tube driven delay-possible?

[ric]

I understand enough about tube circuits to be able to successfully build tremolo and reverb. I like the tube echoplex model on a line 6 but it would be cool to have a completely tube driven rig.

I don't understand the first thing about solid state, so I would not be able to build with it. If this thread goes off in that direction it leaves me out, but maybe someone else could take the info and run with it.

So, what do you folks think? Is delay derived with a tube circuit feasible?

[Mick Bailey]

Probably every tube delay ever built uses a mechanical means to actually create the delay - magnetic tape, drum, disk, electrostatic, or whatever. The tubes are just there to condition the signal and give the correct AC voltage or current along the way, and in the case of magnetic tape delays, to additionally generate the bias frequency.

To build an all-tube delay may be possible. Thousands of tubes could give you the equivalent circuit contained in a BBD chip to give a few ms of delay. But a practical circuit? maybe not.

Edit; R.G. calculated you'd need around 66,000 dual triodes for an equivalent digital delay.

[ric]

Thanks for the reply, Mick.

66,000 tubes sounds a little outside my price range $-(

Hard to find a good used PT the size of a bus for starters. Well, I thought I'd toss the idea out there.

[J M Fahey]

It would probably be like this ENIAC computer or larger.

After all this one had "only"

17,468 vacuum tubes

plus

7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors and around 5 million hand-soldered joints. It weighed more than 30 short tons (27 t), was roughly 8 by 3 by 100 feet (2.4 m × 0.9 m × 30 m), took up 1800 square feet (167 m2), and consumed 150 kW of power

[g1]

R.G. calculated you'd need around 66,000 dual triodes for an equivalent digital delay.

So, about 1,000 of these Cordovox CG-1's should do the trick?

[ric]

It would probably be like this ENIAC computer or larger.

After all this one had "only" plus

Gee, Juan, you're making this look difficult.

[ric]

So, about 1,000 of these Cordovox CG-1's should do the trick?
[ATTACH=CONFIG]29877[/ATTACH]

Ok, now we're getting somewhere. I have a thrift store organ that looks like that in the back. So if I get a hundred more and hook 'em up in series I'm on my way....or not.

[olddawg]

Funny...... that back in the day, we couldn't get rid of our old tape delays fast enough just because of their inherent noise, maintenance, reliability, and cost issues. I actually gave away my Roland RE 201 (or was it a 401, it had a spring reverb in it as well) that people pay a a small fortune for nowadays. How about a tube buffered effects loop and a modern delay/echo. I doubt if you could tell a difference although I'm sure that there are people who say they can. Something about random mechanical error, lol.

[ric]

Funny...... that back in the day, we couldn't get rid of our old tape delays fast enough just because of tactuallyherent noise, maintenance, reliability, and cost issues. I actually gave away my Roland RE 201 (or was it a 401, it had a spring reverb in it as well) that people pay a a small fortune for nowadays. How about a tube buffered effects loop and a modern delay/echo. I doubt if you could tell a difference although I'm sure that there are people who say they can. Something about random mechanical error, lol.

Hey, olddawg.

I wouldn't want a real tape echo either. I've heard of the maintenance issues. The delay modeler has adjustment for tape wobble actually.

I can't figure a way to make tube drive delay, looks like I'm in good company, the rest of the world can't either without a contraption of some sort. Where's Tesla when you need him?

[Justin Thomas]

Just rambling here...
I actually find the noise and unpredictability in old-fangled gear endearing. I'm willing to personally accept a certain amount of "unpredictability" in my gear; keeps me on my toes and encourages a certain amount of aftive involvement in making something new. Now, reliability is a different thing entirely... But the fact that certain pieces of gear never act the same way twice? That I can kind of get into... My amp doesn't sound the same as it did the other day even though I didn't move the knobs? Neato, let's see what different sound I can make with it!

My favorite non-tape/drum/other tube echo was actually a Vox Delay Lab. I had a "Lo-Fi" switch. I'd glue it in that position. It took off a lot of clicky attack that I hear in most of the digital pedal delays; I like he fact that the echos in analog lose fidelity after a while, instead of just cleanly fading out.

Re: 66,000 duo-diodes to make a "digital tube echo"? I've got a box of old TV tubes w. lots of diodes I wanna get rid of... I'll donate to the cause!

Don't give up yet... I wonder if you couldn't rig up some kind of oscillator circuit to get a constant feedback loop and then just rig up some kind of intentional signal interruption thing to get the silence in between. Like a helicopter-chop tremolo on a feedback loop... Hey, it might not be the same as the recording, but, hey, that' already been done. Try something new! I bet Tesla tried all kinds of crazy-ass stuff that never worked, and had a hell of a lot of fun!

Justin

[ric]

Justin I was thinking along those lines today. I was wondering if a partial tremolo circuit could be effected by an inductor, with it's resistance to change, to create a delay. Why not try something and just see what happens. Not sounding so far like there's a known circuit to work from. Might make something interesting even if it fails to be a delay.

[Leo_Gnardo]

I wonder if you couldn't rig up some kind of oscillator circuit to get a constant feedback loop and then just rig up some kind of intentional signal interruption thing to get the silence in between.

By the time you chain up enough circuits to give you a delay you'd recognize as a delay, you'd have a noise-to-signal ratio that swamps everything you try to pass through it. Dial it up to about 900 milliseconds. Hello .... hello .... is there anybody out there ....pSSSSSSHHHHHHHHZZZZZXXXXXXHHHHHHHHHHHHSSSSSSHHHHHFFF FWWWWSSSSSHHHHHHHH....

Nope, just loop some recording tape around some nice clean chrome plated mic stands, that's the way. Sure worked for Floyd.

Just nod if you can hear me, is there anyone home?

[Gingertube]

1 twin triode will make a 1 bit memory (flip-flop), or 1 bit counter.
Multiply that by the bit width you want and then by the memory depth you want and suddenly you are up to "stated" 66,000 tubes.

Look at this digital clock design:
All-tube digital clock, seven years in the making

It only took the guy 7 years to make it (but it is pretty).

If I were to start playing around with delays etc. I would look seriously at Belton (Accutronics) range of digital products:
http://www.accutronicsreverb.com/
Check out the BTDR Digital Reverb Modules or go the "whole hog" and check out the BTSE DSP Modules.


Cheers,
Ian

[Justin Thomas]

But, who says it needs to be recognized as "delay?" Just go for it, and in the process, you'll come up with something ALL YOU! I love making Belligerent-Martian-Zombie-Apocalypse noises with my junk pile here at home. One time, I woke up my friend's kids - they were afraid that the end of the world was coming. I'll use the noise, somehow... same friend will get me to make "digital noises" with my pedal collection in certain songs because he either doesn't have a keyboard player to do it or the musicians he's with are so busy trying to get rid of all that awful useless annoying noise... Boring! And (I'm a Floydacaholic) I think Floyd did the mike stands because... well, when the gear you got don't do what you want, modify! That's another thing I don't like about a lot of effects anymore - the parameters as built are so limiting! Part of me shies away from a piece of gear that says in the review, "we couldn't get a bad sound out of it!" That just means there's not enough space between the lines... Make the boundaries so far apart that at the extremes, "nobody will EVER use THAT sound..." I will!

Justin

[ric]

Justin, I like the way you think. Thanks for spreading a little sunshine.