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#1
General Questions / Re: Rate/Mod Rate LED for Poly...
Last post by wizestwizard - February 13, 2026, 11:25:00 AMThanks Brian! I'll test em out and see how it goes, I'll report back
#2
General Questions / Re: Rate/Mod Rate LED for Poly...
Last post by madbean - February 13, 2026, 03:32:09 AMQuote from: wizestwizard on February 12, 2026, 11:50:33 PMHey guys, recently had a request from someone to add a rate LED to a Polytrog I build for them. I assume it will follow the "rate" pot if I put it in parallel with the LDR LEDs? If I do this, should I put it after all of the vactrol LEDs and then lower R42 to ~250R? This is a complex circuit compared to what I normally mod, so want to make sure I cover my butt before I start poking around in it!
If I wanted it to pulse with the "mod rate" pot, where would be the best place to tap into that voltage? Thanks!
For the Rate pot you would put the LED in series with VC1-3_L, nt in parallel. Lowering R42 might compensate or prove unnecessary. For the Mod_Rate I'd try a 10k CLR and LED connected to pin7 of IC9_B first. Do it on a breadboard where you can easily disconnect the LED and see if it impacts performance.
These are just educated guesses.
#3
General Questions / Rate/Mod Rate LED for Polytrog
Last post by wizestwizard - February 12, 2026, 11:50:33 PMHey guys, recently had a request from someone to add a rate LED to a Polytrog I build for them. I assume it will follow the "rate" pot if I put it in parallel with the LDR LEDs? If I do this, should I put it after all of the vactrol LEDs and then lower R42 to ~250R? This is a complex circuit compared to what I normally mod, so want to make sure I cover my butt before I start poking around in it!
If I wanted it to pulse with the "mod rate" pot, where would be the best place to tap into that voltage? Thanks!
If I wanted it to pulse with the "mod rate" pot, where would be the best place to tap into that voltage? Thanks!
#4
Open Discussion / Re: Got bored, building a bass...
Last post by phreek - February 12, 2026, 06:41:38 PMQuote from: lars on February 11, 2026, 02:30:37 AMMy favorite heavy bass distortion ever was actually the drive circuit built into the Gallien Krueger Backline 250 head. It was kind of a Big Muff sound, but heavier and less scooped. GK tried to build that circuit into their Diesel Dawg pedal, but managed to mess it up, so it never sounded like the amp head. By comparing the schematics of the two you can find the changes, and I actually modded a Diesel Dawg to sound much closer to the 250 head. The key resistors and caps that need to be changed (6th post) are outlined in this posting I made years ago:that sounds like ima have to give this a good look, thanks for the heads up
https://www.madbeanpedals.com/forum/index.php?topic=27915.0
#5
Open Discussion / Re: Got bored, building a bass...
Last post by lars - February 11, 2026, 02:30:37 AMMy favorite heavy bass distortion ever was actually the drive circuit built into the Gallien Krueger Backline 250 head. It was kind of a Big Muff sound, but heavier and less scooped. GK tried to build that circuit into their Diesel Dawg pedal, but managed to mess it up, so it never sounded like the amp head. By comparing the schematics of the two you can find the changes, and I actually modded a Diesel Dawg to sound much closer to the 250 head. The key resistors and caps that need to be changed (6th post) are outlined in this posting I made years ago:
https://www.madbeanpedals.com/forum/index.php?topic=27915.0
https://www.madbeanpedals.com/forum/index.php?topic=27915.0
#6
Build Reports / Re: Polyphemus {One Knob Overd...
Last post by jessenator - February 10, 2026, 04:17:17 AM
#7
Open Discussion / Re: What are you playing? (gam...
Last post by jessenator - February 10, 2026, 03:22:55 AMI still haven't installed BG3... or RDR2...
I did do a large run of Tale of Two Wastelands. I think I've exhausted any and all interest I ever had of FO3. Just vanilla FNV from now on, but after a break.
Finally installed Fallout London and have been very pleased with it. Though, having to install GOG Galaxy to get it installed properly was a faff, if the only one.
I did do a large run of Tale of Two Wastelands. I think I've exhausted any and all interest I ever had of FO3. Just vanilla FNV from now on, but after a break.
Finally installed Fallout London and have been very pleased with it. Though, having to install GOG Galaxy to get it installed properly was a faff, if the only one.
#8
Open Discussion / Re: Got bored, building a bass...
Last post by phreek - February 09, 2026, 10:20:45 PMI did a ton of reading in there... Felt slight panic... Ordered a PCB from aion.
#9
Build Reports / Polyphemus [One Knob Overdrive...
Last post by Aleph Null - February 09, 2026, 04:26:20 PMThis all started with Jessenator giving me the bullying me for building in 125B instead of 1590B. I threatened to put a mosfet boost in a 1590XX just to spite him. That's not where I ended up, but the idea for this circuit did come to me while contemplating mosfets and revenge.
Polyphemus is a one-knob overdrive/distortion with internal voicing options that allow it to be tailored to a variety of rigs and use cases. The idea was, to do all the dialing in up front, then screw the thing shut and just rock! As it's built around a Super Hard On of sorts, it only seemed appropriate to name it after the original one-eyed monster!
The circuit consists of three gain/eq stages. The first stage is a high shelf filter that boosts everything above a set frequency by 20dB. Everything below that frequency stays at unity gain. The second stage is a simple mosfet boost, which is pushed by the first stage into clipping. The final stage is a low shelf, set at a similar frequency to the first. This flattens out the eq again. This makes for a "transparent" overdrive that emphasizes harmonics and retains clarity, since higher frequencies are saturated more and sooner. It also greatly lowers the noise floor!
Switches 1 and 2 set the capacitance/cut-off frequency in the HPF stage. Switches 3 and 4 set the capacitance/cut-off frequency in the LPF stage. HPF and LPF interact to shape the character of the gain, as well as the frequency response. Flat, transparent overdrive, various kinds of mid boost or treble boost, mid scoop, even distortion/fuzz is achievable. Heat sets the range of the Gain control. This is so that the headroom can be adjusted to suit your pickups and maximize the range of the Gain Control. Output is a volume control. With Heat dialed in, there is a moderate change in volume from the lowest to the highest Gain setting (maybe 6dB). I like to set Output so that the lowest Gain setting is about unity with bypass, but you could attenuate or boost to taste.
Here's a demo:
There's a little dedication to Jessenator on the PCB. 😘 I built mine in a 125B, as is my preference, but it'll fit into a 1590B with top mount jacks. Side jacks are possible, but you'd have to push the Gain knob up to accommodate them. And, of course, it's in green, Jessenator's preferred solder mask color.
As always, I have extra PCBs. If you want one, DM me.
Polyphemus is a one-knob overdrive/distortion with internal voicing options that allow it to be tailored to a variety of rigs and use cases. The idea was, to do all the dialing in up front, then screw the thing shut and just rock! As it's built around a Super Hard On of sorts, it only seemed appropriate to name it after the original one-eyed monster!
The circuit consists of three gain/eq stages. The first stage is a high shelf filter that boosts everything above a set frequency by 20dB. Everything below that frequency stays at unity gain. The second stage is a simple mosfet boost, which is pushed by the first stage into clipping. The final stage is a low shelf, set at a similar frequency to the first. This flattens out the eq again. This makes for a "transparent" overdrive that emphasizes harmonics and retains clarity, since higher frequencies are saturated more and sooner. It also greatly lowers the noise floor!
Switches 1 and 2 set the capacitance/cut-off frequency in the HPF stage. Switches 3 and 4 set the capacitance/cut-off frequency in the LPF stage. HPF and LPF interact to shape the character of the gain, as well as the frequency response. Flat, transparent overdrive, various kinds of mid boost or treble boost, mid scoop, even distortion/fuzz is achievable. Heat sets the range of the Gain control. This is so that the headroom can be adjusted to suit your pickups and maximize the range of the Gain Control. Output is a volume control. With Heat dialed in, there is a moderate change in volume from the lowest to the highest Gain setting (maybe 6dB). I like to set Output so that the lowest Gain setting is about unity with bypass, but you could attenuate or boost to taste.
Here's a demo:
There's a little dedication to Jessenator on the PCB. 😘 I built mine in a 125B, as is my preference, but it'll fit into a 1590B with top mount jacks. Side jacks are possible, but you'd have to push the Gain knob up to accommodate them. And, of course, it's in green, Jessenator's preferred solder mask color.
As always, I have extra PCBs. If you want one, DM me.
#10
Open Discussion / Re: Got bored, building a bass...
Last post by jimilee - February 08, 2026, 05:06:23 AMQuote from: phreek on February 08, 2026, 12:17:48 AMHere's a while thread on the Sun on FSB. There's a vero layout, on page 2. I don't read much past that.Quote from: jimilee on February 05, 2026, 09:04:05 PMhah I wish I was better with schematics! Hell if I were I'd cook up a sunn beta bass pre and be done with it lolQuote from: jessenator on February 05, 2026, 07:56:40 PMSadly byoc has closed up shop. Had a final sale end of 2024. Don't recall the reasons.I think the BYOC schematics are linked by someone over on pedalpcb.
I have a mbp Promenade in my build queue. I wonder of aleph null's Otolith could be optimized for bass (maybe just cap values?) That's a very versatile beast and can do super sludgy to punchy.
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https://www.freestompboxes.org/viewtopic.php?t=25813
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