DIY Effects

[disssa]

Peavey F-800B Preamp:

I used the factory schematics and schematics from a talkbass-project to create my own pcb:

 

[bobbass4k]

12 hours ago, Passinwind said:

Just in, some two band Bass/Mid preamp boards from a new US small run circuit board prototype vendor, DK Red. The DK = DigiKey, one of our biggest parts suppliers. Quality looks good and the pricing is just slightly better than OSHpark's basic service, but with far fewer options and a four board minimum as opposed to OSHpark's three. Many of us are hoping that DigiKey will go the next step and integrate parts supply, modeling data, PCB footprints, bill of materials management, and assembly into a one stop shopping experience. I'm nearly certain that they are shooting for that, and sooner than later.

I spent a lot of the time I worked at Farnell trying to convince them they needed to offer a prototype/small run service like that and was repeatedly rebuffed... Should have emailed my digikey contact... 

[disssa]

My latest one: Music Man 120B Preamplifier

[itu]

That 120B looks neat!

What is that Xvive chip there? Are all others opamps?

[disssa]

10 hours ago, itu said:

That 120B looks neat!

What is that Xvive chip there? Are all others opamps?

It is an optocoupler for the limiter-section. 

Edited May 5, 2021 by disssa

[Passinwind]

Simple gain stage/clean boost with variable gain via trim pot:

 

 

I've done a matching mix/blend board as well, both will go up on OSHpark soon as free shares.

[tauzero]

Not quite an effect - a softsynth module. A Squishbox, based on https://geekfunklabs.com/products/squishbox/ but I've been doing some extra programming.

I first saw https://www.instructables.com/id/Raspberry-Pi-Stompbox-Synth-Module/ which was superseded by https://geekfunklabs.com/products/squishbox/

The intention was to build a unit that could be powered by a guitar effects 9V power supply of sufficient current capacity, controlled from a USB MIDI port, and outputting via a 5102 sound board to 1/4" jacks. I didn't bother with a DIN MIDI IN. I also decided to go for a 20x4 display rather than the 16x2 display of the original, which gave the possibility of extra information.

The 5.5/2.1mm power socket goes to a KBP307G bridge rectifier to provide reverse voltage protection (any bridge rectifier with a maximum current of 3A or more will do) and then to a buck converter set to 5V.

This 5V feed goes to a protoboard that is also used to mount the 5102 board and male headers for the display and footswitches. The 5102 board itself has a further male header for the output sockets. On one I used Dupont cables 

With the way I've mounted this, the whole will fit (snugly) into a 1590BBS Hammond box. I've made another one in a 1590C box which gives somewhat more room. There isn't a problem with digital crosstalk even with the sound card sandwiched between the protoboard and the Pi. The one in the larger box has the soundcard on the other side of the protoboard - there's no difference in interference levels, ie. none.

The display is mounted on brass M3 spacers with 6mm of stand-off which are epoxied into the box (Araldite Rapid was useless, J-B Weld has proved rather better). The Pi is mounted on 25mm M2.5 countersunk bolts with a nut and washer holding the Pi, then a 10mm nylon spacer, then the protoboard, then nylon M2.5 nuts. I've put heatshrink around the power supply components.

Note that the power connector must have the sleeve isolated from the case, as the case is attached to 0V and the sleeve of a Boss-type PSU with centre negative is +9V. The power connector I finally used isn't the one shown here - it's a plastic-bodied one with the thread at the business end so it fits from behind the panel and I can remove it along with the protoboard if I need to dismantle it.

I got some audible interference when I first assembled it, caused when metalwork on the Pi USB and network sockets touched the case. I made the cutout a little larger and put heatshrink round the sockets. Problem solved.

I've been indulging in a bit of Python programming to modify the original, as I was using the I2C interface rather than the parallel interface which meant an awful lot of soldering. My version will also play songs (.wav, .mp3, or .ogg) and playlists (just a list of files to play) so set break music can be supplied.
 

[Passinwind]

I found time to try test onboard preamp builds with a couple of new DigiKey DKRed boards this week:

 

The bottom one, a three bander,  is now living in my fretless Marco Bass. I also tested my little mini-mix board yesterday, it works just as expected.

[Passinwind]

Still keeping pretty busy, this week I revisited my variable resonance low pass filter design and worked out the glitches:

 

 

I've now ported the design to all SMD format and plan to add it to my open source onboard preamp collection, so anyone who wants to and can deal with SMDs can build their own.

 

[itu]

4 hours ago, Passinwind said:

I've now ported the design to all SMD format and plan to add it to my open source onboard preamp collection, so anyone who wants to and can deal with SMDs can build their own.

Ahem, I think this is one interesting PCB... any chance to get a board or at least the data of it, please?

[Passinwind]

7 hours ago, itu said:

Ahem, I think this is one interesting PCB... any chance to get a board or at least the data of it, please?

There’s a very long thread on Talkbass with prior art, frequency response graphs,  a schematic link, board share info and bill of materials, and many many tangents: https://www.talkbass.com/threads/the-passinwind-open-source-preamp.1259692/ .
 

At the moment I only have the original Bass/Mid/LPF  three band design on offer as a board share,  but the standalone filter ones should be coming online in the next month or so. I’ll probably start with the SMD version and then look at doing a through hole one eventually too. This is all an open source non-commercial labor of love BTW.

Edited May 20, 2021 by Passinwind

[Passinwind]

On 19/05/2021 at 08:14, Passinwind said:

Still keeping pretty busy, this week I revisited my variable resonance low pass filter design and worked out the glitches:

 

 

I've now ported the design to all SMD format and plan to add it to my open source onboard preamp collection, so anyone who wants to and can deal with SMDs can build their own.

 

And here the new one is, somehow only four days from ordering the PCBs to having a working unit on my test bench:

 

[itu]

No, these are not mine, and I have no idea who is this builder. The units just look different and interesting.

https://metsn.tumblr.com/post/652279198486052864/anaphylaxis-filter-a-multi-mode-filter-with

[bartelby]

1 minute ago, itu said:

No, these are not mine, and I have no idea who is this builder. The units just look different and interesting.

https://metsn.tumblr.com/post/652279198486052864/anaphylaxis-filter-a-multi-mode-filter-with

I think they need to rethink the graphics on the lower pedals.

 

[disssa]

My version of the Music Man HD 150 One Fifty Preamplifier:

 

I used the factory schematics to create my own pcb.

[andruca]

Just finished a GUMA-Drive. Real happy with it. It was above my soldering skills (and gear) so it was mostly done by my brother (an engineer, designs electronics since he was 10 y/o). Also he had all the printing material needed, lacquer, etc. I really only applied primer and yellow to the box, that's about it All in all a nice project and one more great excuse to hang out with my bro, who recently moved close to me after being 12K km away for almost 2 decades. Now I only need to get him to sit seriously in front of a drumkit (he's a SOLID drummer, he just always had to be dragged when it came to making music, simply he leans to other stuff in life).
 

It sounds like this (using my rat rod Jazz, both pickups, then just the neck, EQed and compressed after the GUMA-Drive). Will record a wider variety of samples and do a video once the missing knobs make their way home.

Edited June 2, 2021 by andruca

[Wilson_51_]

Built a couple of pedals this past week. I usually use veroboard but bought a couple of pcbs this time instead. I only tend to build them if there difficult to buy or I’m going to modify them a lot. 
 

The smaller pedal is a dod 250 with switching between Ge or silicon diodes. I couldn’t find an original to buy/modify. So this was easier.

The larger pedal is a megalith fuzz. I wanted a mk1 version but again couldn’t find one for sale. 
 

[paul_5]

Looking to ‘bass-iffy’ a Klone Centaur Clone that I built on veroboard a while ago. My change in guitar playing means that I’m not really using overdrive anymore, as it’s running at 18v I might put an active DI in there and retire my DHA VT1 from active duty.

[PaulThePlug]

Is that a David or Druid?

Are those covers for the pots to stop dust etc?

Neat Jobs... (I'm an Ex Electronics Eng)

Edited June 4, 2021 by PaulThePlug

[Wilson_51_]

Ha it is Druid but does look like David. 
 

yeah the covers are called dust covers but I find them handy as insulation from the pot back touching things. 
 

 

 

[bloke_zero]

On 02/06/2021 at 11:47, andruca said:

It sounds like this (using my rat rod Jazz, both pickups, then just the neck, EQed and compressed after the GUMA-Drive). Will record a wider variety of samples and do a video once the missing knobs make their way home.

Nice - thanks for the recording! I made one a couple of years ago and use it either on a 303 or when I use it on bass I use it much more subtly just to add some thickness - your demo is an eye opener - I feel like thats how it's supposed to be used! A very flexible pedal - after building it I came to think all pedals should have voume and blend.

[andruca]

15 hours ago, bloke_zero said:

Nice - thanks for the recording! I made one a couple of years ago and use it either on a 303 or when I use it on bass I use it much more subtly just to add some thickness - your demo is an eye opener - I feel like thats how it's supposed to be used! A very flexible pedal - after building it I came to think all pedals should have voume and blend.

My main gripe with people testing this kind of preamp is the lack of balance when trying to show what they can do. I mean, blend either all try or wet (when the juice is in the middle really), same with drive control and so on. So there's lots of extremes and little real life usefulness showcased. My samples are usually the tone I run thru' most clean amps set flat (I use to carry my tone with me whatever the device, usually Zoom boxes, but also own a SansAmp RBI) and I record with pretty much that same tone. This is my kinda' tone in real life, I might a different OD flavor when running SansAmp but the function is the same, thick&crunchy. BTW, don't tell anybody, yesterday I was able to almost nail that same tone I got with the GUMA-Drive using just a Zoom G1Xon (tuned with effects from the B1Xon).

Edited June 5, 2021 by andruca

[tauzero]

On 04/06/2021 at 20:25, simon88wilson said:

Built a couple of pedals this past week. I usually use veroboard but bought a couple of pcbs this time instead. I only tend to build them if there difficult to buy or I’m going to modify them a lot. 
 

The smaller pedal is a dod 250 with switching between Ge or silicon diodes. I couldn’t find an original to buy/modify. So this was easier.

The larger pedal is a megalith fuzz. I wanted a mk1 version but again couldn’t find one for sale. 
 

What do you use for the artwork and lettering? And is that just over a plain box?

[Wilson_51_]

4 hours ago, tauzero said:

What do you use for the artwork and lettering? And is that just over a plain box?

Artwork was done using Inkscape, printed onto water slide decal paper. It’s a plain box, cleaned. Bit of lacquer on the box and the decal. Then when the decal is slid on lacquer applied over the top. 

[paul_5]

Nearly finished all of my veroboard a for an effect I’ve been planning for a while; valve overdrive (with bipolar 12v supply) with a 3 band EQ, clean blend and an active tilt Eq on the clean side…

will be boxing it up this weekend…

… the plan was to sound like a DHA, but take up less space and be a touch more versatile. I’ll let you know.

Edited June 11, 2021 by paul_5