Search found 91 matches

by Optical
27 Jun 2020, 07:21
Forum: Pedal Debugging & Troubleshooting Support
Topic: Buffer adding hisssssssss
Replies: 10
Views: 249

Re: Buffer adding hisssssssss

What kind of hiss do you experience? Can you measure it's frequency? What type of IC/charge pump you've used for 30v conversion? Is there any power line ripple (switching noise). If it's switching noise, LC filter would work way better than RC. But in some cases it could be defective power IC (I've...
by Optical
27 Jun 2020, 07:06
Forum: Pedal Debugging & Troubleshooting Support
Topic: Buffer adding hisssssssss
Replies: 10
Views: 249

Re: Buffer adding hisssssssss

Why a charge pump for a buffer? If you wanted lots of clean boost I would understand, but buffering means gain around 1, so unless you are buffering a signal already close to 30v(!) that is wasted headroom and parts and power and... an invitation for trouble... Maybe it's part of something bigger? ...
by Optical
26 Jun 2020, 02:52
Forum: Pedal Debugging & Troubleshooting Support
Topic: Buffer adding hisssssssss
Replies: 10
Views: 249

Re: Buffer adding hisssssssss

RC filter on the power supply? I'll try that, thanks
The ground paths for the audio and power circuits are separated and joined only at one location (input jack)
by Optical
26 Jun 2020, 01:16
Forum: Pedal Debugging & Troubleshooting Support
Topic: Buffer adding hisssssssss
Replies: 10
Views: 249

Buffer adding hisssssssss

I built a buffer using a TL071 (standard non inverting) and a charge pump for 30V. It does the job, but adds a lot of hiss ive noticed. The noise floor is quite high now - at band volumes you have to shout over the hiss to give an idea of how loud it is. Before I go blindly swapping in other types o...
by Optical
22 May 2020, 06:39
Forum: Electric Guitar Rewiring
Topic: Bass cut = high pass filter question
Replies: 8
Views: 601

Re: Bass cut = high pass filter question

Your amp or pedals also have a resistor to ground on the input, usually 1M. So a series output cap forms a highpass filter when combined with the amp input resistor. Read up on "RC filters" Can calculate the cutoff frequency using the formula 1/2.pi.R.C, or just use an online calculator and input yo...
by Optical
12 May 2020, 23:13
Forum: Amplifiers
Topic: How to improve tube amplifier tone by changing one part
Replies: 101
Views: 5384

Re: How to improve tube amplifier tone by changing one part

Also, if you can hear it, then you can definitely measure it. So swapping caps and doing some frequency spectrum analysis should clearly show up differences.
by Optical
12 May 2020, 03:17
Forum: Pedal Debugging & Troubleshooting Support
Topic: Nux looper core pedal malfunctioning
Replies: 8
Views: 633

Re: Nux looper core pedal malfunctioning

possibly a dry or broken solder joint around the jacks or volume pots
by Optical
23 Feb 2020, 21:53
Forum: Ready-To-Build Effect Projects
Topic: BAJA REACTOR 010119 [verified]
Replies: 46
Views: 3000

Re: BAJA REACTOR 010119 [verified]

Ive just built this using one of Bajamans pcbs. Have to say, it works really well. I was trying a tube preamp into a solid state power amp, and it had no mojo. But with this reactor circuit, mojo restored and the result is similar to using a tube power amp. Impressed/10 I tried some various diodes b...
by Optical
17 Feb 2020, 06:20
Forum: DIY Stompbox designs
Topic: The Orange sound ...
Replies: 8
Views: 3839

Re: The Orange sound ...

I saw this circuit floating around for a bax stack with semi parametric mids

Image
by Optical
17 Feb 2020, 06:17
Forum: DIY Stompbox designs
Topic: The Orange sound ...
Replies: 8
Views: 3839

Re: The Orange sound ...

Bump for Orange love
Has anyone played around with the CR120 circuit some more or investigated the bax Bangeetar?
by Optical
04 Feb 2020, 22:19
Forum: Vintage Stompbox Corner ( ... - 1975)
Topic: Barcus-Berry Standard Pre-Amp Model 1330-1 [schematic]
Replies: 60
Views: 7630

Re: Barcus-Berry Standard Pre-Amp Model 1330-1 [schematic]

Putting the EQ into the feedback loop is quite interesting.
I havent seen many other other designs like this but the TC integrated preamp springs to mind
by Optical
19 Nov 2019, 21:50
Forum: Boutique Stompboxes dissected...
Topic: EQD - Disaster Transport JR [traced]
Replies: 10
Views: 6060

Re: EQD - Disaster Transport JR [traced]

For wet only, disconnect R9
by Optical
13 Oct 2019, 21:47
Forum: DIY Stompbox designs
Topic: (Real) JCM800 Pre-Amp in a box
Replies: 13
Views: 3360

Re: (Real) JCM800 Pre-Amp in a box

...and added 39k/10K/4.4k cold clipper cathode resistor switching. As I am playing a strat, I am still trying to max out the gain of the very first stage, as without a booster (a DAM Red Rooster sounds awesome) in front I do not get into mid/high-gain (what-ever that means). If you want more gain, ...
by Optical
25 Sep 2019, 06:44
Forum: DIY Stompbox designs
Topic: High voltage pedal like Victory Kraken
Replies: 13
Views: 2913

Re: High voltage pedal like Victory Kraken

The Victory pedal doesnt use regular tubes, it uses those subminiture tubes whatever they're called.
Would you post some gut shots of your pedal?
by Optical
29 Aug 2019, 22:39
Forum: Modern Stompbox Effects (1975 - ...)
Topic: EQD Sunn O))) Life Pedal [gut shots]
Replies: 2
Views: 1375

Re: EQD Sunn O))) Life Pedal [gut shots]

Ol Bugg being Cagey with the schematics :)

But yeah, Shin-Ei FY octave up + Rat with clipper selector + boost stage
I tried a green ringer into the Rat and it sounds pretty great. Havent tried the Shin-Ey octave yet
by Optical
06 Aug 2019, 23:33
Forum: Amplifiers
Topic: Capacitors in Mesa Boogie Dual Rectifier
Replies: 25
Views: 5788

Re: Capacitors in Mesa Boogie Dual Rectifier

Here's something we can all argue on the internet about

3 caps swapped in a jcm800, these would be two treble peakers and the treble cap

https://www.youtube.com/watch?v=ifC2A5QkbRY
by Optical
31 Jul 2019, 10:50
Forum: Boutique Stompboxes dissected...
Topic: Fulltone - 2B [traced]
Replies: 18
Views: 4660

Re: Fulltone 2B [traced]

Cool, the VFE dragon uses a clipping/compression circuit just like this but with BS170 body diodes as instead of the germaniums
by Optical
23 Jul 2019, 23:48
Forum: Amplifiers
Topic: Capacitors in Mesa Boogie Dual Rectifier
Replies: 25
Views: 5788

Re: Capacitors in Mesa Boogie Dual Rectifier

You were presented with very clear evidence, not anecdotes - Did you read the link with the well presented data? Why is that data not good enough? Do you see errors in the way the tests were conducted? That cap thread is mostly talking about low signal voltages and mostly not talking about low class...
by Optical
22 Jul 2019, 22:34
Forum: Amplifiers
Topic: Capacitors in Mesa Boogie Dual Rectifier
Replies: 25
Views: 5788

Re: Capacitors in Mesa Boogie Dual Rectifier

Gritty sound is a crap description I agree. I'm not saying caps of X type sound like whatever. My only point is that nonlinearlities elicited from certain capacitor types have an audible and measurable effect on the harmonics generated in a high gain preamp; and that builder/designers will trial som...