Author Topic: Another silly dual-stage overdrive  (Read 4162 times)

Mark Hammer

Another silly dual-stage overdrive
« 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.



Vivek

Re: Another silly dual-stage overdrive
« Reply #1 on: January 04, 2021, 02:44:56 PM »
Thank you sir !

I learn a lot from your posts

Fancy Lime

Re: Another silly dual-stage overdrive
« Reply #2 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
My dry, sweaty foot had become the source of one of the most disturbing cases of chemical-based crime within my home country.

iainpunk

Re: Another silly dual-stage overdrive
« Reply #3 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
« Last Edit: January 04, 2021, 04:09:06 PM by iainpunk »
half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail - snail man is fuccing real
『snailpilled』

Mark Hammer

Re: Another silly dual-stage overdrive
« Reply #4 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.

ElectricDruid

Re: Another silly dual-stage overdrive
« Reply #5 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!


jubal81

Re: Another silly dual-stage overdrive
« Reply #6 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?

iainpunk

Re: Another silly dual-stage overdrive
« Reply #7 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
« Last Edit: January 05, 2021, 10:39:52 AM by iainpunk »
half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail - snail man is fuccing real
『snailpilled』

Fancy Lime

Re: Another silly dual-stage overdrive
« Reply #8 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




...
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
My dry, sweaty foot had become the source of one of the most disturbing cases of chemical-based crime within my home country.

Mark Hammer

Re: Another silly dual-stage overdrive
« Reply #9 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.

MikeA

Re: Another silly dual-stage overdrive
« Reply #10 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. 
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Mark Hammer

Re: Another silly dual-stage overdrive
« Reply #11 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?

Vivek

Re: Another silly dual-stage overdrive
« Reply #12 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 ?

11-90-an

Re: Another silly dual-stage overdrive
« Reply #13 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:
flip flop flip flop flip

bluebunny

Re: Another silly dual-stage overdrive
« Reply #14 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.
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Ohm's Law - much like Coles Law, but with less cabbage...

Mark Hammer

Re: Another silly dual-stage overdrive
« Reply #15 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.

MikeA

Re: Another silly dual-stage overdrive
« Reply #16 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?   
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PRR

Re: Another silly dual-stage overdrive
« Reply #17 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.
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MikeA

Re: Another silly dual-stage overdrive
« Reply #18 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
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WIRE 576 -1376 560 -1376
WIRE 672 -1376 656 -1376
WIRE 768 -1376 752 -1376
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WIRE 880 -1376 832 -1376
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WIRE 1104 -1376 1104 -1472
WIRE 1104 -1376 1008 -1376
WIRE 256 -1280 256 -1376
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WIRE 368 -1280 352 -1280
WIRE 464 -1280 464 -1376
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WIRE 880 -1280 880 -1376
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WIRE 1104 -1264 1104 -1376
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WIRE 1168 -1264 1104 -1264
WIRE 1344 -1264 1312 -1264
WIRE 1424 -1264 1344 -1264
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WIRE 1344 -1232 1344 -1264
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WIRE 528 -1216 464 -1216
WIRE 608 -1216 608 -1328
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WIRE 1344 -1136 1344 -1168
WIRE 1424 -1136 1424 -1184
WIRE 464 -1120 464 -1216
WIRE 512 -1120 464 -1120
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WIRE 608 -1120 576 -1120
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SYMBOL voltage 928 -1008 R0
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SYMATTR Value 4.5
SYMBOL cap 400 -912 R90
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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
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SYMBOL cap 352 -1392 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
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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
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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
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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
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MikeA

Re: Another silly dual-stage overdrive
« Reply #19 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. 
 

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