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Warpspeed -An Optocoupler Volume Control

pelliot gave me a heads-up which led me to download the attached...the $60k Altair preamp circuit is by John Curl(?) I think.

Quoted from their description..."Instead of the mechanical potentiometer found in most high-end preamps, the Altair uses optically controlled resistors that can be adjusted to an accuracy of 0.1 dB. To maintain the Altair’s perfect positive/negative signal balance and left/right channel balance in all operating conditions, we use 48 of these resistors—an expensive but undeniably superior design."
 

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The XP30 is pretty spectacular, particularly on sonics. It also has a couple of features that I requested - dual sets of outputs with variable level adjustment between them for bi-amping,... :cool:

A golden nugget of inspiration again from NP...I have some ideas and will try to develop something using the Warpspeed.

Advantages are we can mix and match different design/gain power amps for passive bi-amping the top and bottom; and adjust top/bottom levels to our taste and room requirements. Might also be a good partner to the B5 for active bi-amping...:warped:
 
Warpspeed SE only

Newly minted, first pics...
 

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I received my kit last week and have been busy looking for the perfect enclosure.

Meanwhile, I have a question about batteries. If I was to use a 12v 10ah sealed lead acid (like Dodd's use) would there be any risk of over current to my Warpspeed??? Would some kind of current-limiting be necessary???

Another question... possibly off-topic :)

What is the reason that some of the enclosures pictured in have such tall feet???

Thanks,
 
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Hi Ray, the W'squid has current limiting...but long before it kicks in, with a high current fault the optos would be long gone to semiconductor heaven...they'd blow like a fuse and open the circuit.

The feet...it was just the look and feel (and some damping) I was going for. In my own little imagination, seen from the side the chassis looks like a silver-headed black panther poised to lunge...:)
 
No, you can use whichever is most convenient...as long as the circuit is wired correctly and safely, all will be okay. Since the circuit runs in low current it does not require a humongous SLA battery. The design is quite robust, had been tested...but as always with electronics -accidents, random part failures, etc. are always part of the equation.
 
When you get to a fork in the wormhole, take it!

The Warpspeed CE family is now 3...the engine options are V4, V8, and V12(under evaluation):

V4 -single input Unbalanced only with dual pairs of paralleled outputs

V8 -switchable Unbalanced (in/out) or Balanced (in/out); dual pairs of paralleled Unbalanced outputs

V12 -Unbalanced with dual pairs of outputs with separate control for high and mid/low and master volume control. Passive bi-amping taking advantage of the loudspeaker designer's optimized crossover/driver combo. Two different amps (design/gain) for high and mid/low is now possible.

The inside of the V12 is pictured...
 

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UAV

For those who have been rattling my cage...work is on to develop the RC option.

Like I've been posting before, it's quite a pricey proposition because I do not want to compromise on the motorized high precision potentiometer. This is the only way I want to go to keep the precision, accuracy, repeatability, and the step resolution to deliver controlled power to the optocouplers. With it I am able to optimize an optocoupler's full response curve from totally OFF to fully ON, which gives the Warpspeed the gradual increase/decrease of volume level that we have.

Expected availability is Feb 2012...thank you all!

:warped:
 
Nice work...My warpspeed 10+ has now around 50 hours of listening and its the best manual volume control ever used so far....more to come....

Btw, DIYspaceW kept his word and sent the following by email...

"By the way the warp 10 is so great that I forgot to make reviews, that has never happened. Its the most transparent solution so far. I have also changed the output stage of the DAC, I use a 6s3p-ev tube and the output impedance is smaller, now around 1600-1800ohms.

It is difficult to make any review right now because the time I bought your warpspeed, I also got new output transformers. But it has become a real synergy between all my components now. On first note when I turned the system on I noticed the relaxation and clearness of the sound. I would say the classic R pots deform the harmonic structure of sound so much that the fine fragments get lost in space. This isn't the case with optocouplers. I noticed so much more information in music but not in analytical way, just enjoying the magic of music. The violin is violin with all the harmonics, a piano a piano...instruments are telling you their own stories...So for now I am impressed with my system and warpspeed has become a general important factor."

Thanks Marko! :warped:
 
The spawn...

V4 - 1-Input/2-Output(paralleled) stereo Unbalanced only
V4x2 - 2-Input/2-Output(paralleled) stereo Unbalanced only
V4x3 - 3-Input/2-Output(paralleled) stereo Unbalanced only; future product

V8 - switchable Unbalanced (1-In/2-Out paralleled) or Balanced (1-In/1-Out) stereo; No Unbal/Bal conversion
V8.1 - 1-In/1-Out Balanced only stereo with single level control
V8.2 - 1-In/1-Out Balanced only stereo with dual L/R level control

V12 - 1-In/2-Out Unbalanced only with separate controls for high, mid/low bi-amping, and a master volume control; fully tested
V16 - 1-In/3-Out Unbalanced only with separate controls for high, mid, low tri-amping, and a master volume control; future product

Updates and pic of the V4x2 here... Warpspeed Optocoupler