Troubleshooting Loco Box Spaceship Flanger

[daanestafette]

Hi everybody,

I'm new to this forum and building/modding effects so bear with me  ...i just bought this rare 70's Loco box flanger at the fleamarket (along with a loco box compressor. Score!). Sadly it doesn't work. I opened it up to check for loose wires etc. and found some little metal bits lying around loose on the board. They came off a little part that is the same as the complete one that you see in the picture. What is this little thing? it reads '100k'. I'm sure this thing is at least part of the solution to get this pedal working again so please help me out! Thanks in advance!

[bluebunny]

It's a trimmer.  Like a pot, but without a knob.  Set it once, then forget it.  Somewhat like one of these.

[daanestafette]

Aha thanks for the fast reply! How do i go about replacing the faulty one? Can i just swap in any 100k trimmer? And how do you set these things?

[Scruffie]

Most vertical trims should fit that... depending on your location one could be suggested to you.

How it's set depends on its job in the circuit which requires a schematic or at least tracing and guessing.

I think from a look at a gut shot this is the same circuit as the Aria flanger and a few other  80s Japanese brands... might help with a search.

[Fender3D]

FL01 has 2 100k trimmers:
Bias trimmer and clock trimmer.
If pedal's not working you can assume it's the bias trimmer.
You can swap it with any 100k trimmer and set it where you get the maximum effect level, if you have a scope, you should set it for the minimum symmetrical distortion:
apply a sine signal to the effect then probe @ MN chip's pins 8 or 7

[daanestafette]

Yes there is 2 100k trimmers and a 10k one. I'll google for a similar trimmer and swap it in. I don't have a scope (i don't even know what that is  ) so i guess i'll just have to listen. With maximum effect level you mean the amount of 'flanging' (is that english?) or the maximum level/volume that is possible?

[Fender3D]

Start with the trimmer in middle position, you will hear the effect just in a small portion of the trimmer travel.
Usually, in the exact middle of that travel you'll obtain the highest wet signal level.
That's, more or less, the right spot...

[daanestafette]

Ok i'll do that..Thanks everybody for the quick and clear replies! now i'll have to find a trimmer.. I'll let you know if it worked

[Mark Hammer]

Certainly one of the trimmer is for setting the bias.  Note, though, that many flanger will also include a trimmer to set the maximum feedback/resonance/emphasis.  One generally adjust the trimmer by cranking the regen to max, and then adjusting the trimmer to the point where it stops oscillating.

[trobbins]

Good find. 

How good is the graphic on your spaceship, as I'm after a good image to use for printing on my spaceship, which unfortunately got painted over 

I posted some photos of the pcb, and prepared a schematic that may help you when sorting out if the pot is the only problem.  Ciao, Tim

http://www.freestompboxes.org/viewtopic.php?t=7286&p=75395
http://dalmura.com.au/projects/Locobox%20Spaceship%20FL-01.pdf