Lightspeed Attenuator a new passive preamp - Page 394

udailey · 22nd January 2011, 06:57 PM

It is expensive and the 2sj74 and 2sk170 are a guarantee. I dont blame you. Glad you are enjoying George's creation and happy I could help.

georgehifi · 23rd January 2011, 10:19 PM

Here's an interesting snippet from the latest Stereophile review of the DCS Debussy Dac which has volume control in the digital domain. Yet two stage adjustable analogue level output stage 2v or 6v, this means you can use it straight into a poweramp and only use the top 25% of the digital volume control, this way you should not be "bit striping".

Sterophile Quote: The differences in sound between the Debussy into a preamplifier and the Debussy directly driving a power amplifier will depend on the preamp's transparency, dynamic capabilities, and overall quality. Sending signals directly to my Musical Fidelity Titan amp from the Debussy or through my reference preamp, a darTZeel NHB-18NS, I heard minimal differences. Given the darTZeel's price of $29,500, that's what you should expect. :Stereophile Quote

Guess what the Dartzeel uses as a volume control? you guessed it. A Lightspeed setup, they tried to patent when they first released it but I quickly put a stop to it showing proof to the patent offices in Eu and USA that I first did the LDR volume control back in early 1974.

Quote from the Stereophile Review of the darTZeel NHB-18NS
"For the first time in all audio history," said Delétraz, "the signal path does not pass through any physical switch, relay, or even transistor switch." Instead, inputs are enabled or disabled using electro-optical analog components. Because there is no physical input switch or FET-based analog switch, there is no "diode effect," either electrical or chemical (electrovalence differential), to alter the signal, he explained in an e-mail. Quote

Cheers George

ua100k · 27th January 2011, 09:55 PM

Quote:

Originally Posted by georgehifi

A Lightspeed setup, they tried to patent when they first released it but I quickly put a stop to it showing proof to the patent offices in Eu and USA that I first did the LDR volume control back in early 1974.

George,
Curious, how did you know they were about to patent this idea. Great that you caught it!!

georgehifi · 28th January 2011, 03:11 AM

In the 6 Moons review. The interview with Herve is after the review of the NHB-18NS.
6moons audio reviews: darTZeel NHB-18NS

Quote:
Q: What is wrong with conventional volume controls?
A: You lose something. I use a system that varies resistance with light. However, until all the patents are in place, I would prefer not to specify the details.
Quote:

Cheers George

ua100k · 28th January 2011, 11:39 AM

Great catch. Thank you for doing that and taking care of the community. I see they do not use that statement on they web site now.

Ryelands · 28th January 2011, 06:51 PM

I see that the $23,500 darTZeel NHB-18NS has "a Pleasure control" and an "Enjoyment Source". Is it an amplifier or an upmarket sex toy?

My little Lightspeed is starting to look a bit dull. Can I call it an "Optical Relief"?

sepolansky · 28th January 2011, 08:18 PM

Quote:

Originally Posted by Ryelands

I see that the $23,500 darTZeel NHB-18NS has "a Pleasure control" and an "Enjoyment Source". Is it an amplifier or an upmarket sex toy?

My little Lightspeed is starting to look a bit dull. Can I call it an "Optical Relief"?

Is the darTZeel push-pull?

AndrewGM · 28th January 2011, 08:37 PM

....and does it suffer midrange suck out ?

MoltenLava · 29th January 2011, 06:33 PM

I have a quick newbie question. On the 100k volume control dual potentiometer, what is the purpose of shorting pin 2 and 3 on one gang and pin 1 and 2 on the other gang? Can we just use the pin 2 on both gang, and leave pin 3 and pin 1 alone?

MoltenLava · 29th January 2011, 10:11 PM

Just finished building the Lightspeed kit I bought from udailey. Good news is it works! However the volume control is reversed somehow. The volume goes down when turned clockwise, and goes up when turned counter clockwise. Can I simply swap the leads going to main LDR and shunt LDR from the potentiometer?

22nd January 2011, 06:57 PM	#3931
udailey Passive Aggressive diyAudio Member Join Date: Mar 2008	It is expensive and the 2sj74 and 2sk170 are a guarantee. I dont blame you. Glad you are enjoying George's creation and happy I could help. __________________ You can purchase LDRs anytime to build a standard LDR attenuator or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com

23rd January 2011, 10:19 PM	#3932
georgehifi diyAudio Member Join Date: Sep 2003 Location: Manly Australia (Jewel of the Pacific)	Here's an interesting snippet from the latest Stereophile review of the DCS Debussy Dac which has volume control in the digital domain. Yet two stage adjustable analogue level output stage 2v or 6v, this means you can use it straight into a poweramp and only use the top 25% of the digital volume control, this way you should not be "bit striping". Sterophile Quote: The differences in sound between the Debussy into a preamplifier and the Debussy directly driving a power amplifier will depend on the preamp's transparency, dynamic capabilities, and overall quality. Sending signals directly to my Musical Fidelity Titan amp from the Debussy or through my reference preamp, a darTZeel NHB-18NS, I heard minimal differences. Given the darTZeel's price of $29,500, that's what you should expect. :Stereophile Quote Guess what the Dartzeel uses as a volume control? you guessed it. A Lightspeed setup, they tried to patent when they first released it but I quickly put a stop to it showing proof to the patent offices in Eu and USA that I first did the LDR volume control back in early 1974. Quote from the Stereophile Review of the darTZeel NHB-18NS "For the first time in all audio history," said Delétraz, "the signal path does not pass through any physical switch, relay, or even transistor switch." Instead, inputs are enabled or disabled using electro-optical analog components. Because there is no physical input switch or FET-based analog switch, there is no "diode effect," either electrical or chemical (electrovalence differential), to alter the signal, he explained in an e-mail. Quote Cheers George __________________ Avatar : Production Lightspeed Attenuator www.lightspeedattenuator.com

28th January 2011, 03:11 AM	#3934
georgehifi diyAudio Member Join Date: Sep 2003 Location: Manly Australia (Jewel of the Pacific)	In the 6 Moons review. The interview with Herve is after the review of the NHB-18NS. 6moons audio reviews: darTZeel NHB-18NS Quote: Q: What is wrong with conventional volume controls? A: You lose something. I use a system that varies resistance with light. However, until all the patents are in place, I would prefer not to specify the details. Quote: Cheers George __________________ Avatar : Production Lightspeed Attenuator www.lightspeedattenuator.com

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28th January 2011, 11:39 AM	#3935
ua100k diyAudio Member Join Date: Dec 2009 Location: Bernardsville, NJ	Great catch. Thank you for doing that and taking care of the community. I see they do not use that statement on they web site now.

28th January 2011, 06:51 PM	#3936
Ryelands diyAudio Member Join Date: Nov 2007 Location: Scotland	I see that the $23,500 darTZeel NHB-18NS has "a Pleasure control" and an "Enjoyment Source". Is it an amplifier or an upmarket sex toy? My little Lightspeed is starting to look a bit dull. Can I call it an "Optical Relief"?

28th January 2011, 08:37 PM	#3938
AndrewGM diyAudio Member Join Date: Jun 2008	....and does it suffer midrange suck out ?

29th January 2011, 06:33 PM	#3939
MoltenLava diyAudio Member Join Date: Sep 2009	I have a quick newbie question. On the 100k volume control dual potentiometer, what is the purpose of shorting pin 2 and 3 on one gang and pin 1 and 2 on the other gang? Can we just use the pin 2 on both gang, and leave pin 3 and pin 1 alone?

29th January 2011, 10:11 PM	#3940
MoltenLava diyAudio Member Join Date: Sep 2009	Just finished building the Lightspeed kit I bought from udailey. Good news is it works! However the volume control is reversed somehow. The volume goes down when turned clockwise, and goes up when turned counter clockwise. Can I simply swap the leads going to main LDR and shunt LDR from the potentiometer?