Tonepad Envelope Filter

[duck_arse]

I'm back, w/ diagrams!



above is the reverse switch rewire. I don't know if it's any clearer than the one above, but it does show my alternative wiring. let me know if you don't follow it.

the 3k resistor stays 3k. it can be 2k7 or 3k3, I don't think the value is super-critical. the IC's only run on 3V75~5V0. cmos IC's, when used in the linear mode (ie, as amplifiers instead of logics), draw LOTS of current, and are sometimes reported to run HOT! the 3k limits the current and drops the volts to the ic's to keep them cool. - 4V96 is good -

with the 4066 and TG pins, for the time being, you can use resistor leg off-cuts to link pin 13 and 12, and pin 5 and 6. we'll worry about the other pins when we have a working board. my new computer system is everything different, my html style sheets are messed, so I'm difficults with sorting these pages at the moment .....

I didn't get a chance to look at your second lot of pics yet, but I will. I was worried about the range swith wiring too. with regard to your measures: when we do voltage measures on a circuit, it is usual to say, for instance:

the voltage at R17//R24 will be 4V96 with no signal, and if that section is working, giving a twang on a guitar connected will send that voltage lower, depending on the "threshold" pot setting. it then rises again as the note decays.

(mostly we leave out all the jabber,) but we only need one point where two components connect. if you post both ends of each component, it gets difficult to follow, and the numbers sometimes change. but, I want you to tell the voltage at the point noted, please. also the point R14//R16.

it might soon get to a point that we disconnect all the stuff we don't need, and concentrate just on the circuit board. when we know that is tikkety-boo, we can add the switching and dc conns and leds etc ....

[duck_arse]

more questions, and stuff.

what value is C4 fitted on board? what value C2? as shown in yr pics so far, the reverse switch was wired incorrectly. it would be better to run four different colours wire from those points to the switch, no mistakes then. similar, yet different, with the filter range switch, run wires of the same colour to "A and B", and a different colour to "I and J".

I never attempt to decipher somebodies bypass switch wiring. it always makes my eyes hurt. the same with DC sockets. so, I can't say yes or no about the bypass wiring. I compared the pins of your jacks with one I have here, and they don't seem right. so, you need to test continuity.

jamb a lead into the input socket. jamb a different lead into the output socket. (no power for these tests, no signal either.) set yr meter on low ohms/continuity/beep setting, and connect one probe to the each of the plugs at the other, free end of the leads. what reading, either beep/0R, or 1000 flashing, or similar. these are the only two readings you're allowed. now work the bypass switch: do you get "the other" reading now?

now take the probe from the output lead plug tip, and put it on the circuit board at "in". what reading? work the bypass, what reading now? swap the probe from the input lead tip to the output lead tip, and the other probe to "out" on the pcb. what reading? work the bypass, what reading?

list all yr answers, we'll go from there.

[bilo01]

I've linked pins 12 & 13 and 5 & 6 of the 4066. and changed the wiring of the reverse sweep to your alternative wiring. There is now no sound at all.

R17//R24 = 2.24V.
R14//R16 = 2.70V.

C4=0.047uF (47nK100)
C2=1uF
I changed these values from the original after several posts on tonepad.

jamb a lead into the input socket. jamb a different lead into the output socket. (no power for these tests, no signal either.) set yr meter on low ohms/continuity/beep setting, and connect one probe to the each of the plugs at the other, free end of the leads. what reading, either beep/0R, or 1000 flashing, or similar. these are the only two readings you're allowed. now work the bypass switch: do you get "the other" reading now?

With Leads you mean wire?

[duck_arse]

no, guitar leads, or the little short patch cords will do. or just an empty plug, if you have.

[edit:] does the R17//R24 voltage change with rotating the threshold pot, or with wang on guitar ?

[bilo01]

I've got no signal whatever on the leads. dmm just stays at 1.

Turning of the treshold pot gives no change in voltage.

[duck_arse]

ok, we go from the start.

get some paper, and draw a 3d diagram of your input jack, so you can mark and identify the pins, because I think yours is somehow not right. get and plug in a guitar lead, of any length, with a 6.5mm plug on either end; just a plain plug, with no solders is good too. now with no circuit power, and with dmm on low-ohms, put red probe on the "tip" of other end of the guitar lead (the unplugged end), and then black probe, measure each of the socket lugs. on your diagram, write down whether "o/c" or "short" for each lug.

you now have three readings, from the last pictures I saw, yes? now, put red probe on the sleeve, or ground part of the plug on the far end of guit lead, and black probe all the lugs on the socket. write down all readings, that makes six, no? then, do the whole thing again on the output socket.

tell me your results, you can even show your drawing if you like.

we'll get there.

[bilo01]

Hi Duck
Finally got my answer to your request. Took a while but i had bad voodoo over past weekend.
Don't know if it will get posted right but have to do it for know through my mobile. Any questions, just ask

[bilo01]

Hi Duck
Finally got my answer to your request. Took a while but i had bad voodoo over past weekend.
Don't know if it will get posted right but have to do it for know through my mobile. Any questions, just ask

[duck_arse]

ok. the hFE range is for measuring transistors, it's the "2000" range we want. and I should have said "short the two probes together, what reading do you get?", but it looks like you'd get "001" from your results. I'll have to have a time looking at your jacks wiring and footswitch again. I'll go away and draw a diagram .....

did you get any reading for the fourth lug on the input jack? and can you do this testing as well?

I never attempt to decipher somebodies bypass switch wiring. it always makes my eyes hurt. the same with DC sockets. ... we want to measure continuity from input to output, across the bypass switch, and to and from the pcb to jacks.

plug a lead into the input socket and plug a different lead into the output socket. (no power for these tests, no signal either.) set yr meter on 2000ohms setting, and connect one probe to the tip of the plugs at the free end of each lead. what reading, either "001" or "1   " flashing. these are the only two readings you're allowed. now work the bypass switch: do you get "the other" reading now?

now take the probe from the output lead plug tip, and put it on the circuit board at "in". what reading? work the bypass, what reading now? swap the probe from the input lead tip to the output lead tip, and the other probe to "out" on the pcb. what reading? work the bypass, what reading?

[edit: ] I've looked over the thread, but I can't see; did you point us to a diagram of your bypass wiring scheme somewhere?

how sort of bad voodoo? and thanks for the quote (I was going to draw a down arrow, but I don't have one).

[bilo01]

Hey Duck, here it goes..

"short the two probes together, what reading do you get?", but it looks like you'd get "001"

Indeed, I get 001 here.

did you get any reading for the fourth lug on the input jack? and can you do this testing as well?

The reading for the fourth lug in both variations is 1.

plug a lead into the input socket and plug a different lead into the output socket. (no power for these tests, no signal either.) set yr meter on 2000ohms setting, and connect one probe to the tip of the plugs at the free end of each lead. what reading, either "001" or "1   " flashing.

Probe on both tip of lug free ends gives "001" not flashing. Switching the bypass gives 1, not flashing.

now take the probe from the output lead plug tip, and put it on the circuit board at "in". what reading?

This gives 001. switching bypass gives 1.

swap the probe from the input lead tip to the output lead tip, and the other probe to "out" on the pcb. what reading? work the bypass, what reading?

This gives 001, switching gives 1.

I used the Offboard wiring nr. 5 from Tonepad.

I had severe pain on my chest last friday. Suspected someone sticking needles in a puppet.. Might be you being annoyd of my absolute beginner level lol. Man the pain! Seriously thought of a heart-attaque. Had an ECG today and everything seems to be OK, so I'm good to go again.

[duck_arse]

Suspected someone sticking needles in a puppet.. Might be you being annoyd of my absolute beginner level lol.

it wasn't needles, it was a meter probe. ohh, nothing, move along .....

well, yr above results show promise. it seems the signal should be getting to and from the board. so, now I send you to audio probe land.

http://www.diystompboxes.com/pedals/debug.html
http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=3c3f5593679a95b8263d69b1b295bc86&topic=100003.0

put one together, and we'll start probing.

[duck_arse]

I been getting not very far on the breadboard, although I have managed some noises that might just pass as autowahing, so I still don't know the full correct operations of this circuit, but .....

I have been looking at your pics of boards again, and spotted one something, and one something I've been passing off as bad camera colours. you seem to have a 100k in R14, instead of specified 62k. I dunno if you mentioned changing this since we started, but you can change it if you have a 62k (a fairly odd value) or replace R14 with a 68k and R16 (now 100k) with a 120k. these new values will keep the ratio about right.

but, they'll not make as much difference as R13. the more I'm looking at it, the more it looks like you've fitted red-violet-brown (270R) instead of red-violet-yellow = 270k. 1000X ! put your meter on that one, see what it reads .....

[bilo01]

but, they'll not make as much difference as R13. the more I'm looking at it, the more it looks like you've fitted red-violet-brown (270R) instead of red-violet-yellow = 270k. 1000X ! put your meter on that one, see what it reads ....

Pffff You're absolutely wright duck. Again I trusted the guy at the store who gave me the 270R instead of 270K. I know they don't have the original 240K. Same as the 62K for R14. ( I did mention this change in my second post ).
But i should have checked myself!! To eager to get started i guess.

In the mean while i finished my Nurse Quacky project. Breadboarded it first, etched the PCB, checked everything and wired-up, mounted it all in the box and closed it and then plugged in for the first time. Immedeate succes!!!
I just got to reassemble everything to give the box a nice finish. Only one minor detail: The signal LED shines very faintly. I used a 220K resistor for that. Maybe a 470K would turn out better?
Pics of the Nurse:



So i'll be heading to town to get the 68K, 120K and 270K, make the probe and i'll get back to you with results. I'll be etching the Brittania PCB today and breadboard it. Getting into this lol

[duck_arse]

so, I turn my back for a minute, and you've got a project working and boxed? I should cut you off! the quacky is to your liking?

I once was one of those guys in the store. I know what it's like on the "other side". in those days we were selling components, not mobile phones.

well, as you're showing me, I may as well tell a few things. the led resistor - I like my leds DIM, low current draw on battery, unlike some around here. with a superbright led I use a 15k, sometimes 22k. neither 220k or 470k will do the job. if you have a 10k ~ 18k, just carefully solder-tack it across the resistor you have there now. too bright? fit 22k - 27k. too dimm? you can go as low as 3k3 or so, but you'll be burning holes in the ceiling .....

the led sticking out in the pic looks like you haven't seated it right. I think you might have to pull the rubber plug out the bottom of bezel, then push the led in from under, then plug-up w/ rubber bung, leads poking through. only the top of the dome of the led should be sticking up, really. and you need to sleeve ALL those connections, resistor leads, led leads, anything bare, because THEY WILL CAUSE TRUBBLE if you don't.

what are you using to secure/isolate the circuit board? you can buffer that 9V battery w/ a block of foam, cut to size. if it is allowed to shift inside, it too will cause trubbble. it is also always (seems you got lucky here) better to test the fully wired circuit out of the box first. if you know it works, then put it in the box and it stops, findind the fault becomes easier, because it will most likely be a mechanical, not electrical cause.

I always use a wiring jig. get something, plywood, masonite, corrugated styrene advert banner thing, cardboard even. cut it to the size of your box flattened out. mark where the parts are going, knock through some holes, mount your parts and all your wires will then be "the right length". you have a rigid mount for soldering and testing. you can search wiring jig hereabouts, there'll be pictures and all.

and tropical fish caps?! did the guy sell you those, or did you pick them? having said all this nit-picking, overall, the box looks pretty good. and it works, that's all you want really. what ideas for finishing, something special?

[bilo01]

When i finished her off last evening i tried at low volume and she quacked allright. Today at louder volume the effect seemed to diminish. Gonna test it more tomorrow, wife and kids are gone then.

Went back to the store today. A new guy behind the desk. When i asked him for the 62 and 240 he opened up a drawer with precision resistors with the requested values. Told him about the mix-up and got 2 for free lol.

So i installed the both in R14 and R 13. One thing that changed is that the spaghettibundle makes no more hiss when i touch it. The other thing is that I've got sound again but no effect/quack. Volume loss is about 50% from the bypass signal. When i switch the reverse the volume drops another 50%. Turning the pots doesn't change a thing.

About the nurse:
The LED: thought already it looked funny when i put it together, but it was late last night... I'll check the resistor values you gave.
The Battery: I've got a clip for that but have to drill a hole in the bottom. Haven't done this yet because i don't know if this is a keeper with regards to the MXR clone, which should fit in the same box. For the PCB i've got distance pins which i will mount when it's definate. Then i will sleeve all connections too.

I've got the audio-probe ready too..

I like the plain old vintage-look. Not too much wild figurations. Simplicity works best. It might turn out like something like this:


The brownish part will be old-yellow then, like the MXR.

Yep, I just liked the tropicals. There's always something for the eye...

[duck_arse]

I've got the audio-probe ready too..

ahh, sorry, I musta missed this.

okeydokey, you'll need a signal source. your guitar will do it, if you can get someone to strumm it for you, but an audio oscillator is more usefull in this case, in my experience. you have a choice of builds, you can use a spare 4069, or a single transistor phase shift to produce a decent sine wave, or a dual (even a single) opamp to produce a triangle/square wave, or even a crummy old lm555/lm7555. tell what you have lying around, and I'll find you a circuit. you can put it on breadboard, you might even want to put on a board in a box for future use.

and any old crummy amp for monitoring.

[Kipper4]

Here's the signal generator I use sometimes


http://www.geofex.com/FX_images/q&dosc.pdf

[duck_arse]

well, that ^ saves me drawing a diagram. either of the two from rg, with the 10k pot replacing the string of three resistors would be "ace".

[Kipper4]

Mine has just one off board output on the 100mv output with a banana plug on but with hindsight I should have used a croc clip.

[bilo01]

Ok guys. 2 Am here and very happy to tell that i've got my MXR-EF working!!!!!
The only thing is.... It's not the Tonepad clone anymore, but the GGG instead. As i suggested earlier, this lay-out looks more organized so i desoldered the Tonepad PCB and etched a new one. Mounted it all up and works from the start. Some issues though, volume drop is one. But i stopped because i don't want the neighbours come knockin' at my door lol.
Tommorow i'll try it louder and come back here.

This is how i left the table. Wonder what the wife says when she gets home from nightshift....