The Jerkster -

L´Andratté

Hey!

I just build the Jerkster and it is just as good as I thought it would be!
The first test run went for hours

http://home.comcast.net/~ijfritz/ch_cir2.htm

I just did it on stripboard from scratch in about 12h in a row including panel-drilling, and it worked first try and I´m a bit euphoric about it now.

Of course the module is not a beauty, and I want to do another one with full vc-parameters (and since mine has a real hot output also output-attenuators).

Now my questions:
- Could the hot output be due to different OTA offset-stuff?
- Modulation should be linear, right?
- If so, the simple cv to PNP(grounded base) to OTA approach should work?
- Is switching timing capacitors any use?
- Finally, is there any reason why one should not add more integrators?
- I found the modulation to be very subtle (but I am not), so maybe lower the 220k?

Maybe someone can answer one or the other question or I will try to find out and report but first I will do some VCA mass production for a live gig nxt week!

TheMonkeysOfMadness.mp3

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blue hell · Posted: Sun May 19, 2013 4:22 pm Post subject:

So many questions ... and I just can tell you that you have some very nice beeps there Laughing

Ah .. an Ian Fritz thingie, nice!

L´Andratté · Posted: Mon May 20, 2013 5:51 pm Post subject:

nice!

HypoticOscillations.mp3

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elmegil · Posted: Mon May 20, 2013 8:47 pm Post subject:

nice...

wackelpeter · Posted: Fri Feb 06, 2015 5:40 am Post subject:

this week is the week of Ian Fritz modules for me...

finished yesterday the TGTSH circuit on stripboard that works really well from the start (apart from on of the Trigger Outs not working due to my mistake of putting the resistor and Diode on the base of one trannie to negative rail instead of ground)

half finished is the 5pulser waveshaper... only because i desperately wanted to try it out with my tgtsh...

now today i finished (or thought i did) the jerkster... running it on +/-15V supply...
as suggested increased the resistors going to the 4 bias Inputs from 22k to 27k...

but somehow i think it reacts a bit chaotic (haha... what to expect else from a chaos Generator)
...what i mean is that the rate pot gives only small control over slower cycles turned fully ccw it stops,,, then turning it ClockWise the oututs begin to swing but it then goes very fast from slow into the Audio range... Audio range is achieved when the pot is turned circa a quarter or third in it's range...
tried to solve this with an trimming pot placed between the Center lug of the range pot and the 3 27k pots... but not much successful in the result...
or should i increase all 3 resistors instead of putting on between them and the pot?
I also tried to Change the rate pot behaviour whilst using -15V and Gnd or +15V and gnd on ist outer lugs instead of +/-15V as per schematic... but again not much successful...

also i noticed that the first 2 Outputs when turing gain down went to 0v as expected but the third from U4 goes to a steady high stage (+ 14V)

is this correct? and maybe as L'andratte wrote the Outputs are sometime very hot more than 10Volts voltage Peaks... what's the best way to Limit them without changing too much of it's intended functionality and deforming the Outputs voltages?

any help would be welcome.