Zvex - Lo-Fi Loop Junky  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
User avatar
super velcroboy
Information

Post by super velcroboy »

I like to see the inside of this looper. Anyone has gut shots or schema?

http://media1.zvex.com/lofi.mov

User avatar
super velcroboy
Information

Post by super velcroboy »

guts

Image

User avatar
briggs
Tube Twister
Information
Posts: 1971
Joined: 12 Jul 2007, 10:02
my favorite amplifier: Briggs Custom Suprono
Completed builds: Too many to still class myself as sane....
Location: Breaking into Heaven.
Has thanked: 27 times
Been thanked: 128 times
Contact:

Post by briggs »

That looks pretty intense. Are those resistors soldered under the chip?
Image

I am Klon.

User avatar
junkwork
Information
Posts: 33
Joined: 03 Sep 2007, 03:45

Post by junkwork »


User avatar
DWBH
Cap Cooler
Information
Posts: 498
Joined: 24 Aug 2007, 16:26
Location: portugal
Has thanked: 12 times
Been thanked: 3 times

Post by DWBH »

There was this french website which had almost a project for it. Let me see if I can find that link.

Here it is:
It's not a clone whatsoever, but it might do it.
http://sounddiy.free.fr/AnalogLo-fiLooper.html

User avatar
kriista
Information
Posts: 49
Joined: 29 Jan 2008, 10:19

Post by kriista »

I don't understand the allure of this pedal at all.

The sound/features are something I'd expect out of a under $20 DIY project. It does 1 loop, no overdub, no reverse, AND sounds grungy. Mmmm.

Now, if there's a doable DIY version I'd probably build one(minus the modulation).

User avatar
DWBH
Cap Cooler
Information
Posts: 498
Joined: 24 Aug 2007, 16:26
Location: portugal
Has thanked: 12 times
Been thanked: 3 times

Post by DWBH »

Yeah, I think the problem (although I think I could live with it) is the lo-fidelity of the recorded sound.
Is there any other way to do it, without that lo-fidelity? How 'bout digital?

User avatar
super velcroboy
Information

Post by super velcroboy »

briggs wrote:That looks pretty intense. Are those resistors soldered under the chip?
it looks like it.
i think what he did is used IC sockets around the resistors and overlay the 28-pin analog sampler IC on top. He likes to do these sort of tricks to save space. I love to see one in more detail though.

I saw the payback at diystombox but never any clips, so i can't tell what it sounds like. Probably lo fi.

User avatar
briggs
Tube Twister
Information
Posts: 1971
Joined: 12 Jul 2007, 10:02
my favorite amplifier: Briggs Custom Suprono
Completed builds: Too many to still class myself as sane....
Location: Breaking into Heaven.
Has thanked: 27 times
Been thanked: 128 times
Contact:

Post by briggs »

That's a pretty clever way of doing things.... Gives me a bit of an idea!

As always with zvex - the beauty of his pedals is in the marketing. He knows how to sell them..... Why buy one of these when you can have a great Boss sampler for the same (or less £)? Because it's bootweek! Kudos to the guy for working it all out :block:
Image

I am Klon.

User avatar
super velcroboy
Information

Post by super velcroboy »

briggs wrote: Why buy one of these when you can have a great Boss sampler for the same (or less £)? Because it's bootweek! Kudos to the guy for working it all out :block:
i just want to see how he put this looper together and what chip he used. For $160, you can buy a a boss rc-2 that in every single category except for loop modulation blows it out of the water. But yeah it's the boutique thing.

User avatar
soggybag
Resistor Ronker
Information
Posts: 279
Joined: 07 Aug 2007, 23:29
Completed builds: Fuzz Face, Tone Bender, Big Muff, ICBM, Ugly Face, Green Ringer, Super Fuzz, Multiplex Echo, Multiplex Jr, Rebote, Echo Base, SHO, Fuzz Factory, Titan Boost/Octave, Easy Face, Tone Bender MkII, Trem Shifter, Zero Point Mini...
Location: San Francisco
Has thanked: 28 times
Been thanked: 27 times
Contact:

Post by soggybag »

It doesn't seem worth it for the money I have a line 6 DL4 or whatever it's called. It does an imitation of just about any delay you can think of. It also records 14 seconds of audio, plays it forward, reverse and half speed. Allows over dubs.

Zach gets bashed pretty hard around here sometimes. But to his credit I have to give him props for making something like this into a real product and fitting it into a B box with no SMD parts. You have to admit he does a pretty good job. I have a ringtone and it's pretty amazing what he's fit into the box. The thing sounds pretty good too. He's solved all the problems with carrier bleed. It's a great ring mod. Original concept also.

User avatar
briggs
Tube Twister
Information
Posts: 1971
Joined: 12 Jul 2007, 10:02
my favorite amplifier: Briggs Custom Suprono
Completed builds: Too many to still class myself as sane....
Location: Breaking into Heaven.
Has thanked: 27 times
Been thanked: 128 times
Contact:

Post by briggs »

I would agree with that - his design and execution when laying out his product is great (although not always to practical - very easy to stamp on those knobs!), very minimalist.
Image

I am Klon.

User avatar
Ghengis Jung
Information
Posts: 25
Joined: 20 Feb 2008, 02:49

Post by Ghengis Jung »

kriista wrote:Now, if there's a doable DIY version I'd probably build one(minus the modulation).
There's the Dean Hazelwater Mobius Trip Looper project at GGG:
http://www.generalguitargadgets.com/ind ... &Itemid=26
General Guitar Gadgets wrote:"- Inspired by VZex's LoFi Loop Junkie and
- Based on 20 second voice recorder chip, Winbond ISD1000A - Why, because I had one. Although they are obsolete, some RadioShack stores still have them (276-1325) in their discount bins.
- Three pots: Record Level (to optimize the signal level going into the ISD1000A), as well as Playback Level and Dry Level.
- Two footswitches : Record/Play (lights red 'Record' LED in record position), and On/Off (lights green 'On' LED in on position). 'Record/Safe' switch (toggle or slide) helps to prevent over-writing saved loop "
Any of the ISD1xxx series chips should work. Small bear has ISD1020APs, which are also 20 second chips.

User avatar
marshmellow
Cap Cooler
Information
Posts: 469
Joined: 16 Aug 2007, 07:31
Location: Germany
Has thanked: 20 times
Been thanked: 127 times

Post by marshmellow »

They are produced by Winbond (there's an overview). They also work up to 12kHz if you can get the right one. The reason for the limitation is these chips are intended to work as voice recorders in answering machines and so on, no hifi.

The Lofi Loop Junky is just :slap:. Build something inferior and then call it a feature... :shock: :roll:


I'm planning on a µC + RAM looper including several recordings, overdubs, and so on. But that might take a little while due to general lack of time.

User avatar
Valoosj
Breadboard Brother
Information
Posts: 51
Joined: 28 Mar 2008, 14:03
Location: Antwerp, Belgium
Been thanked: 1 time

Post by Valoosj »

I see you guys know of the existence of the Payback. I have made a schematic for this one, and it worked for a short time, as you can see in the video. At the moment I am having noise issues in bypass. There is some humming like sound that dissapears while recording and playback, but is always there when the pedal is in bypass. I'm was debugging it with tonegod, but he hasn't replied to me in over a week now.Image
C11 and C12 are uF, not pF as I mistyped. And there is a 100K resistor going from pin 14 of IC2 to ground (the ROSC)

Image
This is from when the pedal worked, at the moment there is that noise issue that just appeared.
Bazinga!

User avatar
sebruzda
Information
Posts: 2
Joined: 06 Jan 2009, 00:37

Post by sebruzda »

These are all awesome work alikes. thanks for the contributions. i found this one a few months ago: http://www.instructables.com/id/Looper/ it seems cheap and simple. i am not sure if it works because i never built it. if anyone is successful please let me know. thanks

User avatar
rocklander
Old Solderhand
Information
Posts: 2726
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1406 times
Been thanked: 231 times
Contact:

Post by rocklander »

Ghengis Jung wrote: Any of the ISD1xxx series chips should work. Small bear has ISD1020APs, which are also 20 second chips.
okay, just assembled one of these (the mobius trip looper) and she's a no go. only changes I made were to use an ISD1110P, and I was a bit unsure about the 4001 chip (I couldn't see exactly what I should be looking for) so used a CD4001BE.

assuming I got the other parts right, should I expect this to work at all?
I get no guitar signal, in either record or playback, the red LED comes on in 'record' mode, but the green fails to light up in 'play' mode. I can post voltages on various pins if that would help?

I notice that I lose guitar signal after the 1st 100K resistor (using an audio probe), is that to be expected?

thanks for any help in advance :scratch:
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
Rockprocess
Information
Posts: 12
Joined: 15 May 2010, 16:14

Post by Rockprocess »

Ok. Now that the Dean Hazelwater Mobius Trip Looper project at GGG is discontinued, what's my best bet for finding a PCB for sale that functions like the Lo-Fi Loop Junky?

User avatar
madbean
Information

Post by madbean »

I'll be releasing a project and PCB for the Mobius at some point. I've had a design done for quite some time, but it's not working as of yet. Once I finally get around to ironing it out, I'll post the project here (which will include PCB artwork, of course). My layout is quite a bit smaller, too.

User avatar
Rockprocess
Information
Posts: 12
Joined: 15 May 2010, 16:14

Post by Rockprocess »

Thanks Madbean!

Post Reply