Search found 488 matches

by plush
23 Mar 2024, 11:26
Forum: Pedal Debugging & Troubleshooting Support
Topic: TA-100 'touchy' transistor
Replies: 2
Views: 186

Re: TA-100 'touchy' transistor

mauman wrote: 23 Mar 2024, 01:14 Touching the case of Q2 grounds the collector thru you
MP42B case is tied to the base, not collector.

It's either bad transistor (mp42b are little leaky shits, real 80hfe for them is very rare) or the circuit is not adopted to using mp42b (misbiased).
by plush
24 Feb 2024, 22:03
Forum: Amplifiers
Topic: Mend-It Mark's cap discharger [schematic]
Replies: 3
Views: 14214

Re: Mend-It Mark's cap discharger [schematic]

You can simply use any DMM with low-z function for such purpose.

Provided you don't have such, there's still no need for such overcomplication - simple DMM adapter consisting of couple MOVs across the leads will do the trick...
by plush
10 Feb 2024, 17:36
Forum: DIY Projects
Topic: OGBip-2 overdrive on 2n5088 bipolar transistor
Replies: 11
Views: 844

Re: OGBip-2 overdrive on 2n5088 bipolar transistor

I don't see the need to increase the input impedance, because the treble level will have to be reduced in the next stage. After all, not the entire range of sound frequencies is pleasant for our ears, especially when the signal is overloaded True. But when one starts thinking about his design as of...
by plush
10 Feb 2024, 15:22
Forum: DIY Projects
Topic: OGBip-2 overdrive on 2n5088 bipolar transistor
Replies: 11
Views: 844

Re: OGBip-2 overdrive on 2n5088 bipolar transistor

How would you select the value for a bootstrap cap here? Consider this cap as a piece of low pass filter together with the resistors forming the bias network. Calculate it's value a bit past desired cutoff frequency. That's all. Or you could use Pete Cornish buffer instead, where everything is done...
by plush
10 Feb 2024, 10:31
Forum: DIY Projects
Topic: OGBip-2 overdrive on 2n5088 bipolar transistor
Replies: 11
Views: 844

Re: OGBip-2 overdrive on 2n5088 bipolar transistor

I'd bootstrap vt6 to increase it's input impedance.
by plush
07 Feb 2024, 06:42
Forum: Pedal Debugging & Troubleshooting Support
Topic: NOISE - TAP TEMPO
Replies: 2
Views: 448

Re: NOISE - TAP TEMPO

No grounds should ever be separated. Power supplies should be filtered. Inputs and outputs should be filtered. PCB design is crucial. Type of filtering depends. Ferrites must be. Science. There's no simple answer to your question. But we can recommend some necessary changes, provided we can see your...
by plush
25 Jan 2024, 07:46
Forum: Pedal Debugging & Troubleshooting Support
Topic: Unvibe build noise
Replies: 5
Views: 512

Re: Unvibe build noise

yeah im working on some tracks that i believe have gone through or under the bulb driver circuit, and some similar ones. it doesn't have to be posted here, its SMD, bit hard to figure out by posting pictures on here anyways, its double layered and plenty of vias etc. info is all thats needed. thank...
by plush
24 Jan 2024, 04:04
Forum: Pedal Debugging & Troubleshooting Support
Topic: Unvibe build noise
Replies: 5
Views: 512

Re: Unvibe build noise

Analog LFOs, if not filtered and designed properly, tend to generate a lot if EMI, that is easily picked by unshielded parts of the circuit inside the pedal.
by plush
23 Jan 2024, 15:36
Forum: DIY Projects
Topic: Stupidly Awesome Buffer [documentation]
Replies: 64
Views: 42686

Re: Stupidly Awesome Buffer [documentation]

Liumander wrote: 23 Jan 2024, 11:31
Can you tell us more about the RF bypassing and the 2 diodes? If not drawing the scheme maybe you wanna explain it a little. Thx!
RF Bypassing in that context is a low pass filter (typically RC filter) at the input

2 diodes - you can read more here https://sound-au.com/appnotes/an015.htm
by plush
22 Jan 2024, 18:31
Forum: Pedal Debugging & Troubleshooting Support
Topic: charge pump voltage divider issues?
Replies: 5
Views: 645

Re: charge pump voltage divider issues?

karsten_h wrote: 22 Jan 2024, 18:19
what would that look like?
LM317
by plush
22 Jan 2024, 17:33
Forum: Pedal Debugging & Troubleshooting Support
Topic: charge pump voltage divider issues?
Replies: 5
Views: 645

Re: charge pump voltage divider issues?

2.4k resistor is limiting the current to 3-4 milliamps. It won't work this way, dude. Charge pumps need low impedance input source, not this voltage divider abomination. the option is to use adjustable voltage regulator at the input and dial the needed voltage. just keep in mind charge pump input vo...
by plush
18 Jan 2024, 22:22
Forum: Pedal Debugging & Troubleshooting Support
Topic: Capactitor Questions
Replies: 3
Views: 639

Re: Capactitor Questions

1. Are C6 (50uF) and C7 (50uF) redundant parts? This looks to me like they could be replaced with a 25uF bipolar cap, but there may be something specific I am unaware of. 2. Are C4 (470uF), C12 (1uF tant), and C13 (1uF tant) redundant? They're all caps to ground hanging off the 15V supply rail. I c...
by plush
17 Dec 2023, 16:09
Forum: PCB Guitar Mania - pedal builders group and debug
Topic: Maximum Crank no effect sound
Replies: 9
Views: 1923

Re: Maximum Crank no effect sound

Wow, 1 Meg output pot, really? This circuit is a piece of junk.
by plush
14 Nov 2023, 07:29
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Sabbadius Rainbow Fuzz TFK BC108c
Replies: 3
Views: 1669

Re: Sabbadius Rainbow Fuzz TFK BC108c

FiveseveN wrote: 13 Nov 2023, 03:55 Excuse me sir but WTF is a "passive buffer"?!
Attenuator, kind sir.
by plush
24 Aug 2023, 15:11
Forum: DIY Projects
Topic: Active D.I Box suggestions
Replies: 14
Views: 2179

Re: Active D.I Box suggestions

I show you the other part of the circuit that is the power supply, it is connected with a 3-wire molex connector, I don't think any coupling capacitor is necessary, or maybe I'm wrong? Even though your power supply is already filtered, it's always a good practice to add small deoucpling caps close ...
by plush
24 Aug 2023, 08:02
Forum: DIY Projects
Topic: Active D.I Box suggestions
Replies: 14
Views: 2179

Re: Active D.I Box suggestions

I have finally drawn a new much simpler schematic, what do you think? any suggestions? Add decoupling caps to opamps power inputs. Your ground lift switch is wired incorrectly. It should either connect output and input grounds together direcrtly or through parallel resistor/capacitor/diode configur...
by plush
10 May 2023, 05:04
Forum: Boutique Stompboxes dissected...
Topic: Tim voltage divider
Replies: 5
Views: 935

Re: Tim voltage divider

Yes, but tim is not biased to 4.5v.
by plush
01 May 2023, 09:56
Forum: Pedal Debugging & Troubleshooting Support
Topic: 3PDT PCB sanity check
Replies: 2
Views: 359

Re: 3PDT PCB sanity check

0. You forgot to include drill plot - no holes/vias will be made 1. You should increase clearance for both traces (marked yellow) and 3pdt pads 2. There is no need to route additional ground traces with already existing ground plane (blue) 3. There's enough space to thicken the traces twice or trice...