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DIY Stompboxes => Building your own stompbox => Topic started by: Mark Hammer on January 04, 2021, 12:19:55 PM

Title: Another silly dual-stage overdrive
Post by: Mark Hammer on January 04, 2021, 12:19:55 PM
I made a Bluesbreaker clone some time back and just found it too shrill and finicky.  But I was intrigued by the nature of the gain control, as well as the use of a "softened" clipping in the second stage.  I mused about it and thought that I might be able to get a nice thick sound if I made better use of the first op-amp stage, and did some tone-shaping.  I'm a fan of double clipping anyway.

I'm really pleased with the outcome.  Just a nice thick-sounding drive, with decent sustain even at lower volumes.  I called it the "Wattbreaker", since it reminded me very much of an amp I used some 40 years ago.  I had sat in at a jam in the campus pub, and the band hosting let me plug into a lovely Hi-Watt 50W.  I was impressed with the stoutness and sturdyness of the guitar's sound through that amp.  It just seemed so muscular, even when not diming the drive.  This circuit kind of reminded me of that, although heaven knows how accurate my recollection is after 40+ years.

Two knobs deliver what it has to offer.  Given the filtering distributed throughout, I can't see the need for a Tone control, but I leave that to your tastes.  I've shown where the various rolloffs are throughout the circuit so you can see the logic of it.  There is some extra push for the mids in stage 1, and the additional gain and clipping diodes in stage 1 adds more harmonic content, but any frizz is seriously tamed by both feedback caps and the lowpass on the output.

Just a nice sensible drive that likes both neck and bridge pickups.  I experimented with sticking a back-to-back pair of schottky diodes in series, just ahead of the volume control for some crossover distortion, but it didn't really add anything useful, so I'm not showing that.  Let's keep it as a utilitarian 2-knobber that gives "stout" meat-and-potatoes drive.  Nice bottom end, low center-of-gravity.

Happy New Year.

(https://i.postimg.cc/RNqyZwkG/Wattbreaker.gif) (https://postimg.cc/RNqyZwkG)
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 04, 2021, 02:44:56 PM
Thank you sir !

I learn a lot from your posts
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 04, 2021, 03:31:41 PM
And a happy new Year to you, as well!

Funny, I have been toying with the "Marshall pedal topology" as well recently. So I have no difficulty believing that the Wattbreaker sound the way you describe it. Really great topology for ampish sounding overdrives! I ended up somewhere quite similar yet quite different. More of an Orange kind of deal. It really is a remarkably versatile and good sounding topology. Surprised that it seems to see relatively little use in DIY circles compared to other "topological families" despite the success of the KoT and some other family members.

I was planning to release mine once I finally had the layout done but maybe I should take your post as a sign and publish the schematic right away.

Cheers,
Andy
Title: Re: Another silly dual-stage overdrive
Post by: iainpunk on January 04, 2021, 04:02:44 PM
that dual clipping idea seems interesting, how does it fair with guitars with insanely high output? i have had some disappointing results with soft clippers in combination with that guitar.
one thing tho, the first gain stage's NFB terminates at the Vb, shouldn't it terminate at ground? i feel like the low resistances would bootstrap and influence the gain via the Vb

Andy, cant wait to see your idea

cheers and Happy New Year, Iain
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 04, 2021, 05:00:57 PM
that dual clipping idea seems interesting, how does it fair with guitars with insanely high output? i have had some disappointing results with soft clippers in combination with that guitar.
one thing tho, the first gain stage's NFB terminates at the Vb, shouldn't it terminate at ground? i feel like the low resistances would bootstrap and influence the gain via the Vb

Andy, cant wait to see your idea

cheers and Happy New Year, Iain
That's what I thought, as well.  But it didn't work.  Had to tie those ground legs to Vref to get anything.  I honestly don't know what the relative output of my various guitars is, though I have an old Vantage with some double-creme Schaller pickups that might fit the bill.  I'll try it out and report back.

As for how to make the circuit handle hot pickups, I suspect the answer is to be found by reducing the value of that 20k feedback resistor, and maybe letting the 20k and 12k resistors trade places.  As shown stage 1 has a max gain of around 55x and stage 2 has a max gain of 18x, yielding a combined gain of just over 1000x (  :icon_eek: ), so more aggressive than a Bluesbreaker but not quite into Rat territory.  Set to minimum, stage 1 has a gain of 10x and stage 2 a gain of just under 2x, yielding a combined gain of 20x.

If we switch around the 20k and 12k resistors, we get a combined max gain of just over 570x and a min gain of just under 12x.  So that ought to handle hot pickups a little better.

The basic idea of the circuit is that stage 1 provide a pre-clipped signal with suitable treble cut, that is then pushed a bit harder in stage 2, and re-clipped, again with suitable treble cut.  The stock Bluesbreaker strikes me as providing insufficient bandwidth-management until one gets to the tone control.  Maybe that's why it is so strident to my ears.  Much like a TS-9, the gain in stage 1 also loses top end as gain is increased, such that things like two-pickup "cluck" are still quite audible at low gains, but the tone thickens up when gain is cranked and bandwidth of stage 1 gets decreased.

Again, I have to give credit to the genius of the gain control in the Bluesbreaker.

Andy, do whatever makes you happy.  Me, I have no urge to protect I.P. and get my kicks from simply having something work out as intended.
Title: Re: Another silly dual-stage overdrive
Post by: ElectricDruid on January 04, 2021, 05:23:15 PM
Funny, I have been toying with the "Marshall pedal topology" as well recently.

There must be something in the water! I've also been playing with bluesbreaker/KoT-alikes. I've been working on giving a pedal programmability using MCP42xxx digital pots, so I decided to start with a nice simple four-knob drive pedal, and I needed something that only uses either 10K, 50K and 100K pots since that's all you can get in the digipot range! The bluesbreaker/KoT fit the bill pretty nicely, so that's what I've been working with. Mark, I think your version looks quite a bit better developed than mine, although in my defence I was mostly interested in the programmability and the overdrive was really only a proof-of-concept. That's my excuse for why it sounds a bit hopeless, anyway ;) Thanks for the inspiration though - I think I might try a few tactical modifications to mine!

One side effect of the digipots was that the thing has to run at 5V (there *are* higher voltage digipots, but these aren't them) so I swapped the op-amps for MCP6002s and the whole thing is a 5V overdrive. The lack of headroom is a bit of a nightmare in a gain pedal as you can imagine, but the worst problems come with the active tone control I stuck after it. At least for the gain stage, the clipping can limit things to a reasonable level. It's *not* easy to design audio circuits for only 5V is what I'm finding...the programmability was the easy part in some ways!

Title: Re: Another silly dual-stage overdrive
Post by: jubal81 on January 04, 2021, 06:02:55 PM
Funny, I have been toying with the "Marshall pedal topology" as well recently.

There must be something in the water! I've also been playing with bluesbreaker/KoT-alikes. I've been working on giving a pedal programmability using MCP42xxx digital pots, so I decided to start with a nice simple four-knob drive pedal, and I needed something that only uses either 10K, 50K and 100K pots since that's all you can get in the digipot range! The bluesbreaker/KoT fit the bill pretty nicely, so that's what I've been working with. Mark, I think your version looks quite a bit better developed than mine, although in my defence I was mostly interested in the programmability and the overdrive was really only a proof-of-concept. That's my excuse for why it sounds a bit hopeless, anyway ;) Thanks for the inspiration though - I think I might try a few tactical modifications to mine!

One side effect of the digipots was that the thing has to run at 5V (there *are* higher voltage digipots, but these aren't them) so I swapped the op-amps for MCP6002s and the whole thing is a 5V overdrive. The lack of headroom is a bit of a nightmare in a gain pedal as you can imagine, but the worst problems come with the active tone control I stuck after it. At least for the gain stage, the clipping can limit things to a reasonable level. It's *not* easy to design audio circuits for only 5V is what I'm finding...the programmability was the easy part in some ways!

Hate to veer of on Hammer's thread (very cool design), but as far as using programmable digipots, what about putting them in a 10+ band EQ to make a programmable analog cab sim?
Title: Re: Another silly dual-stage overdrive
Post by: iainpunk on January 04, 2021, 06:04:08 PM
Quote
That's what I thought, as well.  But it didn't work.  Had to tie those ground legs to Vref to get anything.  I honestly don't know what the relative output of my various guitars is, though I have an old Vantage with some double-creme Schaller pickups that might fit the bill.  I'll try it out and report back
the problem i run in to is the ratio between the distorted signal and the clean signal that gets through after the clipping threshold, the portion of clean is so large that the distorted middle of the wave sounds more like crossover distortion than overdrive...
it has enough output to clip LED's on the initial attack and 4148's in the sustain, without needing any boost. i think leaving out that 6k8  or replacing it with a 10k trimmer, would do better with this particular guitar. (it also overdrives a phase 90 on the initial attack)

the gain control topology is genius indeed, i might steal that and put it in the wave folder fuzz i'm building.

cheers, Iain
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 04, 2021, 06:13:44 PM
....
Andy, cant wait to see your idea
...
There you go: https://www.diystompboxes.com/smfforum/index.php?topic=126139.0 (https://www.diystompboxes.com/smfforum/index.php?topic=126139.0)




...
Andy, do whatever makes you happy.  Me, I have no urge to protect I.P. and get my kicks from simply having something work out as intended.
Oh, me neither. I do this all just for fun anyway. The idea was to present it all as a package so people could go make one if they want to, without the tedium of having to make their own layout. I'm just so darn slow with those. I approach DIY stompboxology as a scientist, not an entrepreneur: knowledge shared is knowledge gained. I generally consider my own "intellectual property" to be public domain.



...
There must be something in the water! I've also been playing with bluesbreaker/KoT-alikes.
...
Hehe, nice! Strange place, the universe. Sometimes some ideas just pop up all over the place. Maybe 2021 is the year for this particular idea to be in the spotlight again.

Cheers,
Andy
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 04, 2021, 06:29:32 PM
Funny, I have been toying with the "Marshall pedal topology" as well recently.

There must be something in the water! I've also been playing with bluesbreaker/KoT-alikes. I've been working on giving a pedal programmability using MCP42xxx digital pots, so I decided to start with a nice simple four-knob drive pedal, and I needed something that only uses either 10K, 50K and 100K pots since that's all you can get in the digipot range! The bluesbreaker/KoT fit the bill pretty nicely, so that's what I've been working with. Mark, I think your version looks quite a bit better developed than mine, although in my defence I was mostly interested in the programmability and the overdrive was really only a proof-of-concept. That's my excuse for why it sounds a bit hopeless, anyway ;) Thanks for the inspiration though - I think I might try a few tactical modifications to mine!

One side effect of the digipots was that the thing has to run at 5V (there *are* higher voltage digipots, but these aren't them) so I swapped the op-amps for MCP6002s and the whole thing is a 5V overdrive. The lack of headroom is a bit of a nightmare in a gain pedal as you can imagine, but the worst problems come with the active tone control I stuck after it. At least for the gain stage, the clipping can limit things to a reasonable level. It's *not* easy to design audio circuits for only 5V is what I'm finding...the programmability was the easy part in some ways!
Could be worse.  Could be 3.3V.
Title: Re: Another silly dual-stage overdrive
Post by: MikeA on January 04, 2021, 08:05:57 PM
that dual clipping idea seems interesting, how does it fair with guitars with insanely high output? i have had some disappointing results with soft clippers in combination with that guitar.
When I run this in LTSpice, I notice two things that are unusual for overdrives (granted that simulations are not reality!)
1. The output wave shape doesn't vary much with the input level, and is only mildly sensitive to the Gain knob setting.  Pretty much the same waveform out with 100 mV to 5V in, so I would predict that this layout sounds about the same with hot pickups.  It's a softly rounded symmetrical clip that reminds me of the Ibanez MT10.  Clip increases just a bit at higher Gain settings, but not much.
2. The frequency response doesn't vary with the Gain setting.  All that changes is the output level.  This, along with the voicing, might contribute to the ability to work without a tone control.
Nicely done, Mark. 
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 04, 2021, 09:06:03 PM
that dual clipping idea seems interesting, how does it fair with guitars with insanely high output? i have had some disappointing results with soft clippers in combination with that guitar.
When I run this in LTSpice, I notice two things that are unusual for overdrives (granted that simulations are not reality!)
1. The output wave shape doesn't vary much with the input level, and is only mildly sensitive to the Gain knob setting.  Pretty much the same waveform out with 100 mV to 5V in, so I would predict that this layout sounds about the same with hot pickups.  It's a softly rounded symmetrical clip that reminds me of the Ibanez MT10.  Clip increases just a bit at higher Gain settings, but not much.
2. The frequency response doesn't vary with the Gain setting.  All that changes is the output level.  This, along with the voicing, might contribute to the ability to work without a tone control.
Nicely done, Mark.
It does and it doesn't.  Certainly one expects more harmonic content to be generated as gain and clipping is increased.  However the 680pf cap in stage 1 "pulls back" on that harmonic content as the gain is increased, yielding a fairly consistent amount of harmonic content across gain settings, and the subsequent filtering supports that mission.  At least that was part of the plan.  I imagine that if you measured bandwidth at the output of stage 1, there probably would be some variation in frequency response with gain changes.  Not gobs of it, but some.

Thanks for the appreciation, but a bigger thanks for taking the extra steps to sim the circuit.  Much obliged.

I like the reference to the MT10.  I received my shipment of five CA3260 chips from China a few weeks ago and put one into an MT10 clone I made.  Dare I try one out here?
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 05, 2021, 12:58:08 AM

When I run this in LTSpice,


I was thinking of entering this into LTSPICE too

But seeing that you already did,

Could you share your file please ?
Title: Re: Another silly dual-stage overdrive
Post by: 11-90-an on January 05, 2021, 01:38:28 AM
Happy new year (which has since aged around 5 days, but I digress...)

Thanks for sharing this ckt, MH. Did it on breadboard and sounds lovely. Probably will make a quick perf layout and build it soon...

A quick mod, as I find myself looking for more treble (my taste), so replacing the 10k resistor on the output with a 4k7 in series with a 10k pot gives a tad bit of treble control without too much hiss, etc. This moves the LPF corner frequency from around 1kHz to 3.8kHz

As I said before, great circuit and great sound, thanks for sharing!  :icon_mrgreen:
Title: Re: Another silly dual-stage overdrive
Post by: bluebunny on January 05, 2021, 04:10:08 AM
We've just been locked down again, so what better than an interesting new overdrive to build?  Thanks Mark.  HNY.
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 05, 2021, 09:35:34 AM
Seeing as it is fundamentally an adaptation/perversion of the basic Bluesbreaker circuit, I'm curious as to how may other Bluesbreaker-derivatives there are out there.  Certainly not as many as there are Tube Screamer derivatives, but between Analogman (KoT) and JHS (Morning Glory) that can't be the entire spectrum.
Title: Re: Another silly dual-stage overdrive
Post by: MikeA on January 05, 2021, 05:03:32 PM
I like the reference to the MT10.  I received my shipment of five CA3260 chips from China a few weeks ago and put one into an MT10 clone I made.  Dare I try one out here?
I think you can just drop one in, the bias should be adequate and everything else looks like it will work.

I was thinking of entering this into LTSPICE too

But seeing that you already did,

Could you share your file please ?
  Sure, I'm thinking I can just copy and paste the contents of the .asc file as text into a message?  Or is there a more elegant way to share an LTSpice file here?   
Title: Re: Another silly dual-stage overdrive
Post by: PRR on January 05, 2021, 05:17:04 PM
...I'm thinking I can just copy and paste the contents of the .asc file as text into a message?

Yes, the ASC file seems to be 99% sufficient (unlike my other simmer which needs multiple files).

Use a CODE {#} box here --- it keeps it neat and easy to Select and copy to clipboard.

Code: [Select]
Version 4
SHEET 1 880 680
WIRE 128 -48 -48 -48
WIRE 128 80 128 -48
WIRE -48 96 -48 -48
WIRE 80 128 32 128
WIRE -48 272 -48 176
WIRE 32 272 32 128
WIRE 32 272 -48 272
WIRE 96 272 96 176
WIRE 96 272 32 272
WIRE 96 320 96 272
FLAG 96 320 0
SYMBOL Misc\\battery -48 80 R0
WINDOW 123 0 0 Left 2
WINDOW 39 24 132 Left 2
SYMATTR InstName V1
SYMATTR Value 200
SYMATTR SpiceLine Rser=0.01
SYMBOL Misc\\triode 128 128 R0
SYMATTR InstName U1
TEXT -82 232 Left 2 !.op

It is possible/likely that some non-generic parts will need their bits copied-in from a library. Above I have a "misc\\triode" which may not be stock on your system.
Title: Re: Another silly dual-stage overdrive
Post by: MikeA on January 05, 2021, 06:07:37 PM
Thanks Paul.  Mark's Wattbreaker V1 (LTSpice .asc file in text form), does not include detail on power section from schematic.
Code: [Select]
Version 4
SHEET 1 3116 700
WIRE 896 -1760 880 -1760
WIRE 1024 -1760 960 -1760
WIRE 1104 -1760 1088 -1760
WIRE 880 -1664 880 -1760
WIRE 896 -1664 880 -1664
WIRE 1024 -1664 960 -1664
WIRE 1104 -1664 1104 -1760
WIRE 1104 -1664 1088 -1664
WIRE 880 -1600 880 -1664
WIRE 880 -1472 880 -1520
WIRE 944 -1472 880 -1472
WIRE 1104 -1472 1104 -1664
WIRE 1104 -1472 1024 -1472
WIRE 256 -1376 224 -1376
WIRE 288 -1376 256 -1376
WIRE 368 -1376 352 -1376
WIRE 464 -1376 448 -1376
WIRE 480 -1376 464 -1376
WIRE 576 -1376 560 -1376
WIRE 672 -1376 656 -1376
WIRE 768 -1376 752 -1376
WIRE 880 -1376 880 -1472
WIRE 880 -1376 832 -1376
WIRE 944 -1376 880 -1376
WIRE 1104 -1376 1104 -1472
WIRE 1104 -1376 1008 -1376
WIRE 256 -1280 256 -1376
WIRE 288 -1280 256 -1280
WIRE 368 -1280 352 -1280
WIRE 464 -1280 464 -1376
WIRE 464 -1280 448 -1280
WIRE 880 -1280 880 -1376
WIRE 992 -1280 880 -1280
WIRE 1104 -1264 1104 -1376
WIRE 1104 -1264 1056 -1264
WIRE 1168 -1264 1104 -1264
WIRE 1344 -1264 1312 -1264
WIRE 1424 -1264 1344 -1264
WIRE 992 -1248 960 -1248
WIRE 1344 -1232 1344 -1264
WIRE 464 -1216 464 -1280
WIRE 528 -1216 464 -1216
WIRE 608 -1216 608 -1328
WIRE 608 -1216 592 -1216
WIRE 1536 -1216 1472 -1216
WIRE 1344 -1136 1344 -1168
WIRE 1424 -1136 1424 -1184
WIRE 464 -1120 464 -1216
WIRE 512 -1120 464 -1120
WIRE 608 -1120 608 -1216
WIRE 608 -1120 576 -1120
WIRE 464 -1024 464 -1120
WIRE 512 -1024 464 -1024
WIRE 608 -1024 608 -1120
WIRE 608 -1024 576 -1024
WIRE 800 -992 800 -1024
WIRE 928 -992 928 -1024
WIRE 1024 -992 1024 -1024
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WIRE 608 -912 576 -912
WIRE 240 -896 208 -896
WIRE 336 -896 240 -896
WIRE 448 -896 400 -896
WIRE 512 -896 448 -896
WIRE 800 -896 800 -912
WIRE 864 -896 864 -1024
WIRE 928 -896 928 -912
WIRE 1024 -896 1024 -912
WIRE 448 -800 448 -816
WIRE 240 -784 240 -816
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IOPIN 800 -1024 Out
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FLAG 1024 -1232 -V
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IOPIN 960 -1248 In
FLAG 240 -784 0
FLAG 224 -1376 Vref
IOPIN 224 -1376 In
FLAG 1024 -1024 IN
IOPIN 1024 -1024 Out
FLAG 1424 -1136 0
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WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 9
SYMBOL voltage 1024 -1008 R0
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WINDOW 39 24 125 Left 2
SYMATTR Value2 AC .1
SYMATTR InstName V2
SYMATTR Value SINE(0 .1 1000)
SYMBOL res 464 -1296 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
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SYMATTR Value 3.3k
SYMATTR SpiceLine tol=1 pwr=.25
SYMBOL res 464 -1392 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 2.2k
SYMATTR SpiceLine tol=1 pwr=.25
SYMBOL res 1040 -1488 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 220k
SYMATTR SpiceLine tol=1 pwr=0.25
SYMBOL voltage 928 -1008 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V3
SYMATTR Value 4.5
SYMBOL cap 400 -912 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 0.01µ
SYMATTR SpiceLine V=50 Irms=0 Rser=0.0123831 Lser=188.457p mfg="Würth Elektronik" pn="885012009023 WCAP-CSGP 1210" type="NP0"
SYMBOL res 432 -912 R0
SYMATTR InstName R1
SYMATTR Value 1Meg
SYMATTR SpiceLine tol=1 pwr=0.25
SYMBOL cap 592 -1232 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C2
SYMATTR Value 680p
SYMATTR SpiceLine V=50 Irms=0 Rser=0.064133 Lser=425.3p mfg="Würth Elektronik" pn="885012007062 WCAP-CSGP 0805" type="NP0"
SYMBOL cap 832 -1392 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C5
SYMATTR Value 220n
SYMATTR SpiceLine V=50 Irms=2.37 Rser=0.0592523 Lser=0 mfg="KEMET" pn="C0805C224K5RAC" type="X7R"
SYMBOL cap 352 -1296 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C3
SYMATTR Value 470n
SYMATTR SpiceLine V=50 Irms=3.46 Rser=0.0302434 Lser=0 mfg="KEMET" pn="C2220C474K5RAC" type="X7R"
SYMBOL cap 352 -1392 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C4
SYMATTR Value 56n
SYMATTR SpiceLine V=50 Irms=1 Rser=0.10227 Lser=0 mfg="KEMET" pn="C1206C563K5RAC" type="X7R"
SYMBOL res 224 -912 R0
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SYMATTR Value 2Meg2
SYMATTR SpiceLine tol=1 pwr=.25
SYMBOL Opamps\\UniversalOpamp2 544 -912 R0
SYMATTR InstName IC1B
SYMBOL Opamps\\UniversalOpamp2 1024 -1264 R0
SYMATTR InstName IC1A
SYMBOL potentiometer_standard 672 -1392 R90
SYMATTR InstName U1
SYMATTR Value Rtot=100k wiper={GAIN}
SYMBOL potentiometer_standard 1408 -1280 R0
SYMATTR InstName U6
SYMATTR Value Rtot=100K wiper=1
SYMBOL cap 1008 -1392 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C6
SYMATTR Value 220p
SYMATTR SpiceLine V=50 Irms=31.2m Rser=8.19371 Lser=0 mfg="KEMET" pn="C0402C391K5RAC" type="X7R"
SYMBOL diode 896 -1744 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D3
SYMATTR Value 1N4148
SYMBOL diode 960 -1680 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D6
SYMATTR Value 1N4148
SYMBOL res 864 -1616 R0
SYMATTR InstName R6
SYMATTR Value 6k8
SYMATTR SpiceLine tol=1 pwr=.25
SYMBOL diode 1024 -1744 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D4
SYMATTR Value 1N4148
SYMBOL res 576 -1392 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 20k
SYMATTR SpiceLine tol=1 pwr=.25
SYMBOL res 768 -1392 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 12k
SYMATTR SpiceLine tol=1 pwr=.25
SYMBOL diode 576 -1040 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL diode 512 -1104 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode 1088 -1680 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D5
SYMATTR Value 1N4148
SYMBOL cap 1328 -1232 R0
SYMATTR InstName C8
SYMATTR Value 10n
SYMATTR SpiceLine V=50 Irms=272m Rser=0.391699 Lser=0 mfg="KEMET" pn="C0805C103K5RAC" type="X7R"
SYMBOL cap 1232 -1280 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C7
SYMATTR Value 100n
SYMATTR SpiceLine V=50 Irms=835m Rser=0.0936732 Lser=0 mfg="KEMET" pn="C1812C104K5RAC" type="X7R"
SYMBOL res 1328 -1280 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R7
SYMATTR Value 10k
SYMATTR SpiceLine tol=1 pwr=.25
TEXT 496 -1728 Center 3 ;Mark Hammer's Wattbreaker\nV1 1/4/2021 from original schematic
TEXT 1128 -1184 Left 2 ;Tone 25kB
TEXT 1312 -1304 Left 2 ;Volume 100kB
TEXT 568 -1392 Left 2 ;1
TEXT 1400 -1176 Left 2 ;1
TEXT 768 -840 Left 2 ;Supply voltage +9 to +18VDC
TEXT 712 -1280 Center 2 ;Gain100kB
TEXT 176 -1608 Left 2 !.include potentiometer_standard.lib\n.ac oct 100 10 100000\n;.tran 10m\n.op\n.step param GAIN LIST 1 .84 .5 .17 0 *setting of Gain pot
Title: Re: Another silly dual-stage overdrive
Post by: MikeA on January 05, 2021, 10:16:12 PM
Seeing as it is fundamentally an adaptation/perversion of the basic Bluesbreaker circuit, I'm curious as to how may other Bluesbreaker-derivatives there are out there.  Certainly not as many as there are Tube Screamer derivatives, but between Analogman (KoT) and JHS (Morning Glory) that can't be the entire spectrum.
In addition to these, I'm aware of the Wampler Pantheon and the Heavy Hand side (left half) of King Tone's The Duellist as derivative of Bluesbreakers.  Kevin had a nice Bluesbreaker analysis on the Aion website, but it's not there on his new site. 
 

Title: Re: Another silly dual-stage overdrive
Post by: 11-90-an on January 06, 2021, 02:06:23 AM
Here's a quick perf layout, unverified, of course...

(https://i.postimg.cc/phsQqQTg/Wattbreaker-Perf-layout.png) (https://postimg.cc/phsQqQTg)

"Treble Pot version" is my suggestion here:
A quick mod, as I find myself looking for more treble (my taste), so replacing the 10k resistor on the output with a 4k7 in series with a 10k pot gives a tad bit of treble control without too much hiss, etc. This moves the LPF corner frequency from around 1kHz to 3.8kHz

Of course, stock is the original stock circuit by MH. If there are errors in the layout, please do tell... I will correct them as fast as I can...

Enjoy... :icon_mrgreen: :icon_mrgreen:

EDIT: I noticed an error in the layout, there is a missing 6k8 resistor. I’ll change it in a while...

EDIT 2: Fixed it... :icon_mrgreen:

EDIT 3: Ahh drat... another error noticed... will proceed to fix, again

EDIT 4: Hopefully will be the last, fixed it and updated it again...  I am sad to say I cannot resist a jumper anymore...  :(

Title: Re: Another silly dual-stage overdrive
Post by: Ben N on January 06, 2021, 09:18:05 AM
Eh, never mind.
Title: Re: Another silly dual-stage overdrive
Post by: Marcos - Munky on January 06, 2021, 03:53:12 PM
Very interesting!

As a 1590A guy, I did a 1590A layout for this one. Pots soldered to the board, no jumpers but the output wire have to be taken directly from the pot. Unverified, of course, and easy to be modded for a 1590B (which also solve the output wire "issue").
(https://i.postimg.cc/mzpcjtMv/wattbreaker1590a.png) (https://postimg.cc/mzpcjtMv)

I can't really say when I'll be able to verify it. But I can share the files if anybody wants to give it a try.
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 06, 2021, 04:19:25 PM
Wow!  You guys make me feel like a king.  I hold out my hand and there is instantly a full brandy snifter in it.  I'm spoiled. 

It should be able to fit in a 1590A.  I perfed it on a board that is 12 x 16 holes, and that was only because I didn't have any small ceramic disc caps of the right values and had to use bigger plastic ones.

Just as an aside, these days, I'm finding I like to use these things for IC sockets, breaking off pieces to suit the number of pins in the chip.  It doesn't add much to the height of the components but it provides a little bit of space under the IC for things like 1/8w resistors and small caps running between pins 1-4 and 5-8.  A handy space-saver.
(https://cdn10.bigcommerce.com/s-sxoup5r/products/3183/images/4132/SILSocket__85839.1409778504.1280.1280.jpg?c=2)
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 06, 2021, 04:53:32 PM
Wow!  You guys make me feel like a king.  I hold out my hand and there is instantly a full brandy snifter in it.  I'm spoiled. 
...
Well deserved and earned. Long live the King! (Is something I never thought I'd say but in this case I'll take a short break from the antiauthoritarianism just this once.)

Three cheers,
Andy
Title: Re: Another silly dual-stage overdrive
Post by: iainpunk on January 06, 2021, 05:06:14 PM
Quote
but in this case I'll take a short break from the antiauthoritarianism just this once
don't have to,
https://rationalwiki.org/wiki/Anarcho-monarchism (https://rationalwiki.org/wiki/Anarcho-monarchism)

cheers, Iain
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 06, 2021, 05:26:21 PM
Quote
but in this case I'll take a short break from the antiauthoritarianism just this once
don't have to,
https://rationalwiki.org/wiki/Anarcho-monarchism (https://rationalwiki.org/wiki/Anarcho-monarchism)

cheers, Iain
Interesting, though I tend to favor absolute anarchy with a strong anarch  :icon_lol:
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 07, 2021, 09:02:56 AM
Thank you, Mark, for your insightful comments and advice for so many years !
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 07, 2021, 09:04:04 AM
At which point does having even more gain stages lead to no additional tonal benefit ?
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 07, 2021, 09:06:32 AM
ASDFGH

Another
Silly
Dual-stage
Filtered
Gain-pedal
by Hammer !
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 07, 2021, 12:06:14 PM
ASDFGH

Another
Silly
Dual-stage
Filtered
Gain-pedal
by Hammer !

Sounds like a Lovecraftian monster. Something with nine wings and 17 tentacles on it's back. I like it.

Cheers,
Andy
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 07, 2021, 12:26:55 PM
The "ASDFGH" is on page 19 of the current IKEA catalog.  It is either a kitchen stepstool to reach higher cupboards, or else an implement for stacking comforters in the linen closet.

These days, I find the boundaries between IKEA product names and the names of various pharmaceuticals I see advertised on television, have pretty much dissolved.  Much like the names of holiday resorts and drugs.  Pedals aren't far behind.

Is a Mjolnir something I take for psoriasis, somewhere I should go for a honeymoon, something I use to neatly store over-sized cutlery, or something I use to drive an amp?  I can't tell anymore.
Title: Re: Another silly dual-stage overdrive
Post by: iainpunk on January 07, 2021, 03:26:12 PM
OT: sorry in advance
Quote
kitchen stepstool to reach higher cupboards,
why not make lower hanging cupboards if you are smoll? or just grow more?

Dutch people are the tallest in the world, and i am relatively tall here, wanna know the secret? i was a righ menace when i was a child, and every time i got disciplined, its Dutch culture to receive a kick in the butt, getting more of those upwards kicks makes you grow taller, while having to bend over for a spanking, like in other cultures, slows growth down.
that's why the Dutch don't need stepping stools (in the kitchen, we still use them to clean the roofs of our houses, we're not THAT tall)

cheers, Iain
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 07, 2021, 05:26:09 PM
When I did my masters degree thesis, much of the research I had to draw from was from Dutch researchers, many of whom were affiliated with medical schools.  That latter aspect meant that there could easily be 6 or more authors attached to a paper, since they all get co-authorship by loaning access to an expensive piece of machinery to another lab.  It's like that everywhere in medical schools.  You buy a pricey piece of gear with your grant, and you share it with others who have a different pricey piece of gear, with the understanding that you get a co-authorship when you let them use your stuff.  Upwards of 10 authors on a paper is not uncommon for that reason.

The trouble was that all those Dutch names were bloody long, and conformed to none of the spelling/pronunciation rules of English names.  Some welded the "van" to the second-part of the name, without a space, obliging an upper-case V, while others left the space, requiring a lower-case v.  It wasn't at all like briefly looking at the title page of an American study from a psychology lab by "Smith & Jones", and then turning to the keyboard to type in the reference.  In typing up the references section at the end of the thesis, I grew to hate the Dutch.  ;D  I know I shouldn't, but dammit, they hurt me so bad.  :icon_cry:
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 07, 2021, 05:43:59 PM
A significant portion of the research I cited in my masters thesis was in Russian. A whole new set of problems for the reference list... Needless to say, I don't even speak Russian. Good things that science uses so much jargon that you understand a lot if you can only read the alphabet. So I just learned that and was content with being able to understand the figures. I should learn Russian properly some time and I hope I'll manage before retirement.

Andy
Title: Re: Another silly dual-stage overdrive
Post by: iainpunk on January 07, 2021, 06:24:44 PM
mark, the different forms of last names all have meaning, the vanName is for small land owners or farmers in the west while names ending with -ing or -ink mean a farm in 'de achterhoek' (like Boeing, there is still a farm called that in de achterhoek) and different ways of spelling names that are pronounced the same has to do with social class, and last names changed if you changed in social status, its quite an interesting history, but my english isn's sufficient to translate the whole inner workings of dutch names, and describing words that don't exist in other languages is hard.

i'm glad i don't have a Dutch name, my last name is Romanov Schmaloer (its German, i'm totally not a Russian time traveler)

cheers, Iain
Title: Re: Another silly dual-stage overdrive
Post by: Gus on January 07, 2021, 06:36:34 PM
ASDF

https://www.diystompboxes.com/smfforum/index.php?topic=104029.0 (https://www.diystompboxes.com/smfforum/index.php?topic=104029.0)
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 07, 2021, 07:01:15 PM
Nice!  I should have known you've covered this ground long ago.  And SIX pages of posts?!   :icon_eek:
Title: Re: Another silly dual-stage overdrive
Post by: PRR on January 07, 2021, 11:38:48 PM
...Is a Mjolnir something I take for psoriasis, somewhere I should go for a honeymoon, something I use to neatly store over-sized cutlery, or ....

Kickstarter PC case:
https://www.kickstarter.com/projects/thorzone/mjolnir-the-minimalistic-but-not-boring-pc-case

A Schiit:
https://www.schiit.com/products/mjolnir-1

An overdrive, of course:
https://mythospedals.com/mjolnir

A grave marker:
https://www.fastcompany.com/1672968/how-thors-hammer-made-its-way-onto-soldiers-headstones
Title: Re: Another silly dual-stage overdrive
Post by: Fender3D on January 08, 2021, 05:06:16 AM
...Dutch people are the tallest in the world, and i am relatively tall here, wanna know the secret? i was a righ menace when i was a child, and every time i got disciplined, its Dutch culture to receive a kick in the butt...

Those must have been quite effective kicks, 'cause, here in Italy, I took a wide selection of them (and still I do) and I barely reach 1.70m....  ;D
Title: Re: Another silly dual-stage overdrive
Post by: Sooner Boomer on January 08, 2021, 05:43:13 AM
Quote
but in this case I'll take a short break from the antiauthoritarianism just this once
don't have to,
https://rationalwiki.org/wiki/Anarcho-monarchism (https://rationalwiki.org/wiki/Anarcho-monarchism)

cheers, Iain

Nae king! Nae quin! Nae laird! Nae master! We willna' be fooled again!
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 07:49:38 AM
Is there a concensus on our forum on most preferred range for

Number of gain stages after which there is no additional benefit

Slope and freq of high pass filter before first stage

Need of a high pass filter between gain stages

Slope and Frequency of low pass filters after each stage

Advantage of having variable filter Freq versus fixed filters

Radians where to clip at each stage

Ratio of gain at each stage
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 08:08:31 AM
I'm confused regarding the concept of "gain" of 2 stage pedals

Suppose we have clean stages, and first stage has gain of 10 and second stage has gain of 20, it's clear to see that total gain is 200

But suppose we have 2 stages which include clipping (at different pointsof signal due to different signal levels and different diodes), does it convey all information if we calculate the gain of each stage and multiply them ?


Thought experiment

Suppose we have first stage of gain 100 and LED in feedback loop

We follow that with a second stage with gain 2

For second stage, we first try no diodes, then LED, then Si, then Ge diodes in the loop.

In all cases, total gain would be 200.

But all sounds would be different.

What did we really convey by multiplying gain of each stage and stating the result ?

Is there a better way to more exactly state what is going on ?
Title: Re: Another silly dual-stage overdrive
Post by: Fancy Lime on January 08, 2021, 08:13:58 AM
Is there a concensus on our forum on most preferred range for

Number of gain stages after which there is no additional benefit

Slope and freq of high pass filter before first stage

Need of a high pass filter between gain stages

Slope and Frequency of low pass filters after each stage

Advantage of having variable filter Freq versus fixed filters

Radians where to clip at each stage

Ratio of gain at each stage

Well, if there was a consensus on all of these, all overdrives woul sound the same, if they stuck to the consensus, and wouldn't that be boring. Changing all those things is what makes tinkering with overdrives so much fun. At least that's part of it.

It's a bit like asking "what is the best cake?". People's tastes are varied. But yes, you can change a lot of details of a recipe and still get a very similar cake.

Cheers,
Andy
Title: Re: Another silly dual-stage overdrive
Post by: 11-90-an on January 08, 2021, 08:26:35 AM
Suppose we have first stage of gain 100 and LED in feedback loop

We follow that with a second stage with gain 2

For second stage, we first try no diodes, then LED, then Si, then Ge diodes in the loop.

In all cases, total gain would be 200.

But all sounds would be different.

What did we really convey by multiplying gain of each stage and stating the result ?

Is there a better way to more exactly state what is going on ?

i *think* that the sounds would start to come from the clipping/distortion generated by either opamp or diodes, whichever clips first. Also, perhaps it has something to do with diode forward drop, opamp type, etc.

Here’s at least what I’m trying to say...

(https://i.postimg.cc/ftNpGGQG/9069-CC9-D-A997-4847-A46-B-79-D4-A2-AC1-CEB.jpg) (https://postimg.cc/ftNpGGQG)

And SIX pages of posts?!   :icon_eek:

Don’t worry, we’re halfway there... :icon_lol:
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 08:47:35 AM
Is there a concensus on our forum on most preferred range for

Number of gain stages after which there is no additional benefit

Slope and freq of high pass filter before first stage

Need of a high pass filter between gain stages

Slope and Frequency of low pass filters after each stage

Advantage of having variable filter Freq versus fixed filters

Radians where to clip at each stage

Ratio of gain at each stage

Well, if there was a consensus on all of these, all overdrives woul sound the same, if they stuck to the consensus, and wouldn't that be boring. Changing all those things is what makes tinkering with overdrives so much fun. At least that's part of it.

It's a bit like asking "what is the best cake?". People's tastes are varied. But yes, you can change a lot of details of a recipe and still get a very similar cake.

Cheers,
Andy


There can still be some consensus of this type

5 gain stages do not have a perceived tone or feel difference than 2 stage


First high pass should between 50 to 1 kHz, and preferably in the 600 to 800 Hz range. It's not nice to have a high pass of 2 Khz



Etc...


Yes indeed, many pedals do sound like each other.

Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 08:51:24 AM
Suppose we have first stage of gain 100 and LED in feedback loop

We follow that with a second stage with gain 2

For second stage, we first try no diodes, then LED, then Si, then Ge diodes in the loop.

In all cases, total gain would be 200.

But all sounds would be different.

What did we really convey by multiplying gain of each stage and stating the result ?

Is there a better way to more exactly state what is going on ?

i *think* that the sounds would start to come from the clipping/distortion generated by either opamp or diodes, whichever clips first. Also, perhaps it has something to do with diode forward drop, opamp type, etc.

Here’s at least what I’m trying to say...

(https://i.postimg.cc/ftNpGGQG/9069-CC9-D-A997-4847-A46-B-79-D4-A2-AC1-CEB.jpg) (https://postimg.cc/ftNpGGQG)

And SIX pages of posts?!   :icon_eek:

Don’t worry, we’re halfway there... :icon_lol:


So we did not convey anything much by calculating and stating total gain of a 2 stage pedal.

I feel It is essential to also understand headroom  and signal strength at each stage (what I call clipping radians since that incorporates signal level with level at which signal is clipped )
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 08, 2021, 08:59:31 AM
Cascading gain stages that clip is a matter of adjusting the gain, bandwidth, and clipping thresholds of subsequent stages.  Vivek is correct in being a little befuddled by the multiplicative aspect of gain over multiple stages.  Diodes in the feedback loop will constrain the maximum output of a stage.  Any intention to re-clip in a subsequent stage requires bringing the level up a bit to suit the diode complement in the next stage, but since one starts out with a reasonably hefty signal from the preceding stage, not much gain is required of the subsequent stage to again reach a clipping threshold.

And since Gus astutely brought up the topic of BMP stages wih his ASDF circuit, you'll note that the Big Muff has two identical clipping stages, with the same gain and clipping threshold in each.  Variations of that circuit in various commercial pedals have toyed with differentiating the characteristics of clipping stage 1 vs 2.
Title: Re: Another silly dual-stage overdrive
Post by: Gus on January 08, 2021, 09:06:21 AM
Nice!  I should have known you've covered this ground long ago.  And SIX pages of posts?!   :icon_eek:

I think it is cool you posted the circuit. 

Years ago I traced a bluesbreaker(there was no schematic posted on the web at the time I could find) and when I saw how the circuit was set up I thought that was very cool.

More experimenting with the interaction between gain stages is something I think is "better" than the TS like circuit
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 09:28:07 AM
My friend Dr Buffa made a web page where we can change transfer function, gain, high pass for each stage in a virtual amp

and can add more virtual stages

and hear the effect of adding one more gain stage in real time

or effect of changing high pass filter in real time

https://mainline.i3s.unice.fr/AmpSim5/
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 09:44:57 AM
Cascading gain stages that clip is a matter of adjusting the gain, bandwidth, and clipping thresholds of subsequent stages. 

While one pot to adjust gain of 2 stages looks elegant

It seems to impose a constraint on the relationship of gains of each stage

For example, guitarist cannot say in the one gain pot scenario "Lets keep gain of stage 1 at 150 and then only change the gain of the second stage till we get the tone we like"

or " lets see if high gain followed by low gain is better than low gain followed by high gain"
Title: Re: Another silly dual-stage overdrive
Post by: FiveseveN on January 08, 2021, 09:54:48 AM
guitarist cannot say ...
Have you ever met a guitarists that wished for more controls on their gear? How about one that can properly define "gain"?
Title: Re: Another silly dual-stage overdrive
Post by: marcelomd on January 08, 2021, 10:09:50 AM
I think the "gain" in the gain knob of a pedal is a leftover from the time where you needed to crank the gain knob on an amplifier to get distortion. Nothing else. Even if internally there's a change in amplitude of the signal, the perceived effect is a change in tone/timbre/voice.

Personally I prefer other names. Distortion, drive, dirt, dtc.

The confusion with the term "gain" goes even deeper. In most tube amps, the actual signal gain is fixed and the "gain" knob is an attenuator. Sometimes this knob is called "volume". Sometimes there are two such attenuators, gain and volume (or master).
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 10:31:58 AM
Fulltone Plimsoul had 2 gain stages, with individual control of the gain of each stage

http://revolutiondeux.blogspot.com/2012/03/fulltone-plimsoul.html


(http://1.bp.blogspot.com/-nKJVWJcLM_k/T1X4UruQ5_I/AAAAAAAABDM/vhqoDtuIUHI/s1600/plimsoul.PNG)

There are some interesting videos on the Interweb that show the effect of tweaking each stage independently
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on January 08, 2021, 11:28:45 AM
Interesting circuit.  I doubt the full 100k of that dual-ganged pot are needed to tame the clipping of the LEDS, and suspect there islikely a missing parallel resistor, but that's just speculation on my part.  That said, it's kind of a different take on the one-action-changes-two-parameters control that Gus's ASDF and the Bluesbreaker gain employ.
Title: Re: Another silly dual-stage overdrive
Post by: Vivek on January 08, 2021, 11:43:19 AM
Stage 1 of plimsoll has its own control, labelled "Sustain"

So each stage's gain is controlled independently.

Gus has one pot change gain of both stages
Title: Re: Another silly dual-stage overdrive
Post by: rockola on February 08, 2021, 10:13:33 AM
Now available at a Github near you: https://github.com/rockola/wattbreaker

(https://ola.rinta-koski.net/Pedals/Wattbreaker/600x_wattbreaker.jpg)
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on February 08, 2021, 10:17:35 AM
 :icon_biggrin: :icon_biggrin:

I guess it was bound to happen eventually.
Title: Re: Another silly dual-stage overdrive
Post by: Marcos - Munky on March 05, 2021, 02:38:45 PM
Finally built one. Surprisingly, not in a 1590A, but in a transformer can (or whatever it's the correct name) I had on my parts bin. It's the first bluesbreaker-like circuit I built, and it sounds very good. I really liked the sound of this one plugged into a clean tube amp and using a strat with single coils.

(https://i.postimg.cc/18NgymKL/wbout.jpg) (https://postimg.cc/18NgymKL)(https://i.postimg.cc/Wt6wPn4M/wbin.jpg) (https://postimg.cc/Wt6wPn4M)
Title: Re: Another silly dual-stage overdrive
Post by: Mark Hammer on March 05, 2021, 04:53:28 PM
Nice!  I'm honoured.
Title: Re: Another silly dual-stage overdrive
Post by: ElectricDruid on March 06, 2021, 03:34:37 PM
Now available at a Github near you: https://github.com/rockola/wattbreaker

Nice work. I like to see a schematic where someone took the trouble to put the relevant LP/HP cutoff frequencies in the places where they occur. There are usually several key components that shape the tone in a circuit, but often the schematic neglects to say where/what they are and what they do. I suppose that's not surprising on commercial designs, but it happens a lot on DIY stuff too. Fill us in! We want to know! Your version of Mark's schematic does that very nicely, so thanks both.
Title: Re: Another silly dual-stage overdrive
Post by: r080 on March 06, 2021, 03:54:18 PM
Mark,

Would you consider changing it to Another Silly Bi-stage Overdrive (ASBO), in keeping with some of the discussion here?