Lovetone clones - Wobulator, Doppelganger

[Shed_FX]

Fantastic 

Debugging the wobulator drained my enthusiasm a bit (think i was just knackered). But cloning the Doppelganger would be great. I have about 80% of the PCB layout from piecing together pictures that were previously posted.
I am definitely up for helping with the flange and the doppelganger! Well I've got to complete my set!

Thank you ispeakhopelandic I have been trying to find someone who could take photos of one for quite a while and volunteering is absolutely awesome. Welcome to the forum!

[ispeakhopelandic]

thanks again! i actually have to open my dopp really carfully, as the side is bent and its messes up the paint every time i open it. you may be excited to know that it's the second version, the one with the square wave and super slow option (other wise it only goes down to about 1hz). if i end up not being about to get the flange, then i know someone i can borrow one from.

chris

[Shed_FX]

Woohooo! Thats awesome! Can't wait to get started on it. If you chip the paint opening it, it would be best to take a range of photo's post them, and get feedback on them before you close it up. Basically we need:
A nice clear shot of the back of the board, so we can see the traces and solder joints clearly.
A shot of the front of the board, clear enough to show the resistor values,
A shot of the board showing where any flying leads go to jacks or switches
Check if the chips or transistors/fets have their numbers on and make a note,
Then make a note of the cap values around the board.
I think this unit will contain photo couplers, if you make note of any part numbers that would be helpful also.
That should do it, but take as many as you can from different angles as important details can be hidden by shadows etc.

Thanks Chris you are a legend!

All the best
Tom 

[BRingoC]

I can't wait. A few months ago I put together a phaseur fleur with all the trimmings, to resemble the dop. unfortunately had to set it aside before I got the additional lfo working, but I was/am close to having an alternative.

[Connoisseur of Distortion]

i leave this forum (and stompboxing ._.) for months, and come back to find the lovetone series' flanger in sight...!

thank you, chris, for your efforts. 

[Rectangular]

I'm definitely interested in working on the "?" Flanger with No Name ,  Markus is too, I think. if you can get the shots, I'll throw everything I've got at it, as will others, I'm sure.

please keep us in the know

-rec

[Shed_FX]

Hey Chris while I remember when you have the doppelganger open can you measure the dimensions of the board so that I can scale a layout accordingly.

Thanks

Shed

[ech0es]

if you have it, can you post the doppelganger schematic ?

[ispeakhopelandic]

Hey Chris while I remember when you have the doppelganger open can you measure the dimensions of the board so that I can scale a layout accordingly.

Thanks

Shed

yeah, absolutely. i'm still trying some things as to not ruin it anymore, but my patience is wearing thin with it. come a day or too i might just come flying open. also, if anybody is interested, i am going to fool around with a rackmount layout for the flange/ringstinger (assuming we get the flange done).

a little of topic but,

anybody here ever cloned/owned any buchla synth modules? i'll explain that whole story later .

[ech0es]

Any news of the reverse engineering of the doppelganger ?

[BRingoC]

Having held my breath hoping for a doppelganger schem, I have been working on a phaseur fleur for a while, and have gotten it close to being all finished up in a resemblance of a doppelganger. I posted a pic last week during the time when every post was deleted.  The phaser that I have put together has all the features of the later version of the dopp. and the mods to make similar to the dopp. are relatively easy to create if you spend a bit of time looking at the schem of the phaseur fleur.  One tip on making it though, the caps in the filter section are 6  x 103, these create a subtle effect at maximum, changed to 3 x 104 and the other half 3 x .047 makes for a more pronounced effect.  The square wave mod is done following the waveshaper mod on the commonsound website, instead of using a pot, use a toggle switch 2pdt with a fixed resistor on one side, non on the other.  The super slow mod is done with another  2pdt switch in series with the speed pot, similar to the square wave, just use a really big resistor, select to desired speed.  the stereo out is done with a line out after the first transistor.  The spectral bypass, use one set of lugs on the main on-off stompswitch to break the connection heading to the led, sandwich thing,   add a rotary switch to redirect the signal from the bypass that is normally on the phaseur so that instead of routing around the effect, it runs through the effect at all times, in other words, every time you step on the effect stomp switch you are turning the leds on or off, and with the rotary switch either selecting to remain with the signal routing through the effect, or the normal bypass route.  the phase/vibrato switch is simply breaking the connection with the non-effected signal before the output transistor. The other lfo is the only tricky part, I was never able to make it work as listed on the commonsound website, I ended up using the modulate main speed lfo to accomplish both mods.  use a stomp switch to add in the additional lfo, followed by a rotary switch to select which one you want to change, ie, add to or modulate speed.  run wires from the rotary to each of the spots on the main board that need it. To modulate the main speed run a wire to the +9v pin on the lower tl074, and another to the speed control 3 ( i am typing this from memory and don't have it in front of me, this is correct as best as i can remember)  To add to main, run a wire from the height 2 lug, to the one of the wires from lfo 2, and add the other lfo 2 wire to the tlo74 side of the 100k resistor.  Also the main speed control jack that can be controlled externally, just place use a stereo jack with the internal connections, i used a switchcraft 14b, so when nothing is inserted to the jack, the signal runs to the speed control, and when a stereo plug is inserted, it replaces the internal speed control.  Thats pretty much it, as far as pictures, i had problems posting them last week, and don't feel like trying again.

[mingus]

Hallo,
         some months ago I did a "pseudo" reverse engineering of the doppelganger (1st rev.). First of all, I must say that I never had a chance to try and touch the original, the work is based on several pictures found on the net.
It is obvious that the schematic lacks several informations, but I've understood the functionality of the effect; it is a sort of Univibe/Biphase phaser with 4 stages, it seems to be not really true bypass.
I did some simulation on the LFO and other parts of the circuit and it seems to work; I finally aborted the prototyping of the doppel because I never got the information about the caps and some other parts  values.
If someone wants to help me giving all missing information, we coud reveal the secret inside the doppel...
Bye

Mingus

[ech0es]

Please post your work so we will be able to work on and help you in finishing the reverse engeeniring.
For some of the dopp users, the 1st version is the best, sounds better.

[Shed_FX]

Hi BRingoC, mingus,

It sounds like you've both done some pretty interesting stuff. I am as enthused as anyone else about reverse engineering the doppelganger and hopefully we will be able to create a clone as a collaborative effort of many members of the forum. I realise from doing the prototyping work on the wobulator that it takes a lot of time and effort to put these things together! Please do not feel pressured to "hand over" your work to the community unless you really want to, producing this as a complete project will take a great deal more effort and any contribution that you wish to make in that process will be gratefully recieved.

I also lost a post during the server down time. I have got the majority of a layout created but need another couple of boardside photographs to complete it. This was constructed from the photo's originally supplied by ech0es some months ago.



I just need to know what goes on the other side!

[mingus]

The schematic, with a reference circuit board can be found at

http://www.marcominghetti.it/public/doublegangster%20rev%201.0.pdf

please note that all component values are missing, I have only a 70% of resistor values, the rest, for me, is hand written on a paper with all the notes I did...

Something is still missing, I've never understood the function of the two diodes (or zener or ?) D3 and D4...

If someone has the original maybe could help making a Bill of Material.

Good night

  Mingus

[BRingoC]

that shouldn't be too hard to conjure up something that will work as far as resistor and cap values, the values in the filter section could probably be copied right out of any other phaser you wish.  The ldr section could be the same values found in the phaseur fleur, someone on this forum said they had used vactrols similar to what is used in the mcmeat for that, the resistors in the LED section could be copied from the fleur as well. To make the super slow mod on this you would add a large value resistor in-line with the rate pot.

[Shed_FX]

Thanks mingus, that is really fantastic. I presume the layout component layout included in that PDF is based upon the actual Doppelganger board? Could you send me the photo's that you have of the doppelganger board, I have sent you a PM, this will be able to complete my layout that I posted earlier. We can then find out all of the remaining values from Chris when he posts his photos of his doppelgangers guts. It would be great if I can compelete the board layout and get a head start on building a prototype!

Thanks again

Shed

[mingus]

Shed,
   unfortunately the schematic is taken from photo and movies of the original found in this site and in an italian forum:
http://www.fennecelectronics.it/smf/index.php?topic=128.msg1322#msg1322

the input/mix part is taken from a clone attempt found in the same italian forum
http://www.fennecelectronics.it/smf/index.php?topic=539.msg12300#msg12300

I know that the circuit maybe is enought to start, it's a phaser, so all phasers has the same principle for process the signal... I already did some consideration and I've populated the BOM, but I was wondering am I wrong or right???
This is why I'm looking for someone who has the original and can give me all values.

Anyway I must say again that this is supposed to be a doppelganger maybe 90%, and your solder side layout gave me more confidence about it.

Ciao

Mingus

[Shed_FX]

Thanks mingus,

I have registered with another forum! 
I should hopefully be able to have a look through all of this stuff in the coming days, I could still do with more photos of the original Doppelganger board if anyone would care to oblige! Then the layout can be completed.

I shall post this one to help spark the discussions of what the circuit is based upon! Looks like the BC549's I bought in anticipation will have to go on the shelf!


Thanks again for everyone's input we are inching closer to the full set!

[BRingoC]

There's not much to that thing is there.  Those circled diodes appear to be D10 and D11 (germanium?), with D3 and D4 being the two on the lower left, where it says doppelganger v 3 or v4 i think.  d3 and d4 i would suspect are 1N4001 or whatever is used as D1 for polarity protection, they are used in order to prevent the signal from grounding, it plays a part in the spectral bypass, in and the lfo signal goes to ground, out and the lfo signal goes to the led's. in other words, it does the same thing the old univibes did, it never really shuts of, it just shut the bulb off, and sounded 'by-passed'.  As far as the bc549' s you mentioned and 'what it's based on' what are you looking for?  It is two tl077's two 4458's, check the commonsound forum for what type of ldr sensativity is used in the phaser fleur, i am sure that value would work.  The pots, i guess 100k.  The low frequency span i think works LDR 1 and 2, they I assume would be a higher value cap of .1 (C 11, 12) and LDR 3,4 being the high frequency ldr, using caps of .047 (C 13, C14) or whatever you like for those values, they effect the sweep.  C1 @ 100uf  C2 @ 10uf, as well as C3 and mayve C5.  C4 and 6 i would say 1uf.  On the input section, those are standard filtering parts, borrow from any circuit.  The Color circuit, with C17, i would assume is similar to the feedback section of the phaseur fleur , i think there is a .001 in there.  I would bet the ldr led's have to be green. The resistors in the filter section will be parallel values, ie 45 will be the same as 46, etc, i think. If you can figure out the resistor values, which dosnt look like it would be too hard you could figure out the Vref's, it could be scraped together from this info, i could try it this weekend.