Frequency-Dependant Low Pass Filter

[StephenGiles]

The EH Guitar Synth will provide you with that dream if you can think beyond a 1590 sized box.

[liquids]

The EH Guitar Synth will provide you with that dream if you can think beyond a 1590 sized box.

1-chip circuits and small enclosure sizes are not limitations for me at all.     However the EH guitar synth design is not exactly providing me with that dream..

At the same time, the fundamental 'extractor' is the focus point for me, once you have the a frequency wave cleanly and consistently, the sky is the limit.

And in the EH Guitar Synth, the tracking circuit turns out to be a compressor + self-tuning filter....

I tinkered with a self-tuning filter last evening, and by itself, it didn't improve my tracking all that significantly compared to a cliche and well tuned (and endless spice simulations!) static 3-pole low pass filter found in many devices, unfortunately.  The static filter already works quite well, for me, so it's not that it isn't great, it just isn't the magic ticket, surprisingly, in and of itself.

It's just those blasted wound strings on the first frets, they always seem to 'jump',  eventually, for which reason I completely understand, but am still annoyed by.  Though I suspect that for those with poor playing technique, the self-tuning filter may be a significant improvement over the static filters (not to toot my own horn).

But I didn't put a compressor before it...so Ill try that too.

OR I should simple accept the blasted octave skipping on a few select fretboard locations, ignore them and play on....but the perfectionist part of me won't give up!  

[StephenGiles]

The EH Guitar Synth will provide you with that dream if you can think beyond a 1590 sized box.

And in the EH Guitar Synth, the tracking circuit turns out to be a compressor + self-tuning filter....

No it is not, that is simply signal conditioning prior to the tracking tricks which are performed by the loop consisting of the 2 x 4047, a VCO running at twice the input frequency of the input, and a few opamps.

[liquids]

No it is not, that is simply signal conditioning prior to the tracking tricks which are performed by the loop consisting of the 2 x 4047, a VCO running at twice the input frequency of the input, and a few opamps.

Using logic and CMOS chips and then waveshaping is really the easy part...and how one does it is as wide as the DIY synth world is.  Turning guitar notes into simple and consistent waveform to interface with said chips seems much harder....from the 'sine wave' of the circuit, squaring it with a comparator circuit and logic gates etc...got that part, I think.

Moog freqbox and Loss1234's mini-ark is more my speed as I can actually hear what it sounds like (!), and it has set the standard for what I'm after...he's a really nice guy and has answered lots of question, however, understandable he is not giving away the details of his current tracking circuit after months of banging his head against the wall...and while having one would be fun, I'd rather use the basic tracking for my own circuit purposes and interest, and remain $449 the richer.  

Of course the pigtronix mothership is impressive ($$$) too...

[defaced]

Turning guitar notes into simple and consistent waveform to interface with said chips seems much harder....from the 'sine wave' of the circuit, squaring it with a comparator circuit and logic gates etc...got that part, I think.

Dumb question.  Would amplifying the living s__t out of the input until it clips get you a nice square way of just the fundamental?  This you could then use for whatever your heart desires. 

[liquids]

Dumb question.  Would amplifying the living s__t out of the input until it clips get you a nice square way of just the fundamental?  This you could then use for whatever your heart desires.  

That's what it all turns into and what you want feeding CMOS chips for sync and VCO control etc. That's the plan.

A true comparator and/or inverter does so nicely...which the EH guitar synth shows...check out MarkusW's work.....

But unfortunately, if the fundamental frequency 'warbles' - that is, because the dynamics of a guitars harmonics change over time - so does the square wave frequency.  Again, easy if you are using synthesis and oscillators to create 'pure waveforms.'   Much harder to strip down all guitar notes into a pure (even semi-pure) waveforms, which only gets slightly easier if you use separate pickups/filtering/triggers for each string!

[StephenGiles]

I don't think that the Pig Mothership comes anywhere near the EH Guitar Synth.

[R.G.]

Would amplifying the living s__t out of the input until it clips get you a nice square way of just the fundamental?  

- noise -

[StephenGiles]

No octave skipping with the EH GSynth.

[earthtonesaudio]

It'd be cool to make something like an anti-sustainer that electromagnetically damps the harmonics so you can play pure sines.

[liquids]

It'd be cool to make something like an anti-sustainer that electromagnetically damps the harmonics so you can play pure sines.

I always enjoy your ideas!

[liquids]

I don't think that the Pig Mothership comes anywhere near the EH Guitar Synth.

Do you know that Howard Davis designed the deluxe octave multiplexer, and the mothership?

[StephenGiles]

I don't think that the Pig Mothership comes anywhere near the EH Guitar Synth.

Do you know that Howard Davis designed the deluxe octave multiplexer, and the mothership?

Yes I do.

[merlinb]

Moog freqbox and Loss1234's mini-ark is more my speed as I can actually hear what it sounds like (!), and it has set the standard for what I'm after...he's a really nice guy and has answered lots of question, however, understandable he is not giving away the details of his current tracking circuit after months of banging his head against the wall...and while having one would be fun, I'd rather use the basic tracking for my own circuit purposes and interest, and remain $449 the richer.  

That mini-ark sounds like it has a noise gate. The tracker from a Boss OC-2 works very well as long as you don't let the notes decay, and you play carefully. I suspect he is using something like that (maybe with a tracking filter as well), plus the noise gate to kill the sputtering as the note decays. I could be way off, of course!

[StephenGiles]

Moog freqbox and Loss1234's mini-ark is more my speed as I can actually hear what it sounds like (!), and it has set the standard for what I'm after...he's a really nice guy and has answered lots of question, however, understandable he is not giving away the details of his current tracking circuit after months of banging his head against the wall...and while having one would be fun, I'd rather use the basic tracking for my own circuit purposes and interest, and remain $449 the richer.   

That mini-ark sounds like it has a noise gate. The tracker from a Boss OC-2 works very well as long as you don't let the notes decay, and you play carefully. I suspect he is using something like that (maybe with a tracking filter as well), plus the noise gate to kill the sputtering as the note decays. I could be way off, of course!

EH GSynth does not have that problem - but I know I'm wasting my breath

[merlinb]

EH GSynth does not have that problem - but I know I'm wasting my breath

Haven't we covered the EH guitar synth already on page 1?...

[StephenGiles]

EH GSynth does not have that problem - but I know I'm wasting my breath

Haven't we covered the EH guitar synth already on page 1?...

I just can't see the point in reinventing the wheel, when it has been perfected over 30 years ago!!

[merlinb]

I just can't see the point in reinventing the wheel, when it has been perfected over 30 years ago!!

a: It wasn't perfected. It's functional, but rather inelegant.
b: What if you could do the same thing with fewer parts...

[StephenGiles]

I just can't see the point in reinventing the wheel, when it has been perfected over 30 years ago!!

a: It wasn't perfected. It's functional, but rather inelegant.
b: What if you could do the same thing with fewer parts...

It's never been bettered in a fully analogue way.

[StephenGiles]

I just can't see the point in reinventing the wheel, when it has been perfected over 30 years ago!!

a: It wasn't perfected. It's functional, but rather inelegant.
b: What if you could do the same thing with fewer parts...

What do you mean by inelegant exactly? Surely you realise that if EH could have cut the component count they would. Think rack not 1590 box.