Short Term... Memory Man? An EHX Inspired Analog Delay Idea.

[Scruffie]

Decided to expand on the Full Double Tracker 300X to 320X BBD conversion i've just done and came up with a preliminary idea for a pedal, I still don't have access to any of my breadboarding inventory, or breadboards, so I can't test it but I thought i'd get things moving here.

The basic idea is to expand on the Fixed delay of the Full Double Tracker and offer a very short, very simple BBD Analog Delay that utilises the 8-Pin DIP V3208D chips that Steve at small bear offers to allow for a small footprinted pedal with very available parts and a very simplistic sound and look into the BBD world for beginners.

In principle i'd like it to be like a DIY Memory Toy but offering shorter delays, cheap construction and a basic sound, obviously there is no companding in this, so it's not going to be quiet... but it's analog delay so what the hell.

I've replaced the Full Double Trackers Fixed Clock with the one found in the 'Economy Memory Man' Schematic (Which just to note, used a 3005 and also has no companding) to allow for a more varied delay time but also the addition of the LFO to give chorused repeats but without the need for Depth or Speed knobs to once again, keep the build cheap and the footprint small.

I've then inserted a feedback pot where I THINK it should go, i'm not sure of it, currently with a trimmer so it could be a set to where you want it or fixed resistor value, either way (Someone mentioned on the other forum that a 'SLAM' footswitch could work well on this type of effect, where you'd stomp on it and it would go into infinite feedback, could be a mod idea)

I've also taken one or two parts from other delays, i've added the Low Pass Filter at the end of the BBD as a minimalist option to try and keep things clean without the companding and also put in the Cancel Trimmer that tends to be found on the Output of BBD delays although it wasn't in the Full Double Tracker... this will require testing to see if it's necessary.

Then i've just added a J-FET Input Buffer and Output Gain Stage as the original does suffer from volume drop and to take care of the True Bypassing issues.

As this is my first Foray into fiddling with BBD designs in any interesting sort of way, any input would be welcomed, obviously it is basic and doesn't have the companding you'd expect to find but that's the point of it really, to make it cheap and nasty but kinda fun.

My only real question was if using a 3205 with limited length would be better noise wise than just using a 3208 or if in such a crude design, it wasn't something to fret over.

On to the schematic! :-

[Taylor]

Cool. I haven't built an analog delay before, and haven't been too compelled to do so, but this is one that I could see building for sure.

[John Lyons]

Sounds cool!