I've had my Lightspeed several months now and just tried something that gave me a great improvement. I've had the wall wort pluged into my dedicated ac line. I pluged it into my ballanced power conditioner and it made a huge improvement. The improvement was as good as when I pluged my cd player into the conditioner. More 3 dim. soundstage, better separation of instuments, lower noise floor etc.
I'm now thinking of trying a 12v battery supply to power the LED. Has anyone else tried a ac cond. or batery supply and if so, was it an improvement for you ? |
Grannyring, Feel free to PM me for the speaker cable recipe or for ideas about implementing LDRs in a volume control for an active preamp. davidgarretson@verizon.net |
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Bill, want to hear something funny. You bought your RM-9 from my friend Warren. |
Dgarretson, your the Man! I just looked at your system with all the mods. Very nice job indeed. I have started the whole DIY thing and am learning.
I would love to visit with you on how to try the LDR mod as well as how you made your speaker cables. I have heavily modified my speakers to great effect and completed a tube amp project by gutting a tube amp and building it back up with better parts and improved power supply. I had direction from a tube amp expert but did learn a lot. I was very excited to view your system and work. |
Clio09, Thanks for remembering. I replaced a balanced Shallco attenuator with a 100K balanced LDR attenuator in my AtmaSphere MP-1 phono preamp with great results. It is a relatively simple project, provided that use of LDR is limited to the shunt position in conjunction with a high-quality fixed series resistor such as TX2575. One of the many nice things about this application is that the useful range of attentuation across the full arc of the dual control pot can be varied to your desired gain structure by varying the value of the control pot. To obtain a range of attenuation between around -70db and -30db I used a 500K control pot with dual 50K trim pots for L/R balance. Depending on ambient and chassis temperature one must occasionally rise from the couch to trim channel balance. The improvement in sonic performance is well worth the effort. |
Clio09,
As an FYI. I now own a Music Reference RM9 MKII that I modified with Duelund CAST caps. Based on comments from you and others I thought I would try it. I love this amp! Very musical and engaging. |
Thanks Clio09. I will check with him and his results. |
I believe Audiogon member Dgarretson put an LDR volume control in his Atma-Sphere preamp. In fact he may have mentioned it in this thread somewhere. You might try pinging him. |
When I take temps in my preamp (tube) I have never read temps any higher than 90 - 102 degrees F. If the room temp is 75 degrees, then I assume no issue?
For cost and hassle reasons the thought of an LDR is very interesting. Shallco attenuators are very expensive and a lot of work. They sound fantastic and I must admit doubt that a low cost LDR would sound as good.
But, I have never directly compared in an active preamp and am open to trying. If it sounded as good, then it would be a nice alternative for sure.
Not sure if anyone has done this type of comparison in an active preamp. Hard to do without having two of the same preamp for comparison. I suppose one could solder in and out the two attenuators, but going back and forth would be a HUGE hassle. |
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 |
Last question. What temp fluctuations are you assuming in these cases? How hot? Over 90 degrees F? Thanks... |
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 |
George, are you saying that a DIY guy like me really cannot place an LDR volume control in a tube preamp. It would be interesting to compare to a nice Shallco stepped attenuator.
Would LDR actually sound better then a Shallco in a top notch active tube preamp. Interesting idea. You seem to think the heat in a tube pre may cause problem? |
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 |
George built one for me a couple of month ago. It is by far the best attenuator I have ever used in my system.
Great depth and open soundstage.
Very lively with tons of attack.
Thank you George, the Stereophile recommendation is spot on.
John. (JW Audio) |
By the way George, everything is fine. Thanks. |
Congrats George, a job well done. |
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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 |
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 |
Thanks George, yes my father is looking forward to receiving his Lightspeed. Purchasing a Lightspeed is certainly a no brainer. |
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 |
Looks like Paul did it again. R.I.P. |
Purchased a Lightspeed from George due to what I read in this thread and others. I adhered to all the caveats with respect to input impedance,input sensitivity and interconnect length.
Now , time to report.WOW............an ear opener,took sometime for my auditory senses to settle down with all the extra information. The sound stage didnt get bigger but became more transparent as if a veil has been taken off.Imaging was precise and rock solid. The dynamics was all there as my feet were tapping away with the music.The bass was very controlled and powerful and the highs were as smooth as silk.My ESS AMT 6 speakers are now shinning like a true diva.
All I can say is thank you George for a fantastic product and more importantly sharing his knowledge with the audio community. |
George: Ok. I will contact you from a computer that does not have comcast as its provider. |
Postscript- I hadn't realized that the original thread starter had passed away recently, because I only caught this thread when folks were searching each other out in the last few posts. My condolences to all friends and family.
Best,
Bill Hart |
I don't get why the 'new' Audiogon prevents private messaging. I've heard it speculated that this will protect their fee structure, but it is easy enough to communicate offline via email. I have never screwed Audigon on a commission as a seller and won't- the system protects me, as it does the buyer. But, at the same time, there are many instances where it makes sense to have a private conversation- for example a user wants to follow up with another user about a product, or has a question for a manufacturer that isn't really intended to suggest that the product is defective, but might be interpreted that way. Right now, that can only be done through the mechanism of a product offering where a question can be posed and answered privately. But for other inquiries, not tied to a specific product listing, that still appears to be impossible. We see many times that a disgrundled user will take something public here - and often hurts the rep of the vendor or manufacturer- when more private communications can sort out the problem to both parties' satisfaction. Nor am i suggesting that someone that got burned on a deal- either side- doesn't take advantage of the protections of the system and the dispute process. That's sort of my point- private messaging won't undercut the system.
I'm not suggesting anything that anything between these posters is amiss here at all- that's sort of the point- I don't need to know. But, Audiogon currently makes such communications impossible. Have a little faith, Audiogon- if someone is going to duck their obligations to pay a commission- if that truly is the reason why private messaging was discontinued- they will do that anyway! The real community here is, with few exceptions, pretty scrupulous and that is what the good will of Audiogon is based on.
Best to all- |
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 |
Hey, thanks to George, Minh, and Whart for helping out here!!
George, I have a system on this site but I never made it private. So I guess you've read my email regarding the Lightspeed. If you don't wish to discuss it here, I can send Minh an email from another computer. It's a crappy way to communicate, but if it's all we can do privately, I guess it will have to do. Of course if you wish to discuss it on this thread that's ok with me. Just let me know in this thread what you want to do.
It's a shame about all the comcast.net emails that you are having a problem with. Must be something with the security. |
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 |
and he does show a lightspeed attenuator in his system.
here's the link: http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1275577400 |
maybe it is a different devil boy. the guy i'm thinking of does have a system up called 'the gift and the curse.'
I corresponded with him on his system thread. I don't know his real name.
good luck. hope that helps. |
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 |
I think he has a system on here, why don't you post to his system thread and ask him to email you, or vice-versa? The lack of private messaging here is a PITA. |
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 |
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Great news George. To celebrate the award I gave my Lightspeed a hug today. |
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 |
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 |
Augwest, IIRC the BBAM is a capacitive load with 40K input impedance. This could present a difficult load to an LSA passive. In my instance the challenge is compounded: I split the preamp's output between the downstream BBAM and a sub with 47K input impedance, yielding a combined load of 22K. With the AtmaSphere MP-1 preamp I can't hear any difference between the BBAM placed upstream or downstream of the preamp. However I bet that in your case placing the BBAM downstream of LSA will degrade performance.
I replaced the stock volume control in the Atma preamp with a balanced shunt LSA Mk I type volume control that employs a TX2575 Z-foil resistor in the series position and a Lightspeed/Silonex shunt resitor. This was a major upgrade. Some preamp builders will argue that most of the performance gains to be had in a top-quality active preamp are made at the volume control. Based on this experiment I tend to agree. For a true apples-to-apples comparison it would be interesting to compare your LSA passive to an active preamp with an LSA-type volume control. The only current commercial product I'm aware of that employs an optical volume control is darTZeel. |
Once again a very insightful question. The hitch for me is the need for the Merlin inline bass EQ module (BAM) that constitutes an integral part of my speaker system. In short, Merlin doesn't recommend hooking the BAM directly up to the amp so I stick the Lightspeed in between. A full answer is well beyond the scope of this thread ;-)
I owe thanks to Paul Rosenberg for recommending the LSA and the Atma-Spheres, though I don't think he ever used them in combination. He is dearly missed. |
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 |
Thanks for the comparison. I have used my LSA with an Atma-Sphere S-30 amp for vinyl playback with great results. Right now though until I get my vinyl rig hooked up again I am running my Resolution Audio Cantata direct into the amp via the balanced outputs and using the internal volume control. It works quite well for my digital needs. Have you tried running the AA direct to the amps? |
Excellent question. I've got the Master BAM upstream of the LSA per Merlin's recommendation when using a preamp, but you have to be cognizant not to overload the LSA. My Audio Aero SE DAC puts out 5.5 Volts (!) so if you boost that by 5dB using the BAM you can end up with pretty huge signal (~12V?). The LSA can't handle that.
Fortunately the AA DAC has vairiable output (actually a complete built-in preamp) so I set it at ~ -20dB and forget it. Of course you need to take into consideration the input sensitivity of your amp(s), i.e. how many Volts Input results in Full Output. But if your source puts out a more conventional voltage of a volt or two you might have no issue whatsoever.
RELEVANT ASIDE: I sometimes wonder if part of the reason that the LSA does works well in my system is because of the robust tube output section of the Audio Aero DAC (100 Ohm output impedance). It may not be perfect but I'm impressed with its resolution and musicality, and it will drive just about anything! I will probably be holding on to it until I decide to ditch my CD's in favor of a server. |
Augwest, are you placing the Merlin BBAM upstream or downstream of LSA? |
I recently put the Lightspeed up against three active preamps ranging in cost from $2400 to $9000. These are my notes from the comparison with the best of the three preamps.
--
Preamp Shootout performed 5/14/2012
SYSTEM
custom modified Music Hall cd25.2 transport > Audio Aero DAC > (preamp or LSA) > Atma-Sphere M-60 Mk3.1 OTL amps > Merlin VSM MXe w/Master upgrade
[1] Active costing ~20X the LSA
Sounds more natural than the other active preamps, possibly somewhat less expansive / dimensional sound stage. Broad midrange presence, dynamics, and tonal texture are very good. Somewhat subdued at the frequency extremes? Bass goes deep and sounds full but something's not quite right down way there, it sounds a little overly warm and compressed. Full-bodied without sounding lush like the LA-150. Drums have the decent transients and tonal balance. Very musical overall - honest, smooth and well balanced. Tends slightly toward polite and pleasant. Perhaps not the very last word in resolution and imaging but absolutely will not offend the ear.
[2] Lightspeed Attenuator
Consistent with careful research, the LSA seems to be a very good match for my system. Sounds way more natural than active preamp. The imaging is back, the bass is tight and clean, the midrange is pure, textured, and expansive, and the highs are crystal clear and never harsh. There is no background noise, no coloration. Seems to have all of the detail and dynamics, doesn't sound lean (at least at moderate to higher volumes). Tends to sound a little better the less it does (less attenuation = turned up = less effect on the signal).
CONCLUSION
I've sold my active preamp. The LSA has earned its place in my system. I may go for a dual unit to regain control over the balance but it seems about right in my system. |
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 |
Wish I could come and hear/see, a little far though 10,000mls. Keep me posted Anthony?
Have fun
Cheers George
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Look forward to meeting you Sam. I will obviously be there all 3 days. |
