Percussion, A tiny drummer in a 1590A box

[solderman]

Hi
This is The Percussion. It's sort of a tremolo but goes from normal tremolo to much more brutal and deeper and choppier like on/off kind of sound. Here's a link to how something similar sound. http://www.youtube.com/watch?v=uQGkJJBomA4

I think its based on the same or almost same circuitry. Thanks to JKowalski for adding the flashing LED/Rat bypass part of the circuitry although I realised I probably want need it cause I'm always using a 3DTP stomp switch an i think the base current can drive the LED by its own but I will bread board it before I make The PCB and check that out. As its now the base to stomp switch is hanging and world be always on as i can see it. The stomp switch act as a on off switch for the LED.  As always, in a 1590A box. The 2N2646 is a odd thing but Banzai.com have them for €0.58. Check the pecs it seams like somthing you can build funny things with, like tempo variated filters etc.  I have made some changes shown in collor on the schem.




\\Solderman

[German]

I was thinking, that it's a metronome.. But AGAIN!! Tremolo..

[Taylor]

Yeah, the thread title had me hoping for a little drum machine. 

[JKowalski]

All I have were DPDT... Have to resort to the rat. I need some 3PDT so bad! So jealous.

With the 3PDT instead of the DPDT, just take out the MPSA13 and the 10M reistor completely, and put a trace instead of them.

When I tried it, I could not drive the led with the oscillator directly - it is very sensitive to modification. It died out completely. Having a ton of 741's, it was easy just to plop one in there, didn't have think of anything elaborate.

Woops, looks like i accidentally cout out the decoupler there in the front. Sorry about that - but I guess you got that under control XD



EDIT: Here's a better video of it (In the AMAZING GUITAR the Vox Starstream - has built in bass/treble boost, tremolo, hand operated wah, e-tuner, and fuzz!!!)

http://www.youtube.com/watch?v=hWC1uzg-Yr0

Go to about 1:44 to see it in action. He uses it again at 4:20, to play Spacemen 3's song Repeater.

[connie_c]

nice one, i love the sound of this pedal. there are a few clones of the original vox out there and i was think of giving it a go in a month or two. great to get it spelled out for me.

thanks

[LEON.01]

Yeah, the thread title had me hoping for a little drum machine. 

LOL! yea, and me! i was expecting something like this;

http://www.youtube.com/watch?v=ml6r7Ad-wMQ

But hidden away in a little enclosure!

[jefe]

I was thinking, that it's a metronome.. But AGAIN!! Tremolo..

Yeah, the thread title had me hoping for a little drum machine. 

Yeah, the thread title had me hoping for a little drum machine. 

LOL! yea, and me! i was expecting something like this;

But hidden away in a little enclosure!

"If you can't say anything nice, don't say anything at all."



Anyway... nice work solderman! Thanks for sharing this. 

[~arph]

post did not contribute to the thread...

[solderman]

All I have were DPDT... Have to resort to the rat. I need some 3PDT so bad! So jealous.

With the 3PDT instead of the DPDT, just take out the MPSA13 and the 10M reistor completely, and put a trace instead of them.

When I tried it, I could not drive the led with the oscillator directly - it is very sensitive to modification. It died out completely. Having a ton of 741's, it was easy just to plop one in there, didn't have think of anything elaborate.

Woops, looks like i accidentally cout out the decoupler there in the front. Sorry about that - but I guess you got that under control XD



EDIT: Here's a better video of it (In the AMAZING GUITAR the Vox Starstream - has built in bass/treble boost, tremolo, hand operated wah, e-tuner, and fuzz!!!)

http://www.youtube.com/watch?v=hWC1uzg-Yr0

Go to about 1:44 to see it in action. He uses it again at 4:20, to play Spacemen 3's song Repeater.

Hi
Yes I thouth that might be tha case, thats why I left the LM741 in. Its no big deal since there is  plenty of space left in a 1590A
And whaowww That guitar was some thing else . Yber cool. And the sound just makes me wanne build one this eaven more.

//Solderman
 

[solderman]

I was thinking, that it's a metronome.. But AGAIN!! Tremolo..

Yeah, the thread title had me hoping for a little drum machine. 

Yeah, the thread title had me hoping for a little drum machine. 

LOL! yea, and me! i was expecting something like this;

But hidden away in a little enclosure!

"If you can't say anything nice, don't say anything at all."



Anyway... nice work solderman! Thanks for sharing this. 

Thanks for the kind words.  Sharing is what is all about, at least from my point of view.

To you all who got dissapointed and really wanted a drumsequezer in a tiny box.  Here is a suggestiun

If you bild the percussion layout an build this one and put it in front you have your self a drummer, extreaml static dut he's gonna keep the pace. Mentometer??





Take a deeper Look in to the topic
http://www.diystompboxes.com/smfforum/index.php?topic=75137.0

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[/quote]

[solderman]

Hi all
As you might  notise the layout and the schematics has changed since my original post . I got the 2N2646 yesterday and bread boarded the ting and here I what I changed and why.

I used C547B NPN trannies because I happen to have a truck load. It will probably work with 2N3904 or something like it. I changed R5 for 10K because id did not oscillate under 7K. I added a 10K trim pot in series with R13 to be able to adjust the signal to unity level. This is of cause dependent on the used transistor. I also changed the 4,7nF cap to 47 for more bass. I found that a 20K Rev Log for depth pot worked for me. 100 B only used a portion of the track. The 100nF in Cap I originaly added is not needed. I also took out the MPSA13 and the 10M and connectde the LED to out on the LM741 and it workes fine. But It wont work /flash without the OP amp buffert.

//Solderman

[solderman]

Hi all, (or at least you who are interested if not jup to a better tread  ) 

I have now built this one and this is som findings i made about it and my mods.
1. I added a trim pot in series with R11 to modify to unity gain
2 I added a 100uF over the input rail
3. The used LED has a big impact. The rail to buffer IC seems very sensitive. When I bread boarded this I used a diffuse red LED with a 560R current limiting resistor. Already on the breadboard i discoverd that i needed to raise R5 from the schem 4.7K to 10K to find the point when the you can diale in the speed pot (LED and the sound) max CC to go from non to slowest flash.  In the final build I used a very bright blue LED and a 680R current limiting resistor. I was very surprised when the low speed was extremely fast. More resistance on the pot means less speed so I tried a 500K pot with the result that I finally used a 100K resistor in series with a 200K pot. The C1 has a noticeable impact on the speed. If used the possible lowest speed is lower. But when turning the speed down the chopping will stop for aprox 0,5 sec until the cap is charged. This depends very much on the LED used. The 2N2646 odd ball is available at http://www.banzaieffects.com/2N2646-pr-16504.html at a reasonable price

Sound clips coming
PCB
http://solderman.fatabur.se/Future%20project/per.pdf
BOM
http://solderman.fatabur.se/Future%20project/per.txt




//Solderman

[gtudoran]

By any chance ... is any replacement for that UJT tranny(2n2646)
Best regards,
Gabriel

[solderman]

By any chance ... is any replacement for that UJT tranny(2n2646)
Best regards,
Gabriel

Hi
don't think so. This is really an odd one. Never herd of the type before I run in to this.

//Solderman

[puretube]

By any chance ... is any replacement for that UJT tranny(2n2646)
Best regards,
Gabriel

Gabriel: PM me your mail (post) address...

(there have been some very friendly/kind people in your country in 1966 - time to send something back...)   

[shugs81]

Hi solderman!

I'm interested in building this pedal but have never etched a pcb before and was looking to build this on strip board but am having trouble reading the amendments you did to the schematics. I tried emailing but am not sure if you got it or are still using it!

I'd also like to know what pots you used and where you got them from?

I'm still hoping to keep this in the small enclosure so looking to keep the pots the same... what sized LED and pot did you use?

and have you got a sound sample yet cause this sounds perfect for what I want!!!

Cheers!

[JKowalski]

and have you got a sound sample yet cause this sounds perfect for what I want!!!

http://www.youtube.com/watch?v=hWC1uzg-Yr0#t=1m45s

The effect posted here is the exact same circuit used in the VOX Starstream guitar. This link goes to an example video of the Starstream, at the moment he first turns on the repeater effect. He plays around with it later on, too.

[solderman]

Hi solderman!

I'm interested in building this pedal but have never etched a pcb before and was looking to build this on strip board but am having trouble reading the amendments you did to the schematics. I tried emailing but am not sure if you got it or are still using it!

I'd also like to know what pots you used and where you got them from?

I'm still hoping to keep this in the small enclosure so looking to keep the pots the same... what sized LED and pot did you use?

and have you got a sound sample yet cause this sounds perfect for what I want!!!

Cheers!

Hi Shugs81
Pleased to here that you are interested in building it. It's quite fun all though the use is quite limited to special cases.
For sound samples check The Catalinbread Valcoder.

http://www.youtube.com/watch?v=C3D4NVzbJ64

I don't know if it is the same circuit but it sounds the same. To built my layout check the 1590A part of my site. You will find both the PCB and the layout. Then you can use it to make your own strip board layout in DIY layout creator ( se the top thread in this forum for where to get it) and I'll mail you the DIY file when I get the time. BTW you can find a short PCD etching tutorial on my site as well (there are better ones out there)

About the build. I can see that you are new to the forum. This is quite an easy build. BUT it has some challenges.

The Q1: 2N2646  can be hard to find. This is NOT a FET. It's a unijunction transistor - a unique type of semiconductor - it has two bases and one emitter. www.banzaieffects.com has them. Mind the B1-B2-E orientation

If you implement the flashing LED you need the LM741 OP-amp (can be any single op-amp) to buffer the pulse then you need to find the correct value pot for speed (or rate) cause the choice of LED effects the circuit LFO. It you don't want a LED you can omit that part of the circuit. The odd thing at R13 is just me trying to draw a Trim pot wired up as a variable resistor to control the amplification of the output level.

You might like to consider building the Tremolos Lune in stead. If you do the ramp up/down mod you can almost get the same type of effect and of cause the normal tremolo as well so it is more versatile. But this one is more hard core chop type of sound. see
http://fuzzcentral.ssguitar.com/

BTW
The guitar on the clip that Chris posted is some thing else. I wonder what the VOX engineers had been smoking when they designed it

[JKowalski]

BTW
The guitar on the clip that Chris posted is some thing else. I wonder what the VOX engineers had been smoking when they designed it

...and why arent they still smoking it? 

[shugs81]

would save masses of space on the pedal board! Was looking for the heavy chop effect!! think i liked the tiny case more!