Yes you will also be listening to Cadmium Sulphide instead of carbon or metal film, don't ask me if this is the magic of the sound. As well as no contacts (that may cause "diode effect on transients") in the signal path.
Cheers George
There is no question that at the end it is the resistive element that makes the magic by getting out of the way like few others can do.
The Lighspeed innovation is the fact that we use this resistive element and that it is convenient to alter the level of attenuation. But it is still the resistor that makes it possible for the signal to get thru without as much destruction that is typical of resistor based attenuation.
Again George, thank you for 6 years of Lightspeed joy. Happy new year.
Walter
The Lighspeed innovation is the fact that we use this resistive element and that it is convenient to alter the level of attenuation. But it is still the resistor that makes it possible for the signal to get thru without as much destruction that is typical of resistor based attenuation.
Again George, thank you for 6 years of Lightspeed joy. Happy new year.
Walter
Looking back would you do it the same?
George,
I recall you starting this thread in 2006 and early in 2007 you semi reluctantly revealed the secrets of the Lightspeed.
If you had it to do all over again, would you have kept it a secret or reveal the recipe to the DIY crowd?
I for one am glad you spilled the beans. I am a DIY guy, and would never pay $450 for a volume control let alone pay $20k for a premium linestage. OTOH
I have had great success and fun with DIY Lightspeed... For this I will forever be greatful.
I think there is a DIY market that is distinct from the finished product market. Without a lot of overlap.
In a perfect world, it would be great if you had patented this approach. It would have been great if it's clear superiority was recognized over the established art and that the audio industry moved to your innovation paying royalties as it went.
In this fickle world of high end audio innovation, I don't think that was going to happen. i have to think that by revealing the formula to the DYI community, your Lightspeed garnered some of the fame it deserves, and you likely got a continued run of customers as a result.
Back to the curiosity that prompted this post...
If you had it to do over again, would you have kept is secret or repeated history?
George,
I recall you starting this thread in 2006 and early in 2007 you semi reluctantly revealed the secrets of the Lightspeed.
If you had it to do all over again, would you have kept it a secret or reveal the recipe to the DIY crowd?
I for one am glad you spilled the beans. I am a DIY guy, and would never pay $450 for a volume control let alone pay $20k for a premium linestage. OTOH
I have had great success and fun with DIY Lightspeed... For this I will forever be greatful.
I think there is a DIY market that is distinct from the finished product market. Without a lot of overlap.
In a perfect world, it would be great if you had patented this approach. It would have been great if it's clear superiority was recognized over the established art and that the audio industry moved to your innovation paying royalties as it went.
In this fickle world of high end audio innovation, I don't think that was going to happen. i have to think that by revealing the formula to the DYI community, your Lightspeed garnered some of the fame it deserves, and you likely got a continued run of customers as a result.
Back to the curiosity that prompted this post...
If you had it to do over again, would you have kept is secret or repeated history?
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If I could of I would have patented it, but it's components were not new, it was just the way I used them back in the 70's, from lightmeter parts out of Hasselblad, Lieca and Nikon cameras.
If I was able to patent it i still would have given out how to do it for diyer's, just like Nelson Pass does, but I too then would have a team of legal hounds watching for anyone who was making them for monitory gain from his IP.
Cheers George
If I was able to patent it i still would have given out how to do it for diyer's, just like Nelson Pass does, but I too then would have a team of legal hounds watching for anyone who was making them for monitory gain from his IP.
Cheers George
Those who have a Lightspeed Attenuator and wishing to try a different power supply instead of going battery. As linear wall warts are very scarce these days and let face it smp wall warts are noisy and are all that seem to be available especially in the US.
I've been shown this quite reasonable priced one which is a nice linear regulated product. They take Paypal and shipping is very fair.
Very nicely built, uses Panasonic FC caps, and comes with the correct lead, plug and polarity (2.1mm center positive). This is 9vdc @ 1A which fine for the Lightspeed Attenuator as it converts it down again with it's internal 5vdc regulator.
And has a bonus 5v usb port output for those wanting to power a 5v usb item.
TeraDak U9VA Linear Low noise Power Supply
Cheers George
I've been shown this quite reasonable priced one which is a nice linear regulated product. They take Paypal and shipping is very fair.
Very nicely built, uses Panasonic FC caps, and comes with the correct lead, plug and polarity (2.1mm center positive). This is 9vdc @ 1A which fine for the Lightspeed Attenuator as it converts it down again with it's internal 5vdc regulator.
And has a bonus 5v usb port output for those wanting to power a 5v usb item.
TeraDak U9VA Linear Low noise Power Supply
Cheers George
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not long ago I noticed some older pro/instrument gear that used the LDR as control element
can't remeber how old, and the LDR may have been added later
and now I have forgot where it was
Very common in modulation effects like fasers, noise gates, compressors and more. Even as volume control. Usually only implemented as a singe device in serie or shunt.
I was just reading a book by Walt Jung and came across a concept of the "negative resistance buffer". This reminded me of a circuit that seemed to have introduced lots of ontrovery in this thread a while back such that the part may have been removed. My question is, does anyone know where that part of the thread was moved to and has anyone tried the "negative resistance buffer" with the Lightspeed? Seems like a nice feature to built in.
For those that have an original MkII Lightspeed Attenuator
I found a very good priced very well made linear power supply for the Lightspeed.
TeraDak U9VA Linear Low noise Power Supply
It has all the goods like Panasonic FM caps and looks well built postage is very good as well, and PayPal can be used.
Reports have been very good compared to the wall wart, but I must say the comparison could have been made to a smp (switch mode) wall wart, which yes then it would be better than it.
AudiogoN Forums: Lightspeed Attenuator - Best Preamp Ever?
AudiogoN Forums: Lightspeed Attenuator - Best Preamp Ever?
As when comparisons were made to pure battery power a linear wall wart was still just as good. And Sam Tellig of Stereophile backs this up as well with his Lightspeed.
So if you are running your Lightspeed Attenuator with a smp (switch mode) wall wart you are not hearing the best from it.
It's very hard to pick the difference between smp or linear wall warts, as they look similar.
One good way is to get a little portable AM radio tuned off station low on the dial volume up and go near it, if it squeals like a stuffed pig you have a smp wall wart. Get rid of it and get a linear one or battery or the Teradac power supply.
Trouble is that it's getting harder to find linear wall wart these days as neither smp or linear are marked on them.
Cheers George
I found a very good priced very well made linear power supply for the Lightspeed.
TeraDak U9VA Linear Low noise Power Supply
It has all the goods like Panasonic FM caps and looks well built postage is very good as well, and PayPal can be used.
Reports have been very good compared to the wall wart, but I must say the comparison could have been made to a smp (switch mode) wall wart, which yes then it would be better than it.
AudiogoN Forums: Lightspeed Attenuator - Best Preamp Ever?
AudiogoN Forums: Lightspeed Attenuator - Best Preamp Ever?
As when comparisons were made to pure battery power a linear wall wart was still just as good. And Sam Tellig of Stereophile backs this up as well with his Lightspeed.
So if you are running your Lightspeed Attenuator with a smp (switch mode) wall wart you are not hearing the best from it.
It's very hard to pick the difference between smp or linear wall warts, as they look similar.
One good way is to get a little portable AM radio tuned off station low on the dial volume up and go near it, if it squeals like a stuffed pig you have a smp wall wart. Get rid of it and get a linear one or battery or the Teradac power supply.
Trouble is that it's getting harder to find linear wall wart these days as neither smp or linear are marked on them.
Cheers George
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Hi, I've done a lot of reading about the lightspeed attenuator. I am very keen on building one, but where can I get a pair/quad of Matched LDRs for the Lightspeed Attenuator?
I contacted some (old) suppliers mentioned in the different threads but no luck there.
I will place a thread in the Swap Meet department.
I contacted some (old) suppliers mentioned in the different threads but no luck there.
I will place a thread in the Swap Meet department.
Hi Xerxes, to do your own quad matched set , just purchase one of these in the link, around $10 Use your DMM with it and match your own. You need about 10 to 15 NSL32SR2S and you may get 2 matched quad sets from that many.
http://www.diyaudio.com/forums/anal...uator-new-passive-preamp-491.html#post3329168
Get the NSL's from Element 14 or elsewhere in the Netherlands.
Cheers George
Hey guys,
I have read many posts but not all, cause 500 is huge
Has anyone use the ldr shunt/resistor in a tone stack ?
I have some nsl32sr3 but it is very difficult to drive them in regions of 250kohm.
I saw a schematic witch is controlled with a Dallas digital pot and the solution is maybe what I'm searching for, cause I will control the Ldr via an atmega.
Thanks in advance
Sven
I have read many posts but not all, cause 500 is huge
Has anyone use the ldr shunt/resistor in a tone stack ?
I have some nsl32sr3 but it is very difficult to drive them in regions of 250kohm.
I saw a schematic witch is controlled with a Dallas digital pot and the solution is maybe what I'm searching for, cause I will control the Ldr via an atmega.
Thanks in advance
Sven
Member
Joined 2009
Paid Member
Hi Big-un, First off, in Australian slang that means you have a big one.
As for caps in the signal path, I have yet to hear one that equals DC coupling, but if you have too much dc offset and can't get rid of it, then your at the mercy of putting a cap or a transformer in the signal path.
As for which cap sounds best, I'll leave that to someone else.
My system is now dc (direct coupled) from the output of the dac chip all the way to the output of the power amps speaker terminals, and there is only an audio transformer in the path on the ESL panels, but the dynamic bass drivers are direct coupled from the dac chips, and it's the best the bass has ever sounded.
Cheers George
Also agree. If direct coupling bothers you then you might try a transformer. Transformers are wonderful for a few reasons and not so hot for a few reasons. You can attenuate or amplify without changing the noise floor! Thats a big deal. They act as a buffer. Thats a great thing when using a passive pre. Common mode noise is eliminated up to the transformer. If you buy a cheapie you will have limited frequency replication and phase shift as well as loss of dB at higher and lower frequencies. If you go with something nice like a Cinemag you can call or email Dave there for a good recommendation and you will get a 1:1 transformer that has near zero phase shift or frequency loss with all the advantages listed. Also, they dont break and you can get them extremely transparent or intentionally soft sounding.
Uriah
Uriah
Member
Joined 2009
Paid Member
Secretly I was hoping to hear that capacitors are just fine as this provides great flexibility in design (I have a simple way to use LDRs without having to calibrate them).. oh well !
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