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A question about BBD delay

PostPosted: Thu Dec 22, 2016 2:56 am
by moogforum2
Well, i have been reading about BBD delay technology and i'm almost sure it is normal on this pedal, but i would like to know why the MF delay reacts differently to high frequencies and low frequencies, cause i had noticed that both low and mid frecuencies tend to have more repetitions than high frequencies using the same feedback levels, i read something related to the filters that this devices use, but i would like to know if this is normal on this pedal and some details about the science behind this, thanks.

Re: A question about BBD delay

PostPosted: Thu Dec 22, 2016 12:17 pm
by stiiiiiiive
You’re right : the BBD technology involves low pass filters, hence the high frequencies being silenced quicker.
I don’ know the details but I know the behavior you describe is normal.

Re: A question about BBD delay

PostPosted: Fri Dec 23, 2016 9:57 pm
by moogforum2
Thank you Stiiiive, about this topic i get this info from Moog:

Hi MF2

Analog delays that use BBDs will always have a bit of rolloff in the higher frequencies. This is one of the traits that make analog delays desirable, especially for guitar players who might enjoy more mellow repeats. This behavior is normal. An analog delay uses "BBD" (bucket brigade delay) chips. The audio signal is stored (in a short burst) in one stage of the chip, then fed into the next stage where it is stored again, then fed into another stage, etc. Each time it is stored there is a gap in the passage of the sound to the output; each time it is released it plays but loses signal strength and fidelity. This results in a repeated pattern of one sound being repeated at diminishing levels with a smearing of the sound.

Happy Holidays!




Re: A question about BBD delay

PostPosted: Sat Dec 24, 2016 7:25 am
by stiiiiiiive
Voilà ! :)

Re: A question about BBD delay

PostPosted: Sat Dec 24, 2016 8:38 am
by GregAE
FWIW, the term 'bucket brigade" refers to a human chain where an item (like water) is moved from point A to point B by passing them from one stationary person to the next. Originally, it referred to firefighters passing buckets of water to each other to extinguish a blaze, but now refer to any item transferred using this method.

Continuing with the water bucket analogy, some contents are lost during the transfer (i.e. some water gets spilled). The same thing happens electrically through a BBD delay chip (i.e. some charge is lost), and a reduction of signal accuracy is the result (generally a darker sound than the original signal, and with less volume).