DEMO Caesar Chorus (Walrus Audio Julia)

This post contains an audio or video demo

MichaelW

Well-known member
So this build was way outside my comfort zone having not yet built a BBD analog device.

Also, seems like there's a disproportionate amount of troubleshooting threads for this pedal. I've been somewhat hesitant to even start it, there was always an excuse to build something else in my queue:) Plus the chips were pricey and hard to find and blah blah blah......(I have a lot more excuses if you want to hear them:))

Anyway, with a bit of encouragement and advice from my pedal sensei @fig I finally decided to dig into it and see if anything I've learned since starting my pedal building journey could be applied.

I got the BBD and Clock chips from Cabintech so I was pretty confident that I had legit CoolAudio chips. I didn't have enough 2N5088's so I substituted 2N5089's.
I also followed @PedalPCB's suggestion and replaced the red led's with 2u2 MLCC's.

Triple and quadruple checked all my component values before stuffing. Otherwise I just followed my usual workflow. Despite the dense parts count it all went together pretty quickly. The only thing I goofed on was not accounting for the height of one of the film caps when I was dry fitting the pcb into the enclosure. It would not allow me to seat the 3PDT board. If I were doing it over again I would have mounted that cap on the reverse side. I wound up angling the 3PDT board and "just" had enough solder lugs showing for the pin header and foot switch to make a solid mechanical solder connection.

My recent builds have become reliable enough that I don't bother rocking before boxing, and I decided what the hey, may as well roll with it on this one too, so I boxed it up and even installed the knobs before firing it up. Of course this time it kinda bit me in the butt:)

When I started biasing I was able to get a very faint chorus effect but something was definitely not right. I had spent that last few weeks reading all the troubleshooting threads I could find on this pedal so I knew it was going to be a very narrow range on the trimpot when the effect comes alive, but all I was able to get was a very faint chorusing effect. If I turned the LAG knob I could manually make it chorus but otherwise there was only extremely faint chorusing if I hit the right spot on the trimmer.

So as my heart started to sink and I was resigning myself to breaking out the audio probe, I literally visualized a post from @Chuck D. Bones saying:
"Have you performed a thorough visual inspection?" 🧐

Heh, so I started just taking a real close look at what I could see without removing the board from the box and started wiggling components, and sure enough one of the 2N5089's was loose in the socket. Pretty much fell right out when I tipped it upside down. So I pulled a fresh one out and put a bit more bend in the legs so it would hold tighter. Fired up the pedal and BAM, lush chorus sounds started filling the room, the sky opened and angelic beings were carrying a gilded litter with @Chuck D. Bones reclining on it and smiling benevolently down on me.....(ok not really but it COULD have happened.....:)

Definitely an awesome sounding chorus pedal. I really like the "Blend" knob but I did have to go look up on the Walrus Audio website how it worked. Once I figured that part out I was able to dial in a lot of different cool "subtle movement" sounds with the blend knob between 9 o clock and noon.

I'm not a huge Chorus user, but I've had the classic TC Electronics chorus pedal as well as a Boss CE-2 pedal and back in the day when everyone was using rack gear (me included) there was always some digital chorus patch. This Caesar really sounds better than all of them (but I am going from memory).
I'm probably not going to be using it a whole lot but there are a couple of guitar parts that call for a chorus in my recording project list (that I can never seem to get to).

Very glad I built this! Now I have a few more sets of V3207/V3102's that I need to find something to build around, so any suggestions would be welcomed!

I recorded a simple short clip on my Strat with no backing. Just guitar pedal into my interface and clean amp model. The settings in the recording clip are as shown in the first pic below. All around 10 o'clock with the toggle on the "triangle" setting.

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Nice work!! I built one of those myself recently and really love it. I had the original Julia for a while and they sound identical to my ears, which is always cool.

Lots of interesting, lofi warbles with the lag and mix knobs turned up a bit, depth around noon and the rate knob dialed back
 
What's the benefit to using the mlcc's over the red leds? I didn't come across that suggestion when I ordered all the parts.
 
What's the benefit to using the mlcc's over the red leds? I didn't come across that suggestion when I ordered all the parts.
I built mine with LEDs and then swapped in some MLCC 2.2uF caps. Not much difference that I could hear. Maybe slightly cleaner, maybe nothing.
 
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@MichaelW - How is the top end on yours? It sounds OK in the clip, but is there a noticeable high cut when the pedal is on? Mine sounds good but is so dark that I can't use it for anything without some kind of top boost engaged as well. Tried swapping in various BBD chips and they all sound the same. Muddy.

Annoyingly, my very cheap Twinote BBD chorus pedal sounds much better and clearer. No idea if there's even a real BBD chip in there - I'd have to pull it apart and I'd really prefer not to.

I'm making an Aion Azure (CE-2 clone) modded for bass, so we'll see how that one sounds. The Caesar is too muddy for bass, so I'm hoping the Azure will be an improvement, low pass filter and all.
 
Nice build! And super demo, love that crispness.

I haven’t had a problem with muddiness in my build.

Looking forward to seeing what recommendations come up for the extra chips, I bought around 20 cheap-arse 3102/3207 pairs from eBay and tested them through a CE-2 clone. Half the 3102 were fake but the rest were working well, which was surprising since half have no dots/indents and labels are askew etc. Still not sure I’d recommend for anything you can get easily in production though.
 
Great demo. One could always build a Cepheid, which also calls for the clock/BBD pair. Begs the question: how many choruses must a man build on, Before you call him a fig? The answer, my friend, is chorus in the wind, and so on. Apologies to all concerned for this quantum level of corn.
 
Ditto, “replaced the red led's with 2u2 MLCC's”. What difference does this make?
It was from this post that I read.

from @PedalPCB:
"Personally I recommend substituting the two 3mm Red LEDs with two 2.2uF MLCC capacitors. These are part of the Sine/Triangle wave shaping circuit, Neither give a perfect sine by any means, but the capacitors are much smoother than the LEDs."
 
@MichaelW - How is the top end on yours? It sounds OK in the clip, but is there a noticeable high cut when the pedal is on? Mine sounds good but is so dark that I can't use it for anything without some kind of top boost engaged as well. Tried swapping in various BBD chips and they all sound the same. Muddy.

Annoyingly, my very cheap Twinote BBD chorus pedal sounds much better and clearer. No idea if there's even a real BBD chip in there - I'd have to pull it apart and I'd really prefer not to.

I'm making an Aion Azure (CE-2 clone) modded for bass, so we'll see how that one sounds. The Caesar is too muddy for bass, so I'm hoping the Azure will be an improvement, low pass filter and all.
I'm not noticing any high end loss but would characterize this as a "warm" chorus pedal. As opposed to say the re-released TC Electronic Classic SCF which a brighter more glassy sounding chorus. I have not tried the Caesar with any other pedals yet except boosting it with my Clandestine and pushing it with a compressor. It sounded best in that clip without either and just naked by itself with a slight bit of software reverb and delay.

One thing I did notice when dialing in the trimmer, in some of the settings the whole pedal was a lot darker. I biased it by ear with all the knobs set at noon and tweedled the trimmer until it sounded good to me. I was reminded of the scene in the movie "Contact" when the young version of Eleanor was being taught by her father to use the ham radio and he kept saying "Small moves Elly, small moves..." heh. Minute moves of the trimmer had a pretty big impact to the sound.
 
Great demo. One could always build a Cepheid, which also calls for the clock/BBD pair. Begs the question: how many choruses must a man build on, Before you call him a fig? The answer, my friend, is chorus in the wind, and so on. Apologies to all concerned for this quantum level of corn.
I was actually a bit torn between building the Aion Azure, Cepheid, and Caesar. My understanding is that the Caesar is based on the CE-2 with some expanded capabilities (Blend knob and wave selector) and the overwhelming positive reviews of it pushed me in that direction. I think if I build another Chorus I would want a stereo chorus (not sure who makes a PCB for that) and maybe something a little "different" than the Caesar.
 
I’ve had plenty of duds and/or out-of-spec pieces but nothing to suggest fakery. Batches of pulls (used) are where I have found the most non-working ones.
This is what I've read about these BBD chips. Which is why I bought 4 sets of the chips from Cabintech...."just in case". Of course now I have a bunch of extra chips. If anyone needs a set for their build DM me....happy to share.
 
I’ve had plenty of duds and/or out-of-spec pieces but nothing to suggest fakery. Batches of pulls (used) are where I have found the most non-working ones.
That's what I think is happening here, they look to be sanded and reprinted for whatever reason, but are working when they do. Even if only 20% work then they're still cheaper.. I end up with more BBDs than clock signal generators though.
 
I think if I build another Chorus I would want a stereo chorus (not sure who makes a PCB for that) and maybe something a little "different" than the Caesar.
You mean the Blueshift ? Of course, this is the hardest and most rewarding path... Are you ready for such perfection ? Will you be able to build a Blueshift ?


This one is based on an older version of the circuit, not exactly the same as the unit currently in production. I looked on the web to see how much they are priced these days... old DC-2 version from the 80's can go up to 600 or 700 us $... You would be lucky to find a real one somewhere...

This is two choruses criss-crossing each other, so you can't really feel the modulation going up and down : when one goes up, the other goes down... Giving the sensation that the modulation last for ever, with no beginning and no end.

Aion's Blueshift can be calibrated without oscilloscope, it takes some time to find the perfect spot on both trimmers, but it's perfectly doable.
 
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