A few questions and trouble shooting

Detrital

New member
Hi,

I'm Detrital, new here but not to building pedals.
If I've posted in the wrong spot - Sorry. Please bump me to where I should be...

I've got a few builds that are giving me trouble. Any help is appreciated.

ElectroVibe - No build docs yet, but the silkscreen is mostly complete. I need to know TO-92 what goes above the 47R and LT1054. Suspect it's a 78Lxx of some sort as the middle pin connects to ground. Also what LED is recommended for the opto. Looks like it could be a bi-colour from the orientation of the flat side?? or will a diffused 5mm red/orange/yellow work well here?

HAARP - Build works as it should but the wet output is very noisy. No noise when it's off or from the dry signal path. I'm testing on battery so there is no PSU noise. Have tried adding a few 104 MLCC caps to the rails and Vref and no improvement. Also a 100pF in parallel with the 2n2. Possibly a dodgy FV-1 ???

Low Tide Modulator - It just sounds a bit off. I mean all of the controls work but it doesn't sound like any of the demo's. I think I might have got a fake MN3207 as there is no real delay component to the sound. The modulation seems to only effect the filter (low pass gate). If I turn up the LPG it starts to distort too. I've got a V3207D on the way to test with and see if it sounds any better.

Cheers - Detrital
 
Last edited:

Detrital

New member
Here are some photo's to help. I'll upload some photo's of the HAARP when I get home tonight.
 

Attachments

  • 20210914_120230.jpg
    20210914_120230.jpg
    1 MB · Views: 28
  • 20210914_120325.jpg
    20210914_120325.jpg
    1.1 MB · Views: 28
I can only help with the Electrovibe. I have built 3 now, f'ing killer.
78L12
Here is a thread I started regarding the bulb.
 
Last edited:

Detrital

New member
Thank you !! I've already got ton's of 78L05 so I'll pop one in, and order the bulb. Much appreciated.
I really can't wait for it to be finished. Not surprised you built three :cool:
 

Detrital

New member
ElectroVibe - I've put a 78L12 in. Now I'm only waiting for the 12V globe to arrive. Thanks to everyone who helped to clear up my questions for this build.

HAARP - Have replaced the FV-1. There is still noise but not quite as bad. I might try replacing the 32k768 crystal next, as the noise is at fairly regular intervals. Maybe the Ext CLK and an Int Clk are getting out of sync??? Just a guess. FV-1 chips were from AliExpress so I tend to assume they are to blame, after checking the power rails. Will try a few other things before dropping $50 on a FV-1 chip I know to be genuine and guaranteed. Welcome any suggestions as to what to test, replace, or try next.

Low Tide - still waiting for a replacement BBD. Fingers crossed it's the cause.
 

zenhunter72

New member
I bought 2 FV-1 chips from Electro-Smith and they charged half the amount of the chips for shipping - one of them didn't work very well in the Hydra Delay, and the other worked great in the Arachnid. Then I bought 1 from Small Bear and it worked perfectly in the Octagon without the extreme shipping cost!
I'm not sure if the Hydra Delay was because of the chip though, I had some problems with that build. Had a couple wrong resistors and I kind of screwed up installing the switches - want to try rebuilding that one for sure!
 
Last edited:

Detrital

New member
Thanks for the tip. Unfortunately small bear and electro smith are both out of stock. I'm in Australia too, so the shipping costs are insane since USPS stopped shipping here. I was quoted about $100 USD to ship 4x 2164 IC's with fedex from Cabintech :confused:

I've replaced the 32k Xtal and still no luck. Noise is still there about every second like clockwork. Here's a photo of the build.

I might try bumping up the 1uF connected to the output to 3.3uF, and dropping the 10uF connected to the FV-1 pin3 back to 1uF. To be more in line with the FV-1 datasheet.
 

Attachments

  • 20210920_122522.jpg
    20210920_122522.jpg
    1 MB · Views: 17

fig

Well-known member
Screen Shot 2021-09-20 at 6.28.13 PM.png
Is this IC backwards, or just the socket? I haven't looked at the schematic.

I looked. The IC is oriented correctly.
 
Last edited:

Detrital

New member
I think they are OK
 

Attachments

  • 20210921_085119.jpg
    20210921_085119.jpg
    336.5 KB · Views: 16
  • 20210921_093332.jpg
    20210921_093332.jpg
    426.5 KB · Views: 16

Detrital

New member
HAARP - Looking at the schematic, if the noise is only present when the WET control is turned up, I think it must be coming from the FV-1, 3v3 or Vref. Any thoughts?

Low Tide - The silkscreen in the build doco doesn't match the PCB I have. It makes checking component values and build errors very difficult.
Does anyone know where I might find the schematic or an image of the latest component overlay? Or where I could request this?

I've completed the ElectroVibe. It's STUNNING !!! It's the kind of pedal that will probably trigger a pedalboard re-build so I can fit it on.
 

Detrital

New member
I got it the low tide going !!! Ended up top soldering all of the resistors so I suspect I had a dry joint somewhere. It required VERY careful trimming of the gate and BBD, then all of a sudden it sprang to life !!!
 
Last edited:
Top