@billy
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I can’t quite see the 4th multiplier band on R20 the bands should be brown green black red brown 15K
Yes you would solder TR1 to both the pcb and switch
From the schematic when you press the switch it looks like you bypass the trimmer and pot so the only resistance in the feedback loop would be RA
The idea being you want it to give you a momentary blast of infinite repeats when you press the switch without having to alter the repeats pot but you’d also want it work normally when the switch isn’t pressed
So your RA value needs to be small enough to work in both scenarios
The way I would do it is socket RA and try different values set repeats to max then adjust TR1 until you get infinite repeats for normal use you should then get exactly the same when you press the switch with the repeats pot in any position
If you don’t there must be a mistake elsewhere
Here’s the V4 build doc
https://drive.google.com/file/d/1ElKNvJISHXxjPiFddrfmgE2DuW3DaZvN/view?usp=drivesdk
I think you’d first need to set the trimmer so that with the repeats pot at max you get infinite repeats then you’ll know if your RA value is low enough
As you know pots have a tolerance of 20% so your 50K may be up to 60K which would affect determining your RA value
When you press the footswitch it bypasses the trimmer resistance going to lug 2 of the repeats pot and gives you just the value or RA temporarily taking the pot and trimmer out of circuit so you’d want to make sure your RA value is going to allow infinite repeats
Obviously make sure you’ve soldered the switch to lug 1 of the trimmer it’s not always obvious which is lug 1 and 3 the best way to determine that is to continuity check which trimmer pin connects to RA
Ooh I like the look of them they look really good
It’s definitely a nice idea it’d take all the pain out of drilling enclosures etc
If an enclosures too hard to drill ie its got more than 2 knobs I’d buy it with the box already done
This version is exactly the same apart from changing the reverse polarity protection diode to a series 1N5817 which obviously wouldn’t affect gain
The gain of the op amp is provided by resistance in the negative feedback loop increasing that would increase gain as Barry says
The only thing I can’t clearly see is your LED orientation It’s difficult to tell whether you have the cathode flat side going to the flat side of the silkscreen
I’d also double check you have the correct value for the gain pot it’s easy enough to mix them up
Post some nice well lit in focus images so that all your component values and orientation can be clearly seen and offboard wiring to in and out jacks, DC jack and 3PDT can be traced
It could be several things incorrect power wiring or component value etc
Do you get bypass signal
A 2N5088 wouldn’t work as a buffer without modifying the circuit It’s a completely different pinout, transistor type etc a 2N5088 is a BJT vs 2N5459 a JFET ones current controlled the other voltage
You should let Klaus at musikding know I’m sure he’ll send you a JFET
Check your input jack is wired correctly and you haven’t accidentally mixed the ring and tip connections up see image below simply insert a jack and follow the connections around to their solder lugs
You don’t require C3 for an OP07 it has internal compensation you can either just leave it or snip it out
All you component values and orientation that I can see look correct where did you get your JFET from for Q1
I’m taking it voltages are collector base emitter top to bottom are Q1 voltages 0.3v etc and Q2 aren’t negative voltages are they
I wouldn’t change any component until I know they’re a problem it only increases the potential for lifting pads etc
I realise it’s frustrating but I wouldn’t do it
Try Lumberg KLBM3 jacks
They’re much smaller than the open style jacks my go to’s these days
You can also bend the solder lugs flat once you’ve soldered your wires to them
I don’t use anything else now but make sure it’s Lumberg brand
We need a clear well lit image of the whole component side of the pcb so that we can clearly see all values and orientation
It’s fairly difficult to see anything in your pics and very easy to miss something even after checking several times I’ve done it many times
As you’ll know C8, 9 and 10 charge and discharge in combination with the rate pot to adjust oscillation make sure the solder joints are good
Quick mark it solved! we don’t want to tempt fate now ?
Glad it’s working enjoy! its defo my favourite chorus
Unfortunately I don’t have a pcb to test but any I’ve built I’ve always ran 2 separate grounds from the DC jack to GND and G2
Easy enough to continuity check the G2 pad is connected to GND pads on your pcb
It’s a weird one because when you think about it if they both connect to the DC jack then they will have continuity but if you check yours now you’ll know whether they actually connect on the pcb
It’s difficult to know without seeing the DC jack are you taking both GND and G2 separately from the DC jack ground lug to the circuit pads as I say I can’t tell but it looks like only G2 or 1 ground wire goes to the DC jack
From the build doc
This board has 2 separate ground planes to prevent audible clock noise. Both ground planes need to be connected. Please make sure that pads GND and G2 are both grounded.
The optional wiring is if you want to use a footswitch for your speed and kill switches with LEDs to indicate whether they’re engaged or not ie on or off rather than a toggle switch so it’s just showing you how to connect speed and kill footswitches as an option
The ground connection to those switches simply switches the LEDs on or off by connecting the LED cathode negative pin to ground to visually indicate whether they’re engaged ie on or off
As Barry says you can use any ground point you don’t have to use the pad shown in the diagram you can connect them to the DC jack ground lug or the in and out jack sleeve lugs whatever is easiest for you as long as all ground points are connected to ground
Are you going to use footswitches for the speed and kill switches?
It’s down to personal preference so if you think you’ll use them go for it we’re here to help so if you are unsure just ask
As Playsforfun says you’ve got your in jack tip going to the ground pad on the main sho nuff pcb and your in jack sleeve/ ground going to BI (board in) on the 3PDT pcb
Swap the black and white wires around on the actual in jack solder lugs
It’s a lot easier to desolder and swap the wires on the in jack solder lugs rather than the pcbs
It’s difficult to clearly see your out jack connections with the black tape but it looks like it’s correctly wired
