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    IN PROGRESS JHS Crayon

    I haven't seen anything that makes me think this thing is not running on 9V. Does anyone know what are the voltages V and N on the Neve?
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    OTAs

    Cool! Do you think, in this case, the expander could be contributing with some distortion? I've heard samples from the preamp and it looks to me as if there is some grit coming from the preamp
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    OTAs

    Thanks for the explanation, Chuck. It's the Peavey Mace. I forgot to include the model, my bad. Apparently, they also use a CA3094 (marked 478 in peavey schematics)
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    OTAs

    Nice one, as always, Chuck, thanks! I have a little question about preamp circuits that use OTAs for distortion (like the Peavey and the Lab L5). It looks to me, that the signal being fed to the diff amp is also being fed to the amp bias input. Should it make the distortion more dynamic this way?
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    Can you guys help me understand some OTA distortion circuits?

    Hello everyone! I've been a bit obsessed with solid state preamps, and recently I've found the ones that employ an OTA for distortion (e.g. the Lab Series L5 and the Peavey Mace). From what I understand, they benefit from the soft distortion characteristics of the differential input. What I fail...
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    JFET Biasing - part 1

    Nice, thanks!
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    JFET Biasing - part 1

    Hey Chuck, would using jfets in parallel (like it's done in the Wampler '57) affect biasing?
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    This Week on the Breadboard - ROG Britannia

    I built one a few years ago, and I completely agree with Chuck's impression that it sounds very good. Brilliance and (misspeled) Treble are incorrectly labeled. Might be time for a makeover with some better selected fets
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    This Week on the Breadboard - The Engineer's Middle Finger Compressor

    Hey Chuck, should tr1 and tr2 be as well matched in the Pellucid rectifier as they should in an octave circuit, for example?
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    Everything You Wanted to Know About JFETs (but Were Afraid to Ask)

    Cool, thanks for the reply! I think I've understood it
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    Everything You Wanted to Know About JFETs (but Were Afraid to Ask)

    Hey Chuck, is there any particular reason for the different source and drain resistors in the two stages of the phase shifter? I'm willing to give it a try when I find the time
  12. L

    Neurocyton Preamp - Greer Soma

    I think I've read somewhere (but please don't quote me on that) that the 42tm018 (which is pretty similar to the 141P) can be installed backwards, and that makes sense since it's a 1:1 transformer
  13. L

    SOLVED Effects Layouts Tracksuit DRV- no audio

    Checking voltages and trying to trace the audio with the probe are steps that I would take, as well. Bear in mind that the LED turning on and off does not mean, necessarily, that the relay is working, as it depends on the 555 chip.
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    Earthquaker Bellows

    I totally agree with the bellows being the best sounding Bass Fuzz out there. Well, now it's back to the breadboard, cause i'm certainly interested in placing a pot between the collectors
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    Earthquaker Bellows

    It is a folded aluminum enclosure that I bought locally. It is prety much the size of a 1590b
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    Earthquaker Bellows

    Built a bellows with a couple 2n3904's forming a darlington pair instead of the MPSA13. Really nice distortion and fuzz tones (and some cool overdrive tones, too). Very simple circuit, but really effective.
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    End-All Red Internal Trim Pot Biasing?

    The service manual of the amplifier dictates 15v on the drain of the first jfet and 11.5V on the drain of the second one. I don't know what exactly is the ouput of the charge pump, but you should go for roughly 60% and 50% of VEE.
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    Design Challenge #2

    The L5 is an awesome project! It takes a completely different approach (an OTA is used for distortion), but sounds really good as well! The multifilter stage is also really interesting
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    Design Challenge #2

    Thanks for taking a look, Chuck! From what I could find, it sounds really sweet. From clean to pretty overdriven. I'm kind of obsessed with good sounding SS preamps, so I might try and recreate it (minus the reverb driver and recovery)
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    Design Challenge #2

    Sure, there you go: https://music-electronics-forum.com/filedata/fetch?id=831483&d=1382636822 If I'm not mistaken, they use some servos for biasing (but I could very well be mistaken)
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