Waveulator ME Saturator Construction Information

Construction information for DIY projects, including the MS Mid Side Matrix, Elliptic Equalizer, Mastering Console, Phono Transfer System, Insert Switcher and the Dual Class-A Amplifier. You can post your baby pictures here.
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mediatechnology
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Re: Waveulator ME Saturator Construction Information

Post by mediatechnology »

Updated assembly instructions 102823. Final copy: https://ka-electronics.com/images/pdf/W ... 2823_1.pdf
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Re: Waveulator ME Saturator Construction Information

Post by mediatechnology »

I've been getting asked a lot of questions about what's required to wire up a Waveulator and thought a picture would be helpful.

Image

The power supply is a TDK CUT-35FF/A enclosed version.

The meter is a Pico Compressor GR20 running on the TDK's 5V supply. The full scale is 10 dB peak reduction. The orange/blue pair hanging off to the side are for a power LED. The GR20 board is out of production and I don't have the layout. I'll be working on a similar meter and hope to have some boards soon.

The two coiled harnesses at the top are for the customer's "Process" switch (aka Bypass) and a European-coded AC power harness for their own IEC connector. My IEC harness and bypass switch are in the picture.

To the left are the audio leads for termination to XLRs.

I use headers for connection the the Phoenix connectors to keep things tidy.

The leads for the Gain pot are made a little longer than the rest so it can be placed at the right hand side of the controls. The normal flow is Threshold, Ratio/Hardness and then Gain.

I'll try to get some BOMs posted for the parts required to rack it.
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Re: Waveulator ME Saturator Construction Information

Post by mediatechnology »

Several years ago Doug sent me some drum tracks to Waveulate. I just stumbled upon them and decided to process them with the new unit.

The first sample is unprocessed the second has about 7 dB of brickwall peak limiting. The makeup gain was manually adjusted to be close to the original peak level using a K-meter plugin.

Drum sample, unprocessed, then processed: https://ka-electronics.com/content/Wave ... miting.wav
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Re: Waveulator ME Saturator Construction Information

Post by dagoose »

I ordered the pcb and chips last week, really looking forward building this and using it in my chain!
Another great project from Wayne, thank you! 8-)

I was wondering if someone already found the perfect stepped attenuator (23 steps) values already for ratio and threshold, though the threshold can be trimmed more easily/
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mediatechnology
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Re: Waveulator ME Saturator Construction Information

Post by mediatechnology »

Jeffrey - Thank you!

The Threshold should ideally be a log taper and the values for the stepped switch on page 17 of this pdf is what you might want to use: https://www.ka-electronics.com/images/p ... 2020_1.pdf

It's drawn as a rheostat since it's being used for the IGFO gain control but the values are what you'd want for a 23 step 0.5 dB/step 10K log taper pot. For a larger step size I think I have a workable spreadsheet we can use.

VR3 will set the threshold at maximum CW rotation and the steps will be 0.5 dB until the bottom step, which is ground. At ground the threshold is about -2dBu which is an effect setting. My recommendation is to set VR3 so maximum CW rotation is the converter's 0 dBFS point.

The Makeup gain should be 10 K linear. A 23 step 10K has 22 resistors so 453Ω per step seems about right.

Ratio is the area I need input on. Alex aka gp6669 used a 100K with a 10K from the top of the pot to the wiper to emulate an antilog response. You could scale that to a 10K pot with a 1K bowing resistor and the 5532s would still be able to drive it. I would suggest what Alex did and that would be to use a pot at first, develop a feel for it and we can come up with a good switch taper.

The sweet spot on ratio depends a lot on how aggressively one typically processes and the typical working level of the chain. I don't master for a living and probably push it aggressively but do so with working levels and sound file crest factors that are probably lower than you guys typically use and experience. My USB-powered converter has a maximum output of +15 dBu. I seem to work in the upper third of the control a lot and that correlates with Alex's use of an anti-log taper to move that upper range further down into the working range.

One thing I should point out is that the Waveulator should ideally be last in the chain just prior to the converter and definitely after any EQ. EQ or EEQ will undo the processing by shifting the phase of the bent waveform so its no longer acting as a limiter. In that situation the Waveultor is introducing distortion that doesn't reduce crest factor.
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Re: Waveulator ME Saturator Construction Information

Post by dagoose »

wow, thanks for such a long and detailed answer, brilliant! :)
It's planned on being last in the chain, right before it hits the AD, so all good in that sense.

I will dig into the stepped switches, I already love the fact that threshold and makeup gain is just a single pot.
I have to see what the ratio will do by trying things out with a potmeter then. It needs to be subtle, but also when needed it needs to be a bit more bity and aggresive. I think I will indeed base my ratio on that and I will report back about what I used in the end.
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Re: Waveulator ME Saturator Construction Information

Post by dagoose »

It's up and running, well, on the bench that is, not tested in the studio yet.
It's a nice sounding thing, maybe a bit too rough for mastering right now, but that can be tweaked.
Stepped switch for threshold and makeup working as expected, though I need to change the makeup gain to smaller steps since the gain range is over the top now and so the steps are to big as well. Something like 3dB max gain and 0.25dB steps would suit way better. We are talking mastering here. :)
Ratio is still a potmeter now, I have to figure out in practice what is a suitable range.

I do have some strange behaviour with the GR20 meter though which I have to dive into.
The first LM3914 works fine, first 2 or 3 leds of the second LM3914 as well but as soon as it goes above that, it looks like it 'pops full scale' right away, like it's clipping or something.
I think i've seen something like this in the past when I build a meter like that for an ssl compressor, but I can't seem to remember what was that was.
That's been over 10, maybe even 15 years ago :)
Maybe the resistor values needs tweaking.

But so far, liking this!
Last edited by dagoose on Wed Dec 27, 2023 9:29 am, edited 1 time in total.
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mediatechnology
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Re: Waveulator ME Saturator Construction Information

Post by mediatechnology »

Cool!

On the GR20 is the 20K pullup resistor (R1) installed?
There are two links that need to be installed in the Bar/Dot jumper locations.
You might check those as well.

If you're using a 5V supply and have it in bar mode you might check to make sure the 5V supply is not going into current limiting.
The first time I tested the board I saw a similar behavior and it was the bench supply set for an artificially low limit.
It pulls about 170 mA when fully-lit.
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Re: Waveulator ME Saturator Construction Information

Post by mediatechnology »

dagoose wrote: Wed Dec 27, 2023 5:06 am Something like 3dB max gain and 0.25dB steps would suit way better.
The best way to reduce the range is to scale R55 and R56.
For 0 to 10V to be +3 dB gain they would need to be about 4X larger.
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Re: Waveulator ME Saturator Construction Information

Post by dagoose »

mediatechnology wrote: Wed Dec 27, 2023 5:15 am Cool!

On the GR20 is the 20K pullup resistor (R1) installed?
There are two links that need to be installed in the Bar/Dot jumper locations.
You might check those as well.

If you're using a 5V supply and have it in bar mode you might check to make sure the 5V supply is not going into current limiting.
The first time I tested the board I saw a similar behavior and it was the bench supply set for an artificially low limit.
It pulls about 170 mA when fully-lit.
Yes, R1 is installed and both jumpers for bar/dot as well. R1 is easily missed BTW.
I'm using an 7805 on the PCB coming from the PSU pcb i'm using (meanwell 2x IRM20-24 with added rgulators for regulated +/-15v), but I was also thinking of checking the voltage drop on the 7805 when it's at full scale in bar mode. Need to do that this week.
I have a feeling that when in dot mode it seems to work as it should which would explain things, it's less current.

I already fixed the makeup gain in a different way which works great. I added a 10k in parallel with the 10k lin switch and a 4k7 in series to the -10v line. It's about 0.25 per step now, which is what I wanted.
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