PaiA motion filter

[DUCKFACE]

Hello everyone
im boulding Paia motion filter but i have few problems.
1. i think that schematic has smoe mistakes. Pins 4 and 7 are replaced ? Thats not a big issue.
2. I have signal on pin 4 of IC2 but no signal on pin 1.
3. what is controlling the swithces of the IC2 ?

for now i have just clean sound on output.

[antonis]

Make sure for correct pinout connections on your build..

[DUCKFACE]

im using tl074 as replacement for 4136. thats why for first point i had a solution. but for the second and trird points - still no solution.
edit: why they are not using a simple resistor voltage divider instead of that trimpot 500k ?

[antonis]

why they are not using a simple resistor voltage divider instead of that trimpot 500k ?

'Cause resistors can't be trimmed..

[DUCKFACE]

'Cause resistors can't be trimmed..

probably they cant
according to the instructions the ofset suppose to be in the middle of the trimpot. isnt it 250k
and i still cant get the idea of 4066 controled only by V+ and gnd

[ElectricDruid]

TL074 is not a replacement for the 4136. As Antonis posted, the pinout for the 4136 is unusual, whereas the TL074 uses the now-standard quad op-amp pinout. The schematic seems to follow the 4136, so a TL074 in there is going to be wrong in many different ways. It won't work.

The pinout on the 4066 switch on the schematic is also a bit weird, and I'm not sure there aren't mistakes in the pin numbering there too.

As to what's controlling the switch, that's simple enough - SW1 is. The 100K resistor acts as pull-up and give a high voltage when the switch is open, and when the switch is closed you get a low voltage (ground). Since the switch is driven by a logic signal, that's all you need - high or low.

HTH

[Mark Hammer]

The trimmer needs to be there to set the reference voltage for the 4066 to work properly.  If it was my pedal, I would just skip the 4066 and use a 3PDT stompswitch to bypass the circuit.

[m4268588]

I've never needed Vr trimmer in my experience. However, in that case, a DC blocking cap is required on the output, so there may be a reason for this circuit that I am not aware of.

[Eb7+9]

a DC blocking cap is required on the output ...

and a large'ish pull-down

[DUCKFACE]

TL074 is not a replacement for the 4136. As Antonis posted, the pinout for the 4136 is unusual, whereas the TL074 uses the.....

as i said before i changed the pinouts to the proper ones according to specifications of the 74. So the opamp parts are working... i think

thy should i use a switch in the motion filter? it suppose to be auto wah envelope filter so if the 4066 is acting as a regular 3pdt switch then i dont need it.

still no sound on pin 1 of 4066

[DUCKFACE]

The trimmer needs to be there to set the reference voltage for the 4066 to work properly.  If it was my pedal, I would just skip the 4066 and use a 3PDT stompswitch to bypass the circuit.

as far as i see there is no Rf on the 4066 ? or im missing something ?

[ElectricDruid]

as i said before i changed the pinouts to the proper ones according to specifications of the 74. So the opamp parts are working... i think

Ok, good. Sorry, I hadn't got that.

thy should i use a switch in the motion filter? it suppose to be auto wah envelope filter so if the 4066 is acting as a regular 3pdt switch then i dont need it.

They're not even using all of it! It's just switching between an output signal taken from the input buffer (so no effect), or the output signal from IC1d.
Honestly, I agree with Mark, a 3PDT would be easier.

still no sound on pin 1 of 4066

Have you got sound on the output of the IC1c and IC1d stages?

[DUCKFACE]

Have you got sound on the output of the IC1c and IC1d stages?

when i remove the 4066 and the resistors around it i have clear sound on the output of IC1c and 1D stages.
edit: no sound on pin 14 and pin8

[rankot]

Hello everyone
im boulding Paia motion filter but i have few problems.

Never heard of that one. Is there any demo available, now I'm curious!

[DUCKFACE]

Never heard of that one. Is there any demo available, now I'm curious!

https://reverb.com/item/15182123-vintage-paia-motion-envelope-follower-5720-filter-auto-wah-effect-pedal-rare
https://www.talkbass.com/threads/paia-5720-motion-envelope-follower-filter.28385/

[Fancy Lime]

Hello everyone
im boulding Paia motion filter but i have few problems.

Never heard of that one. Is there any demo available, now I'm curious!

Looks like an EHX Doctor Q with all the obvious optimizations to the envelope section and unusual switching.

[Mark Hammer]

Hello everyone
im boulding Paia motion filter but i have few problems.

Never heard of that one. Is there any demo available, now I'm curious!

Looks like an EHX Doctor Q with all the obvious optimizations to the envelope section and unusual switching.

There was a brief period, forty years ago, when Craig Anderton was designing effects for PAiA, including the Motion Filter, Rocktave octave divider, Axe Grinder distortion, Hot Lyx sustainer/compressor, Quadrafuzz, and Hyperflange.  All of this was well before the development and availability of 3PDT stompswitches.

The Motion Filter uses one of the filter modes of the Dr. Q, but also includes the "Frequency" control to adjust where in the spectrum the filter sweep begins.

The recommendation for adding a DC-blocking cap (e.g., 10uf) and large-ish terminating resistance (e.g., 100k) to the output of IC1D.

The 10k feedback resistance of IC1D could be replaced with 4k7 and a 25k pot to provide degrees of boost to the output.

The unit can also have variable decay, if you're interested.

[ElectricDruid]

What would we do without you, Mark?!? 

[Mark Hammer]

My guess is you'd probably have a lot more spare time on your hands. 

[DUCKFACE]

ok. iv rebuild it from scratch on the bredboard and its alive!
first of all - NOISY - really noisy. iv changed the 100p to 220p and things get better. But when you increase the sensitivity it sounds like dr.quack with fuzzface iv changed the transistor to 2n3904 but still the same noise. then i twist the transistor and the silence apear. But i lost the frequency control.