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Projects => Build Reports => Topic started by: thomasha on November 24, 2017, 11:27:57 PM

Title: Loophole with opamp LFO
Post by: thomasha on November 24, 2017, 11:27:57 PM
Hi, I finished my loophole build. After simulating the LFO in spice I could find something that worked for me.
It has really a nice depth, but I prefered to keep it at a constant value, varying between 4.5 and 3.9V.

Initially I made a new Layout to fit in a smaller box. I could find the ISD2560G, so hope that the extra time is worth it.

Here you can see one side of the board, the ISD is on the other side.
(https://i.imgur.com/qDIw4vrl.jpg)

and the LFO board with the onboard pots to save some space.
The switch is to turn the LFO off. Sometimes it's too much to have it on while recording and looping.
On the other hand, it gives this symmetry where sometimes it accelerates and sometimes not.
(https://i.imgur.com/OpqBo1jl.jpg)

In the box it looks like this>
(https://i.imgur.com/ksvcjH7l.jpg)
(https://i.imgur.com/vRjdvlOl.jpg)
To adjust the trimmer I need to stick the screwdriver between the jack and the dpdt.
Hopefully this DPDT is a little smaller than the normal ones.

Here a  better picture of the etch. It's time&ouroboros related.
(https://i.imgur.com/08mrX0al.jpg)

And with the record mode on:
(https://i.imgur.com/LpqmZY2l.jpg)
(https://i.imgur.com/DSQSoekl.jpg)

It is really a nice pedal. It is a little dirty, I'm not sure if it was a mistake or what, but still sounds nice.
The thing with the LFO is that it has that vibe. And if you record the riff with it the recording plays faster!
So I liked the lowest velocity setting where it really sounds like a bad reel-tape.
It requires some skill to record everything properly though, an stomp on time.

I made an attemp using the cellphone camera and at a very low volume. Still needs a proper video, until then just to give an idea of how it works with the LFO.

cheers, and happy holidays



Title: Re: Loophole with opamp LFO
Post by: zombie_rock123 on November 24, 2017, 11:34:56 PM
You sir, are a machine. Thats a flawless build and Im astounded you got that into an A. Hats off to you.
Title: Re: Loophole with opamp LFO
Post by: alanp on November 25, 2017, 12:00:34 AM
Holy shit. That's even more impressive than the solderman flanger.
Title: Re: Loophole with opamp LFO
Post by: bsoncini on November 25, 2017, 12:58:06 AM
That is impressive. I get annoyed just putting simple boosters I'm 1590a.
Title: Re: Loophole with opamp LFO
Post by: mjg on November 25, 2017, 01:54:54 AM
That is pretty amazing.  Which ISD chip did you use?

I wonder if the dirt is just coming from the ISD chip - from what I understand, they are 'voice quality' so a guitar signal might not sound clean.

An amazing build though. Seriously impressive fitting it all into that space!
Title: Re: Loophole with opamp LFO
Post by: oip on November 25, 2017, 06:51:22 AM
madness!  what a great build

i love the whole idea of these answering machine loopers, been tempted by the zvex version many times
Title: Re: Loophole with opamp LFO
Post by: thomasha on November 25, 2017, 09:54:43 AM
I used the ISD2560G, while the loophole uses the ISD1020AP.
The ISD2560G should have some extra seconds at a higher sample rate.
Title: Re: Loophole with opamp LFO
Post by: Coda-effects on November 26, 2017, 10:28:31 AM
This is crazy! No SMD is quite impressive for such a complex build with 2 switches and 5 pots!