Joranalogue DELAY 1 - Split-Phase Bucket Brigade Delay Line

[timoka]

The XAOC Sarajewo is great for long echos, and obviously much more controllable than any echo, but it does unfortunately have some slew when changing delay times, I think somebody else in this thread mentioned. I suspect this is due to digital control over its internal HSVCO, but it might just be a design choice--I've been meaning to bug XAOC about it, since it means that you can't get a really crisp pitch shift effect.

Thanks for your post, I found it really interesting and this aspect connects to some information I've been trying to process from the long thread on the Mungo d0 - which is that on almost all available delays there is a fixed rate of slew applied to delay time changes to avoid noise and unwanted artefacts, and that the d0 gives you access to that slew as an adjustable parameter.
Have I understood that correctly? I'm curious if anyone can expand on this, and explain what's going on when noise & artefacts are introduced when a device is trying to change delay times very rapidly.

d0 is digital so its pretty much free from these bbd artifacts

I think there are separate issues here which I'm finding confusing. Users of the d0 clearly do get noise and glitches with certain slew settings on the module. This is a post by jjclark (who designed Rainmaker) from the d0 thread explaining why: it's clearly a separate issue to the one being discussed here relating to analog modules, but I don't fully understand the technical information.

Suppose you had a 1-second delay, and feed a 1KHz 10Vp-p triangle wave through it. The slope of the triangle waveform is +/- 20V/msec.
Now suppose you modulate the delay time with a signal that gives a full-scale variation (so the delay time can be modulated from 0 to 1000 msec). If there is a noise step in the modulation signal of 1/2000th (1/20 %) of the whole range there will be a 0.5msec change in the delay time. Doesn't sound like much, but on a 1KHz triangle it can result in an output change (glitch) of 10V!
Even if the noise step is 1/2,000,000 of the whole range there will be a glitch of 1/10V on the output, which would be clearly audible. In the digital world 1/2,000,000 is 3 bits of noise in a 24 bit signal. A Digital-to-analog converter can easily produce this sort of noise level.

The way to avoid this is to slew the delay time control signal so that glitches turn into frequency shifts instead of step amplitude changes. Some may find the frequency shifting caused by the slew objectionable, but the alternative is a noisy output.

I also own an OTO Bim which freaks out and produces bitcrushed noise sounds when switching between tapped tempos rapidly - I have no idea what's going on there!

the noise introduced within the d0 comes from the attenuverters which also carry some gain to boost incoming signals. so even if unpatched the two attenuverter can on some settings introduce noise if they aren't nulled properly. with some slew this noise isn't really audible or recognisable, but since you can alter the slew on the d0 you can make the noise audible. this sounds like a fault but it is indeed one of the greatest things about the d0 (and also g0 noise with too short grains). i can create amazing noisy freaked out delay sounds which with a turn of a knob become elastic slewed feverish delaytails....ah, the d0
the c0 or better the c1 however they both really introduce the typical crushed bbd sounds with lower frequencies!

@joranalogue: if one uses the + and - outputs hardpanned left right....doesn't this introduce phasing issues and cancel frequencies out when again summed to mono?

[joranalogue]

the noise introduced within the d0 comes from the attenuverters which also carry some gain to boost incoming signals. so even if unpatched the two attenuverter can on some settings introduce noise if they aren't nulled properly. with some slew this noise isn't really audible or recognisable, but since you can alter the slew on the d0 you can make the noise audible. this sounds like a fault but it is indeed one of the greatest things about the d0 (and also g0 noise with too short grains). i can create amazing noisy freaked out delay sounds which with a turn of a knob become elastic slewed feverish delaytails....ah, the d0
the c0 or better the c1 however they both really introduce the typical crushed bbd sounds with lower frequencies!

@joranalogue: if one uses the + and - outputs hardpanned left right....doesn't this introduce phasing issues and cancel frequencies out when again summed to mono?

Yes, that's right; on its own, it is not a mono-compatible technique to create a stereo image. However, D1 can be used in various other ways for mono-to-stereo conversion (Haas effect is another). Enhance 2 is a good companion for this application.

[beechemist]

Thanks so much for the information both of you!

[dreamrobe]

Will the delay 1 be dc-coupled?

[joranalogue]

Will the delay 1 be dc-coupled?

Unfortunately, DC-coupling a BBD is technically not feasible, so Delay 1's audio signal path is AC-coupled.

[Amyto]

@joranalogue

Does clocking the delay faster than 1ms / 1000hz introduce any artifacts, or otherwise degrade the signal?
Delay times faster than 1ms can make some fun sounds.

[joranalogue]

@joranalogue

Does clocking the delay faster than 1ms / 1000hz introduce any artifacts, or otherwise degrade the signal?
As mentioned previously, the Mungo d0 has a minimum delay time faster than 1ms, and this can give you lots of fun sounds to explore.

We've unfortunately found that BBD performance degrades very quickly with clock frequencies over 1 MHz, which is already an order of magnitude beyond the typical 100 kHz maximum.

[kugua]

Super excited for this module, especially a YouTube demo of it. At what slower clock speed to you think the degradation / artifacts become obtrusive? Does it sounds okay a 1s delay?

[Amyto]

@joranalogue

Does clocking the delay faster than 1ms / 1000hz introduce any artifacts, or otherwise degrade the signal?
Delay times faster than 1ms can make some fun sounds.

We've unfortunately found that BBD performance degrades very quickly with clock frequencies over 1 MHz, which is already an order of magnitude beyond the typical 100 kHz maximum.

Oh well, that's cool. I'm still gonna buy it!

I love short delays, so having a fully-analog module dedicated for this is perfect

[joranalogue]

Super excited for this module, especially a YouTube demo of it. At what slower clock speed to you think the degradation / artifacts become obtrusive? Does it sounds okay a 1s delay?

Below 20 kHz (50 ms delay time), the clock frequency will become audible as a high-pitch whine, in addition to the expected aliasing, reduced bandwidth and increased noise floor. This is why the internal clock VCO has this frequency as its lower bound, although the external clock input has no such limitations.

[funksy]

Damn, has it really been since Aug that we heard about this? I know Step 8 was the priority and glad to have that in the system now, but curious where this is at. Hope development is going well!

[Illwiggle]

Damn, has it really been since Aug that we heard about this? I know Step 8 was the priority and glad to have that in the system now, but curious where this is at. Hope development is going well!

Ironic that the Delay has been so delayed.

[Pagoda-100]

Well, They did have to PIVOT and refine Step8.
Worst joke ever but needed done...

Damn, has it really been since Aug that we heard about this? I know Step 8 was the priority and glad to have that in the system now, but curious where this is at. Hope development is going well!

Ironic that the Delay has been so delayed.

[Paranormal Patroler]

Well, They did have to PIVOT and refine Step8.
Worst joke ever but needed done...

Damn, has it really been since Aug that we heard about this? I know Step 8 was the priority and glad to have that in the system now, but curious where this is at. Hope development is going well!

Ironic that the Delay has been so delayed.

I need to STEP in and say that these kind of jokes will not fly.

[kugua]

Well, They did have to PIVOT and refine Step8.
Worst joke ever but needed done...

Damn, has it really been since Aug that we heard about this? I know Step 8 was the priority and glad to have that in the system now, but curious where this is at. Hope development is going well!

Ironic that the Delay has been so delayed.

I need to STEP in and say that these kind of jokes will not fly.

That’s cause they’re already in ORBIT.

[soundular]

Maybe we can generate some more interest, without so much pressure that the company folds and morphs into something we all compare and contourast, and eventually select something that will be well received, without any add-itional or mix-ed feeling.

[Pagoda-100]

Well played.

Maybe we can generate some more interest, without so much pressure that the company folds and morphs into something we all compare and contourast, and eventually select something that will be well received, without any add-itional or mix-ed feeling.

[Powerdwarf]

maybe it was reconsidered that there are so many short bbd delays, similar to this

[Kosmikos]

You mean it should have been called Brigadia and said “coming soon… (ish)” on the announce?

This is still high on my list, I’m curious about the split phase approach.

[drxcm]

maybe it was reconsidered that there are so many short bbd delays, similar to this

So many similar? Like what?

[Powerdwarf]

maybe it was reconsidered that there are so many short bbd delays, similar to this

So many similar? Like what?

cg delay1022, a-188 1 with lower stages chip, erica diy bbd, analog systems rs 120 comb filter, ssf triptych… And I bet there are more, like many more

[revelc]

maybe it was reconsidered that there are so many short bbd delays, similar to this

So many similar? Like what?

cg delay1022, a-188 1 with lower stages chip, erica diy bbd, analog systems rs 120 comb filter, ssf triptych… And I bet there are more, like many more

but none of those are new, some over 20 years old, so this was designed to be very different since he was aware of what was available.
The CG is the only one that's similar, but that even uses a different BBD type/brand.

[Powerdwarf]

maybe it was reconsidered that there are so many short bbd delays, similar to this

So many similar? Like what?

cg delay1022, a-188 1 with lower stages chip, erica diy bbd, analog systems rs 120 comb filter, ssf triptych… And I bet there are more, like many more

but none of those are new, some over 20 years old, so this was designed to be very different since he was aware of what was available.
The CG is the only one that's similar, but that even uses a different BBD type/brand.

welp. VERY different )) same shit different package. dont see any paradigmatic change. bbd chips has its limitations, so producers work around them with different labeling and stuff.

what was new in euroland regarding bbd - sarajewo stacking 3 bbd chips. but its nothing new in terms of history of bbd delays. check old yamaha or dynacord bbd units, it was done since ages.

[revelc]

welp. VERY different )) same shit different package. dont see any paradigmatic change. bbd chips has its limitations, so producers work around them with different labeling and stuff.

what was new in euroland regarding bbd - sarajewo stacking 3 bbd chips. but its nothing new in terms of history of bbd delays. check old yamaha or dynacord bbd units, it was done since ages.

yeah, stacking chips is common in pedal and rack delays, the Blacet time machine used 2 stacked. EDIT: it does not! I was mistaken.
The Reticon chips can sound/perform very differently, as in the Serge WAD.

I was only pointing out nothing has changed in the euro BBD market since this was announced that would be a reason to scrap the design.

[Powerdwarf]

welp. VERY different )) same shit different package. dont see any paradigmatic change. bbd chips has its limitations, so producers work around them with different labeling and stuff.

what was new in euroland regarding bbd - sarajewo stacking 3 bbd chips. but its nothing new in terms of history of bbd delays. check old yamaha or dynacord bbd units, it was done since ages.

yeah, stacking chips is common in pedal and rack delays, even the Blacet time machine used 2 stacked.
The Reticon chips can sound/perform very differently, as in the Serge WAD.

I was only pointing out nothing has changed in the euro BBD market since this was announced that would be a reason to scrap the design.

on that one i agree. its seems like a nice module for karplus things in the end.. good package