Bucket Brigade Delay FX Chain

I wanted a Bucket Brigade Delay (BBD) effect in Studio One. Seriously.

Although some analog delays (e.g., Binson Echorec) were based on tape, others used analog bucket brigade technology. Bucket brigade integrated circuits (like the Panasonic/Matsushita MN3005 or Reticon SAD-1024) incorporated thousands of capacitive elements controlled by a clock. Each clock cycle passed the analog signal at the input from one stage to the next, so slower clocks meant longer delays. But because sampling (albeit analog) was involved, so was the Nyquist theorem-the more you slowed down the clock, the more likely you'd hear aliasing and distortion. At really long delays, sometimes you'd even hear leakage from a clock that had gotten down to the audible range.

So I emailed Arnd Kaiser, the General Manager for PreSonus Software, and told him I wanted to modify the Analog Delay into a BBD. He seemed puzzled and said that if you turn up the Drive and lower the High Cut frequency at longer delays, you'll get the BBD sound. True, but that sound is of a clean, well-designed BBD where the designer didn't push the chips, and knew how to layout a circuit board. That's fine, but I wanted filth time for an FX Chain (Fig. 1).

Figure 1: The Analog Delay plug-in is the heart of this FX Chain.

The solution was tracking the Delay Time with the BitCrusher's Downsampling parameter, so at longer delay times, those lovely violations of Mr. Nyquist's theorem could grace the sound with aliasing and sonic nastiness.

I was running late submitting the tip because of going down this crazy BBD rabbit hole, so I emailed Ryan Roullard at PreSonus (who among a zillion other things makes sure my Friday Tips roll along smoothly every week) to apologize for the delay and give him a heads-up of what to expect for this week's tip. He asked if I'd included the clock leakage whine as part of the sound. I was embarrassed to say that I had overlooked it, but Ryan said that if I figured out how to add it in, he'd never tell anyone of my shameful omission.

You can download the Bucket Bridge Delay.multipreset, so I won't go into much detail-reverse-engineer it to find out how it works, or modify it to do even stranger things. Please note: It's probably best to insert this into an FX Bus with the Mix control set to wet only because unless none of the three switches is enabled, there's no way to have a completely clean sound.

The important part is the three switches-Arnd, Craig, and Ryan. You can select none of them or any/all of them. With none of the three switches selected, you have a standard Analog Delay sound, with the other knobs and buttons doing their standard Analog Delay functions. But

Click Arnd, and now increasing the delay Time increases the State Space drive, and pulls back on the High Cut, to get that BBD-but-still-fairly-clean sound.

Click Craig, and now the Bitcrusher Downsampling tracks the Delay Time as well.

Click Ryan, and you'll introduce that lovely clock whine, whose frequency also tracks the Delay Time. The whine has its own dedicated level control so you can decide how much clock leakage you want in the sound. (Pro Tip-turn it up to emulate the sound of a bad circuit board layout!)

And there you have it-delicious, modern digital meets filthy, vintage analog. Have fun!

Download the Bucket Bridge Delay.multipreset Here!

LINK:	https://blog.presonus.com/index.php/2020/08/07/bucket-brigade-delay-fx...
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