# grand orbiter



## djmiyta (Jun 6, 2022)

Can anyone post their working voltages for the grand orbiter. Mine still only phases by manually turning the sweep pot. It's so close. noticed and odd thing. when turning te sweep pot my finger touched the range switch which gave it a noticeable jump in the effect's effect.


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## Barry (Jun 6, 2022)

Sounds like a cold solder somewhere


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## Chuck D. Bones (Jun 8, 2022)

The LFO in that pedal is finnicky; it runs right on the edge of not working.  Posting voltages won't help because the voltages you're interested in are constantly changing as the LFO runs.  

The board has to be very clean.
Did you build V1 or V2?  If V1, disconnect the RATE side of the bi-color LED by cutting or lifting one end of R33 and see if that fixes it.
C13 & C14 must be very low leakage.  Aluminum caps can be too leaky.  I recommend tantalum for C13 & C14.
And do some (more) visual inspection!


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## djmiyta (Jun 8, 2022)

Thank you CDB. The LFO is finnicky puts it mildly. The pedal sounds like it would be awesome if it swept automatically.
I did all your mods including tantalums for C13 & C14. I'll have to check the version later tonight. And yeah visual inspection is so underrated. Too many times have I had a build not work spend many hours troubleshooting ,inspecting, etc to no avail. Put that build away and a day or week later come back and find the issue.
For visual inspection: Solder bridges, wrong component, wired incorrectly, continuity, cold joints, and voltages.  Did I happen to miss anything in the visual inspection you could add?Thanks for your time by the way much appreciated.


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## Chuck D. Bones (Jun 8, 2022)

That's pretty much everything.  Also check part orientation. A backwards electrolytic cap might work, but usually causes problems.  Backwards transistors & ICs; very bad.

Inspection is doubly important when making mods.  It's very easy to get lost and muck things up.  When I was modding the Circulator, I had trouble getting it to work because I was off by one IC pin when I stuck on a resistor.

Voltage is more of a test & measurement thing than an inspection thing.

Good luck!


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## mybud (Jun 9, 2022)

djmiyta said:


> Can anyone post their working voltages for the grand orbiter. Mine still only phases by manually turning the sweep pot. It's so close. noticed and odd thing. when turning te sweep pot my finger touched the range switch which gave it a noticeable jump in the effect's effect.


I’ll gladly do this in the course of today.


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## mybud (Jun 9, 2022)

mybud said:


> I’ll gladly do this in the course of today.


Here you are, as attached. 

Stock version (no mods). Both toggles to left and all pots at midday.

Because the voltages vary, a single figure represents a rough average while two figures represent a more widely-varying range than I can convincingly average to a single voltage.

Hope this helps. Best wishes for resolving your build in due course.


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## mybud (Jun 9, 2022)

djmiyta said:


> Can anyone post their working voltages for the grand orbiter. Mine still only phases by manually turning the sweep pot. It's so close. noticed and odd thing. when turning te sweep pot my finger touched the range switch which gave it a noticeable jump in the effect's effect.


Given the symptoms you describe, I wonder if it's not worth checking the switches (esp. the range one).


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## Chuck D. Bones (Jun 9, 2022)

IC3 is the LFO, that's the one we're interested in.  Many of the pins are tied together, so you should see the same voltages on pins 13, 4, & 8.   
Pins 9, 10 & 12 will be the same.
Pins 5 & 7 will be the same.
Pins 3 & 14 will be the same.
Pins 2 & 15 don't matter.
Pins 1 & 16 should both be around 1.2V to 1.3V and not vary much, if at all.
Pin 6 is power, Pin 11 is ground.

With the LFO stalled, all of the voltages on yours should be constant.  

Have you verified R28-R30?  If any of those are off, the LFO can stall.

If the LM13700s are socketed, you can try swapping IC3 for one of the other ones.

Where are the photos?  I want to see if you got the mods right.


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## djmiyta (Jun 9, 2022)

Here’s the pictures and thanks for the input now with voltages I have something to shoot for. 
golden rule for me is sockets so got that never lost a tranny or IC can’t fry what ya don’t burn.
Gonna check voltages in just a bit 
And verifying the values of R28-R30? I can and will if that’s what you meant.
So I got some sleuthing to do with new info.


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## Chuck D. Bones (Jun 9, 2022)

Verify R28, R29 & R30 visually.  If any of them are off, it will affect the LFO.  Check R31 while you're at it.  

IMO, comparing voltage on an LFO, running or not, is likely to produce results that are inconclusive at best.

I guess I'm on the hook to verify you did the mods correctly...


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## djmiyta (Jun 9, 2022)

Here’s all my voltages. Nothing jumps out at me aside from the non fluctuating voltages
R28-31 are the correct values according to the  color bands and BOM.
I think I've got 1 or 2 more LM13700's I can try


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## Chuck D. Bones (Jun 10, 2022)

The voltages on IC1, IC2, IC4 & IC5 are all good.

Let's focus on IC3, that's the LFO.  The voltage between pins 7 & 8 is too large, meaning IC3 is either FUBAR or one of the pins is not in the socket.  Before you replace IC3, make sure there are no shorts or bad solder joints around IC3, R32 or R33.


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## djmiyta (Jun 10, 2022)

I will have to do that tomorrow gotta be up for work at 4 a.m. Really hoping to get this workingI think I need to reflow my wiring since when the FTSW got moved pin 15 and pin 10 would fluctuate a bit


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## djmiyta (Jun 11, 2022)

So taking Chuck D bones advice looking over my build for the 10th time. I see I didn't install R34 when doing the mods. up to that point I got the effect only by manually turning the sweep pot. After installing R32 I can get no effect whatsoever AND now no signal in vibrato mode.What the hell happened. Did I fry something not having R34 in and powering it up? I know others have built a working one seemed it was closer to working without R34 in place, very odd and now back to square one and stumped. Time to swap out IC3 ? Cause I've got no idea where to go from here after the swap. Maybe rechecking voltages?


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## Chuck D. Bones (Jun 11, 2022)

Re-inspect to make sure there is no collateral damage from the last work you did.  Fix the mistakes, replace IC3.  

Omitting R32 or R34 will stop the LFO, but won't damage anything.  

Vibrato mode should pass signal whether the LFO is running or not, or whether R34 is installed or not.  Something else is messed up.  Keep looking.


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## djmiyta (Jun 11, 2022)

Okay got it where it used to be I get signal in all toggle switch positions, bypass. In Vibrato mode there is no vibrato in phase mode phasing can be heard only by moving the sweep pot by hand and the phasing is audible but pretty subtle.


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## Chuck D. Bones (Jun 11, 2022)

So we're back to troubleshooting the LFO.  As is said on Thurs, the voltages on IC3-7 and IC3-8 tell me that IC3 is blown or a pin is not making contact in the socket.

Here are my comments so far. I can't see everything I need to see in order to verify you implemented the mods correctly.  Some stuff is obscured or hidden inside heatshrink.  Moist of what I can see looks ok.  There are some resistors that have been abused.  You say they're ok, I'll have to take your word for it.


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## djmiyta (Jul 21, 2022)

In the 2nd picture stating “there shouldn’t be a wire connected to pin 16”. It’s the angle of the picture that makes it look like a wire connected there. There isn’t. Still have not gotten this one to work properly having revisited this one several times over this year. I’m not one to give up easily so it may sit on the back burner for a week or months eventually I come back to a non working build with fresh eyes and clear head and find my stupid mistake. Not with this one! It’s a stumper


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## Chuck D. Bones (Jul 21, 2022)

IC3 is bad. If you haven't changed it already, that would be the next logical step.


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## djmiyta (Jun 6, 2022)

Can anyone post their working voltages for the grand orbiter. Mine still only phases by manually turning the sweep pot. It's so close. noticed and odd thing. when turning te sweep pot my finger touched the range switch which gave it a noticeable jump in the effect's effect.


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## djmiyta (Jul 23, 2022)

Chuck D. Bones said:


> IC3 is bad. If you haven't changed it already, that would be the next logical step.


Thank you. I will give that a shot.


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## Chuck D. Bones (Jul 31, 2022)

Well?


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## djmiyta (Aug 14, 2022)

Chuck D. Bones said:


> Well?


Sorry I’ve been in limbo hell. I just ordered some 13700’s should be hear next day or two. Definitely got my fingers crossed. I have a couple other pedals with working ones but they’re old builds early in my build history and feel messing with either could create a problem (stupidly no sockets). I’ll  post as soon as I get em in. Apologize again for leaving you hanging because I really do appreciate your help and input.


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## djmiyta (Sep 26, 2022)

Well I finally got more 13700's. Swapped out IC3 and still the same with one small twist when switched to vibrato mode the sweep pot acts and sounds as it does in phase position unless this is normal function when in both positions.


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## Chuck D. Bones (Sep 26, 2022)

If the problem is not bad parts then it can only be one other thing.


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