Diy BBD possible?

[11-90-an]

Just wanting to know if it is possible to make a BBD out of discrete components like caps, resistors, transistors, etc. Just curious...

Any input welcome....

[PRR]

In theory, yes.

In practice: you won't live long enough to put many stages together, and stray parasitics will give bad performance compared to a chip.

It is literally the same question as: can you build computer memory at home? Yes, a lot of computer memory was built by hand from common parts. It took a government contract to put a few K of memory together. Whenever possible they used methods that scaled better. Writing on a CRT. Weaving iron beads. A more direct technology for audio delay: bouncing ultrasound in a bucket of Mercury.

[idiot savant]

I remember a thread from like 10 years ago or more where a user named stm came up with a 0.5ms delay with something like 24 cascaded all-pass sections.

If I recall it was intended for a TZF flanger. So maybe 8000-10,000 opamp filter stages for 500ms...? 

[idiot savant]

found it!

https://www.diystompboxes.com/smfforum/index.php?topic=25168.0

photos are gone, but it's a fun read anyways!

Blast from the past, sometimes I wonder what happened to some of the old-school posters like Ton aka puretube.

[11-90-an]

Ok.. sad though, i wanted to build a delay with out bbd chips .... heh maybe next time

[vigilante397]

Ok.. sad though, i wanted to build a delay with out bbd chips .... heh maybe next time

PT2399? FV-1? There are plenty of non-BBD options out there.

[Fender3D]

There's plenty of BBDs also....

[Mark Hammer]

You can also buy yourself a 50ft garden hose, coil it up, stick a speaker at one end and a mic at the other.  You'll get a reasonable slapback echo.

Of course not exactly gig-friendly.

[EBK]

You can also buy yourself a 50ft garden hose, coil it up, stick a speaker at one end and a mic at the other.  You'll get a reasonable slapback echo.

Of course not exactly gig-friendly.

It would be smaller and lighter than the amp I used to carry to gigs, i.e., a trivial addition to my standard gear load. The stage visual would be memorable. 

"Ravenous Bark Beetle*?  They were the band with the garden hoses. Remember?"

*I'm pretty sure that name is available if anyone wants to use it for a band (or a pedal). 

[11-90-an]

You can also buy yourself a 50ft garden hose, coil it up, stick a speaker at one end and a mic at the other.  You'll get a reasonable slapback echo.

But I have a 50ft garden hose...

What type of mic would be good for this, anyway? 

[bluebunny]

But I have a 50ft garden hose...

What type of mic would be good for this, anyway? 

A waterproof one.  Just in case...   

[Mark Hammer]

Plenty of inexpensive electret condenser capsules available.  If you're serious about doing this, I'd recommend buying one of those plastic end-caps that screw onto the end of a hose or spigot, with the standard thread.  Drill a suitable hole in it that allows you to insert the mic capsule in the middle.

The other end of the hose is to be treated somewhat the same as a talk box.  A speaker of reasonable output level would have some sort of funnel or bezel that directs its output into the hose.

Note that delay time will depend on tube length, but as tube length increases, bandwidth will decrease.  As well, because sound will bounce around inside the hose, it won't be discrete repeats, so much as a blend of one repeat and a bit of reverb-ish mush.  It may be musically valid, but will be no substitute for a simple PT2399 circuit.

If you're up for the experiment, I tip my hat to you.  But realistically, it's an awful lot of trouble to go to for something that may sound interesting but won't sound especially good. 

[11-90-an]

Plenty of inexpensive electret condenser capsules available.  If you're serious about doing this, I'd recommend buying one of those plastic end-caps that screw onto the end of a hose or spigot, with the standard thread.  Drill a suitable hole in it that allows you to insert the mic capsule in the middle.

The other end of the hose is to be treated somewhat the same as a talk box.  A speaker of reasonable output level would have some sort of funnel or bezel that directs its output into the hose.

Note that delay time will depend on tube length, but as tube length increases, bandwidth will decrease.  As well, because sound will bounce around inside the hose, it won't be discrete repeats, so much as a blend of one repeat and a bit of reverb-ish mush.  It may be musically valid, but will be no substitute for a simple PT2399 circuit.

If you're up for the experiment, I tip my hat to you.  But realistically, it's an awful lot of trouble to go to for something that may sound interesting but won't sound especially good. 

Yessir, thanks for the input. Quarantine driving me nuts, i guess

[samhay]

I built a very short optical delay some years ago - the pictures and gone, but don't bother - and the thread came up with a few other innovative options for DIY delay:
https://www.diystompboxes.com/smfforum/index.php?topic=116243.0

[Kevin Mitchell]

I'v been meaning to do this as a ridiculous yet functional art piece. Kinda like this;



There are plenty of BBDs out there so this FAR from practical. I'm in it for the the amusement and to educate on these delay circuits.

I feel the market of in-production devices are also expanding as demands increase - between XVIVE and CoolAudio.

-KM

[amptramp]

BBD chips are relatively rare and scarce now.  But one easy way to do this is with a CCD camera chip.  Modulate a LED with audio, focus it on a particular pixel and let a relatively show (for video) clock send it to the output.  You have access to all the pixels so you can use any particular pixel on the sensor to select the time delay, as well as modulating the clock frequency.

Building the optics necessary to focus an LED requires a lens (which, if you are using a camera, is going to be there) and a restrictor plate with an opening one pixel in size.  But the latter could be simulated by just clocking the output through and taking only the sample that came out at a specific time as the valid output and dropping it into a sample-and-hold.  That way, there would be no need for an optical restrictor plate - you just select the output that came out at a particular time.

There are a lot of cameras that have been scrapped due to low resolution and a number of phones that have this feature.  Camera CCD's should not be hard to come by.

[Kevin Mitchell]

BBD chips are relatively rare and scarce now.

Only if you're looking for 512 stage - single or dual BBDs. Everything else is currently back in production.

-KM

[11-90-an]

Could a sample-and-hold circuit hold a certain note...?   

[Kevin Mitchell]

Could a sample-and-hold circuit hold a certain note...?   

I think you're mixing this thread with the one I had posted.

They "hold" a voltage. That voltage can translate to a note through a VCO (voltage controlled oscillator) as a synth voice or relevant to my thread - the thread you probably meant to post in, it was more about holding a voltage for generic recall purposes. Which is the same principal.

The sample/hold stuff we're used to here for stompboxes is mostly in respect to the FSH-1 where the circuit uses a transistor as a noise source for *randomish* voltages to sample and holds to control a filter causing the sporadic filter effect. Imagine playing a wah pedal with severe parkinson's disease.

-KM

[ElectricDruid]

BBD chips are relatively rare and scarce now.

Only if you're looking for 512 stage - single or dual BBDs. Everything else is currently back in production.

-KM

+1 agree with Kevin. Far from being scarce, there are far more BBDs now than there were ten years ago.

There are still things I'd like to see that we don't have, and I don't understand why modern chips seem to have worse clock input capacitance than the originals, but there's definitely plenty of options.