Recent content by jubal81

Ground should be the lowest impedance node in your circuit, which makes it ideal as a reference voltage. When you use any other voltage as a bias point, you're increasing the chance of noise in your audio from that voltage source. DC voltages can also be buffered in a similar way to AC audio...

Very cool! This is a new one to me. Did you try the BAT85s clipping diodes?

Awesome project! Really great of you to take that on and it's neat to hear she jumped in and built it.

Putting the 100pf capacitor in parallel with the drive knob makes the low pass filter drop as you raise the gain. At max gain, the cutoff frequency is about 1.5Khz. At minimum gain it's like 48khz. It's going to get a lot darker as you turn up the gain.

Discrete JFETs are still around because their practically infinite input impedance makes them a specialty device. It means their gate is extraordinarily sensitive. Vero makes it tricky because there's no ground plane under the traces and more wires flying from the board. First thing I'd try is...

If you're going for small, you can get an LMC555 in a package that makes a sot8 look like a giant.

Setting aside the details of this particular circuit, it sounds like what you're after is a standardized footprint for an "IC" that satisfies several functions repeated in every pedal. If that is the case, then it means compatible effect PCBs must be designed purpose built to work with this...

Kicking out some parts I found: Nexperia Schmitt trigger 74HC14D,653 (BASIC) OPA1679: Quad opamp in 4X4 QFN package. Rail to rail. CMOS. Audio grade: C1512997 I think the real design challenge with a project like this is how many redundancies you have to engineer into it: Polarity protection...

Put a 100uf capacitor in series with the signal coming out of the "reverb send" jack. Probe that output with the clip on the scope probe clipped to metal on the chassis. Then send a 0.5V sine wave into the amp input and see what you get. If it's distorted, turn down the amp gain and see if it...

Thanks for making a new thread. It always helps if you can provide a link to a schematic. I found this one. That's quite a beast of a solid state amp. They do all the switching with JFETs and first I'd try a patch cable in the effects loop because the loop goes into the reverb. Also check all...

Run a jumper wire from 75 to 54. If it sounds good, just leave it there and rewire that pot as master volume.

This sounds like a really fun project. The TDA2030 is pretty decent, but you don't want to make it clip. Here's what I'd do: 1. Replace all the electrolytic caps. 2. Put an opamp buffer between volume pot (VR2) and C20. Power it from the +v and-v rails as the other opamps. 3.Replace C20 with...

I'll throw in some tips: 1. To prevent crosstalk, the distance between traces should be 3X the width of the trace. I've gone down to 8mil trace width to keep it narrow but wide enough to not risk PCB production issues. A 6 mil trace can easily carry 1A of current, so don't sweat it. 2. Try to...

Seems like it'd be something interesting to play with - especially since you could get quite a lot of power in a single-ended Class A output stage. Feeding it a low impedance is easy enough. The heatsink? Maybe not so easy - or light.

These are pretty interesting. I've been looking at options for driving a reverb tank and I haven't been able to setting on one yet. I don't like the headroom for most of these as most new stuff is designed for 5V-ish supply. I like the TI series of bridge tied amps like the LM4876. They're AB...