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Aquaboy triple delay mod)))

Started by deadTalash, April 22, 2014, 10:51:41 AM

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deadTalash

Hi folks! I've built Aquaboy 2012 and I love it so much. Unexpectedly I got 2 more MN3005s (haha) So, I started thinkin' of triple delay time mod, usin' Brian's schematics of double delay mod as a reference.
I want you folks to take a look at what I got to say am I right. Or maybe I'm terribly wrong :-[

Scruffie

The MN3101 is only spec'd to clock up to 2 x MN3005 BBDs so you'd have to buffer the clock lines too.

You'll also be suffering some signal degradation at this point and really need to add some make up gain a la deluxe memory man.

Otherwise you're technically right, apart from not having any source follower resistors (R1 & 2) at the output of the 3rd BBD.
Works at Lectric-FX

deadTalash

Thank you for reply! So I should build a buffer for a clock signal with double opamp, right? And a makeup gain stage  like this

Scruffie

Noo sadly you can't just use a Dual OpAmp, it'll have to be a digital CMOS buffer, 4069, 4049, 4011, something like that.

Yes a bit like that but remove the bias pot from IC6A pin 3 and attach it straight to v.ref, add a 1uF electrolytic from pin 1 to the BBDs pin 7 and then add the bias trim from the Aquaboy after the electro, that way your gain and bias wont interact and you wont loose the headroom of the OpAmp & BBD optimal bias most likely not quite matching.

As you'll be adding a dual opamp, you could ideally make two gain stages and place them after each BBD.
Works at Lectric-FX

deadTalash

Me again) Look what I found on the web https://dl.dropboxusercontent.com/u/89725007/Yamaha1010delay.jpg  It's an analog delay unit with 4 mn3005s.
Here it's clock generator
The clock pulse is generated by the BA617 chip, so what happens next? What is the purpose of TR11 and TR12? As far as I understand, splitted signal then goes  to the TC4049 IC,  and one part of it gets "phase reversed"?
I dont have clear understanding of what 4049 does. Clock pulse of MN3101 has a square waveform, right? As I understand, 4049's output will be something like that    How can I be sure that 4049's output will be enough for 3005's input capacity?

Scruffie

#5
That's a lot more complicated than you need and you don't need to use an entirely new clock, the 4049 is being used to split the clock signal in to the tick and tock needed by the BBD from just a tick and you shouldn't need a buffer for each BBD.

Go to the current lover project and look at how the 4049 is used there to buffer the 4013 clock, IC23 etc are doing the same but it's probably just a bit clearer.

One 4049 buffer should be enough to overcome the input capacitance on the 3rd 3005, the 3101 can already drive 2 of them and it just has to stop the 3101 pulses (square wave) from 'rounding off' due to the capacitance of the extra BBD.
The 3101 is only going to struggle to when it comes to high frequencies so shorter delays so this is just a helping hand.
Works at Lectric-FX

deadTalash

First, thank you very much for help! Please take a look at my drawing :-\
Not sure about the 5k6 resistors marked red (do we need them?)   I supposed to get 1...2 gain. One more question. Why do we use inverting amplifier type?

Scruffie

Before the 5k6, add a 1uF NP cap (the other 1uF should be NP too) you don't need the 100ks going in to pin 7 of the 3005s.
Works at Lectric-FX