Experimental Delay & AmpMod from Noise Workshop

[moid]

Ignore question 2 - I can get completely clean signal if I really want it by turning the volume on the pedal down to nothing and setting the blend to be completely the original dry guitar.

is there a specific component that creates the loud popping sounds?  I was wondering if I could make a pot to adjust how strong those are to soften them a bit...  I was also wondering if it is possible to make the repeats louder without them becoming completely noisy? They are about half the volume of the original guitar sound and it would be nice to make them louder but without more noise/ crackle / pops if possible. This is a very cool circuit

[duck_arse]

good work on the fixxings. the soldering heatsinks need only last until you gain enough confidence really, or get one of those Hirschmann hook-probe things. as for the circuit hacks, I think you need knutolai for those, his circuit differs from others I'd be able to say "here" to/at.

[moid]

Well I spoke to soon, the pedal isn't generating anything except noise now I tried swapping the pT2399 out for one of my cheaper models, and that yields louder noise, but nothing more... I guess I'll try to drill a box for this at the weekend and get it in an enclosure and see if that fixes it. If not then I'm back to the drawing board I guess... maybe time to learn to breadboard this circuit.

Thanks for mentioning Hirschmann hook probes, I'd never heard of them - I can get a similar brand cheaply in the UK and I could use those to draw away heat while keeping the components flush to the board... as soon as I get paid I'll get some of those.

[moid]

OK some news - I've just built the circuit on breadboard and found two mistakes in my vero layout at the same time, so my breadboard version works, albeit with a lot of hum and the overall circuit (dry and wet guitar) is quite quiet. This is the first time I've built on breadboard, so maybe this is to be expected? Maybe the circuit needs a volume boost first?

OK I'd like to add some more damage to the repeats. It looks to me that pin 14 of the PT2399 outputs just the repeats, so presumably I can  pass that through another circuit and then bring it back to the EKKO delay and create more broken sounds? I was thinking of using a Devi Ever OK Fuzz, but I noticed it has three transistors and I think that three transistors inverts the phase of the signal so that if I blend it back into the original circuit I would loose volume? I'm possibly wrong on this, but if I added an LPB1 circuit as well to create four transistors in series, would that be OK - the signal would not then be inverted?

Devi Ever Fuzz Schematic:

[duck_arse]

moid, according to botophucket, that image/page does not exist.

it has been a while since I've had this on the bb, but it should be close to unity gain, there shouldn't be much volume lost. perhaps some photos of your BB layout, and some voltages?

have a look at a circuit like the hamlet delay (transistors) or the rebote2 (opamps) which both have external buffer and mixer. these may give you some usable ideas.

[moid]

I'm really sorry I forgot to reply, work was crazy at that time (just got promoted). I haven't been able to touch a soldering iron since Thanks for your suggestions, I forgot about them until last night (see below).

I've finally got some holiday so I looked at the breadboard to discover that most of the components are randomly scattered / no longer in it (we had a flood and had to clear a lot of stuff in a hurry and the circuit is now ruined...) Anyway I looked at my original vero layout and noticed a number of mistakes on it which I corrected last night and then decided to work over my original vero board with those fixes instead of breadboarding it (because what could possibly go wrong with that eh?) and the result is that, well nothing works (kind of) and definitely in a weird way. I'll put my new vero layout below:



(the floating capacitors and a jumper are parts I removed from the circuit, I also moved a few cables around to be in their proper positions and yes the layout is a mess)

This layout passes sound through when bypassed, but if I use the same daisy chain power supply for the circuit and amplifier, my amplifier turns off! (whether bypassed or not). If I power the circuit with a 9Volt battery on a battery snap with a 2.1mm plug on the other end, and the daisy chain for the amplifier then the amp works and then sound goes into the circuit (but seems to stop at pins 15 and 16 of the PT2399 where it can be heard but my audio probe can't get any sound from any of the other pins of the PT2399 (maybe that's normal? I think I should be able to hear sound from the feedback pot at least) ) None of the LEDs in the circuit will light up which is highly suspicious - is this some form of grounding problem? Maybe my power socket is busted? I've tried swapping out different pt2399 chips with no success either.

I've just looked at Knutolai's schematic again - and I noticed the section at the bottom right with the 1N5817 diode in it. I didn't use that section and although I have no idea what it does I've tried searching online and I think maybe it is some form of power protection for the circuit? Should I be running the power from the power jack to the P1 of this section, then through the diode and capacitors and then take the +9v on the right side to the +9v on the section of the schematic with the 78L05 in it? Because I haven't done this and maybe that causes the amp to short out when the circuit and amp share the same power? With this little section of the circuit I'm unsure what to do with the P2 GND part - do I run a cable from the ground of the power jack to it, and then the schematic shows it should go to ground, so would that be the strip on the vero that I connected all the other grounds to? This is the part I'm referring to:




Any opinions / advice / condolences gratefully received! Thanks.

[duck_arse]

congrats on the promotion. comiserations on both the flood and the breadboard and the vero disasters.

the D1 C1 C2 section is reverse polarity protection. it SHOULD have a +9V and a V+, or a Vcc, instead of two "+9V" points. the anode of D1 goes to the external universe, and the kathode supplies only the correct polarity voltage to the innards. the 2 caps are there to provide some supply filtering, hopefully to "short to ground" any of the carp generated by the digital sections. generally good practise, and they can hardly ever hurt.

I see on your board "22 cuts". you need 23, one under the most left 10k. is it there? move left the black wire to the board edge. move the 220nF cap to the right of the link. now you have acres of space for that 10k, and its cut. I doubt this is the cause of your shut-down problems, but it needs fixxe anyway. I'll have to have a look at the rest of the layout, at my leisure .....

also move that purple modulate wire out to the edge. can we see photos of your built board? over and under? maybe not quite as large as the layout dia?

get yer multimeter, and measure the DC voltages around the IC (ignore pin 5, it will produce nonsense). power off, and measure continuity between all the grounds and continuity between all the V+'s. then test for any shorts between supply and ground.

and when you see the ground symbol, whichever one the designer chooses to use, all those points are commoned, joined, shorted, connected, as one, at the same potential. sometimes the supply connections will be "shorthanded" as well, and there is a range of generally understood symbols apply there. in this inst, P1 is the (+) connection and P2 is the (-) connections on the DC jack.

[moid]

congrats on the promotion. comiserations on both the flood and the breadboard and the vero disasters.

Thanks very much (and for the quick reply!) Floods: don't do them kids, not even once... what a mess.

the D1 C1 C2 section is reverse polarity protection. it SHOULD have a +9V and a V+, or a Vcc, instead of two "+9V" points. the anode of D1 goes to the external universe, and the kathode supplies only the correct polarity voltage to the innards. the 2 caps are there to provide some supply filtering, hopefully to "short to ground" any of the carp generated by the digital sections. generally good practise, and they can hardly ever hurt.

Great so I was sort of right - but this section shouldn't prevent the pedal from working? Maybe I'll build it as an extra daughter board (I can't squeeze it onto the current board) and insert between the power jack and the circuit.

I see on your board "22 cuts". you need 23, one under the most left 10k. is it there?

No there isn't a cut (the resistor is mounted standing vertically to squeeze it into two holes of the vero, so I can't make a cut between the holes - also (if you don;t mind me asking) why would I need to - the signal flows through the 220nf cap to the 10K resistor and then to the modulation pot - nothing else is attached to that track so I'm unsure why I need to make a cut - ahhh! is it to ensure that all the signal goes via the 10K resistor and not some of it going through just the vero track and some of it through the resistor?  Bugger, I bet that's the answer! OK that will require some careful surgery of the board...

move left the black wire to the board edge. move the 220nF cap to the right of the link. now you have acres of space for that 10k, and its cut. I doubt this is the cause of your shut-down problems, but it needs fixxe anyway. I'll have to have a look at the rest of the layout, at my leisure .....

I'll move the black wire - the reason it is where it is, is because on the schematic the signal from pin 6 of the pt2399 splits into a T-junction and I thought that meant I should keep those two splits as close to each other as I could; presumably it doesn't matter if one is further away or not. I'll fix this and update the layout after I finish typing this.

also move that purple modulate wire out to the edge. can we see photos of your built board? over and under? maybe not quite as large as the layout dia?

OK I moved that to make the vero look like the schematic, but presumably it doesn't matter. I'll shift it to the edge now. I'll take some photos, but they might have to wait until tomorrow so there is some decent light to see things by (it's almost midnight here).

get yer multimeter, and measure the DC voltages around the IC (ignore pin 5, it will produce nonsense). power off, and measure continuity between all the grounds and continuity between all the V+'s. then test for any shorts between supply and ground.

and when you see the ground symbol, whichever one the designer chooses to use, all those points are commoned, joined, shorted, connected, as one, at the same potential. sometimes the supply connections will be "shorthanded" as well, and there is a range of generally understood symbols apply there. in this inst, P1 is the (+) connection and P2 is the (-) connections on the DC jack.

When I measure the DC voltages around the IC, this is with power on to the circuit I presume, but no signal going in? Sorry, what does "measure continuity between all the grounds and continuity between all the V+'s" mean? How does one test for shorts between supply and ground? Thanks for your help

[duck_arse]

nearly midnight? your're too soft, is the problem!

I looked over the layout, and couldn't see any glarings. mind, I'm not trying to follow the footswitch wiring, or the clean mix pot, not until you draw me an actual circuit diagram of what's going on there.

and yes, if you tie both ends of a 10k, 100k, 1M, 1R resistor to the same copper strip, it gets no work done. but cutting the 0R copper, you force the current through and work gets done as intended. simple surgery to what's on your diagram would be - cut the track left side of the bottom leg of the 220nF, move the 10k left one and turn it right angle, with the bottom leg now in row I, then the pink wire comes in at I as well. that's how vero works. if you've moved that black wire ......

a schematic shows the electrical connections only. it uses continuos black lines to indicate "this connect to this, and this, and this" for inst. it does not imply a physical layout of the components. that's explicit in you layout diagram. it translates those black lines into copper traces, so electricity goes where it told. either end of an unbroken trace is the same, same as the middle.

DC voltages with the power on, yes, no signal. we want the static conditions. AC is a different method. and continuity and/or resistance is ALWAYS !! power off. otherwise the meter will read silly. continuity is like resistance, except you expect very low (0R is good) resistance. you check the continuity of the black lines translated to copper, like. and, if you have odd behaviour, you look for shorts, continuity where there should be resistance, sometimes infinite(-ish) resistance.

make sense? any sort of a help?

[moid]

I blame my advancing years; I used to be able to do all nighters in my sleep

Anyway, Yay! success I made the changes you suggested then re-knifed the hell out of every track on the board (I found one possible sliver of solder bridging two tracks near the start of the circuit) and now the whole thing works The LEDs function, the same daisy chain can power the amp and the pedal and the guitar plays through it

Thanks very much for your patience, I've learned a lot from what you've said. I'd like to think I'm slowly improving and I'm really happy to have now (with a lot of help) created my vero layout from a schematic.

Of course I now want to ask another question. The repeats are wonderfully crumbly and distorted but also only about half the volume of the clean guitar sound. I'd like to make them a lot louder if possible. Is there a way to get just the wet repeats (no dry sound at all) out of the pt2399 somewhere, connect that to a booster circuit of some sort to make them louder and then blend them back into the clean signal going through the circuit?

Aha it seems that lug 1 of the modulate pot has pure wet repeats only (no dry signal) - so I tried connecting that to the volume pot lug 3 so it would blend with the signal coming from the circuit... which it does, for one repeat which is wondrously loud, but then rapidly becomes the sort of sound that has you ripping your headphones off and wondering if the real world has always had that high pitched tone to it? Ow... note to self, don't do this again.

So then I started to experiment I connected the lug 1 modulate pot to a new pot (started at 100K lin) and connected lug 2 of this new pot to the volume pot's lug 3. Depending on how I turned the pot I got either very little repeats at all, or quite interesting soft swells of oscillation that rose up and down in volume, but gradually became deafening noise that resisted all other sounds from the guitar. They were interesting for about 10 seconds though - a sort of drone accompaniment, but one that only plays your first note and refuses to play anything else. I then tried a 1K lin pot in place of the 100K - this gave me loud oscillating noise of the same type that just having no pot in this place did - it was quieter and by turning the pot I could get different noises, but nothing resembling an actual guitar sound. I next tried a 10K lin pot, now this was much more varied - quieter oscillating noise at one end, square wave super choppy tremolo effect on the signal around the middle, and a lack of repeats at the other end of the pot. Interesting, but I already have a good tremolo so I'd prefer to avoid that one.

Presumably I can't just connect the wet repeats from the modulate pot to the volume pot. Would this be possible through some sort of mixer / boost circuit - something where I could feed both the wet repeats in one part and the 'normal' delay output in the other and then have the repeats boosted and mixed together to go to the final output jack? (some sort of ABY pedal?) If that sounds plausible or at least doesn't make you laugh too hard, would you mind suggesting a circuit that might be capable of doing this? If that is impossible I might make a second output jack to the pedal so I can run the repeats out to one channel and the dry+wet normal circuit output to another channel and mix them on my computer. Thanks again and sorry for the wall of text.

[moid]

Aha, I think I may have fixed my own problems by connecting the right part of the circuit together (instead of the wrong part). I have now connected lug 3 of the Volume pot to lug 1 of a new pot (250K log). I then connected Modulate pot lug 1 to lug 3 of the new pot. Lug 2 of the new pot goes to the signal out of the pedal. This allows me to get excellent control over the volume of the repeats.

The only issue now is the repeat are extremely bass heavy, so I think I should be able to put a high pass filter between the modulate pot and the new pot - a 100nF capacitor and a 15K resistor high pass filter circuit should do the trick (that cuts 3dB at 106Hz I think). I'll do that tomorrow, I need some sleep.

[duck_arse]

... errr ..... well ..... yes, of course you can. wot? draw a circuit diagram, my head is spinning. good work on the fix, and yes, you can connect any point to any other point, until the smoke or the shrieking starts.

then it's too late. really, we want knutolai back to answer for his sins, and for the finer points of hacking his circuit. it's been a while since I've had this near a bb. [?] also, there is a cap, C13? that you can play with to get more/less of a reverb-y sound, or more shrieking if you go too far. [/?]

[moid]

Err yeah sorry about the garbled wall of text, it was late and I was excited that things were actually working (that's not exactly a common experience for me and pedal building!). Anyway, another post, another large image to look at - but hopefully a smaller one - I scaled it down so I hope you can still read it.  The below is my current guess at what the circuit is / should be  - I need to remove a pot from the actual circuit that I have done on this image and I need to re connect various cables to where they should be. That will have to wait until tomorrow alas. The bass cut pot and circuit I added definitely helps the repeats not become totally overwhelmed by a wall of bass noise, but it allows the option to leave that blast of sound in if I feel the need to use it. I used a different high pass circuit in the end, the proposed one above refused to work despite some very enthusiastic swearing at it...

Yes I'd love to see what Knutolai could add to this version of his circuit Hopefully it won't make him cry!

Regarding what you say about C13 - that would be cool to get another different 'sound' for the repeats, and I like reverb as much as most people enjoy breathing so before I attempt to box this spaghetti monster I think that definitely deserves investigation. I think I'll put two capacitors on a pot - the audio from the board will go to lug 2, one cap will connect to lug3, the other cap to lug1 and the spare legs of the two caps will connect together and then join to a cable to go back to the board. That way I can swap between the original sound and the hopefully more reverby sound and maybe into shrieking territory if required I need some sleep before any more surgery of this board takes place.... Hmmm a 7 pot delay pedal

[duck_arse]

excellent. I'll have a closer look at your amended layout diagram in lieu of a circuit diagram with your additions soonest. I'm not sure knutolai cries easily, and I'm not sure those caps on a pot will do right. maybe caps on a switch.

never mind that, as PRR would say, do you have enough modulaion maddness to hand with this, or do you wish for a bit more? I put this on the bb tonight, with just the delay pot adjustable, and added an envelope-controlled ldr (from a different circuit, on a different BB, far far away) across that pot, to seek for the vowels I once heard.

got masses of weirdnesses instead, tape spilt all over, space sounds up and down, etc ..... more investigations, me thinks.

[moid]

OK I'll try to learn to draw a circuit diagram soon What software would you use to draw one? Ooops ignore that it looks like DIYLC has that sort of functionality. I'll try but I suspect it may not be very accurate!

I tried the C13 change you mentioned, both on a pot and also just switching different capacitor sizes in and out of the circuit and I couldn't really hear much of a difference - at sizes as low as 47pF the repeats seemed a bit smoother and going up as high as 100uF they became slightly more distorted, so there is a little difference, but it's not worth adding as a feature. It doesn't sound like reverb though - so perhaps it should be a different capacitor? I'll put the 10nF capacitor back in that slot I think.

Yes the circuit has loads of modulation fun in it at present (hell the fact that it even works is something of a celebration for me!) so I could box it as is, but if you can generate more weirdness in a way that isn't too complex for me to understand then I'd gladly try them out - I prefer to have some signal left in the sound though (I have enough failed circuit builds for generating random noises already ) so if the weirdness is at the expense of no actual guitar playing coming through I would probably say no. If I can still tell that I'm playing something to generate the sound then that sounds cool I like guitar sounds like Fennesz and Jefre Cantu-Ledesma if that's any guide - fuzzy, glitchy, noisy, distorted but still containing a grain of melody - I'm not into pure 100% noise assault (nothing wrong with it of course) but personally I like to feel that I had some slight control over the sounds that are created by a pedal Thanks for your help - I will PM Knutolai and ask him if he knows of any modifications he would try regarding reverb sounds.

[duck_arse]

hmmm, C13. I tried upping in steps, and got about as far as 47nF as still usable. as I reacll, going higher meant more ... erm ... stuff appearing, and going around and around until it was just stuff, with no control. I'm not much good in explaining the sound, but it got more springy? deep? I'm sure that cap is mentioned in other builds, ?perhaps the hamlet?

I'll record some sounds of my enveloper for you tomorrow, stay tuned.

[moid]

OK feel free to call me stupid but I now know why changing the C13 capacitor didn't work While testing swapping capacitors out I had the new pot (called More Wet in my vero layout) set to be fully Wet, and the effect of changing c13 must happen after the modulation effect has been applied (and only to the original circuit signal), so all I was hearing was the modulated loud repeats but none of the reverby echoes you were mentioning. I swapped the More Wet back to just the original signal going through the circuit, changed C13 from a 10nF to a 100nF and yes indeed the repeats become a lovely reverby wash, although rather quiet. Is there a way to get these repeats louder or to get the effect to apply to the loud repeats I got from the Modulate pot? It's quite a lovely sound and I can see why it's hard to describe, but it would be cool if it could be dialed in via a pot to vary from very little to a lot of reverb, but I'd like to apply that to the new loud repeat signal as well or it will never be heard... oh and can I have the moon on a stick while I'm asking for things? Ta muchly I'll test whether it works on a pot between two different capacitor values (also because I want to find out what it sounds like with lower than 10nF on one side of the pot range).

I'm looking forward to hearing your recordings; once I get this pedal in a more finished state I will ask my son to play something lovely through it so you're spared listening to me fumble my way through a selection of random notes.

[moid]

Hmmm I can't seem to get c13 to work as a pot blending two different values of capacitors together I can swap one capacitor for another and there is some difference, but blending with a pot must confuse the circuit and it seems to cut repeats out entirely when I try that! I think I'll place a socket over where c13 is and stick the original 10nF back in... if the gentle reverb effect can't be applied to the whole signal I don't think it's worth adding to just the normal signal when it's rather quiet and I want to mix in the louder modulate repeats on top. I think I'll fix a few cables on the circuit and then I'd better practice some guitar playing

[moid]

...and replacing all the crocodile clips with proper soldered wires was a mistake, I removed the old blend pot that I didn't need, followed my layour and got rid of various floating bits, tidied up the cables and soldered everything and now nothing works (oh the LEDS light up so that's nice).... grrrr I think I'd better get some sleep before I through this circuit out the window.

[duck_arse]

OK I'll try to learn to draw a circuit diagram soon  What software would you use to draw one?

some of us older types remember pencil and paper, still eminently usable for drawing circuits. many here do that, then take a photo of the results, all comes out the same. often, drawing it up means you realise the inherent folly, or otherwise, of what you are thinking.

eagle. a very steep learning curve, it will do more than you'll ever need. and it's free. there are others, there are threads hereabouts on that very topic.

and now this:

I'm looking forward to hearing your recordings; once I get this pedal in a more finished state I will ask my son to play something lovely through it so you're spared listening to me fumble my way through a selection of random notes.

you will be sorry. it is here for the next three days:
http://dropcanvas.com/712e5
(does anyone know of an anonymous file hoster (not googoo, not dropbox, not soundcloud, not [t.b.a.]), it seems "filedropper" just wants to dick me around, with 87% of a file uploaded.)

[excuses] it will become apparent that I have only one chord. also, that the input buffer I've got on this circuit makes my sh!te guit rather brittle/bright/over trebbley. [/excuses]

circuit was with a fet input buffer feeding the enveloper, f/back set 50% and none of knutolai's modulation parts. the only fiddles were delay time, envelope decay and direction. listen carefully, you might hear the wobbles.

and no, the C13 probably won't work with a blender pot arraingement. it needs to be switched for range. fit the 10nF, then switch-add in parallel a larger cap. but, playing about at the BB, I think that effect I heard was i a different circuit. could'a bin the smalltime, or the angel, or the jenny greenteeth. or part of the hamlet.

I'm not sure about your repeats volume business, a diagram might provide a clue. what leds are you lighting? the one on the pt2399 is not an indicator, except perhaps of a fault.