Circular Delay Changed?

MKeditor

Experienced
PCM70.jpgI'm a fan of how Steve Lukather used PCM 70 delays back in his rack days. Although I've never owned a PCM70, I've endeavored to emulate the circular and pan delays. I was thrilled when Fractal added these to it's ample arsenal of delays a few years ago. The settings were pretty much the same as below. I updated firmware today and was auditioning the new fab Aurora delay and decided to compare it to the circular....but the circular settings are significantly different than before. Has anyone else experienced this?

Here's info someone posted on Hugeracks INC that I've used for years as a benchmark:

"Actually, you don't need the PCM70. There is no real "magic" behind any of those presets. Here is the info from the PCM70 presets:

PCM 70 v2.0 Presets:

Code:

1.2 Pan Delays

0 1 2 3 4 5 6 7 8 9
0 100 0 0 0 31 0 - - - Pan Delays
1 0 max max OFF OFF OFF OFF - - -
2 0 768 376 0 0 0 0 - - -
3 0 0 0 0 0 0 0 - - -
4 0 15 15 15 15 15 15 - - -
5 0 50L 50R C C C C - - -
6 (Patches OFF)


Code:

1.3 Circular Delays

0 1 2 3 4 5 6 7 8 9
0 100 0 0 42 30 0 - - - Circular Delays
1 0 max max -3 OFF OFF OFF - - -
2 0 888 584 292 0 0 0 - - -
3 0 0 0 0 0 0 0 - - -
4 0 15 15 15 15 15 15 - - -
5 0 C 50R 50L C C C - - -
6 (Patches OFF)


Notes:
Same delay algorithm, uses (up to) 6 delays (x.1-6)
0.0 Mix Level (%)
0.3 Diffusion ("the magic parameter")
0.4 Feedback (%)
1.x Levels (dB)
2.x Delay Times (ms)
3.x Low Cut (kHz)
4.x High Cut (kHz)
5.x Pan (50L is full left, C= Center)


Sooooooooo. Basically this is what they are:

Panned Delays:
This is a 2 tap delay, not 2 different delays, dual delays etc or anything like that. Normal 2 tap delay (one left/one right), one set at 376ms and the other at 768ms. No high/low cut, and about 10-12 repeats ( last 2-3 ones are really faint). Yes that is a lot, but that's the way it is. This is the delay that Luke uses as his normal delay, quite loud in level.

There is A TON of unit's that can do this exact thing, so it's really not exclusive to the PCM70 at all. You can do this on a G-Force, Axe-FX, other Lexicon units, Eventide stuff etc.

Circular Delays:
This one is a bit more complicated, but it's not as magic or special as many think, because other units can do this one too.

It's a 3 tap delay ( so it's one delay with 3 taps, and NOT 3 individual delays as many, including I, thought in the past ). No high or low cut on this one either.

The first delay is 292ms, damped 3db, and panned to the right
Second one is 584ms, and panned to the left.
Third one is 888ms, and panned to the middle.

The way it's panned etc, it sounds like the echos cross from one side to the other in a circular manner. If you would record a stereo clip of this preset, and then convert it to mono, the repeats would appear to come in groups of three. The first one (292ms) is damped 3db ( which is like cutting the volume in half), the second one (584ms) is not damped and is 3db louder than the 292ms, and the last one (888ms) is 3db louder than the 584ms.

So each repeat in a group of three gets twice as loud (3db) than the previous one. The reason for the last (888ms) getting twice as loud as the one before (584ms), is because its' panned to the middle, which means it's sounding through both left and right, instead of just one. When forcing this to mono, it means that this third (888ms) repeat gets twice as loud as the second (584ms) because the second is only sounding through one speaker.

It has about the same number of repeats as the other one ( around 10), maybe just slightly less. The real magic is the diffusion control. It makes the delays sound fuzzier and fuzzier with each repeats. It basically schmears the high transients in the sound. Some liken it to sounding like a pseudo-bit reducer. This parameter isn't all that common, but other units can do it, the Axe-FX Ultra being one of them. I seem to remember other Lexicon and some Eventide units have this parameter as well. Basically, if a unit can do a 3 tap delay with diffusion, it can do the Circular Delay thingy just as good as the PCM70s."

Thoughts?
 
Interested to hear any info on this. I cant check my unit at the moment but should have access to it tomorrow and will have a look if I get a chance.
 
The MTD has a "Circular Delays" setting, and a "PCM Circular" setting.
There's also a "Circular Delay" factory preset, and a "Circular" scene in the "Delay Leads" factory preset.
Spot on. I didn't know there were more than one circular profile for the MTD now. Such a simple fix. Thank you.
 
Since I'm the guy who did the PCM70 emulations on the Axe, and wrote the quoted article from HRI (long time ago so it's not entirely correct), I had a look. The recalled values from PCM types are correct from what I sent Cliff last year. I have updated them since then (considered final version now), but held off on sending them to Cliff since I was waiting on test clips of a TC1210 from someone (which never materialised), and was going to have him update that type as well.
 
Since I'm the guy who did the PCM70 emulations on the Axe, and wrote the quoted article from HRI (long time ago so it's not entirely correct), I had a look. The recalled values from PCM types are correct from what I sent Cliff last year. I have updated them since then (considered final version now), but held off on sending them to Cliff since I was waiting on test clips of a TC1210 from someone (which never materialised), and was going to have him update that type as well.
I'm grateful for the info you've shared past and present. Thank you.
 
Since I'm the guy who did the PCM70 emulations on the Axe, and wrote the quoted article from HRI (long time ago so it's not entirely correct), I had a look. The recalled values from PCM types are correct from what I sent Cliff last year. I have updated them since then (considered final version now), but held off on sending them to Cliff since I was waiting on test clips of a TC1210 from someone (which never materialised), and was going to have him update that type as well.
Thank you for your contributuions!
 
Since I'm the guy who did the PCM70 emulations on the Axe, and wrote the quoted article from HRI (long time ago so it's not entirely correct), I had a look. The recalled values from PCM types are correct from what I sent Cliff last year. I have updated them since then (considered final version now), but held off on sending them to Cliff since I was waiting on test clips of a TC1210 from someone (which never materialised), and was going to have him update that type as well.
I remember lusting for the PCM70 (along with other high end rack units) but the NEED vs WANT was just never something I could convince myself, or (and heavy emphasis on the “More Importantly”) my wife! Scroll forward 30+ years, and with the Fractal AxeFX3, we have our cake and get to eat it, too! Thank you for your part in making this available! 👊
Cheers,
Lee
 
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