This is another Big Muff clone. It’s a green Russian built with a Madbean PCB. I milled the enclosure.
We’ll call this the BZ-1. What got me started on these Boss rehousings was seeing the Boss Tone Bender TB-2w going for 3k on Reverb.com. These were super cool pedals but not worth more than than the list price of $350. I understand the idea of scarcity and knew there were only 3000 made, but I wasn’t going pay even $350 for a fuzz pedal. So I figured I could make one!
The Burns Buzzaround
If you’re curious about the Burns Buzzaround and how it relates to the Tone Bender check out here articles:
Building the BZ-1
There is always a solution when you can make your own! Since it was hard to get a two knob Boss enclosure, I decided to go with a three knob Tonebender variation. There are a couple to choose from. In the end I decided to go with the Madbean Pasty Face which is a clone of the Burns Buzzaround which is variant of the three transistor Tonebender family. I had read some good reviews of the Buzzaround and hadn’t built one before which made it more attractive.
I started with a used Boss DS-1 from Reverb.com. Used these seem to go for about $40. I ordered a board from Madbean and I had most of the other parts on hand. The DS-1 comes with a lot of parts that can be reused: switch, LED, jacks, and the enclosure itself. I pulled everything out and except the jacks. I left all of the original wiring in place since I can reuse it.
The LED is mounted to a small PCB along with two wires. These wires were too short to reach the far side of the enclosure where the switching board will be so I replaced them with longer wires.
I built the Pasty Face circuit board first. I left the transistors off since these need some special selection. The build is pretty easy there are only a handful of parts and there is plenty of space to work.
Since I’m putting this into a Boss enclosure the pots will be mounted off board. I cut a piece of strip board to mount the pots to. This was tight fit using 16mm pots but just makes it. Then I soldered some strips of ribbon cable to the this board and then to the main PCB. I made the ribbon cable a generous length since to allow me to pull the PCB out without having to also remove the pots.
Boss uses an electronic switching and the enclosure is nice the way it is. I wanted the switching to work as it was without adding a 3PDT switch. To do this I used a MadBean Softie PCB. This is a relay switching system that works with a Microcontroller. The microcontroller is triggered by the original Boss SPST switch. The relay is a DPDT that handles true bypass switching, while the microcontroller handles the LED.
This system works pretty well and offers a couple advantages. The relay has a failure rate of 100k cycles which beats the 30k cycles of those blue 3PDT switches. Also, if power is lost, the relay switches to bypass. Overall I’d say this relay switching works well and is easy to install. The downside would that the cost is higher than the mechanical switch, and the parts are harder to get, I had to order relays from Mouser.com.
The circuit uses three germanium transistors. With these old circuits there was a lot of variation with some Devices sounding better than others. I found this great thread with some suggestions about the gain and leakage for each of the transistors:
All pedal questions seem to lead to answers at DIYStompboxes.com. Great site and community, I highly recommend you check it out.
I have bag of germanium transistors. I got these from eBay and other sources and have been pulling parts from it for a while. What’s left are parts with less desirable values at this point. Luckily the thread above recommends lower gain devices for Q1 and Q2 and I have plenty of these!
In this circuit the first two transistors are setup in a Darlington pair. You can think of the two together as a single transistor with an hfe that is the product of the two. For example if both transistors had an hfe of 10 the pair in this configuration would act like a transistor an hfe of 100. This also multiplies the leakage of the two transistors. Which can increase noise.
Seems like the best choice here is low leakage, and low hfe/gain. Two transistors with an hfe of 50 would be considered low gain but in this configuration as a pair they would have gain of 2500!
Q3 seems like where all of the distortion/fuzz magic happens. From what I read in the thread above a higher gain, hfe 100+, is better here.
I identified three transistors that I thought would be suitable. I soldered some sockets into the board and auditioned the transistors with the back of the box open.
Everything was sounding pretty fuzzy good, so I removed the sockets and soldered the transistors to the board. I left about an inch of leg since I’d need to bend them over to fit everything into the enclosure with the back on. I wrapped the legs and the transistor body (not shown) in heat shrink tubing to make sure nothing shorted when I closed up the box.
What’s it sound like?
Sounds a lot like all those other 60s fuzz pedals but with its own character. The sound is thick and fuzzy. The tone control has a useful range. The sustain control goes from a muffled to tight buzz. Sort of like fuzzy bumblebee to swarm of wasps.
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.
This is a clone of the 1981 Inventions DRV rehoused in a Boss DS-1 enclosure. I used the PedalPCB Informant PCB and the MadBean Softie for this project.
Good question! I suppose I saw the ridiculous prices people were paying for the Boss Tone Benders that had come out recently and thought I could just make my own. While I was exploring the idea it seemed it was easiest to three knob Boss enclosures. The cheapest pedals seemed to be the DS-1, SD-1, and the BD-1. So building a three knob was the best option. There are many three knob pedals out there. Big Muff, Tube Screamer etc.
I got a little sidetracked and built a Big Muff in a DS-1 enclosure first, see my post here. The second build was this 1981 DRV. I have a board for a three knob Tone Bender and am planning to work on that next.
The process The process was pretty straight forward.
The Boss enclosure is pretty roomy. Figure you can fit anything that might fit 125B sized box into a Boss enclosure. The donor pedal comes with LED, Jacks, much of the wiring already. No need to drill or install these things.
One thing that needs some work is the power jack. The power jack is mounted to the original DS-1 PCB in my build there was no place to mount this. To solve this I used one of those standard DC jacks with a nut. I needed to ream the enclosure to allow it to fit. I added a couple spare washers so the jack didn’t extend too far out of the enclosure.
Switching is an area that needed some thought. Boss uses an electronic switching system. The system uses a couple JFET transistors to route the signal either through the effect or from the input to the output. Another part of the circuit turns this off or on. There is also buffer.
A side effect of this system is that your signal is always passing through some electronic components unlike true bypass where the signal is essentially traveling through a wire from the input to the output when the effect is bypassed. I’ve never heard any complaints about The Boss bypass. Another potential problem is the signal is lost when power is lost, even when the effect is bypassed.
I used the MadBean Softie which uses a micro controller and an electronic relay. The relay is an electromechanical switch. It’s a DPDT switch that is activated by an electronic signal. This offers a couple advantages. First, it works with the existing switch in the Boss enclosure. Second, when in bypass it acts as true bypass, the signal is essentially traveling through a wire from input to output when in bypass. Third, if power is lost the relay switches to its default state which bypasses the effect. Last, the relay has a failure rate of 100k cycles so it should outlast a mechanical 3PDT switch, which typically has a failure rate of 30k to 50k cycles.
It isn’t all upside. The cost of the Softie PCB was $4 and you’d need an SPDT monetary switch which is another $2.50. That’s $6.50 compared to $2.50 for one of those standard blue 3PDT switches. In this case the Boss enclosure came witch an SPST.
I thought the Softie worked well. Madbean makes three versions of this board for different sized enclosures. I chose the smallest version that was meant to fit 1590B enclosures. I think I could choose a one of the other boards for the Boss enclosure. The reason the board I chose has a small footprint but mounts parts on both sides of the board making it taller than other boards, which makes it a tighter fit than it would appear.
The Informant/DRV needed three A100K pots. The DS-1 has two B100k and a B20K pot. I could have tried the B100K pots. Since I needed to replace on of the pots I replaced them all.
I used some of those 9- degree PCB mounted pots, two 16mm and one 9mm. I cut a piece of strip board and mounted the post to this. Then ran the wiring from the Strip board to the PCB.
I color coded the wires by the PIN number of the pots to make it easy to get them matched up to the correct holes on the PCB. I just did it alphabetical to make it easy to remember: Brown, Gray, Orange. Notice the center pot is backwards,
The cost of this project was higher than a typical pedal but not as bad as i was expecting. The cost of the donor DS-1 was the biggest expense. The DS-1 was $40 and it replaces about $10 of other parts. So this was roughly about $30 more than your typical pedal build.
The total cost was about $60 which was not that bad, or at least than I thought it might be when I started. The pedal is pretty solid and works well.
What’s it sound like?
Hopefully like the 1981 Inventions pedal. I haven’t tried one of the originals but this sounds similar to the demos I’ve seen on YouTube. Its a really driven sound with a tight low end. It has a very 80s sound.
The drive control starts at distorted and goes quickly to high gain. I find it sounds best to turn up the Cut control as you increase the gain to “shave” some of the “hair” off as gain increases.
For myself I like the lower range of the Drive control. Everything past 25% (9 o’clock) sounds very similar. I’d like to play with Drive and gain in the future. This might be replacing the Drive pot with a 50k pot, or possibly changing some of the other components to get a more useful feel for this control.