Search found 233 matches

by R.G.
18 Jul 2016, 15:41
Forum: Boutique Stompboxes dissected...
Topic: Imagine a pedal gooped this way:
Replies: 10
Views: 5514

Re: Imagine a pedal gooped this way:

How much would it cost to fill the whole cavity with goop? That's actually not a straightforward process. Most of the catalyzed goops are exothermic while curing, so they get HOT inside if you pour more than about 1/4". It's a recognized problem in potted military units. You can cook the components...
by R.G.
18 Jul 2016, 01:18
Forum: Boutique Stompboxes dissected...
Topic: Imagine a pedal gooped this way:
Replies: 10
Views: 5514

Re: Imagine a pedal gooped this way:

I've been at this for far too long to worry about gooping. But it is fun to imagine the looks on the faces of the folks trying to de-goop. And on those of the pedal builders trying to prevent de-gooping. As we say here in God's Country, never a horse that couldn't be rode, never a rider that couldn'...
by R.G.
17 Jul 2016, 19:32
Forum: Boutique Stompboxes dissected...
Topic: Imagine a pedal gooped this way:
Replies: 10
Views: 5514

Imagine a pedal gooped this way:

1. Use a 4 layer PCB, placing traces on the inner layers to connect points which should connect, and have about 20% of the outside layer traces look like they connect but really don't connect, to places that should not connect. Otherwise, make the outside traces easy to follow. 2. Leave some traces ...
by R.G.
17 Oct 2015, 01:24
Forum: DIY Stompbox designs
Topic: Wampler style voltage divider ?
Replies: 5
Views: 3421

Re: Wampler style voltage divider ?

I suspect that it's habit or layout that drives this one. References have some very peculiar issues, and using multiples has some virtues, but the differences are subtle. You can trick yourself without meaning to. It gets difficult to figure out what is what sometimes. For instance, in this circuit,...
by R.G.
27 Feb 2015, 00:49
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Vox - Repeat Percussion (V 809) [schematic]
Replies: 145
Views: 90877

Re: Vox - Repeat Percussion (V 809) [schematic]

i think i grasped that 'cut-only' by instinct and feel, and have a vague understanding of how tremolo is a wave thing and there can be different textures and depth of wave that offer tremolo. but hadn't yet understood (technically) why the repeater sounds more 'sucky' and 'concave' than other tremo...
by R.G.
26 Feb 2015, 03:28
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Vox - Repeat Percussion (V 809) [schematic]
Replies: 145
Views: 90877

Re: Vox - Repeat Percussion (V 809) [schematic]

Design note on the RP: The repeat percussion works by shunting a lot of the input signal to ground. In that sense, the circuit is a "tremolo down" or "cut only" circuit. It would be much quieter than the original signal for that reason if there was not a post-tremolo amplifier to bring the signal le...
by R.G.
20 Nov 2014, 02:13
Forum: Absolute Beginners
Topic: A Power surge from badly grounded amp killed my stompbox
Replies: 3
Views: 7453

Re: A Power surge from badly grounded amp killed my stompbox

I'm sorry for your misfortune. A spark from the pedal enclosure to the floor indicates that there was significant voltage between the "signal ground" on the pedal enclosure, and the floor, which presumably was a real, true, down-to-the-dirt ground. One thing that's good about this is that it killed ...
by R.G.
18 Aug 2014, 23:22
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Visual Sound - Pure tone buffer
Replies: 8
Views: 6729

Re: Visual Sound - Pure tone buffer

It's a buffer...


:lol:
by R.G.
27 Apr 2014, 13:44
Forum: DIY Stompbox designs
Topic: question about effects schematics and internet
Replies: 10
Views: 4146

Re: question about effects schematics and internet

:?: why are there limited info on the internet...why aren't they ALL online by now.I know it supposed to depend on people who are nice enough to upload obsolete music electronics info/projects,but...Why doesn't the government,library of congress,etc release all music electronic related articles,pro...
by R.G.
02 Jan 2014, 02:10
Forum: Boutique Stompboxes dissected...
Topic: Regarding the Jack Deville Deuce Coupe Bypass System
Replies: 5
Views: 1712

Re: Regarding the Jack Deville Deuce Coupe Bypass System

Both MOSFETs and BJTs have some significant limits here. Neither one can mute big signals both well and quietly. The MOSFET is limited to signals of a diode drop peak before it distorts, as you have guessed. A BJT can do bigger signals, but has offset voltage and other issues. A P-channel JFET is pr...
by R.G.
01 Jan 2014, 00:54
Forum: DIY Stompbox designs
Topic: A new vacuum tube PSU design
Replies: 10
Views: 5335

Re: A new vacuum tube PSU design

As regards the idea and schematic I think: - Using high frequencies for switching power supplies has two major reasons in this milleau; it makes the reactive components to transfer and filter the unavoidable noise of switching much smaller, and it moves the "power line frequency" above audio, or oth...
by R.G.
04 Dec 2013, 20:00
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Full wave rectifier vs birdge rectifier in Octave effects
Replies: 4
Views: 2812

Re: Full wave rectifier vs birdge rectifier in Octave effect

I'm just thinking out loud here, but what if you were to use mosfets as the diode in the bridge, the manufacturing process of the mosfet has a internal diode across drain/source which gives a very low voltage drop (I'm thinking of the same principal of R.G.s mosfet polarity protection circuit which...
by R.G.
04 Dec 2013, 14:07
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Full wave rectifier vs birdge rectifier in Octave effects
Replies: 4
Views: 2812

Re: Full wave rectifier vs birdge rectifier in Octave effect

You're not missing anything. I answered the same question with an elaboration of the same answer over at diystompboxes. The diode forward drop must be overcome by the signal, so the output only consists of the portion of the signal that exceeds the diode drop, if any. A FWR signal sounds best if the...
by R.G.
26 Jun 2013, 20:43
Forum: Ready-To-Build Effect Projects
Topic: Shin-ei/Univox Uni-Vibe [Replica Files]
Replies: 481
Views: 67300

Re: [Replica Files] Shin-ei/Univox Uni-Vibe

If you're up for mods there's plenty of alternatives - R.G.Keen got some hard-on projects, including one for Cry Baby shell Actually, the Neovibe, which has changed almost not at all since about 1997(? I'll have to go look; it predates web pages) is *exactly* the electronic circuit of the factory s...
by R.G.
09 Jun 2013, 15:53
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Vox / Orange / Apollo - Treble and Bass Booster [schematic]
Replies: 113
Views: 72909

Re: Vox / Orange / Apollo - Treble and Bass Booster [schematic]

Replace the two 220nF caps on the front end with 47nF to 100nF.
by R.G.
06 Jun 2013, 13:52
Forum: Transistors
Topic: Piggyback Si transistors to simulate Ger ???
Replies: 82
Views: 75865

Re: Piggyback Si transistors to simulate Ger ???

Could I get a similar effect with a 2n3440 low gain (@50hfe) silicon transistor with a 1n34a tied to the base and collector to simulate leakage? Probably. I've tried it and this reintroduces the temperature drift to an otherwise-temperature-immune silicon device. I posted this in other fora at some...
by R.G.
23 May 2013, 23:49
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Douglas Self - Compressor/Limiter
Replies: 4
Views: 3600

Re: Douglas Self - Compressor/Limiter

Hi, I've gave a try to this compressor ( found on book "Self on Audio" ) but seems it's not suitable for guitar use, even with a buffer.... Anyone has some experience on this circuit ? Try putting gain of ten before it and a 10:1 attenuation after it. Most compressors of that ilk are optimized to t...
by R.G.
26 Mar 2013, 22:58
Forum: Davidoff Library
Topic: My schematics collection on Skydrive
Replies: 35
Views: 19007

Re: My schematics collection on Skydrive

It's probably not all that edutaining. It's pretty focused on the issue of schematic to PCB. I tried to hold in my normal commentary. :lol:
by R.G.
25 Mar 2013, 20:08
Forum: Davidoff Library
Topic: My schematics collection on Skydrive
Replies: 35
Views: 19007

Re: My schematics collection on Skydrive

There are a number of related concepts for students of the oppositions between individualism and collectivism. It's worth reading about "the tragedy of the commons" and "bad money drives out good". Fact is, humans are selfish in many ways. There are exceptions, but the tendency is there. Human natur...
by R.G.
25 Mar 2013, 00:40
Forum: Davidoff Library
Topic: My schematics collection on Skydrive
Replies: 35
Views: 19007

Re: My schematics collection on Skydrive

Intellectual property is really important. Otherwise, someone could do something like build up a pedal company around a Marshall Bluesbreaker clone. Intellectual property laws do not protect the circuitry inside a Marshall Bluesbreaker. It's not protected by copyright law, and is (probably) not pat...