@billy
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Once we get your images something might jump out to someone
It’s definitely a strange one which makes it interesting!
I don’t fully understand the internal workings of the PT2399 but I’d imagine with the voltages you have on pin 7 current control 1 and 8 current control 0 it’ll have some strange affect on the output
Hard to find any info but found this from Rob Strand, which is why I said check the op amp voltages thinking it could be a biasing issue
I’ve been told by the manufacturers (and there’s no other way to find this out) that pins 7 and 8 are used to smooth the a biasing supply inside the modulator (MOD) and demodulator (DEM) blocks.
the majority of the PT2399 pins ie op amp ins and outs should be vref supplied by pin 2 so half of whatever’s going into pin 1 from the regulator
I’m assuming you mean R19 with regards to IC1 easy enough to check, with no power to the circuit, remove IC1 from it’s socket and check the resitance between VR and pin 3, I’d use the junction of R17 and 18 as my VR point
Just on a whim I’d visually check your IC sockets too, I’ve had flimsy socket pins bend upwards more than once and cause weird issues
Hello J,
Post some pictures of both sides of the board and offboard wiring so that it can be traced
Pin 1 of the PT2399 should be getting around 5v
Check the op amp voltages which should be around half the power supply 4.5v for inputs and outputs pins 1,2,3,5,6,7 with pin 4 ground and pin 8 +9v all the points on the schematic marked VR should be half power supply
I suspect your problem may lie in the buffer / mixer area IC1A and B pin voltages will tell us for sure
Expected voltages are also noted in the build document
Just in case you don’t know here’s how IC pins are laid out dot or notch indicating pin 1 then down around and up in a U shape same for any number of pins
Seeing as there are non in stock
You can hack it to work, with a bi colour LED.
Using a common anode LED place the anode to the LED+ pad, whatever colour you want in effects mode to the LED – pad, add a wire to the other cathode – leg and solder the other end to 3PDT lug 6 the bottom middle lug
It must be a common anode bi colour LED
All your actually doing is grounding 1 LED pin or the other to change colour via the switch, so effects colour cathode say green lug 4 connects to ground via lug 5 in effects mode and switched the other way bypass cathode colour say red connects lug 6 to ground
Can’t find much on it
https://www.freestompboxes.org/viewtopic.php?t=6688&start=60
This may actually be the Heathkit fuzz I remember you posting about
Paintings not my strong point
The secret to getting it right I think is nice light even coats and allowing it to dry
When I do paint, impatient as I am I always leave it to dry overnight
Getting your spray distance right is important also squirting the nozzle to clear any paint build up stops drips etc all together you’ll get a nice run free coating
You’ve done a great job
Very nice build Geno looks great inside and out, it’s well laid out I particularly like the way you’ve got the 3PDTs flush with the enclosure wall! very precise drilling
Yeah I can see it’s top quality wire Bruce just found it hard to trace with red being used for both power and ground etc
I knew as soon as Bryan said he’d got it from yourself it’d all be quality gear I’d asked coz there’d been a few mishaps from another vendor recently on here and other forums with their kits
Bryan you’re probably best not to alter or rewire anything, I know you’ll be keen to get it fired up as we all were with our 1st creation but I’d wait till you get all the parts
Remember to turn that TL074 around I notice it’s still the wrong way round in your photo
While you’re waiting for it to arrive post some pics of the solder side of the pcb
It does but you’ve got it the correct way lugs horizontal and I think with Barrys 3PDT boards it’ll only fit in the right way
Normally you’d solder the switch to the underside but it doesn’t matter it may just be more difficult for you to fit it in your enclosure
The crackling may be the TL074 it could be fried with it being in the wrong way and power applied if you have a multimeter take the voltages on the pins and report back
To take voltages just in case you don’t know, set your meter to 20 VDC put the black probe in the COM socket and the red in V for voltage socket then place your ground probe on the main pcb ground pad and touch each IC pin with your red probe
Pin numbering goes top left of the notch pin 1 then down and round in a U shape like this it’s the same for any number of pins in your case down 1 to 7 then up 8 to 14 you should get 0 volts ground on pin 11 and power to pin 4 all other pins should be around 4.5v or half the power supply
Hopefully it’ll just be a fried TL074 and no other errors but no matter I’m sure we’ll get it going
Whilst yer waiting for parts have a read of the beginners guide to components which will give you a better understanding
Just for reference this is how most folks have their 3PDT boards, they’re great for neater wiring the newer ones even having a trimmer onboard giving you the ability to adjust your LED brightness and if you ever build a combo pedal they’re a must for easy wiring
Bruce is very good with his kits he’s actually a moderator on here
Yes I edited my previous message you’ve got a 10M ohm in there now it won’t light with that it looks like you had a 1K in your previous photo that would light but pretty bright, I can see you’ve now put the 1K in R1 which is correct, a normal value for a clr is around 4K7 I like them dull and use a 10K with mine I’d just leave it for now till we hopefully get the circuit working, it won’t affect the circuit the LED just won’t light so not important at the moment
I’ve checked over your build all the values looked correct can’t actually see the value on C5 which should be 47nf so don’t be nervous they’re all correct and as I say Bruce has great customer service, he actually designed a number of these circuits including this one I think
I’d advise reflowing the solder joints on your jacks the ground on the out jack looks ball like and could be dry inside also doesn’t look well connected to the jack so stick your iron back on it till you get a nice solder flow around 4 seconds should do it
Yes just carefully remove it from the socket and turn it around Bryan so the notch is at the other end as per the silkscreen below
There is no transistor in the circuit where did you get the kit
I notice you’ve changed your CLR (current limiting resistor) on the 3PDT pcb it looks like a 10M ohm your LED will definitely not light with that you want between 2K to 10K depending on how bright you like it
All your resistor values look correct can’t fully see R18,19,20 and 21 but from what I can see they look correct and orientation aside from IC2 obviously, looks correct.
It’s difficult to trace your wires in some places because you’re using the same colours a lot as far as I can make out you’ve got the 3PDT grounded and powered those 2 red wires bottom left so your LED should light up
Anyway hopefully it’ll fire right up once you turn the IC around
Meant to say you’d posted it in the wrong forum so I moved it over you’d put it in the ‘how to use the forum’ part, that’s perhaps why it took so long to get people looking
You’ve got IC2 in the wrong way round Bryan
Some ICs have either a notch or a dot indicating pin 1 and some have both when they have both the notch is pin 1
Your IC1 TL072 is correct
Hopefully IC2 TL074 has not been damaged
R1 1K resistor and D1 1N4001 diode need to be installed also
Your DC jack is correct RED to pcb 9v, black to ground and pink to battery +
With your jack you can see where the tip connects to so you can simply follow that around to it’s solder lug
or you can continuity check which lug connects to which part the longer being the tip and the shorter one the ring for battery ground
If you have lost bypass then it must have been wired correctly initially
Make sure the solder lugs connect as shown in this picture or as I say follow them round from the tip to it’s solder lug
As Barry says carefully try and remove some of the solder, ball like joints may be dry inside simply heat up with your iron for around 4 seconds and remove some, be extra careful with your 3PDT switch lugs too much heat can damage the switch internally if you have a solder sucker great use that if not you’ll have to use your iron to remove it, try reflowing the blue wires on your 3PDT first once you get bypass back of course!
