EHX - Riddle QBalls VCF

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
uncleboko
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Post by uncleboko »

Any clues as to whether an OTA or opamp VCF is used?

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Post by uncleboko »

And any guesses as to how tthe envelope generator is made up - it does sound very very good, and the slow sweep sounds as smooth as the Space Drum decay :D

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Post by uncleboko »

Maybe something will surface eventually.

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Post by uncleboko »

A youtube to circuit diagram function might be useful :cry:

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Post by uncleboko »

A blank!

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Post by uncleboko »

I'm wondering if they use a new in house IC for the VCF or whether a stash of CA3094s has been uncovered :hmmm:

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Post by uncleboko »

uncleboko wrote:I'm wondering if they use a new in house IC for the VCF or whether a stash of CA3094s has been uncovered :hmmm:

:hmmm: :hmmm: :hmmm:

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Post by R.G. »

The LM13600, LM13700, CA3280, and NE5517 are all closely equivalent in function to two CA3094s in a single DIP. There are differences in the Iabc input and the pre-distortion diodes as well as lower overall noise. Takes a bit of circuit adaptation, but not much.

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Post by uncleboko »

R.G. wrote:The LM13600, LM13700, CA3280, and NE5517 are all closely equivalent in function to two CA3094s in a single DIP. There are differences in the Iabc input and the pre-distortion diodes as well as lower overall noise. Takes a bit of circuit adaptation, but not much.
This really is a riddle :lol: :lol: :lol:

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Post by earthtonesaudio »

Is there some reason to assume this is an analog pedal?
rocklander wrote:hairsplitting and semantics aren't exactly the same thing though.. we may need two contests for that.

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Post by uncleboko »

Because it sounds analog.

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Post by Scruffie »

Quick Specs
80 Hz to 5 kHz frequency response tailored for guitar
Optional expression pedal control
Fully-analog circuit
Switch selectable analog distortion designed for guitar
Start and Stop sweep control
Low Pass, Band Pass, High Pass filter select
Start and Stop for filter sweep and Q control
Separate Dry and Effect outputs
9.6VDC 200mA power supply included
So yeah, it is analog.

LM13700 Based Envelope Filter I guess, they seem to use them alot now... no clue about the detection.

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Post by uncleboko »

How are they doing the start & stop frequency envelope generator I wonder?

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Post by earthtonesaudio »

Scruffie wrote: So yeah, it is analog.

LM13700 Based Envelope Filter I guess, they seem to use them alot now... no clue about the detection.
Aha! I didn't scroll down enough on the EHX page, obviously. :slap:
rocklander wrote:hairsplitting and semantics aren't exactly the same thing though.. we may need two contests for that.

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Post by Scruffie »

earthtonesaudio wrote:
Scruffie wrote: So yeah, it is analog.

LM13700 Based Envelope Filter I guess, they seem to use them alot now... no clue about the detection.
Aha! I didn't scroll down enough on the EHX page, obviously. :slap:
Haha, I assumed it was digital myself, I just happened to catch that in the specs.

Easily done.

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Post by Ice-9 »

Could be a clue in this picture.

Image
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by uncleboko »

Am I seeing + and - 9v at the top?

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Post by Ice-9 »

uncleboko wrote:Am I seeing + and - 9v at the top?
No it looks more like 9v centre negative logo to me.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by uncleboko »

Amazing that no circuit has surfaced after all this time!

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Post by Ice-9 »

uncleboko wrote:Amazing that no circuit has surfaced after all this time!

Did you not see my post above where I circled in black a clue. :secret:
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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