Walrus Julia Chorus Vibe

[Robert]

1 33R
1 470R
1 1K
1 2K7
4 4K7
1 6K8
15 10K
4 12K
1 22K
3 33K
5 47K
1 56K
2 100K
1 330K
1 470K
3 1M

1 47p
2 100p
2 470p
2 3n3
2 6n8
2 8n2
1 10n
3 33n
1 47n
2 100n
2 1u MLCC or Film
2 10u
1 47u
1 100u
1 220u

1 9V1
2 3mm Red or 2.2uF MLCC capacitors (see below)
1 1N914
1 1N914
1 1N5817

1 RC4558
1 V3207D
1 V3102D
1 TL072

5 2N5088

1 SPDT ON/ON

1 B10K
2 B100K
1 B250K
1 50K TRIM


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.

 

[Nostradoomus]

I was close!

 

[untamedfrontier]

Would it be possible to have more BOMs listed this way (in addition to how they currently are)? Makes it a lot easier to stay organized when buying parts/adding to spreadsheets

 

[Robert]

Would it be possible to have more BOMs listed this way (in addition to how they currently are)? Makes it a lot easier to stay organized when buying parts/adding to spreadsheets

Sure, I can try to start doing that.

I always create a list like this when verifying a new PCB, it makes assembly a breeze.

 

[Vildhjuggah]

yeah i pretty much go through and make a list like this everytime i order parts, so if you have a lists already done up like this that'd definitely be helpful

 

[ojeebiso]

Any suggestions for alternatives to the RC4558? Only seeing the SMD version of the RC4558 on tayda right now. TL072 or NE5532?

 

[benny_profane]

Any suggestions for alternatives to the RC4558? Only seeing the SMD version of the RC4558 on tayda right now. TL072 or NE5532?

NJM4558D 4558 Dual Operational Amplifier General Purpose IC

NJR/JRC - Get It Fast - Same Day Shipping

www.taydaelectronics.com

 

[Robert]

Yep, NJM4558D is what I used.

 

[r.callison]

Any updates on a build doc for this one?

 

[lukevosper]

looks great, thanks for this! do you think the stereo version 'julianna' would be much different? would love to see your schem for this as i'd love to try and addapt this to stereo out

 

[Boba7]

1 33R
1 470R
1 1K
1 2K7
4 4K7
1 6K8
15 10K
4 12K
1 22K
3 33K
5 47K
1 56K
2 100K
1 330K
1 470K
3 1M

1 47p
2 100p
2 470p
2 3n3
2 6n8
2 8n2
1 10n
3 33n
1 47n
2 100n
2 1u MLCC or Film
2 10u
1 47u
1 100u
1 220u

1 9V1
2 3mm Red or 2.2uF MLCC capacitors (see below)
1 1N914
1 1N914
1 1N5817

1 RC4558
1 V3207D
1 V3102D
1 TL072

5 2N5088

1 SPDT ON/ON

1 B10K
2 B100K
1 B250K
1 50K TRIM


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.

So it is basically a CE2
Yeah I remember doing the led trick to get a sine wave for my CE2B (wonderful and ugly pedal that was easily modded to be a CE2 with a mix pot).
Thanks!

 

[Robert]

So it is basically a CE2

Yep. It's modified CE-2.

 

[asbestosaurus]

Does anyone have a schematic for this or at least an idea of how the dcv/blend contol is set up relative to the CE-2 schem?

 

[Boba7]

Does anyone have a schematic for this or at least an idea of how the dcv/blend contol is set up relative to the CE-2 schem?

I don't know for sure, but I feel confident it uses a similar mix configuration as for the example the Madbean Florist (https://www.madbeanpedals.com/projects/_folders/FilterMod/pdf/Florist.pdf)
See also the VFE Blueprint schematic, or various others using the same arrangement.

Just a guess

 

[Robusto]

Yep, that's a Vref bias adjustment. I don't think there'd be any reason to adjust it once it's set.

Where is that measured and what should it be?

 

[HamishR]

I wonder why they would use a TL072 and a NJM4558? How different could it be to use 2x TL072s?

 

[youngkong10]

Anyone who's making one of these, the pedalpcb version seems to have a much slower maximum rate than the Julia, you can fix this by changing r6 from 1M to 470k and changing the rate potentiometer from B100k to B1M. It will still go as nice and slow as before but also be able to go a little over twice as fast.

 

[Robert]

Anyone who's making one of these, the pedalpcb version seems to have a much slower maximum rate than the Julia

That's odd, the component values are correct (and also the same as the CE-2), but hey, nothing wrong with a little more range on the speed pot!

I like my modulation to be able to hit raygun territory.

 

[Knotty Pine]

I only have A250K for the LAG pot, how will it affect the sweep?/should I just use a B250K pot?

 

[Knotty Pine]

Could I also substitute the 1N914 for the 1N4148?