DSV
New member
I have some history with Peavey products.
I auditioned for a local band four years ago. Eventually they didn't choose me as their bass player but I managed to snag a Peavey mk3 bass head they had in a corner collecting dust. "Broken, Something smelled burned inside. 10€ and its yours" It seemed like a bold task for me to take. I mean I was familiar with a soldering iron, I had built 30-something pedals mainly copying vero-layouts I could find online. But without having any formal electronics knowledge I did not know why the stuff that I built was working, I was just copying the layouts.
Eventually, after searching forums I found out the amp had a common issue. A power amp transistor was shorted and one would need to replace all 8 with modern replacements. After fixing this issue I refurbished the amp , changing its electrolytics and doing other maintenance.
What I was reading in facebook groups was true. The amp had such an amazing sound, full of character. It was versatile and gave me that Steve Harris - Geddy Lee clank and growl I was looking. Effortlessly, without the need of pedals. The Darkglass pedals I had bought and cloned seemed too niche, modern and instagram-player-equipment compared to the character of the Peavey.
Then there was a crossover circuit built in the amp. A knob to choose the crossover frequency and separate outputs for lows & highs along with a preamp and line output. I experimented a bit with that, sending the deep lows to a compressor and the line out to a TwoNotes CAB-M cab sim. Shit, that sounds amazing for silent practise !
I wanted to clone the preamp section of the mk3 bass head. Mind you I had not even designed the simplest vero-layout before. I reached to some hobbyists whose work I admire. "Is it doable?-Better learn PCB design on your own. I would need to charge 1000€+ for something like this". So I did. I learned how to use EAGLE from youtube videos , checked how others like AION electronics have taken on similar tasks for other preamps-into-pedals projects. The most daunting task I took up to that time! I wanted it to run on bipolar 15V volts, basically an exact clone of the original. I had JLCPCB fabricate me the PCB and it worked ! the result was quite crude as you can tell, but functional. This project taught me so much when it comes to reading a schematic!
Since then I went on a Peavey hunt! I have bought more than 10 Peavey units from the brand's golden era of the 70s-80s. Bass, guitar amps, racks, speaker cabs anything. Some I repaired/maintained and resold others I kept and modded. There's so much character there, with features people are still looking for in modern equipment nowadays.
Last year I made the jump to KiCad, since the free version of EAGLE will be discontinued. One of the first projects I wanted to do: The crossover section of the mk3 on a standalone pedal so I could use the LOs to compressor and HIs to cabsim with other preamps . Those damn OTAs from the mk3 are not easy to find. Let's check how the mk4 does it. A 4741 instead, much better !
Here's the Separatist : the crossover section of a Peavey mk4 bass head.
The lows should be sent to a DI before hitting my DBX rack compressor. Maybe I could fit it in the same box ?
Let's design a PCB for the EDB-1 I had traced a while back. The Parallelogram (A tribute to Lemmy. The man who managed to use the word parallelogram in a rock'n'roll song. heh "Fourth day, five day marathon, We're moving like a parallelogram")
Here are the PCBs I got fabricated + the PS section using a Traco TEC 2-0923.
(The red one is a Super Hard On clone. I was thinking of boosting the lows a bit before sending them to the DI. Turns out that was not needed.)
The end result. Here's the Tactician . Both of the above circuits in one box.
I have plans to make some more preamps that run on bipolar 15V, so I added a bipolar 15V out. Apart from the crossover frequency the other knobs control the Level of 1. Preamp out (that would go to a FX return of an amp), 2. Line out (to go to my Cab M), 3. LO out unbalanced and balanced (the latter goes to my dbx rack compressor).
If it does look like a cold-war era military communications device to you, I am happy. I achieved the aesthetic I was going for, hehe.
Hope mr. Hartley sees this as a homage to his work, not a way to keep his legal team busy. I am just building this for myself!
I auditioned for a local band four years ago. Eventually they didn't choose me as their bass player but I managed to snag a Peavey mk3 bass head they had in a corner collecting dust. "Broken, Something smelled burned inside. 10€ and its yours" It seemed like a bold task for me to take. I mean I was familiar with a soldering iron, I had built 30-something pedals mainly copying vero-layouts I could find online. But without having any formal electronics knowledge I did not know why the stuff that I built was working, I was just copying the layouts.
Eventually, after searching forums I found out the amp had a common issue. A power amp transistor was shorted and one would need to replace all 8 with modern replacements. After fixing this issue I refurbished the amp , changing its electrolytics and doing other maintenance.
What I was reading in facebook groups was true. The amp had such an amazing sound, full of character. It was versatile and gave me that Steve Harris - Geddy Lee clank and growl I was looking. Effortlessly, without the need of pedals. The Darkglass pedals I had bought and cloned seemed too niche, modern and instagram-player-equipment compared to the character of the Peavey.
Then there was a crossover circuit built in the amp. A knob to choose the crossover frequency and separate outputs for lows & highs along with a preamp and line output. I experimented a bit with that, sending the deep lows to a compressor and the line out to a TwoNotes CAB-M cab sim. Shit, that sounds amazing for silent practise !
I wanted to clone the preamp section of the mk3 bass head. Mind you I had not even designed the simplest vero-layout before. I reached to some hobbyists whose work I admire. "Is it doable?-Better learn PCB design on your own. I would need to charge 1000€+ for something like this". So I did. I learned how to use EAGLE from youtube videos , checked how others like AION electronics have taken on similar tasks for other preamps-into-pedals projects. The most daunting task I took up to that time! I wanted it to run on bipolar 15V volts, basically an exact clone of the original. I had JLCPCB fabricate me the PCB and it worked ! the result was quite crude as you can tell, but functional. This project taught me so much when it comes to reading a schematic!
Since then I went on a Peavey hunt! I have bought more than 10 Peavey units from the brand's golden era of the 70s-80s. Bass, guitar amps, racks, speaker cabs anything. Some I repaired/maintained and resold others I kept and modded. There's so much character there, with features people are still looking for in modern equipment nowadays.
Last year I made the jump to KiCad, since the free version of EAGLE will be discontinued. One of the first projects I wanted to do: The crossover section of the mk3 on a standalone pedal so I could use the LOs to compressor and HIs to cabsim with other preamps . Those damn OTAs from the mk3 are not easy to find. Let's check how the mk4 does it. A 4741 instead, much better !
Here's the Separatist : the crossover section of a Peavey mk4 bass head.
The lows should be sent to a DI before hitting my DBX rack compressor. Maybe I could fit it in the same box ?
Let's design a PCB for the EDB-1 I had traced a while back. The Parallelogram (A tribute to Lemmy. The man who managed to use the word parallelogram in a rock'n'roll song. heh "Fourth day, five day marathon, We're moving like a parallelogram")
Here are the PCBs I got fabricated + the PS section using a Traco TEC 2-0923.
(The red one is a Super Hard On clone. I was thinking of boosting the lows a bit before sending them to the DI. Turns out that was not needed.)
The end result. Here's the Tactician . Both of the above circuits in one box.
I have plans to make some more preamps that run on bipolar 15V, so I added a bipolar 15V out. Apart from the crossover frequency the other knobs control the Level of 1. Preamp out (that would go to a FX return of an amp), 2. Line out (to go to my Cab M), 3. LO out unbalanced and balanced (the latter goes to my dbx rack compressor).
If it does look like a cold-war era military communications device to you, I am happy. I achieved the aesthetic I was going for, hehe.
Hope mr. Hartley sees this as a homage to his work, not a way to keep his legal team busy. I am just building this for myself!
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