EHX - Micro Synth XO Version  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

Re: Micro Synth XO Version EHX (half-schematic)

Postby Bernardduur » 18 Feb 2013, 16:01

C51 is tied to ground
'No more....... loud music.......'

For this message the author Bernardduur has received thanks:
modman (23 Aug 2015, 20:28)
Bernardduur
Transistor Tuner
 
Posts: 1141
Joined: 24 Aug 2007, 08:36
Location: Losser.........
Has thanked: 87 times
Have thanks: 482 times

Re: Micro Synth XO Version EHX (half-schematic)

Postby fbiramba » 18 Feb 2013, 17:34

thanks a lot
for the ferrite bead, what sort I must buy?

for U5, is there an inversion between + and -: the + on the first 4558 must go to the - of the second?
could you confirm

is there a part list of made ? (to know the characteristics of capacitors (tantal, ...))

have you made this effect ; is there others mistakes, because I would like to do it myself

thanks a lot bernard
fbiramba
 
Posts: 2
Joined: 16 Feb 2013, 16:02
Has thanked: 0 time
Have thanks: 0 time

Re: Micro Synth XO Version EHX (half-schematic)

Postby vagos21 » 05 Feb 2014, 17:21

Hello everyone on this thread, it's a great starting place for the new microsynth!

i know it's been quite a long time since the last reply, but did anyone actually build this? did the LM13700 version work in the end? I've only started building pcbs and stompboxes about 5 months ago and they've all been successful, so i'd love to try this monster (i actually made a dual PCB and soldered it for the older version for 4 days but left it in the drawer in a plastic bag after realising the thing about the 3094s, ouch!) i love putting schematics to PCBs and would really love to try this one, i just need to know,

has anyone else tried a PCB design already? is the schematic somewhat verified?

thank you for your time!
vagos21
 
Posts: 3
Joined: 10 Jun 2013, 13:04
Has thanked: 1 time
Have thanks: 0 time

Re: Micro Synth XO Version EHX (half-schematic)

Postby lufox15 » 03 Mar 2014, 05:02

well vagos21 it looks like nobody tried to do a pcb of this monster, and I'm not a erudite of pcb-tracing so I didn't tried, but I tried the circuit with all the part that are in the schematic, and it works except exactly the same as the big trace version, except for the sub octave stage, that doesn't works for me, and I didn't try it again, without oscilloscope I have no much to do, we need help here, but I think it's too much work for this pedal it's better buy it, only if you like to do some diy electronics stuff it's nice but otherwise better buy it.
User avatar
lufox15
Breadboard Brother
 
Posts: 52
Joined: 30 Oct 2009, 03:03
Has thanked: 3 times
Have thanks: 0 time

Re: Micro Synth XO Version EHX (half-schematic)

Postby vagos21 » 10 Mar 2014, 16:57

you tried all of this on breadboard?? :) i love DIY and i've made pcbs for quite a few projects, so i'd love to try this one too. you followed the three schematics towards the end of page 1? i could PCB it and see what happens, i don't mind if it takes a week, i'm sure many would like it on LM13X00, the 3094 are so d*** expensive now...

anything to notify that was strange in the schematic? :)
vagos21
 
Posts: 3
Joined: 10 Jun 2013, 13:04
Has thanked: 1 time
Have thanks: 0 time

Re: Micro Synth XO Version EHX (half-schematic)

Postby lufox15 » 13 Mar 2014, 22:37

everything works fine but the sub octave stage, maybe it was just the noise or bad conections as I said I didn't have my oscilloscope and I haven't tried since the last time, clean signal, octave up, square, the frequency filter, the attack stage, trigger stage, everything was working well with the values of the components but that suboctave stage, maybe was my Cmos IC that messed up or something like that.

I would be really nice to have a pcb of this monster, doens't matter if it's two sided board only needs to fit into a DD enclosure.

Good Luck!!!
User avatar
lufox15
Breadboard Brother
 
Posts: 52
Joined: 30 Oct 2009, 03:03
Has thanked: 3 times
Have thanks: 0 time

Re: Micro Synth XO Version EHX (half-schematic)

Postby lufox15 » 13 Mar 2014, 22:38

everything works fine but the sub octave stage, maybe it was just the noise or bad conections as I said I didn't have my oscilloscope and I haven't tried since the last time, clean signal, octave up, square, the frequency filter, the attack stage, trigger stage, everything was working well with the values of the components but that suboctave stage, maybe was my Cmos IC that messed up or something like that.

It would be really nice to have a pcb of this monster, doens't matter if it's two sided board only needs to fit into a DD enclosure.

Good Luck!!!
User avatar
lufox15
Breadboard Brother
 
Posts: 52
Joined: 30 Oct 2009, 03:03
Has thanked: 3 times
Have thanks: 0 time

Re: Micro Synth XO Version EHX (half-schematic)

Postby Liquids » 10 Sep 2014, 01:39

I know it's a little late, but I'm comparing schematics of the old to the XO version. Not that the old schematic didn't have a few errors, but I breadboarded most of it (Especially the filter and trigger sections) running on bipolar power, so I'm familiar with the errors on the late "original version" schematic alongside the "fabian hartley" schematic.

Anyhow, the transistor that may be said to be 'between' the filter stop time and start time is reversed in the XO schematic version.

Is there any chance someone can check and see? Again, I know it's a little late. But it'd be worth it. At some point I'll try it both ways on the breadboard and see if it makes a difference, but until then...
User avatar
Liquids
Breadboard Brother
 
Posts: 142
Joined: 24 Apr 2009, 20:29
Location: USA
Has thanked: 15 times
Have thanks: 24 times

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 27 Apr 2018, 18:00

Has there been any progress in recent years on this?
I'm crazy enough to hop on the breadboard gang for this one 8)

For this message the author KevinMitchell has received thanks:
Nocentelli (27 Apr 2018, 22:08)
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 02 May 2018, 14:54

I have all the parts I need - almost. I had to order 4 TLC2272 since I don't have any CMOS rail to rail opamps. But I'll try others once it's put together.

If I can get this working properly on breadboard to have a verified schematic I will have some circuit boards fabricated to distribute. Right now the idea is to have two PCBs - a main board and a control board within a 1590XX/1790NS enclosure. There will also be two versions of the control board. One for rotary pots and one for slide pots. With the pots and opamps alone I'm more into the project than I had anticipated. So I certainly aim to have something produced from this endeavor.

If anyone has suggestions for replacements on the opamps, transistors and the FET please feel free to chime in. Here is a short list of what I'll be working with as well as some ideal substitutes.
TLC2272
NJM4558 (I imagine almost any dual opamp should work)
LM13700 (LM13600 should work here too)
1N4148 for all signal diodes (or 1N914)
2N5088 (will try 2N3904)
2N5087 (will try 2N3906)
BF5458 (this is SMD. I have to find an appropriate through-hole replacement for this one. Will try common FETS that I have kickin' around)
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 09 May 2018, 16:04

I seem to be having the same issue with sub octave. So I'm doubting it's an problem with the breadboard - though it is difficult to have a stable circuit on there I don't think that's the serious issue.

The hand drawn schematic in this thread is a little different than the latest one for the sub-octave part. The latest one shows the JFET connecting to the output of the 4013 and the hand drawn one does not - which corresponds with the original (big) version of the pedal. But neither connections fixes the issue.

The original used an OTA there instead of a PNP transistor. So comparing the two doesn't really help me at the moment. I've also tried a few different JFETs with no luck. Maybe I should swap out the 2N5087 for other types?

I'll keep pushing forward. Any advice would be appreciated.
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 09 May 2018, 19:48

I've just noticed the the bottom part of U5 in the schematic - the inputs should be flipped. So that would be the big problem for sub-octave.
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby P-Trash » 24 May 2018, 08:31

KevinMitchell wrote:I've just noticed the the bottom part of U5 in the schematic - the inputs should be flipped. So that would be the big problem for sub-octave.

Hi, Kevin, how is the works going?
P-Trash
 
Posts: 5
Joined: 31 Jan 2018, 13:25
Has thanked: 5 times
Have thanks: 0 time

Re: EHX - Micro Synth XO Version

Postby P-Trash » 24 May 2018, 08:35

And maybe someone have a scheme, that is on the first page of the topic?
P-Trash
 
Posts: 5
Joined: 31 Jan 2018, 13:25
Has thanked: 5 times
Have thanks: 0 time

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 06 Jun 2018, 19:56

Hey sorry for the lack of update. There didn't seem to be much interest in this as I was picking away at it. I've got everything working on breadboard minus the filter section since the breadboard became pretty out of hand the further along I got.

I'm confident enough in my revised schematic to move forward, finished my PCB layout and send them out for fabrication. I always seem to be in the middle of a half dozen projects and put things aside when I get bored with them.

You could use the schematic on page 2 and consider my latest notes.
KevinMitchell wrote:The hand drawn schematic in this thread is a little different than the latest one for the sub-octave part. The latest one shows the JFET connecting to the output of the 4013 and the hand drawn one does not - which corresponds with the original (big) version of the pedal.
KevinMitchell wrote:I've just noticed the the bottom part of U5 in the schematic - the inputs should be flipped. So that would be the big problem for sub-octave.

And Liquid's note which I had not gotten far enough to verify
Liquids wrote:Anyhow, the transistor that may be said to be 'between' the filter stop time and start time is reversed in the XO schematic version.


Hang tight I'll be back soon :wink:

For this message the author KevinMitchell has received thanks: 3
mr coffee (21 Jun 2018, 18:23), Nocentelli (07 Jun 2018, 12:40), P-Trash (11 Jun 2018, 14:03)
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby Nocentelli » 07 Jun 2018, 12:41

Following this closely. I sold a big box years ago and cannot bring myself to buy one, would love to build one.
brownwhopping wrote:How can I learn by reading threads an making circuits, when some day I can see a lawsuit or somebody beat me in the face for that?
User avatar
Nocentelli
Tube Twister
 
Posts: 2087
Joined: 09 Apr 2009, 08:06
Location: Leeds, UK
Has thanked: 860 times
Have thanks: 837 times

Re: EHX - Micro Synth XO Version

Postby mr coffee » 21 Jun 2018, 18:26

Please put me down for one of your PCBs,
Awesome you are laying out a PCB for this really cool circuit!!! :applause: :applause: :applause:

mr coffee
mr coffee
 
Posts: 24
Joined: 10 Jul 2009, 04:54
Has thanked: 45 times
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 22 Jun 2018, 17:04

Glad to see interest!

I hope to have a prototype etched and working by next week. I'll share my progress and put up some sound clips - then a little more layout work and I'll send them out for fabrication.

I'll likely do a version with rotary pots first - since these are typical parts. But for anyone interested and not intimidated with the idea of drilling/filing your own slide pot slots, these are the parts I suggest using;
Slide Pots

I might do one board and hand wire the controls. We'll see where I'm at next week :D

Thanks!
-KM
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

Re: EHX - Micro Synth XO Version

Postby Serge75 » 22 Jun 2018, 17:26

Very interested in pcb too. What a great project!
Serge75
 
Posts: 8
Joined: 06 Sep 2012, 11:12
Has thanked: 1 time
Have thanks: 0 time

Re: EHX - Micro Synth XO Version

Postby KevinMitchell » 28 Jun 2018, 02:47

Just a little update.
Haven't had much free time but it's coming along okay. About half way through just need to work out the trigger, filter and output.

-KM
You do not have the required permissions to view the files attached to this post.

For this message the author KevinMitchell has received thanks: 3
mr coffee (03 Jul 2018, 21:58), P-Trash (05 Jul 2018, 12:45), Serge75 (29 Jun 2018, 12:23)
User avatar
KevinMitchell
 
Posts: 18
Joined: 27 Jan 2015, 01:52
Has thanked: 0 time
Have thanks: 12 times

PreviousNext

Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: Google Feedfetcher, nenecarrizo83, zoxi and 7 guests