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Thought you all might enjoy this one.
The slightly earlier version of this pedal is essentially a 9v germanium FZ-1 with controls to boost the highs or lows. This version has three 2N 5172 transistors and works in the same way, but sounds quite a bit more aggressive. Not sure if this circuit is reminiscent of anything else?
The FD-3A version seems to have been made in 1967 and 1968, and this version from what I...

Complicated switch wiring always throws me for a loop for some reason so I'm hoping you guys could help me out. I have a 10 pin 2P3T slide switch that I would like to replace with a DPDT toggle. Using the schematic attached, how would I go about wiring the DPDT to the same effect? I copied this connection info from another thread:

Pins 1 and 5 connect to the same plane, as do pins 6 and 10.
The two sliding switch contacts move in tandem.
Contact 1 connects pins 1&5 to either 2, 3 or 4....

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I've had the idea of an envelope-controlled VCA effect pedal for a few months. Of course, many existing circuits fall into this broad definition, including compressors, the boss slow gear and tremolo effects, for the VCA part.
So what would set mine aside? One focus is on versatility. Once you have a way to control your output with a voltage, you can do whatever you like with it: swells, plucks, tremolo or even compressor if you try hard enough. I wanted to have at least a few of these modes at...

I have a long secret relationship with cab sims. I'm talking about analog cab sims, the ones that aren't anything more than a very specific equalizer. I know that digital and IR cab sims exist and are very popular, and can account for other characteristics of a guitar loudspeaker, but those are both outside my interests and my capabilities. I think a glorified filter can be very effective indeed for playing without a speaker and a microphone, quietly or not, and surely its hardware, being...

I’m currently struggling with the small stone layout from tagboardeffects.blogspot. I’m not getting any power to the ICs, but my build keeps frying the BC337 transistor on the power supply end of the circuit. Has anyone experienced this problem and has a solution?

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I've been on a bit of a delay kick (see EchoWreck and T60) and thought why not try a double tracker? However, one reason there are so few of them out there is that the PT2399 doesn't do short enough delay times for a lot of double tracking. It's got a 29 ms or so minimum time. I was repairing a CE-5(t) that uses the ES56028 and found it had very low delay times, but it's a 40 pin chip. Turns out there is a 16 pin ES56033. I bought five on Aliexpress to try out and the Stalker came out of it....

Hi to all! i have a beta-aiven (boss ge-7 copy) give me some tips to change the frequency of each sliders??

I'm experimenting with the EHX Small clone, but don't really understand why they put the transistor at the start of the circuit, why not just have a bit of filtering instead of the extra stuff.

Just curious.

I should add, I'm using two LM13700 OTA Ics instead of multiple CA3094s.

I am still trying to get a Rockman X100 I built a year or so ago fully working. I am getting too much compression despite adding a potentiometer to try to control it better. I have been looking at rockman.fr which is a mine of information on all the Rockman products. I think my problem relates to the 2n4339 FET transistor which needs to be properly biased. On the schematic, there are two resistors with guide values of 6.8 M and 5.1 M with a note that the specific values are factory selected to...

I need to replace the potentiometer on a Ross Phase R1 (Purple).
The potentiometer is utterly destroyed.
There is absolutely no resistance reading between the outer pins and the CTS potentiometer is not marked for value.

It seems someone put brakefluid in the potentiometer which in turn ate up the carbon track completely.

If someone has a purple Ross Phase R1, I would really appreciate it if you could
1) just measure the resistance between the outer potentiometer pins for the two cases of...

Full article in PDF: Practical-Electronics-1969-02 Harmonaphone.pdf

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some gut shots that might be of interest! :)

In patent 4627094 of December 2, 1986, Tom Scholz described a guitar compressor.

He also highlighted an issue with the release times of the compressor.

Tom described the ADSR curve of a guitar signal as follows:

On a guitar, the first sound or pulse that comes out can be a huge peak which is almost always much stronger than the signal that follows after a few milliseconds.

Then he described the problem with his earlier versions of the compressor:

The operation has not been found to be...

Moving soon so I need to sell some heavier stuff. Have these great amp building books that I no longer need.

Books by Kevin O'Connor - $60 each plus shipping (can make a deal for multiple purchases):

The Ultimate Tone Volume 1
The Ultimate Tone Volume 2
The Ultimate Tone Volume 4
The Ultimate Tone Tonnes of Tone

Books by Melin Blencowe - $40 each plus shipping (these are the out of print first editions in excellent condition):

Designing Power Supplies for Valve Amplifiers
Designing Tube...

I traced this one a few months ago and never got around to putting the schematic up here. The only thing that bothers me is how the 9v supply is hooked up to the cathode of the bypass LED. I still have the box but the owner is not willing to desolder the caps to find the values. Any way to measure them in circuit to get a rough idea of what the are? In my experience NP0/C0G caps are usually lighter in color....like a grey and the X7R caps are a darker brown so that's how I marked them on the...