News:

Forum may be experiencing issues.

Main Menu

Another Friend for my Sagan Delay (Pedal PCB Caesar Chorus)

Started by Bio77, January 31, 2021, 07:42:49 PM

Previous topic - Next topic

Bio77

Continuing with my Sagan Delay themed pedals:

https://www.madbeanpedals.com/forum/index.php?topic=32079.msg308259#msg308259
https://www.madbeanpedals.com/forum/index.php?topic=32333.0

This is my Space Chorus.  It's a Pedal PCB Caesar, which is a copy of the Walrus Audio Julia.  It's super cool.  The build docs don't have a schematic.  I'm curious to see how the delay lag (Space control) is implemented.  I think it would be cool to mod some other chorus circuits with this, like the Small Clone.  Biasing the 3207 looked weird on the scope (no position on the trimmer gives anything close to a symmetric waveform on the output), but it sounds great.  That's been messing with me, maybe an artifact of the delay pot?

Enclosure is no film on polished metal with a 10 mm LED.  The transfer came out a bit rougher than the other two, but it looks fine in real life  ;D  I have a NE5532 in there, which I think sounds better.







The soft touch really did not want to go in there!  It took flipping some caps to the back and angling in the PCB.  The pins on the blend pot are barely poking through.


gordo

Gordy Power
How loud is too loud?  What?

jjjimi84

Man this trio is killer! I love how clean this build is, nice work.

Thewintersoldier

Damn John, you should do all your builds like this, looks so good! How does it sound co.pared to a regular CE-2? It's just a modded ce-2 I believe. Awesome build.
Who the hell is Bucky?

cooder

BigNoise Amplification

jimilee

Nice; very nice indeed.


Sent from my iPad using Tapatalk
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

diablochris6

Once again, excellent work!

I figure the lag control connects one lug to the LFO output, and the other lug connects to basically a 5V source. The wiper leads to the clock chip. It's probably similar to a Manual control you see on a flanger that sets how wacky the wooshing can get. On a PT2399 type of circuit, I'd imagine it is something like the Animate control on EQD's Sea Chorus/Madbean's Gravity Wave.
Build guides of my original designs and modifications here

artstomp

...I think the LAG control is the 220K resistor between the depth control and Q4 (CE2 schematic)...the Caesar chorus substituted a 250K potentiometer as the LAG control..if i'm not mistaken.

dan.schumaker

Quote from: artstomp on February 01, 2021, 12:20:51 AM
...I think the LAG control is the 220K resistor between the depth control and Q4 (CE2 schematic)...the Caesar chorus substituted a 250K potentiometer as the LAG control..if i'm not mistaken.

I would agree with that.  I have the same control on my Replicant series chorus pedals (even though they are Small clone based, same principle).  It works the same as changing the timing capacitors (like on the VFE Choral Reef).

Bio77

Thanks everyone!  8)

Thanks for the info on the Lag.  It adds another dimension to this thing.  I'm surprised it's not on more common.

matmosphere

Super cool man, you're going to have a pretty sharp looking pedal board pretty soon.

Drew Hallenbeck

Building with my daughter and occasionally selling as "Daddy Daughter Pedal Works"
Not for any real profit, just trying to have a self-funding hobby.

Bret608

I love how this looks like a mashup between vintaxe EHX and Boss aesthetics! I was also really curious about that lag control. Makes sense I'd say.

RDL68

Outstanding job.

What I found mysterious was when you said your scope wasn't happening when biasing the BBD. Similar happened to me once when I did the Blueshift. It worked first try, trims tuned in by ear, all good, but the scope wasn't able to do it's thing on that particular build as far as optional fine tuning is concerned. Fortunately it was a minor non critical thing, whatever caused it. So, as it sounded great as is, I left it as is, because it was just an optional troubleshooting job (potentially very time consuming) for an unnecessary optional fine tuning option.

Bio77

Thanks Guys!  8)

[/quote] I've
Quote from: Thewintersoldier on January 31, 2021, 08:38:43 PM
How does it sound co.pared to a regular CE-2? It's just a modded ce-2 I believe. Awesome build.
I wanted to spend some more time playing with this before a gave a full endorsement, but now I'm sure.  This thing sounds incredible.

Quote from: RDL68 on February 01, 2021, 06:56:44 PM
What I found mysterious was when you said your scope wasn't happening when biasing the BBD. Similar happened to me once when I did the Blueshift. It worked first try, trims tuned in by ear, all good, but the scope wasn't able to do it's thing on that particular build as far as optional fine tuning is concerned. Fortunately it was a minor non critical thing, whatever caused it. So, as it sounded great as is, I left it as is, because it was just an optional troubleshooting job (potentially very time consuming) for an unnecessary optional fine tuning option.
I've built a lot of BBD pedals and the scope biasing has been very reliable for me.  This one was weird.  The bias point (by ear) is towards the middle of the trimmer and there's only a narrow range that will produce chorusing. But the output from the BBD looks like more like an EKG than what I normally see.  Because it is chorusing in the middle of the trim, I don't think adjusting resistors values would resolve the issue.  I've had other BBDs that biased at the end of the trim rotation and those needed a resistor change.  Anyway, it works real good  ;D So, maybe I'll let this this one slide.