hi jamos, here's the schematic for the power supply I'm working with [...] See this thread . That schematic is incorrect, and does NOT match the circuit on the PCB. On the PCB, one of the AC inputs is connected to 0V, the other to both diodes. If you are trying to drive two of those from a single A...

Reading the parts list to discover these problems is simply one of the new skills that you have to learn when moving from complete kits. (And I don't think that's obvious when you start - I haven't seen any instructions that begin with "make sure you can still find all these bits".) Like any other s...

For me it is a quality thing, a personalisation thing and, as I discovered, also a Zen-like thing as I find making my own cables a good way to empty my mind (which otherwise tends to be very busy more or less 24/7 :mrgreen:). I find making my own cables a good way to fill my mind with rage and frus...

My little home brew case is around 95mm deep. Could be taken to gigs, in theory...

But why not to connect the pots straight to the +-12V of my circuit ? Did you encounter issue connecting the pots straight up to the +-12V ? Because the power supply voltage is not necessarily perfect. In particular, if it is overloaded, then the voltage may drop, or there might be noise or mains h...

Thanks for your very detailed answers! A small questions regarding the Tri to Saw circuit above: shall I also add a 1k resistor at the input (in series with the triangle out) of the circuit and also at the Saw output? the BC550 could be replaced with BC547 as well? No (tri to saw) / yes (saw out). ...

As I'm planning to build two of the vco-1 I wanted to know If I can normalised the Sin output of vco1 to the switched lug of both the lin FM input and exp FM input of vco2 and vise versa (vco2 sin out tip lug to exp and lin FM switched lugs of vco1) Can I just solder a wire from the tip lug of the ...

Are you using this as a guitar pedal, or as part of a modular system? If it's a guitar pedal, what kind of trigger are you using? You can't easily convert an arbitrary square wave to a sine without some kind of memory, because you can't tell the frequency phase of a square from its current value. [E...

The main functional difference is that the 2164 has an exponential control response, while the 13700 has a linear response. Other differences - the 13700 chip contains two VCAs, while the 2164 has four VCAs. The 2164 has (I'm fairly sure) lower noise and distortion. The 13700 also has two output buf...

The major difference is the lack of a mixer/buffer on the signal inputs, and the decision to use a 4.7k / 10R resistor divider on the signal input to the 13700. I've built a couple of the Barton VCAs and I always replace these with a 100k / 220R pair instead, to give a more usual input impedance. (I...

The footswitch on my unit has six lugs, and it seems to act/work as a momenraty switch (maybe it's broken, or it has been replaced?). It's a footswitch, so it's designed to be stomped on. If you just push it with your fingers, you might be pushing it hard enough to change the contacts but not enoug...

Some American makers are doing 4-40 Because it's really important that we don't stick to the few standards that we have. :sarcasm: and it’s so similar you can almost cross thread them. They're so similar that you will cross thread them. Now you need to buy new rails. :bang: Stick to metric, for goo...

I would try to remove the plastic frame first (either cutting it up with a sharp knife, or getting underneath it and sliding it off the pins), and then desolder the pins one at a time.

Any chance of getting a schematic? Looks like a lovely delay and has all the features I would want as well. I started doing right angle front panel boards for my DIY builds although I use right angle headers for more mechanical strength. Did you CNC mill the board? I'll have to draw up a clean circ...

My homemade take on the PT2399 delay. I wanted a couple of things: it should be usable both standalone (like a guitar delay pedal), and as a simple signal in, delayed signal out module for building complex patches. It should also have voltage controlled delay (because if it's not voltage controlled,...

There is something fantastic about building the circuits that make the wave that makes the sound. This. It's why I first got into computer graphics - writing code is much more fun when you can literally see the results. I enjoy building electronics, the fact that I can then hear the results make it...

At first glance, that seems odd. The 3340 is a triangle core, so if it's the chip that's glitching, you would expect it on the other outputs as well. If it's not the 3340, then you wouldn't expect it to change when you swap the chip. Is there an op amp buffering the triangle output? Maybe it's self-...

On doepfer page there is just a patch example where (as i think i understood) you can control the VCA (volume) and then with other antenna you control an LFO ??? why? where the VCO is gonna be? Just to answer this specific point - The oscillator is labelled as an LFO, but the frequency can be adjus...

The CEM is seated correctly and I did hook up positive to position and negative to negative from the power supply. That doesn't quite answer the power supply question. Do you have positive, ground, and negative connections from a power supply providing +12V, 0V, and -12V (three separate terminals)?...

You say 12V, but the circuit needs both +12V and -12V, are you using a bipolar power supply? (Also, it helps a lot if you can either include a schematic, or link to one. Don't assume that everyone knows what circuit you are talking about. If you're asking for help, you should make it as easy as poss...

You might be able to find 16V AC wall warts, I believe they're used for alarm systems or something.

If you wanted you could change R4 to 390k, but I would just leave them alone. There should be plenty of range available. Out of curiosity, how are you picking 390? I did nodal analysis on the frequency input pin and didnt quite get what was happening. I assumed that pin 15 was the input to an op am...

If you wanted you could change R4 to 390k, but I would just leave them alone. There should be plenty of range available.

"Wouldn't work" is a bit strong. Need to be used with care, and probably with an eye on the schematic, yes.

recently I've been exploring more and more different projects involving sensors. Right now I have a code (which msot of it unfortunately isn't mine) which uses Piezo sensors. For my purposes I've decided to use FSR sensors so the change in the code is required. I would think the most important chan...