Search found 699 matches

by earthtonesaudio
29 Dec 2013, 15:57
Forum: DIY Stompbox designs
Topic: Analog tap tempo for PT2399
Replies: 12
Views: 5529

Re: Analog tap tempo for PT2399

Mbas974 wrote:tx again..

Anyone in this forum , did build it ?
I built it. It basically works, meaning holding the switch resets then ramps up the delay time, but it is neither user-friendly nor optimized to work *well*.
by earthtonesaudio
26 Jul 2013, 13:00
Forum: DIY Stompbox designs
Topic: Overdrive design
Replies: 8
Views: 3604

Re: Overdrive design

Do you have a specific question about this circuit?
by earthtonesaudio
25 Jul 2013, 15:24
Forum: DIY Stompbox designs
Topic: Overdrive design
Replies: 8
Views: 3604

Re: Overdrive design

Based on the schematic it ought to be capable of massive distortion. Do you suspect something wrong with your build?
by earthtonesaudio
26 Jun 2013, 17:15
Forum: DIY Stompbox designs
Topic: anybody ever mess with the ESR Graphic Fuzz?
Replies: 3
Views: 2308

Re: anybody ever mess with the ESR Graphic Fuzz?

I would make a version like this to compare. Note that besides converting to a single supply, I added a series 100 ohm resistor before the level control. This is to protect the opamp from having its output shorted to a low impedance when the volume is turned all the way down (in this case the low im...
by earthtonesaudio
25 Jun 2013, 12:25
Forum: DIY Stompbox designs
Topic: anybody ever mess with the ESR Graphic Fuzz?
Replies: 3
Views: 2308

Re: anybody ever mess with the ESR Graphic Fuzz?

The original is powered by +/- 4.5V because the battery is floating.

This *may* impart something unique to the sound, or maybe not. One way to tell would be to build a more standard version without the floating supply, and bias it to +4.5V, capacitively couple in and out, etc. Then compare the two.
by earthtonesaudio
24 Jun 2013, 13:57
Forum: Amplifiers
Topic: The size of capacitors
Replies: 12
Views: 5678

Re: The size of capacitors

Small capacitors are fine, as long as you have good technique.
by earthtonesaudio
22 Jun 2013, 23:54
Forum: Pedal Debugging & Troubleshooting Support
Topic: How ask for debugging help
Replies: 4
Views: 928

How ask for debugging help

If you have a debugging question for the forum, there are some things you can do to get the best, most timely advice possible. Some suggestions: 1. Describe the problem *as observed* (just the facts) 2. Include a complete (as-built) schematic and layout of the circuit 3. Include relevant measurement...
by earthtonesaudio
22 Jun 2013, 23:19
Forum: Pedal Debugging & Troubleshooting Support
Topic: Help me debug this before I murder it...
Replies: 27
Views: 672

Re: Help me debug this before I murder it...

Next step is post your voltages:
V+
input
output
each IC pin
each transistor pin
by earthtonesaudio
04 Jun 2013, 19:03
Forum: Software Room
Topic: codewheel maker
Replies: 1
Views: 2848

Re: codewheel maker

Gray code works now!
by earthtonesaudio
04 Jun 2013, 15:44
Forum: Software Room
Topic: codewheel maker
Replies: 1
Views: 2848

codewheel maker

I know what you're thinking, "finally, a suitable wallpaper pattern for the nursery". https://dl.dropboxusercontent.com/u/74334755/opto/opto.html I made this because I wanted a software codewheel generator but couldn't find one that would run on my Chromebook. :block: Also as an excuse to learn Java...
by earthtonesaudio
20 Mar 2013, 19:56
Forum: Software Room
Topic: Schematic software for Mac
Replies: 31
Views: 44711

Re: Schematic software for Mac

+1 kaludjerko, I have started using CircuitLab on my Chromebook recently. It has an offline mode too which is nice.
by earthtonesaudio
02 Mar 2013, 21:10
Forum: Software Room
Topic: Programming an Arduino with a Samsung (ARM) Chromebook
Replies: 0
Views: 3026

Programming an Arduino with a Samsung (ARM) Chromebook

This is a guide to getting Arduino development working on your $249 Chromebook.

It's rough, and only applies to the ARM Chromebook and Arduino, but it's worked for me.
I really like being able to switch to the other OS without having to reboot.
by earthtonesaudio
21 Feb 2013, 00:35
Forum: DIY Stompbox designs
Topic: A FET compressor
Replies: 22
Views: 8906

Re: A FET compressor

very nice mictestor. I haven't looked at it too hard yet but would this design be capable of downward expansion below a certain threshold with the right addition to the circuit? Not with the OTA in the feedback loop. You could take the OTA out of the feedback loop and make it more of a true side ch...
by earthtonesaudio
20 Feb 2013, 00:38
Forum: DIY Stompbox designs
Topic: A FET compressor
Replies: 22
Views: 8906

Re: A FET compressor

i like the idea, but can the effect be modified for those of us who don't have transconductance op amps? i would like to make this thing... unless it doesn't do much squash. i like the punchy, plunky type sound, and am always looking for new compressor designs. any help is appreciated. Not easily. ...
by earthtonesaudio
20 Feb 2013, 00:38
Forum: DIY Stompbox designs
Topic: A FET compressor
Replies: 22
Views: 8906

Re: A FET compressor

So... how is this a FET compressor? The OTA does the compressing, the FET is just a buffer. Any old buffer would do the same job. Two reasons: 1. it's common practice to name a device after the coolest part of it (i.e. "tube" reverb units) 2. (better reason) because "any old buffer compressor" does...
by earthtonesaudio
18 Feb 2013, 01:20
Forum: DIY Stompbox designs
Topic: A FET compressor
Replies: 22
Views: 8906

Re: A FET compressor

The audio is not directly fed through the 3080 - it's used as part of the feedback around the FET buffer stage. You're hearing the FET, not the 3080 Don't miss a teachable moment, Mic. :wink: The transfer function from gate to source of the JFET is approximately something like: gainOfJFET/(1 + gain...
by earthtonesaudio
17 Feb 2013, 20:23
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Crews Maniac Sound - DPA-2A Discrete Acoustic Preamp [schematic]
Replies: 9
Views: 3250

Re: Crews Maniac Sound DPA-2A [schematic]

Why the designer chose SEPP stages I don't know. Yeah that's just crazy. It looks like they chose a 5532 for whatever reason, and then ran into the problem of its low input impedance (especially with a piezo). So they tacked on the buffers, choosing a SEPP over a single JFET for reasons best left a...
by earthtonesaudio
20 Nov 2012, 20:40
Forum: Ready-To-Build Effect Projects
Topic: A Switching Scheme
Replies: 245
Views: 21474

Re: A Switching Scheme

A single schmitt inverter can handle power-on reset, debounce, and bistable flip-flopping duties simultaneously. If that schmitt inverter is a standard non-CMOS 555, it can drive the relay too:
https://www.freestompboxes.org/viewtopic.ph ... 55#p156714
by earthtonesaudio
20 Nov 2012, 20:30
Forum: Ready-To-Build Effect Projects
Topic: Soul Sonic - Crackle NOT Okay! [verified]
Replies: 196
Views: 25184

Re: Soul Sonic - Crackle NOT Okay! [verified]

Good point. 10% increase in gain is 20*log(1.1Vout/1Vin) or about 0.8 dBV. Doesn't seem like much but don't forget it has to be amplified by a power amp before hitting the speakers and finally your ears, so that small increase in dBV becomes a bigger change in dB(SPL).
by earthtonesaudio
20 Nov 2012, 17:34
Forum: Ready-To-Build Effect Projects
Topic: Soul Sonic - Crackle NOT Okay! [verified]
Replies: 196
Views: 25184

Re: Soul Sonic - Crackle NOT Okay! [verified]

any help? is this how its designed? nope. i don't think so. The gain equation is (roughly) Rf/Ri where Rf is the parallel combination of the two 2.2M resistors, and Ri is the setting of the gain control. Minimum gain is 1.1, or 10% louder than unity. A couple solutions: 1) add 100k in series with t...