Tube Chorus?

[bassmannate]

I know, this might be a crazy idea. I like my Valvecaster and I've seen the Vibracaster. However, as a bass player, a chorus would be more useful to me and I really like the sound of tubes!

I know it may not be practical since chorus is time based instead of pitch based, but has anyone thought of it? I've seen some boutique tube chorus pedals advertised on the internet for something like $400    I just can't imagine spending that much when the valvecaster was so cheap to build!

[Taylor]

I imagine if you add your clean signal to this:

http://www.diystompboxes.com/smfforum/index.php?topic=74262.0

You'd have tube chorus.

[earthtonesaudio]

Some vintage pedals that are labeled "chorus" are in fact phase shift circuits, like the one in the thread Taylor linked to.  Most modern "chorus" pedals, however, use true time delay (rather than phase delay) to create their sound.  It would be prohibitively expensive, massive, and just plain ridiculous to construct a true time delay with tubes.  To do it this way, you're probably looking at a "pedal" with upwards of 10,000 tubes and nearly impossible power requirements.
















...Which is exactly why you should do it.   

[R.G.]

I know, this might be a crazy idea. I like my Valvecaster and I've seen the Vibracaster. However, as a bass player, a chorus would be more useful to me and I really like the sound of tubes!

I know it may not be practical since chorus is time based instead of pitch based, but has anyone thought of it? I've seen some boutique tube chorus pedals advertised on the internet for something like $400    I just can't imagine spending that much when the valvecaster was so cheap to build!

Depends on what you mean by "tube chorus". If all you mean is a chorus pedal that has tubes in it somehow, it's pretty easy. Take a chorus pedal, any chorus pedal, and rip out the input buffer and output mixer. Replace those with a dual-triode to make two tube buffers. Done. Now charge $400 for it. Is this a tube chorus?

In my mind, you get almost as good a sound by taking the same chorus pedal and rubbing tubes on the outside of it.  

A chorus is a time delay device. Choruses at their hearts must have either a bucket brigade delay or a digital delay to provide the time delay. If you search, I did once do a quick and dirty design of an **all tube** delay with enough stages to do a chorus. It took literally tens of thousands of tubes and a major power station to run it, let along air condition it to keep it cool.

An all-tube delay is impractical to the point of almost impossible. If you're not going all tube, the sound quality is determined largely by the sampled time-delay, not the tubes that are "rubbed on" the front and back end of the delay.

I imagine if you add your clean signal to this:
http://www.diystompboxes.com/smfforum/index.php?topic=74262.0
You'd have tube chorus.

Actually, no. At best you'd have a tube based phaser. Magnatone did a tube based vibrato in some of its amps. I did a triode phaser about 10 years ago, using photocells like the reference. It works fine, as you'd expect, because a phaser needs an accumulated and variable phase delay and a mixer, and you can do that with JFETs, bipolars, opamps, tubes, and probably magnetic amplifiers.  

[Taylor]

Well, ok.

The $400 tube chorus to which the OP refers is the Effectrode Vibrachorus. Based on its ad copy, I'm guessing its of the phase shift variety. I agree that it is not a chorus as generally defined. But it does answer the OP's question.

[mac]

If you search, I did once do a quick and dirty design of an **all tube** delay with enough stages to do a chorus. It took literally tens of thousands of tubes and a major power station to run it, let along air condition it to keep it cool.

A guy I knew in Brazil at a bar showed me after a gig a delay pedal he had made, a big box, that had zillions of caps and resistors looking like a railway.
I did not pay much attention then... I wish I had. That was more than 20 years ago.
Best delay I ever heard.

mac

[Taylor]

Choruses at their hearts must have either a bucket brigade delay or a digital delay to provide the time delay. If you search, I did once do a quick and dirty design of an **all tube** delay with enough stages to do a chorus. It took literally tens of thousands of tubes and a major power station to run it, let along air condition it to keep it cool.

I can beat that. Behold my Speed of Propagation Flanger!

My first submission to a contest. My ~30 seconds of research tells me that an electrical signal moves around 95% the speed of light. In my flanger, the signal is split and run through lengths of wire. The first wire is 1/1000th the distance a signal travels per second, which gives 1ms delay. Each successive wire gives another 1ms delay.



You could either use a decade counter to turn on and off the lines for a seek-flange, or an LFO-driven mixer to give you that classic tape flange sound without all the fuss.

Anybody know any line driver circuits that can drive 1,000,000 meters? Maybe just a couple of LPB-1s in series...

[Renegadrian]

Depends on what you mean by "tube chorus". If all you mean is a chorus pedal that has tubes in it somehow, it's pretty easy. Take a chorus pedal, any chorus pedal, and rip out the input buffer and output mixer. Replace those with a dual-triode to make two tube buffers. Done. Now charge $400 for it. Is this a tube chorus?

In my mind, you get almost as good a sound by taking the same chorus pedal and rubbing tubes on the outside of it.  

A chorus is a time delay device. Choruses at their hearts must have either a bucket brigade delay or a digital delay to provide the time delay. If you search, I did once do a quick and dirty design of an **all tube** delay with enough stages to do a chorus. It took literally tens of thousands of tubes and a major power station to run it, let along air condition it to keep it cool.

An all-tube delay is impractical to the point of almost impossible. If you're not going all tube, the sound quality is determined largely by the sampled time-delay, not the tubes that are "rubbed on" the front and back end of the delay.

I agree on this - altough there are a lot of "tube-based" pedals (I mean "HYBRID") that sound quite good, I am more on the "ALL-TUBE" philosophy...Else as RG wisely said, you can take every pedal and put a tube at its input and voila' you have a tube pedal!!! We know it's not that...That lends me to see with a suspicious eye pedals like the tonebone, or even the butler tube driver...

[frequencycentral]

I imagine if you add your clean signal to this:

http://www.diystompboxes.com/smfforum/index.php?topic=74262.0

You'd have tube chorus.

I'm really pleased with that pedal, I use it a lot, on guitar, bass and my Fender Rhodes. It's been compared by some as sounding very Magnatone-esque. Vibrato is not quite chorus but Vintage Vibe does animate the sound in a very pleasing way, and does give a somewhat chorusy feel. I think of vibrato as the closest you can get to chorus in the analogue domain, without resorting to BBD's.

R.G. is correct of course, adding the clean signal would give phasing not chorus, though I feel that particular design, with only two shift stages, is lacking the ingredients for a deep phaser. I have tried it with four stages but never got it phasing properly, I've since built a couple of solid state phasers to really get my teeth into what makes a good phaser. My next project is exactly that, low voltage submini tube phaser attempt #101, based on this schematic that I recently came across.

[bassmannate]

So, basically, I'm better off just building a CE-2 if I want good chorus 

[Taylor]

Well, I think if you take anything away from this, it should be that the whole thing about "effect+tubes=better effect" is not something you can count on. It makes for good hype when you want to sell pedals, but that's often all there is to it. I'm not saying that's necessarily the case with the Effectrode, but don't assume that tubes make everything better.

[aziltz]

if I really wanted a tube chorus, I'd make an analog BBD chorus and use tubes for all the audio-path buffers and gain stages.

[bassmannate]

Yeah, I know just sticking a tube somewhere in the signal path is not necessarily going to give a nice tube sound. Just wondered if it was possible. I'm not so much a pure tube guy. Heck, I use an all solid state Hartke amp for my bass. It's just nice to have that extra warmth now and then. The Valvy will probably continue to add that sound.

[Renegadrian]

That's why I love the Valvy...just a few common parts and a tube, surely it's not THE stompbox, but it's IT - nice boost, doesn't eat sound, and add a good fatness...and it's PURE tube...Like my own device, the TUBE STAR...Pure 12AT7 madness, nothing more...Still I am a Zoom guy, I love that $h.t, so if I want good sounds I can go digital too! But TUBE pedals, I want them to be PURE. Altough some sound so good, I don't like HYBRIDS...

[bassmannate]

Yeah, I used to be a digital guy. I even have a Bass Pod Pro from Line6. But, in the past year, I've just noticed how dead it seems compared to real analog circuits. Now, I'm starting to go about building my own analog effects. Just the basics. I like the reliability of my solid state amp but like I said, it's nice to add that warmth and fatness of a tube. The Valvy really does it for me.

I'm still a bit unsure of whether I want a chorus like a CE-2 next or if I would rather get a compressor like an Orange Squeezer or an LA-Light. Maybe I could put both an Orange Squeezer and an LA in the same box and make them switchable.

[mac]

So, basically, I'm better off just building a CE-2 if I want good chorus  icon_lol

Thta's what i did, I bought a CH1 and a DD3. I tried to get parts for a zombie chorus but had no luck. Same for delay.
Delay is so and so, the chorus acceptable. When I figure out how to go analog I'l build both.

mac

[puretube]

...
... Choruses at their hearts must have either a bucket brigade delay or a digital delay to provide the time delay...
...

Fullheartedly disagreed with that statement!


Any other way to raise/lower the pitch of a (guitar-) signal (simultaneously) has the effect-historic right
to be called (and sound like) : "Chorus"...

(closely related to: "Celeste", "Ensemble", a.o.),

(not far away from: "Phaser", "Vibrato", "Vibe", "Leslie").



(there are differences in between above mentioned effects concerning the spectrum being modulated frequency-dependant or -independant, though...).

[mac]

Another crazy idea for a delay:
speed of sound depends on temperature, so by lowering it inside a long tube a signal can be delayed compared with another at room temp. My two cents.

mac

[R.G.]

Fullheartedly disagreed with that statement!

Any other way to raise/lower the pitch of a (guitar-) signal (simultaneously) has the effect-historic right
to be called (and sound like) : "Chorus"...
(closely related to: "Celeste", "Ensemble", a.o.),
(not far away from: "Phaser", "Vibrato", "Vibe", "Leslie").
(there are differences in between above mentioned effects concerning the spectrum being modulated frequency-dependant or -independant, though...).

Yeah - there are differences. Celeste and Ensemble are done with sound *generators* in organs. Phasers, vibratos, 'vibes' and Leslies are all quite different in actual sound from the apparent sound of a time delay generated chorus.

So does one need a time delay to generate that which we call a chorus?  There are multiple answers.
- if the result is to be the somewhat-accurate, if imperfect, simulation of two sound sources, then yes,
- if one wants to take the other side of the question and argue about the legalities of effects-rights, or dinking with the semantics of the word "chorus", three quotations spring to mind.
(1) ...What's in a name? that which we call a rose. By any other name would smell as sweet (William Shakespeare, Romeo and Juliette)
(2) ... "It depends on what the meaning of the words 'is' is." (Bill Clinton, during his 1998 grand jury testimony on the Monica Lewinsky affair)
(3) ... Either "one man's meat is another man's poison" or "one man's fish is another man's poisson", depending on your outlook.

[mac]

If you search, I did once do a quick and dirty design of an **all tube** delay with enough stages to do a chorus. It took literally tens of thousands of tubes and a major power station to run it, let along air condition it to keep it cool.

RG, do you have the schem or link? I'd like to take a look at it.
Thanks

mac