expensive projects to make. The PCB from PedalPCB is great, it’s works well, the layout is good, the pots and switch are mounted on the board. But it is also large and costs $18. That makes it the most expensive piece of the whole project by a large margin.

It is also requires 1590XX or larger enclosure. These run about $13. This and the board alone cost as much building a Big Muff in a 1950B enclosure. It also requires three switches 5 pots, and hard to get mini rotary switch. Overall I calculated the costs at about $65! Which is pretty high for a DIY project.

Besides the big ticket items some of the smaller parts are more costly and hard to get.

  • 1590xx enclosure
  • Switches 3PDT x 3
  • 4PDT mini switch
  • PF5102 x 3
  • 1N34a
  • PCB
partcosttotal
1590XX$13$13
3PDT Switches$3 x 3$9
4PDT rotary switch$4$4
PF5102$1 x 2$2
1N34a$0.50 x 4$2
PCB$18$18
knobs$0.50 x 6$3
total$51
here’s a code break down of significant parts.

Here is a cost break down of significant parts. There is jacks, caps, resistors, and shipping.

What about the LM308?

These are hard to get and cost about $5 a piece. Personally I dont think the choice of op-amp will affect the sound of this circuit. All of the clipping happens after the op-amp, and then there’s the analog octave. Maybe my ears have been to too many loud rock shows, I can’t hear the difference. I had some suitable single op-amps on hand so used one of those.

Here is a list of op-amps that will work here:

  • LM308
  • OP07
  • CA3130
  • 741

Let’s talk about those transistors

The circuit uses a few transistors: PF5102, 2N5087, 2N5089, and BS170. Most of these are easy to get and I had them on hand. The PF5102 is FET and these are getting hard to find these days. Tayda had these stocked at the time I was building but they were about $1 each which is pretty high for a single transistor. Some research on the PedalPCB form found some alternative part numbers that were suggested as working. These included:

  • J112
  • J113
  • 2N5457
  • 2N5458
  • BF244

Be sure to check the pin out on any of these they may not be the same!

And the diodes

There are a few diodes of different types used here. Two of the diodes are used in the octave circuit D1 and D2. These are listed as GE, they might do better if matched. I read a few suggestions people had good results using 1N5817 diodes here.

The rest of the diodes D3-9 are used for clipping to ground and these could really be any type. Feel free to experiment and use what have on hand for these.

The last diode D100 is used for power supply reversed polarity protection and should be a 1N5817.

Results

I built three of these. The build process was made easy by the great job PedalPCB did on the board. The off board wiring is significant due to the three 3PDT switches, each of these has 9 connections. The wiring is not difficult since the box is so large.

Of the three I kept one pedal and sold the other two on Reverb with an asking price of $200. I got $200 for one and took an offer of $165 on the other. After the Reverb fees I’m keeping 92.3% minus another $0.50. So I got roughly: $336.50. I spent roughly $195! So that left me with about: $141.50. I also have Parentheses Fuzz for my trouble. There is a possibility to cut some costs here but that also takes time energy and some up front investment. I’m just doing this as hobby.

I started the work in November 2020 and sold the second pedal in February 2021. Which wasn’t too bad on turnaround time. I have a few pedals on Reverb that I listed before starting building these that are still on Reverb.

So over all it was worth the efforts but I don’t think I’m going to quit my day job any time soon. I don’t think this is going to pay the rent but it’s not just losing money either. On the contrary it’s financing the next project!