[Warpspeed CE]

max, "paralleled" is split OUT internally for bi-amping/sub line out L/R channels.

mhconley, I'll pm in a bit...

Sorry kit availability is suspended indefinitely...concentrating on fully-built ones.

[jk@home]

Allan, Mr. Warpspeed, emailed me several weeks back that he's not selling the DIY kit any longer.  I was going to try one myself. 

Appears this fellow is still selling kits:

http://www.buildanamp.com/

Here's the PDF build manual:

https://docs.google.com/fileview?id=0B0N-dmOQiKmAYTZmMDdjNDUtZTkyOS00YjU2LTk1ZDEtZjZiYjg1OTNjMzdm&hl=en

Or you could read the monster thread on diyaudio, and build one from scratch:

http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp.html

[Warpspeed CE]

...and bypasses for?

A member asked me if it can be done and this option came about. Bypass mode is for owners who have common power amps for both music and movies. They can use their Receiver's processor for control instead of the W'speed...without having to disconnect and reconnect cables specifically to the front L/R power amps.

rklein, I PM'd you too.

[BFitz]

Appears this fellow is still selling kits:

http://www.buildanamp.com/

Here's the PDF build manual:

https://docs.google.com/fileview?id=0B0N-dmOQiKmAYTZmMDdjNDUtZTkyOS00YjU2LTk1ZDEtZjZiYjg1OTNjMzdm&hl=en

Or you could read the monster thread on diyaudio, and build one from scratch:

http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp.html

Yes, a good plan for those wanting to DIY. I wouldn't get too carried away by the "marketing stuff".

I bought a set of matched LDRs for $35., which is the guts of this passive attenuator design, and the same manufacturer and part is used by all designs.

The LDRs are the guts of it, the difference between all the designs is in how they are controlled. And the audio signal is totally independent of the control side of things.

I developed my own voltage/current control technique. It's pretty simple, and uses common principles seen everywhere in audio today. Anyone who is technical could probably also do it. And it will work well with cheap remote controls like the Alps. Heck, if you were really cheap, you could use a wired remote box with 2 buttons to control the motorized pot.

Or just build the original Lightspeed design.
George, the guy who *originally* developed this thing, was bragging that HIS version (design is public) just made the  Stereophile recommended list, again, for the 5th time.
http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-440.html#post2890637

This is cheap and cheerful, right? It started out DIY and cheap, but is starting to look like a site sponsor forum.   
 

[guest1632]

Thank you Dave, for your kind words and compliments! I'm glad that you and especially the Boss like it...guys like you who take the leap help me in developing new models in the lineup otherwise they remain TBD:) I hope you will have late nights enjoying it for a long time.

jk@home, the way you planned your layout I don't see any issues with heat...

Hi Allan,


I was just wondering if I could use a wallwart with the coupler. I was thinking about the idea of throwing a couple of caps in series? with the power input to further quiet down and further smooth out any pulses. What or how much current is required? Also, you said it would take somewheres from 9 to 24VDC so has anyone actually tried this with a veriack, to see what the optimum voltage versus current ratio this would work at? I do have some adapters that are 12V 600MA 300Ma and 1 amp. I even have an 18VDC at 1 amp. So what do you think?

Ray Bronk

[Letitroll98]

Yes, a good plan for those wanting to DIY. I wouldn't get too carried away by the "marketing stuff"..................
This is cheap and cheerful, right? It started out DIY and cheap, but is starting to look like a site sponsor forum.   
 

As the facilitator around these parts I've had the same concern and have been watching closely.  Warpspeed CE has been pretty good about not doing any direct sales or promotion, for the most part just answering questions, which is what he is allowed to do.  There have been a couple of instances where the envelop was pushed a bit, but he stays just this side of the line.

Additionally, no one with any competing ideas or plans are shouted down, in fact Warpspeed CE generally tried to help them out with their project.  There are no potted parts and the plans are linked to on the diy forum, so anyone can get full access to build anything they want to.  Your concerns are valid, and I'll keep monitoring, but so far I think we're still within rules and guidelines.

P.S. Welcome aboard and you're invited to display your build and share whatever parts of the design you feel comfortable with, love to see it.

[doug s.]

letitroll (and everyone else) - i can tell you from experience that, if "bfitz" shares his handiwork here, take notice!  it will be as good as anything out there.  i speak from experience.     he is a fine engineer; i have experienced it first hand in the fm tuna world, which, as i understand it, makes things like amps, preamps, ldr's, etc., look like child's play.   

bob - glad to see you here.     i especially like and appreciate the comment you made:

The LDRs are the guts of it, the difference between all the designs is in how they are controlled. And the audio signal is totally independent of the control side of things.

which is why it makes no sense to me why one would need to spend $700 yust to add a remote, as any ol' remote would do, since it's completely out of the audio signal path...  the remote in my eva-2 is digitally controlled, and only offers 23 steps, but it is more than sufficient.  (and, it also offers switching of 3 inputs.)  however, if more steps are wanted regarding wolume control, there's other options, while still keeping it cheap-n-cheerful...

doug s.

[Early B.]

bob - glad to see you here.     i especially like and appreciate the comment you made:

The LDRs are the guts of it, the difference between all the designs is in how they are controlled. And the audio signal is totally independent of the control side of things.

which is why it makes no sense to me why one would need to spend $700 yust to add a remote, as any ol' remote would do, since it's completely out of the audio signal path...  the remote in my eva-2 is digitally controlled, and only offers 23 steps, but it is more than sufficient.  (and, it also offers switching of 3 inputs.)  however, if more steps are wanted regarding wolume control, there's other options, while still keeping it cheap-n-cheerful...

Not sure if this has been done already, but it would be interesting for a few people to compare the sound quality of the Warpspeed with the digitally remote controlled eva-2. My guess is that even in the land of "cheap & cheerful," you get what you pay for. 

[Rclark]

 If anyone is in the Seattle area with a different type of ldr, I'd be willing to bring mine for a "shootout". However, if you do some searches, I know over on DIYaudio the Warpspeed compares favorably against other ldr's.

 

[doug s.]

Not sure if this has been done already, but it would be interesting for a few people to compare the sound quality of the Warpspeed with the digitally remote controlled eva-2. My guess is that even in the land of "cheap & cheerful," you get what you pay for.

my guess is there would be no difference in sonics whatsoever.  as bfitz said, the ldr's are the guts of it; design differences are how they are controlled, which are outside the audio signal path.  i was gonna get on the audition list for a warpspeed, but battery power and no remote are non-starters for me...

doug s.

[Warpspeed CE]

Whoa, gentlemen! I'm not forcing any of these on anyone...last time I looked everyone has still the freedom to choose. If you're going to be happy with another design, it's fine by me.

I have from the start been forthcoming with the RC option, with pricing, with design choices, etc. It's an option you can either choose or NOT...you don't have to be sore about it. Please don't forget to be "Cheerful" now. Maybe a Thread on BFitz's design will give it a voice and audience...and maybe he'll let us examine it?

Thank you to the admin and all who've been very supportive...

RayB, you can get away with 150mA and 300mA is more than enough. Just remember a clean, pure DC source, like the battery, will always have an advantage -with current demand, and voltage variations being minimal.

[doug s.]

there is one possible area that could result in sonic differences w/these ldr attenuators, (so i was told/read); i queried the designer of the eva-2 about this, before i took the plunge:

q:
does eva have have fixed series resistors and variable shunt LDR’s for each channel; or variable series LDR’s for each channel and the variable shunt LDR’s for each channel?

a:
Eva2 is design with 2 LDRs per channel; configured in variable series and shunt. This yield the best sonic result compared to fixed series resistor and variable shunt design.

that's all i know...

doug s.

[doug s.]

hey warpspeed, don't misunderstand me, please!  i have no qualms about your posts, your products, or your input in this thread.  you are correct; everyone has their choices, as do you, regarding the product you feel comfortable with offering.  i was only expressing my opinion, which is that i am completely uninterested in spending $700 for a remote that may be operationally a bit better, but doesn't make anything sound better, as it is completely outside the audio signal path.  (and, of course, that it is no longer anything resembling cheap-n-cheerful.)  you, and others may feel different; i have no issue w/that!

carry on!   

doug s.

[InfernoSTi]

Not that anyone cares, but I'm so very happy with my Warpspeed...I don't mind getting off my ass every once in a while and adjusting the volume.  My gosh, it's only 12 feet away.  The Warpspeed really set me off on a new direction of clean power and signal path with my entire system. For that alone it was worth it...but the unit sounds great, looks great, and is rock solid. It has really kept pace with my recent upgrades...in fact it demanded them!

Cheers,
John

[mhconley]

Or just build the original Lightspeed design.
George, the guy who *originally* developed this thing, was bragging that HIS version (design is public) just made the  Stereophile recommended list, again, for the 5th time.
http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-440.html#post2890637

That was my original plan until I contacted George about building a balanced version and received this reponse, "balanced (XLR) is impossible to make to be reliable".  My sources all have balanced out and my DIY amps have only balanced input.  I'll keep kludging along with what I have cobbled together and keep looking.

The main stumbling block I've run into is too many wants:

• Passive (LDR or TVC)
• Balanced
• Remote control
• Multiple input
• Cheap & cheerful or DIY

Sowter attentuator transformers look interesting, finding a motorized multi-position switch is the trick.

Martin

[jk@home]

Something like this?:

http://www.bentaudio.com/DLFILES/STEP-REM-R1.pdf

But using a 4 channel pot?

[mhconley]

Something like this?:

http://www.bentaudio.com/DLFILES/STEP-REM-R1.pdf

But using a 4 channel pot?

Yes!

This document describes the options and wiring of the Bent Audio Stepped Attenuator kit. This kit can be used to
add remote control function to a variety of different switches and attenuators. We can adapt the kit to many OEM switches
for production orders but most commonly the kit is used with:
1- Goldpoint Mini-V Attenuators
2- Dact CT2 Attenuators.
3- Shallco C series 2 deck 23 position switches (Bent Audio Version with shaft extension and custom springs).

Very interesting - thanks!

Martin

[BFitz]

As the facilitator around these parts I've had the same concern and have been watching closely. 

Additionally, no one with any competing ideas or plans are shouted down, in fact Warpspeed CE generally tried to help them out with their project.  There are no potted parts and the plans are linked to on the diy forum, so anyone can get full access to build anything they want to.  Your concerns are valid, and I'll keep monitoring, but so far I think we're still within rules and guidelines.

P.S. Welcome aboard and you're invited to display your build and share whatever parts of the design you feel comfortable with, love to see it.

Thanks for the welcome. In general, I'm a DIY guy at heart, and like to help other DIY people build and learn. 
In response to comments above, there is one thing I think you have mistaken - my experience is the parts in the Warpspeed control ARE potted, and the design is proprietary. There are no public domain schematics published. The kit manual tells you how to wire in the potted module. So the only way to get one is to buy a finished unit. The DIY option, which was a kit with potted module, is no longer offered.

I have no problem with protection of IP. In this day and age, it makes sense, if you are a "business". I guess cheap is all relative. Not knowing the finished unit price, I can't really call that one. 
     

[BFitz]

bob - glad to see you here.   

Doug thanks for the nice words. So everyone puts this in context, Doug has been a contributor to the Yahoo FM Tuners group for a long time, over 10 years now. He often contributes to discussions on inexpensive but good sounding FM tuners, which we call "sparrow feed" class, typically costing less than $50.

He also was a contributor to the Yahoo Art D/IO DAC group, again going back 10 years. I founded / help moderate those groups, so we have a common interest in cheap good sounding audio stuff that goes back a while.

[doug s.]

hey bob, don't sell me short - i also am fond of tuna that ain't sparrow feed!   

like the rotel rht-10 i am presently enjoying.  while not as spendy as some, it is far from cheap.  (it retailed for $1500 in '93 and only 500 were made; i have seen them sell for anywhere between $400-$1200.)  and it sounds superb. 

the rotel rht-10, in fact, is one of the better sounding tunas around.  let bob have his way with one, tho, and i dare say it doesn't get any better.    

doug s.