Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - add4

Pages: [1] 2 3 ... 22
Thanks! i'll try that and let you know how it goes!

thanks, some things to try there. I think it's a common problem indeed.

do you need something specific to help with this?

Hello guys,

So i am building a 2015 8 ball (i know, i know, i'm late in my builds).
The circuit is working, but unstable. When i push the gain up, D1 and D2 (LEDs) light up alternatively, like 10 times a second. And the circuit produce a kind of motorboating sound.

Funilly, I had the same issue with the same circuit when i breadboarded it, and with another bluesbreaker type circuit I built before. But not with madbean's King of klones which works perfectly. So i guess it's a common problem for this circuit topology

Does anyone know why this happens? and more importantly, how to solve this?


Hello everyone

I'm usually always putting a ground plane to my pcbs. but since it's usually pretty simple circuits without LFOs or digital parts, i'm not worried about ticking and other digital noise sources.
Now i've heard that if you go digital you have to separate ground planes for the analog and digital part. How can i physically do that?
- the ground is, in the end, common for all my circuit and comes from my power jack, at one single point of the PCB. Do i need to do it another way?
- The way i imagine this is to make a ground plane on top for the digital part of the circuit (where does it stop? coupling cap beyween the digital chip and the first analog 'brick' of my circuit the signal with hit?) and the ground plan on the bottom for the analog part. Will it be enough?

What are the general rules to do this right?

Thanks in advance

Build Reports / Re: Polytone preamp
« on: March 14, 2017, 08:57:44 AM »
Looks neat. What is your rail to rail voltage? I only glanced at the original schematic, but it looks like the circuit goes from -15V to +15V. Are you using a charge pump?

Yes. I used -9v/+9v

Envoyé de mon iPhone en utilisant Tapatalk

Build Reports / Polytone preamp
« on: March 13, 2017, 03:48:16 AM »
Thanks to everyone for your kind words and your interest! I more or less learned a majority of the few things i know here, because of you, and the madbean projects (and the other great forums, and sites that some great people maintain, but here is where the heart is).

For those interested in a PCB, are you ok with some minor mistakes? With this version of the PCB we need to lift one leg of 2 different capacitors and run a wire from both of these floating legs to the leg of a pot. it's a bit messy, but i've seen that on some madbean projects (egodriver :) ). Actually the PCB also works without the mod, but it's not doing what i wanted it to do .. so you cna even try without the correction and with them and keep what you prefer..
The correction removes bass from the signal with a switch (it's just adding  caps in // to the very small one decoupling cap I put really... the values I propose should probably be tweaked, especially for bass..) , without correction, the switch adds mids/highs by adding/tweaking a rc network in the feedback loop of the amplification stage. which also sounds cool.. but it keeps too much bass actually be useful to prevent feedback on jazz guitars .. which is the goal here
if you are ok with it, i have some boards ready right now, they are verified.
I can provide the BOM with the notes for the error correction on PDF, but i don't have a fancier doc ready yet, even if it would be fun to make one..

How does that sound?
Whats the usual price for something like this ? :D

Build Reports / Re: Polytone preamp
« on: March 09, 2017, 04:59:21 PM »
Is that a silk screened enclosure? Did you do it yourself?

Also, show us the guts!

Guts as requested there are a few cuts and offboard wiring on the pcbs as my boards are still not mature

Envoyé de mon iPhone en utilisant Tapatalk

Build Reports / Re: Polytone preamp
« on: March 09, 2017, 04:53:57 PM »
Looks cool!

Any chance you would share the project files?


I can point you to the original polytone schematic which is publicly available but I'm not confortable with sharing the files since I'm making a few for some people.
I have no problem to provide you a board and BOM however, but this version of the PCB still has errors and I had to do off board wiring to actually make it do what I wanted (actually it's a change of the way the LEC switch works ... I didn't like my first way of making it work).
If some of you are interested I could make a few more for madbean people when the boards are correct and provide a doc how does that sound?

Envoyé de mon iPhone en utilisant Tapatalk

Build Reports / Re: Polytone preamp
« on: March 09, 2017, 04:48:28 PM »
Is that a silk screened enclosure? Did you do it yourself?

Also, show us the guts!

A local guy is doing UV printing so it's getting very easy to have this kind of finish . Which is the only reason why I accepted to do a small run of these for people. Haha.

Gut shots are coming

Envoyé de mon iPhone en utilisant Tapatalk

Build Reports / Polytone preamp
« on: March 09, 2017, 12:06:06 PM »
As i have a passion for jazz, I also love the jazz sounds and a few of these are linked to the polytone mini brute amps.
I have one myself and it literally kicked out all my other amps of the house when I needed space because of the babies.

I thought of putting the polytone mini brute preamp in a pedal to get closer to that very specific sound even in a normal amp at a gig or jam session.

It's basically an OpAmp clean boost stage followed by a bass/mids/treble bandaxall. The voice switch controls the freq response of the boost stage with different switchable RC network to ground and goes from Wes Montgomery to fusion/rock sounds (hence the name "multitones") and I added the LEC (Low End Control) switch as a request for some people who wanted to control the "boominess" when used with an archtop.

It's actually a project for some jazz guys in a forum who would order me a few of these so wish me good luck


Envoyé de mon iPhone en utilisant Tapatalk

Build Reports / Re: My most beautiful failure to date!
« on: March 07, 2017, 12:02:18 AM »
With graphics like that you don't need to make it work. Seriously put that on your pedalboard right now it's cool as hell. Who wants dual modulated delay anyway? Being cool is my much more important.

Envoyé de mon iPhone en utilisant Tapatalk

Open Discussion / Re: I lost my best friend
« on: March 02, 2017, 12:50:24 PM »
I have no words to express how much I grief for you and your family.
I hope you'll find the strength needed to recover from that pain soon and remember the good things to be remembered.

Envoyé de mon iPhone en utilisant Tapatalk

Build Reports / Variation on the RC boost
« on: February 28, 2017, 07:50:41 PM »
See, another covers band ....  ;D

It looks great.

Haha the idea for the artwork at the beggining was to have a few small texts explaining what the effect does. And some of those would be stupid/obvious to give a kind of "cute" effect. A bit like knobs does on his effect pedals demos

Most of these texts disappeared to make room for the band logo.

This is a the box I have made for my pedalboard.

Envoyé de mon iPhone en utilisant Tapatalk

Open Discussion / Re: Jonny Greenwood Glitch Pedal
« on: February 26, 2017, 06:43:06 AM »

Well, the old 'let's go a bar, I hear a band's playing' days are over. Unless you know how to translate your gazillion facebook friends into a decent showing at a local club chances are your band is not going to be that successful playing original material. So at least playing material from famous bands might actually get you some gigs.

these days are (sadly) also gone because of the general level of the bands playing into bars..
some really beleive it's enough to produce some sounds more or less together to try to get an audience..
back in the days, most well known bands actually had a really huge proeficiency at their instruments..

and it makes the difference (for me at least .. but i'm certainly not representative of the majority, just one weird guy)

Pages: [1] 2 3 ... 22