Hi, everyone.
Firstly, I'd like to state that I wasn't sure where to start this topic because it's not exactly about an effects unit of any kind, but it is meant to switch effects, so here it is. If it's in the wrong place, I'd like to apologize and request that the Moderators move it somewhere proper. Thank you.

I've been thinking about building an effects switcher for my pedalboard to be able to turn on multiple pedals at the click of one footswitch. So, in search of ideas for selecting a given patch, I've found R. G. Keen's article at GeoFex and one by Rod Elliott, among others. Links here:
http://www.geofex.com/article_folders/fxswitchr/fxswitchr.htm
https://sound-au.com/project163.htm
Now, I'm wondering how to overcome the problem of accidentally engaging two (or possibly more) patches simultaneously if I wanted to build a CMOS-based controller. The way I understand R. G. Keen's design (schematic in question), if two footswitches are stomped on, two outputs of the 74HC373 go high, thus turning on two patches. The same is true for most designs provided by Rod Elliott (except the one built around the CD4017 Johnson counter and perhaps the one using SR latches).
I do understand that it'd be easier to use a microcontroller of sorts and make the code something along the lines of:

if input A is HIGH, output A is HIGH else LOW;

and duplicate it for other inputs.
However, I'd like to learn how to do that without turning to digital technology. I am also aware that it will add to the complexity of the circuit which will probably send me down digital path anyway. I'd like to learn nonetheless. Thanks for any suggestions, directions, and explanations.
Have a good one, everyone.
M.

Greetings, oh, collective wisdom.
I've got this solid-state guitar amp from the 1980s. It's operational, or at least it was last time I checked, but it's not quite the kind of tone I like. So, a thought of modifying it popped into my mind.

I was thinking of leaving the power section alone and changing the preamp to the one inspired by Joe Davisson's designs switchable to something else. It's not decided yet.

The amp as it is now uses a bipolar power supply and the preamp I was considering runs on a single PSU.
I'm wondering if it's not going to upset the power amp's PSU rail balance due to the extra current draw, which compared to the PA section is minuscule, I know, but it's still there.
Am I being paranoid here?

Hello, everyone.
First of all, I'm sorry if this question has been asked and dealt with before. I have done some searching, but haven't been able to figure out a straightforward answer. I'm new to solid state amplification. Now, to the point.
I've been looking at Rod Elliott's 40W power amp design and I don't know which components should be matched. I started reading teemuk's book, but for now it's quite a bit to digest, so I'm taking my time.
So, should I look for matched pairs of any devices found here?
The whole article:
https://sound-au.com/project215-p27-revisit.htm

Circuit diagram:
https://sound-au.com/p215-p27-revisit-f6.gif

Thanks for any input.
M.

Hi, everyone, first build-related post of mine   
Soon, I'm going to build Joe Davisson's 4-stage Vulcan preamp using the schematic posted on his website and I have a few questions before I embark on this project.
1. Has anyone tried it?
2. If so, how does it sound? Judging by the number of gain stages, it's a hard rock / heavy metal machine.
3. I'm going to use BC337 transistors because I have a lot of them (not much of anything else tbh). Apart from pinout and biasing, is there anything I should specifically pay attention to?
I'm going to breadboard it first and, of course, I'll keep the forum updated on the progress. That, however, may take a while because adult life is the way it is
Stay tuned.