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
Someone else has found the "diode effect", funny that?
Cheers George |
All this is not an issue, most amps/speakers are fine.
If you have an amp that is .5 or 1v input for full output sensitivity and 110db speakers, then you my have a problem with having to use the Lightspeed way down on the volume and never being able to go past 8 o'clock on the volume. And an active pre would be even worse in this situation. But this is very rare as most amps are 1.5 to 2v sensitive and most speakers are 93db below.
Cheers George |
With the Lightspeeds output at worst 7k, this together with a 1mt cable with a max of 100pf per foot gives a -3db point at 75khz, which is plenty high enough and still higher than any cdp noise filtering.
Cheers George |
Everyone who has bought one, including Sam Tellig from Stereophile has said they think the battery is better than the wall wart I supply with the Lightspeed Attenuator. But it's a small difference, and they cannot say what the differences are, this also includes myself. I think maybe it's psychological perhaps. It cannot be noise as the supplied wall wart into the Lightspeed measures 200uV of noise on the output, that's not mV (millivolt) but uV (microvolt) this is undetectable.
Cheers George |
Kcloone,
I believe it does have some form of LDR controlled volume in the new version with lcd readout on the front. I did ask Norman the owner of Arte Forma Audio to remove all references to Lightspeed Attenuator which he kindly did, he now calls his ldr volume the Nature Audio Light Sensor Volume Module.
I have no idea if it is my old MkI version, easy for manufacturers and much cheaper to implement into an amp.
I don't think it's the far better sounding MkII version as this would not be a stable environment for it, as the heat inside would change up to 20c at times inside an amp, and the MkII Lightspeed would go in and out of calibration, it could not be listened to without changing balance calibration every 10 mins.
Cheers George |
Sorry Kclone,
I was a little wrong with the models, it's not the amp but his new $2500usd preamp that has the Nature Audio Light Sensor Volume Module in it to be released in March.
Cheers George |
Thank you for your appraisal and the pat on the back Brislander.
As you have now experienced the no contacts in the signal path sound of the Lightspeed Attenuator, it will be difficult to go back to an active preamp with a normal pot, as I maintain all pots are flawed because of their lightweight wiper contact (diode effect), that's why they all sound different.
Cheers George |
Even if it is a MkI Lightspeed setup and not MkII in those little boxes, they will still sound better than any industrie standard volume pot you can get.
I asked him to remove all references to the Lightspeed name because it's the name of my product, and he was trying to capitalize on the name that's all.
Cheers George |
From a customer who has both the Lightspeed and Eva II
----- Original Message -----
From: Sirot Seta
To: George Stancheff
Sent: Thursday, December 23, 2010 4:32 PM
George,
The lightspeed is great and is "light" years ahead of diyparadise's EVA II.
It is much quieter and linearity is perfect.
BTW I wrote a review of a DAC and did mention the use of the Lightspeed, just FYI.
http://www.digitalaudioblog.com/2010/12/review-db-audio-labs-tranquility-dac.html
Regards,
S
Cheers George |
Yes the Aragon's 22k is the problem you would need a buffer after the Lightspeed, but if your handy or know someone who is you could change the 22k input resistor to say 82k.
If the input of the Aragon is fet then all will be fine with the 82k. But if it is bi-polar then the Aragon may give out bit of dc offset with the 82k if switched on with nothing connected to it's input. (just make sure the Lightspeed or something else is always connected)
Cheers George |
Lstack, thanks for the write up on the Lightspeed Attenuator in a system that was not a prefect impedance match as this has never been done before. I have listened to it in the same situation and thought it was still better than listening to active pre's and other passives, and this is what I tell customers when they ask.
It's just not functioning at 100% of it's capabilities, so when you do manage to listen to it properly matched up you will only then realize it's full potential.
BTW there is no problem using it this way, no harm is done to anything.
Cheers George |
Kevinzoe
Am I missing anything by not having the volume at a higher setting (11-1 o'clock for example)? Besides getting louder, will the sonics improve as I turn the volume up louder?Kevinzoe
Unless you have very high capacitive interconnects (more than 200pf per foot) you will not hear a difference, even with 200pf per foot = 600pf for 1mt, the -3db point will be at 38khz at the worst position (highest output impednace) of the Lightspeed output impedance.
If you use better interconnects 100pf per foot = 300pf per mt, the -3db point will be at 76khz.
I use interconnects that are 40pf per foot = 120pf per mt, this with the Lightspeed is -3db at 190khz. and so on.
Cheers George |
Just looked at the specs of the Sony CDP-CA7es and the 10k for the output is the min load recommended, I would say with this figure it has an output impedance of around 200ohm which is fine.
You will not do any harm to anything using the Lightspeed at 8 or 9 o'clock, the only detriment is the range you have is minimised, sound will be the same with good interconects at 9 o'clock or at 12 o'clock and with 180kohms input impedance this is a great high input for any passive.
Cheers George |
To reconfigure it and have it so it plugs directly into the poweramps rca's, would be a nightmare to do. As there is no standard distance between left and right rca's on a stereo poweramps and then there's monoblocks to contend with.
You would have to make two independent Lightspeeds each with their own power supply, they would need to be about the size of a cigarette packet each, this would be hanging of the amps rca's, and because it's on the back of the said poweramps, they would need to be remote volume, so double the size of those cigarette packets and you have your nightmare.
KISS KISS KISS KISS KISS
Cheers George |
No negative impact using a remote, but no improvement in sound either, but there is a negative impact using any form of input or output switching.
It has has always crossed my mind to do a remote volume, but as it is the Lightspeed Attenuator has 99.9% reliability for minimum dollar expenditure.
Put in a remote receiver sensor circuit, a motorized pot and a good quality remote control, plus another 2 power supplies one for the receiver circuit and one for the motorized pot. And you have diminished that reliability by quite a bit. Plus you need a bigger chassis to house it all, and you have increased the price 3 fold. The cheap skates are already complaining about the $470 shipped price, can you imagine if it were to go over the grand mark.
I have a "KISS" reflection every now and again to bring me back to earth to make me realize why it is such a good product to begin with, and if it ain't broke don't ---- with it.
Cheers George |
Like I said two lager than cigarette size boxes hanging off each rca on the back of the amp/s, and a third power supply unit, you need a remote volume control as they would be behind the amps, then there's the problem of the remote receiver in both units not picking up the remote controls signals because they're being block by the amp itself.
Then there's the price, definatly tipple or more, I doubt anyone would buy it after you've tooled up for all this, like I said a nightmare, but for DIY'ers worth a shot to get rid of one set of interconnects.
Cheers George |
You guys will be happy to know that the Lightspeed Attenuator has made Class B in preamps again in Stereophile Recommended Components, it got 5 star value as well because most of Class B is $3K +.
An email to me said it would never get to Class A because of it's $470 price, how's that for $'s count in what placement you get.
Cheers George |
Jult52
1) With my 1.8v DAC feeding my 2.1v input amp, I find most of my listening to be in the 12-2 o'clock range.
2) I swear there was some break-in in the bass with the LSA, lasting maybe 5 hours.
3) I am a newbie compared to the very experienced audiophiles here. I think suggesting a DAC/passive preamp/high impedance amp combo is a must whenever recommending a path forward for a newbie or someone with a less expensive system. I have a combined $2.5k sunk into my components between transport and speakers (ex-cables) and I think I'm done. Beat that price/performance ratio!
Jult52
1: At 1.8k your dac does not reach the 2v Redbook CD standard, if it did then your volume on the Lightspeed Attenuator would be around 11 o'clock, but there is no problem with where it is on your system at 12-2 o'clock.
2: I don't have an answer to this, but maybe you just got used to now having bass that is tighter and goes down to 0hz (dc) instead of what you were using for a pre before.
3: Yes the Lightspeed Attenuator represents great dollar value as seen in the latest recommended components in the April issue of Stereophile, as the $25,000.00 Dartzeel NHB-18ns preamp uses a Lightspeed Attenuator volume control with a lot of switching facilities and a lot of glitz.
Cheers George
|
Hi Mcondon, if you can use the digital domain volume control within it's final 20% of full output, IE if it's 100 steps, then 80 or more you should not hear any bit stripping, if lower than 80 forget it your starting to go back to the days of good 14 bit of the first Marantz cdp which were pleasant, but no detail.
In theory if the digital domain volume control is over 80% or close to full output it should be the only thing better in transparency and honest to the source than the Lightspeed Attenuator, because you have removed another set of interconnects, and this is always a good thing.
Cheers George |
Thos pesky little people are at it again, I've been sent a few sites where they are charging $10-$50 for the Lightspeed Attenuator circuit.
I have put it up free on DIY Forums, but they are out there trying to make money on someone else's I.P.
So here is the circuit again FREE so you can make one yourself if you up to it, and not pay for it. Hope the moderators allow it.
http://diyaudioprojects.com/Solid/DIY-Lightspeed-Passive-Attenuator/Lightspeed-Passive-Attenuator-Schematic.png
Cheers George
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Thanks Clio, it's just the circuit diagram they are trying to sell, no components at all.
Cheers George |
Jylee
The only concern is the soundstage imaging which is not as good as before.Jylee
This from experience may be because it does not use the far more expensive NSL32SR2S (S=sorted)+(tighter impedance span) "quad matched" as in the production Lightspeed Attenuator.
Rather it use the cheaper NSL23SR3 (non sorted)+(wilder impedance span) units and only "pair matched". And from experience even though the channel balance is fair, the i/o impedances vary quite quite a bit compared (because of the wilder impedance span)to the quad matched NSL32SR2S, and yes from listening to these the sound stage image does seem suffer at the different points of resistances.
Cheers George
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Sorry typo above "Rather it use the cheaper NSL23SR3" should read "NSL32RS2" no "S" on the end for sorted.
And also thumbs up for the chassis Jylee wish I could incorperate it in my production one and keep the price the same.
Cheers George |
Hi Jylee, I have been asked this too many times to remember, if I do it for one I have to do it for all. Being it's the most expensive and labour intensive part of the Lightspeed Attenuator, sorry but it's only for the production Lightspeeds.
For you to do it to get a quad matched set, you would have to get 20-30 X NSL32SR2S's and match a quad set out of them at 5 different mV settings to get 4 that are equal resistances at 1 2 5 10 & 20mV each. The place you can get them from is here.
http://australia.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=NSL32SR2S
Cheers George |
Sorry typo above
"5 different mV settings to get 4 that are equal resistances at 1 2 5 10 & 20mV each."
It should read mA not mV
Cheers George |
Excuse my ignorance, what is meant by TV/BR? TV? but what is BR?
Any source is compatible, so long as it has over 1v out and is lower than 200ohms output impedance.
I have customers with tuners, Dat-tape, reel to reel, cassette and phono stages all used very successfully with the Lightspeed. There should be no reason a TV should not work either, and the earphone outlet could be used also as they are generally low output impedance to drive headphones.
Cheers George |
Channel to channel matching using quad matched sets as I do, gives the obvious left/right channel balance (centralized sound image & stagging), and more a more stable i/o impedance.
All the other copiers of the Lightspeed Attenuator on the market, do 2x matched pairs only, which is still very hard to do, some are not even doing matched pairs but series resistance and only one matched pair. Doing matched quads is exponentially more difficult than doing 2x match pairs, but the difference in sound quality and sound stagging can be heard, when A/B'd against each other.
I go for plus/minus 1-2 db and then calibrate for the majority of the usable volume range. Then all matched quads are potted in hard wax to keep them as temperature stable as each other, so drift is keep to an absolute minimum. Then a final calibration done again before a 24hr paying time, then checked once again before being shipping out.
Cheers George |
Wow this threads been active since I went on an outback holiday to the deserts of Australia for the last week.
As for some of the questions asked.
When the power is disconnected from the Lightspeed Attenuator both the series and shunt ldr's go high in resistance to around a few megohms they never go open circuit, so even with power disconnected they still allow some small amount of signal to pass through.
As for never being able to go to zero volume, most do not find this a problem as if they want zero they can mute,pause, or stop the source with the remote.
If the source is vinyl the gain of phono stages are quite small compared to a cdp and is never a problem either but a very small signal can be heard through the speaker if next to them.
Saying this if someone has one of the many clones getting around, most use the NSL32SR3 led/ldr combo, these do not go as low in volume as the NSL32SR2S that is used in the Lightspeed Attenuator because the minimum resistance is higher on the NSL32SR3, and cannot be shunted to ground as well as the NSL32SR2S.
Also some clones are using the MkI Lightspeed circuit which I first used 25 years ago, which has one a fixed value resitor for the series component and a ldr for the the shunt component, these are far cheaper and easier to make but are quite high in volume at minimum and also don't sound as good because of wildly differening I/O impedances.
Cheers George |
Tried that one 4 times, keeps boucing back.
----- The following addresses had permanent fatal errors -----
I think his virus guard or fire wall is set too high for international emails.
Cheers George |
Hi guys, I need to get info to Scot Hull that he has asked for about the Lightspeed Attenuator. But my emails bounce back. Anyone know him?
He has a web site http://parttimeaudiophile.com but no contact there either even at the bottom of the contact page, it also bounces back.
Cheers George |
Don't do face book, not into it at all. I joined it ages ago and got bombarded with all these strangers wanting to be my friend. Being homophobic (not really) I ran for the hills and instantly cancelled my face book account.
He will eventually sus out what happening, get to me, probably after calling me and arrogant s.o.b for not answering so far 3 of his enquiries.
Cheers George |
Wish I could come and hear/see, a little far though 10,000mls. Keep me posted Anthony?
Have fun
Cheers George
|
There are light's being turned on in all circles now even Paul McGowan is seeing them.
http://www.pstracks.com/pauls-posts/preamp-conundrum/6539/
Cheers George |
Hi Paul (Augwest) I had no idea that was you that gave the glowing review on the Lightspeed Attenuator I sent to California.
As said with a source that could give out 5.5v this the Lightspeed will take but if it goes through the BAMM as well before getting to the Lightspeed this can add a further 5db boost to the bass which takes the 5.5v up to something like 10v before hitting the Lightspeed.
That is why I would try the BAMM after the Lightspeed, or my second choice if the BAMM must go as you have done is to turn down the 5.5v of the source to a volt or two as you have also done.
Good to hear that it still sounds better than all those preamps you put it up against, as I always claim the Lightspeed Attenuator will give the most transparent and dynamic way from lows to highs of controlling the volume from a source to a poweramp, and at the same time being totally honest to the source not adding or subtracting anything. The closest thing one can get to a straight piece of wire with control over the volume.
Cheers George |
You are correct Dave, from what I've been told the $23k Dart'Zeel NHB-18NS preamp uses the same volume control as the Lightspeed Attenuator, though they go even further and use the ldr's also for doing the input switching and balance control, they have also found why all switches and potentiometers sound different and decided to get rid of them altogether, but at a big cost $23k give me a break.
Cheers George |
Just to let you Lightspeed Attenuator owners know, Stereophile have just released their August 2012 Recommended Components and the Lightspeed has once again made it with highest $$$ value.
http://www.stereophile.com/content/2012-recommended-components-preamplifiers
Cheers George |
Yes he has even posted on this thread a few times, and he is a private user, no system thread and not selling anything, so no way of getting in touch.
It's been a few days now that I can't answer him, he must be starting to think what kind of back up service I have for the Lightspeed, I really hate not being able to answer peoples questions, especially customers ones, comcast.net sucks!!!
Cheers George |
Ah great it was driving me nuts, this is not the place to start discusing this, the moderators monitor me closely being a manufacturer.
Can you get to me with another email either by droping the spam filtering on the comcast account or by another internet provider, maybe at work or somewhere?
Cheers George |
Hi guys, does anyone know "Devilboy" "Luka Kostrencic", to send him a message to change something or send from a different internet provider.
As he has sent me an email about his Lightspeed Attenuator he bought last year, but I cannot reply as it bounces back all the time, this always seams to happen to me with ---@comcast.net addreses, too much security or something not allowing emails from Australia, I'm really staring to dislike comcast.net
Cheers George |
Thanks for the help Whart that could be him but still no way of contacting him.
Banquo363 "Minh" another Lightspeed owner in the U.S. emailed me and said he knows him and will try to get an email to him to either turn of the comcst.net blocking or to email me using another provider, I hate all this stuff.
Cheers George |
It's more that if you calibrate for ambient ie: 15c to 35c that's ok, but when the tubes and their transformers can add another 40c or so to that ambient inside the chassis, the ldr's will need to be recalibrated to that temp.
Where in the production stand alone Lightspeed Attenuator there is nothing inside the case to add to whatever the ambient is, so it stays in calibration, unless someone sits it on top of say a Pass Labs XA***.5 class A amp,then your asking for trouble and the same will happen to it.
Cheers George |
Seshkir hi, thanks you for your encouragement and for the great review.
And most of all thank you for your second order/purchase of another Lightspeed Attenuator for your father.
You now know how true to the source the Lightspeed is, nothing added, nothing taken away, just what the source is giving.
Cheers George |
Your Lightspeed Attenuator now has wings, it should get to you soon, hope your father enjoys it as much as you like yours.
Cheers George |
For all the owners of the Lightspeed Attenuator, you will again be pleased to know that it has once again been listed in the Stereophile Recommened Components (October 2012) list with highest value $$$ rating.
Cheers George |
For those who want an integrated amp or preamp with a LDR controlled type of volume control in the designs.
The Japanese company Arte Forma Audio have used (I'm not sure if correctly used) a form of the Lightspeed Attenuator in their Susan and Susan MkII integrated as well as in their Perla preamp.
Correctly they have refrained from inserting it into their tube products, because they probably have found that the fluctuating heat environments within tube products leads to an LDR type volume control not be able to stay in calibration.
Cheers George |
Anyone can put one in a tube pre or tube power amp, but the temperature fluctuations will make it go out of calibration very quickly.
Comparing the Shallco to the Lightspeed in a preamp where there are no switches or balance controls, in other words no other switch contacts that the signal has to travel through. The Lightspeed will sound better than the Shallco.
Cheers george |
Cable capacitance will not influence the overhaul volume level, but it will effect the high frequency -3db roll of point.
eg: If you have 1mt interconnects from the Lightspeed to the amp that are 100pf, the -3db is at 227khz
If the the 1mt interconnects are 300pf the -3db is then at 76khz.
Your Chordette had more gain (output level) than what you were previously using to change the normal volume level on the Lightspeed from 11 o'clock to 10 o'clock
Cheers George |
TelWire (pure copper?) Mogami (pure copper?) This is what I use as well (99.99% copper) but different manufactures, no multi fine strands, but a couple (4-6) of good size solids cores per phase, this combo give me power heft and tightness as well as transparency through the mids and highs. And of course low capacitance.
I've tried silver at either or both positions, while initially impressive they quickly sounded too highlighted in the upper ranges, not harsh but highlighted, it was quickly obvious that it was disjointed from bass/mid bass to the mids and highs, in other words it didn't flow.
For speaker cable, for my bass (ACI SV12 IB 4cuft 150hz to 20khz) I use again 4 x solid core per phase 99.99% copper.
Cheers George |
For some reason the last paragraph got edited this is how it should read.
For speaker cable, for my bass ACI SV12 IB 4cuft 25hz to 150hz I use 4 x 1mm solid core silver per phase.
Then for the ML ESL's 150hz to 20khz I use again 4 x 1mm solid core per phase 99.99% copper.
Cheers George |
Hi B_limo (Bruce) , thanks for the very concise and accurate review of your new Lightspeed.
As for interconnects with it, it is always good to use good quality low capacitance ones from the output to the poweramp, as is the same for tube preamps, <100pf (picofarad capacitance) per foot is fine.(which most hi-end cables are).
Manufactures should be able to answer this, or have it printed in the specs on the packaging.
The input interconnects from the source can be whatever good ones you have handy and like the sound of.
As for the brand/construction this is more system dependent, I for my system prefer copper, some may like silver, which to me is always a tad brighter.
Cheers George |
