Lovetone clones - Wobulator, Doppelganger

[Rectangular]

markus- 

if he's a time=money kind of guy, perhaps we could all chip in a couple bucks, and get a pool/fund going. if we can get 20-30 bucks worth of convincing, maybe he'd be less reluctant to sit down and write the values of that flanger.

of course, if he really hasn't the free time to do this kind of thing, that's another story

shedFX- I'm always enthusiastic about these cloning projects  ,  I learn a lot better from reverse engineering

-wreck

[markusw]

markus- 

if he's a time=money kind of guy, perhaps we could all chip in a couple bucks, and get a pool/fund going. if we can get 20-30 bucks worth of convincing, maybe he'd be less reluctant to sit down and write the values of that flanger.

of course, if he really hasn't the free time to do this kind of thing, that's another story

To be honest, I think we'll have to wait for another opportunity....

I learn a lot better from reverse engineering

That's definitely true in my case too. Before starting with rev-engineering the Ring Stinger I didn't have an idea how VCOs, LFOs....work.
I did all the schem drawing in LTSpice. This was really helping a lot for seeing how it works. Also it helps finding severe bugs in the schem.

Markus

[markusw]

Here's a schem for the Wobulator v3 I did about a year ago. I never built it because I mainly rev-engineered it out of curiousity but I'm very confident that the schem is correct. Also when simulated in LTSpice everything  "worked" as supposed.

http://www.aronnelson.com/DIYFiles/up/Wobulator_v3.pdf

Have fun! 

Regards,

Markus

[Shed_FX]

Wow Mark, what can I say?!?!?!? Thank you that is absolutley awesome. I will now have a go at sorting out a layout for it and posting it in the next few weeks. I am excited beyond words! (You know you are a pedal geek when .......)!

Thanks again

Shed

[TELEFUNKON]

IIRC, my Doppelganger has that kind of fliptop PCB where you`re able to look at the component- and at the copperside at the same time?

[Shed_FX]

Hey Telefunkon, would it be possible for you to take some hi-res photos of the component side and provide some capacitor values. It would be a great help!

Thanks in advance 

[markusw]

Wow Mark, what can I say?!?!?!? Thank you that is absolutley awesome. I will now have a go at sorting out a layout for it and posting it in the next few weeks. I am excited beyond words! (You know you are a pedal geek when .......)!

Thanks again

Shed

You're mostly welcome! Glad you like it 

Markus

[Shed_FX]

Right so with the schematic provided by Markus I have created a layout for the Wobulator. I have not been able to do it to match the Lovetone board like the String Ringer project but it is pretty compact. It is the first layout I have ever done so your comments would be much appreciated. I was hoping that someone could check this over for me and point out any glaring errors. The next stage will be to add on the rotary switch parts of the layout which I will do once it has been verified. From there I will hopefully compile the whole thing into a project file with info on all the components (similar to the String Ringer).

Thanks to anyone who checks it and I look forward to hearing your comments.

Thanks Shed

[lowstar]

hey shed,
sadly i cannot help at this stage of checking but once a prototype project file is out i´ll be happy to build it and help with the debugging (if there is any  ).
but i highly appreciate this attempt and your work.

cheers,
lowstar

[Shed_FX]

Right I have nearly completed the layout of the Wobulator but I have a couple of problems. To simplify the layout and to make it compact I have drawn it with two quad op amps. I am however worried that by combining the different elements on the same chip may result in audible ticking. Is this suspicion founded or will I just have to try building the circuit to see if it ticks. I know dirk said that this circuit was very prone to ticking and I have heard a number of people who owned a real version complain about the noise of the oscillator. What do you guys think? Is there anyway of predicting it or is there some methods I can employ to reduce the likelihood of ticking.

Thanks

[Processaurus]

If everythings on the same chip you can't do much if that's were the problem is.  I did made a small clone chorus with a BYOC board, which I thought ill advisedly used a quad opamp (LM324)for the LFO and signal stuff, but was very suprised that it didn't tick. Who knows, maybe your layout is just fine the way it is.

[petemoore]

  Someone said 'ticking'...I would start with Dual Opamp design..

[no one ever]

good show! but i would re do that schem with moosapotamus's larger traces + parts pack... the default values won't etch in the least!


or are you going to get these done by ExpressPCB? 

[Shed_FX]

Just a quick wobulator update. After completing the layout using two quad op-amps (mainly done for simplicity and reducing space on the board) i thought S#?T! this thing is probably gonna tick and should probably do it how Mr Coggin's designed it,with dual op-amps. Since then i have gone down the route of using 4 dual op amps in this circuit instead of 1 quad and 2 duals just to split it down a bit further. So this is the 4xDual layout:



The board size is 20cm x 9cm

Its in its basic form and i haven't checked it thoroughly yet. The plan is to check it through this week and then begin sorting out all of the bits to make it. Ive been working on a project file and piecing all the formalities together so we can have a complete fully confirmed clone. I will post a final layout that im going to use as the prototype incase anyone else wants to have a go. Its all on its way!

I'd like to that everyone who supplied any information or support for this project and hopefully people should get some enjoyment out of it!

Take it easy and I'll post an update soon.

P.S. Has anyone else got any more photos of the doppelganger? Or even better has anyone got one they can take photos of! I really want to build the full set (well maybe not the flange!)!

Cheers

Shed

[Dirk_Hendrik]

TickTickTick....

Do try to eliminate the 90 degree angles in the traces. At least for the Square Wave part of the LFO's. These traces wil really work as a transmitting antenna.

[lowstar]

how bout having the two rotary switches on a daughterboard so everything would fit in a 1590D ?

cheers,
lowstar

[Shed_FX]

Hi Dirk,

Thanks for the advice but can I clarify what you mean? Should I round off the corners of the right angles or should I try and give them short 45 degree sections. After you posted the comment I did look at the lovetone board and think there maybe a reason for using 45's instead of right angles.

Thanks in advance for any further advice you can provide.

Thanks again

Shed

[Shed_FX]

Evening Gentlemen,

Thought I would start my bank holiday weekend by putting the final touches to my wobulator clone with my proposed circuit layout. I got the LED's flashing last night and everything seemed to be going quite well. I have just finished things off today and plugged it in.....

I have a tick (As predicted by Mr Hendrik!) The circuit itself works well and the layout was pretty much correct (from a schematic point of view) The tick is there and it only really noticable at high volume but would like to get rid of it if I can. I believe that some of the production wobulators has a tick problem as well. Are there any quick fixes or methods of reducing the level of this tick. I had thought of wether coating the copper trace side of the board with goop! An extreme measure but would it work. The problem is, that I've got this far and really don't want to have to go all the way back to the beginning. The basic circult is arranged as above. I have run traces for connecting on board rotary switches.

I thank people in advance for their help.

Shed 

[markusw]

Cool!!

Glad you got it working!

Regarding tick I can't really comment. You could try to add a cap to the LFO opamp (from V+ to gnd), maybe temprarily solder it to the trace side...... Maybe it helps.

Markus

[Shed_FX]

Thanks for the quick reply Markus! Ive just had a bit of a play and putting a 10uf cap across the op-amp reduces the ticking by at least half! Its now at a level where I really don't mind the tick! Ive got to fully test it with 2 amps for the panning effects and so forth but I think its going to be ok. I will mess around a bit more with the capacitor value a bit further to check it out!
Won't have time to do all the testing this week but should hopefully be all done by next friday, then I'll put together a project document.

Cheers,

Shed