DIY Effects

[tauzero]

2 hours ago, LukeFRC said:

I have one - If you want me to open it up and compare voltages going through it I can

 

Thanks, I'm initially going to do some basic checks - IC supply voltages, ground offset from supply, see if there's signals on the + and - inputs on the op-amps and on the outputs.

[Mottlefeeder]

17 hours ago, tauzero said:

 

Thanks, the build instructions are probably those on the website - https://schalltechnik04.de/en/instructions/vong-filterung but if there's anything else I'd be glad of it.

 

That's all I've got, sorry.

Having said that, the block diagram shows a fairly conventional set of 'blocks', so you could probably work out the circuit from the components in the vicinity of each i.c.

David

[Mottlefeeder]

Just a thought, if you have LEDs working but no audio at all, it might be worth looking at the voltage doubler first. 

David

[tauzero]

4 hours ago, Mottlefeeder said:

Just a thought, if you have LEDs working but no audio at all, it might be worth looking at the voltage doubler first. 

David

 

Good point. I shall work myself up into an appropriate frame of mind soon.

[ped]

I’ve had this pedal for ages, bought from a member here but can’t remember who. It was sold as an fx25 clone with LPF mode and synth. I was deep into my Fx25s at the time and didn’t really give this a proper go and it broke shortly after. 
 

Well today I decided to fix it (just a broken connection) and got it working again. 
 

I’m pretty certain it’s actually a Prunes and Custard clone/type pedal (which is good because that’s a fav me of mine). The synth mode gives that same wet spattery fuzz but this one doesn’t blend in any clean. The envelope modes (fast and slow) sound amazing, especially on fast where the thing farts when you dig in, like an fx25 does, but with no low end loss or big bass whump as the filter closes. 
 

Weirdly the ‘level’ knob doesn’t do anything except at the very start of its sweep where it turns off the signal so I’ve renamed it a DFA knob. The other two are really responsive. 
 

So kind of a free pedal. Reckon it might be my fave filter for the Mustang at least… and that’s saying something!!

 

 

[bassman7755]

So I've been looking at designing a very crude HPF, not for bass use as it happens but to filter out some nasty DC thuds that my computer sound card generates when it wakes from sleep.

 

Playing around with http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php#answer1  I was looking for an RC that would do the job with a couple of common components and using 22uf / 1kohm gives a 3db point of 7 ish Hz so would seem to do the job. Am I right in assuming that pretty much any single pole RC HPF gives (at least theoretically) infinite attenuation at DC ?.

[itu]

@bassman7755 I think you could go far higher. 7 Hz is very low, you can go easily up to 30 Hz without losing anything significant or important. You would still cover audible frequencies.

[Woodinblack]

3 hours ago, bassman7755 said:

Am I right in assuming that pretty much any single pole RC HPF gives (at least theoretically) infinite attenuation at DC ?.

 

Any high pass filter you can practically make as near as dammit infinite attenuation at DC.

Although if you are talking of thuds when your sound card wakes, they clearly aren't DC, or you wouldn't hear them!

[bassman7755]

22 minutes ago, Woodinblack said:

 

Any high pass filter you can practically make as near as dammit infinite attenuation at DC.

Although if you are talking of thuds when your sound card wakes, they clearly aren't DC, or you wouldn't hear them!

 

The thuds arnt very loud but you can see the cone leap alarmingly like you get when you connect a 9v batter to a speaker, but yes obviously what is actually being heard is the audible overtones of the transients. Thing is I'm not trying to filter out the sound completely - just get rid of the DC (or near DC) component which is causing the extreme speaker excursion.

[tauzero]

It might even be DC, if there's no DC blocking capacitor in the output of the sound card or input of the amp and there's a DC offset. In that case, just a large value capacitor in line with the input would do the job.

[disssa]

Acoustic 360 preamp:

First I tried the viva-analog Version, but I dont like it. The assembly instructions are not easy to understand and also contain errors.
The potentiometer layout is terrible and looks amateurish.
So I used the Factory schematics and designed my own PCB layout. I kept the blend function.

[bloke_zero]

15 hours ago, disssa said:

Acoustic 360 preamp:

First I tried the viva-analog Version, but I dont like it. The assembly instructions are not easy to understand and also contain errors.
The potentiometer layout is terrible and looks amateurish.
So I used the Factory schematics and designed my own PCB layout. I kept the blend function.

The Viva-analog is in my queue - I've held off as I've never done single side PCB soldering. You are making me think it might not be worth it at my skill level!

I love that early Larry Grahahm sound and want to see how much the pre is part of the recipie!

[rmorris]

On 10/03/2023 at 12:58, bassman7755 said:

Am I right in assuming that pretty much any single pole RC HPF gives (at least theoretically) infinite attenuation at DC ?.

 

Yes.

[Chienmortbb]

On 17/03/2023 at 13:27, rmorris said:

 

Yes.

The problem my well be the rapid change in DC , effectively a low frequenct AC signal, albeit of short duration.

[ped]

Guys where's good to buy a pink LED for a pedal? It's for an older DOD type, not sure if that matters...

[Woodinblack]

Aren't the pink LEDs (the old ones) actually just red LEDs in clear plastic (as opposed to a red LED in red plastic? So would be listed as Red LED in (water) clear lens?

[bartelby]

24 minutes ago, ped said:

Guys where's good to buy a pink LED for a pedal? It's for an older DOD type, not sure if that matters...

https://www.ebay.co.uk/itm/152555238306?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=ZOYjs14ATBa&sssrc=2047675&ssuid=inrZpCH7Rj2&var=451948240514&widget_ver=artemis&media=COPY

 

I've used this place before.

[KingBollock]

I am not in the mood for thinking beyond the “ohh, I wonder…” stage, so I thought I’d ask here.

 

I have a pedal that I built, it’s two Big Muffs in one box, a ‘73 Ram’s Head and a Musket. I have made several modifications to it and plan on making more (I am even considering installing it into a rack unit, to give me more space. And I love the look of a busy rack). One thing I added was an order switcher, which decides which effect goes first. 
 

What I am wondering is if it’d be possible to make that switch (not the same switch, obviously, but a single switch) change the series order or make them parallel (A / A+B / B), and how I’d go about it.
 

I don’t even know how useful such an option would be…

 

I have several more different clipping options I want to add to it, as well as a boost to one side. The boost would even up the amount of transistors (the ‘73 has 4, whereas the Musket has 5). I have also added a wet/dry blend, but am now wondering, if I can run them in parallel, would I be able to have a blend that works between the two effects?

 

All this for a pair of Muffs! I do love a pointless tinker.

[nekomatic]

4 hours ago, Woodinblack said:

Aren't the pink LEDs (the old ones) actually just red LEDs in clear plastic (as opposed to a red LED in red plastic? So would be listed as Red LED in (water) clear lens?

The pink LEDs I’ve seen look like they’re white LEDs - which are blue LEDs with a yellow-emitting phosphor in front - with a pink filter on the phosphor. 

[itu]

@KingBollock

A simple switch may be too simple, but a rotary one would solve your need.

[Passinwind]

6 hours ago, ped said:

Guys where's good to buy a pink LED for a pedal? It's for an older DOD type, not sure if that matters...

The Tayda ones are very inexpensive and look great IMO.

[Passinwind]

A contributor to my ongoing open source preamp project submitted this idea for an inexpensive FR-4 pedal fascia plate sourced from JLCPCB:

 

 

They offer several other board colors as well, and their turnaround time is typically very short. I'm spoiled by having a really great local option for direct UV printing, but that seems to be far from the norm, unfortunately.

Edited March 28, 2023 by Passinwind

[Chienmortbb]

15 hours ago, Passinwind said:

A contributor to my ongoing open source preamp project submitted this idea for an inexpensive FR-4 pedal fascia plate sourced from JLCPCB:

 

 

They offer several other board colors as well, and their turnaround time is typically very short. I'm spoiled by having a really great local option for direct UV printing, but that seems to be far from the norm, unfortunately.

I find that strangely attractive and at least available the world over.

[Passinwind]

5 hours ago, Chienmortbb said:

I find that strangely attractive and at least available the world over.

Agreed, but for less than 5 dollars more you could just have Tayda do a UV print directly on that box before they send it to you with all the rest of the parts. Nice to have options in any case!

[bobbass4k]

Finally boxed up my parasit studios multiwave mega. Glad I went to the effort of adding the oscilloscope, though it's come out a lot rougher looking than I would have hoped.