What was the output of your low MC's? (maybe I screwed something up, I'm a vinyl newbie) Dynavector 20XL low output version rated 0.25mV. However, mine was going into amps whose sensitivity was rated 1V and 0.7V respectively. As for being a vinyl newbie, maybe I'm mistaking you for someone else, or maybe the vinyl set-up listed in your system is a mirage. However, I've been to that pictured location in San Pedro listed on your system page (I think you've moved since then) and bought one of your two Scheu turntables at the time. Having two of those tables, me thinks you're probably not a vinyl newbie, but hey, when it comes to vinyl set-up we all make mistakes. Try again and see. |
The 0.25mV 103D into my phono pre+active stepup's 64dB gain yielded 0.4V, that just didn't cut it into either of my amps, especially the 1.5V monoblocks.
Looking at those measuremnts you should have had 2.65v output more than most cdp's.
You either have a fauty phono stage not giving 64db of gain, or the cartridge is faulty and not giving .25mv
Cheers George |
09-09-10: Clio09
I have used the Lightspeed with both MC and MM cartridges. No issues whatsoever. With MC I use 68db gain on my phono stage and the Lightspeed is at about 2 o'clock or so on the dial. With MM I use 42db gain and the Lightspeed is at 11 o'clock or so on the dial. What was the output of your low MC's? (maybe I screwed something up, I'm a vinyl newbie) The 0.25mV 103D into my phono pre+active stepup's 64dB gain yielded 0.4V, that just didn't cut it into either of my amps, especially the 1.5V monoblocks. I suppose other important factors would be size of room, sensitivity of speakers, listening distance from speakers, musical complexity, and desired listening volume. |
Anthony, I agree. There are many reasons to own a full-featured, robust active preamp and yes, even the "audio jewelry" aspect is as legitimate as any other reason for prefering a piece of gear.
What I am missing is the "active" argument solely on the basis of sound in a system with appropriate gain and impedance matches. There was some conversation earlier on about "true to the source", and by that I don't mean true to the live event being recorded, but true to everything in the signal coming out of the source (e.g. CD player output) - at least once removed from the live event - but anyway all the rest of the system has to play with. It seems to me that if anything is different, in any way, from the direct connection, it is an artifact and not true to the source. I won't argue that some, many may prefer the sound of those artifacts, and they are perfectly right to choose according to their ears and preferences, what I don't think can be argue logically is that any active preamp, no matter how expensive, can be as "true to the source" as the Lightspeed Attenuator (assuming proper gain and impedance matches). There may a difference in preferance based on accurate versus pleasant, and we are all free to choose the camp that makes most sense to us, and that choice can't really be argued with. I would though argue that a neutral preamp can be mixed with the widest range of sources and amps, which are then left to present their own sonic signatures. |
Great sound does not have to cost a lot. Great looks are nice to have, but it doesn't necessarily equate to great sound. Convenience seems to be something many audiophiles want, but a remote or multiple inputs can do more harm than good. Tubes are fun to play with, but can inject noise or colorations.
We get to make our choices and we get to live with the results, for better or worse. |
I have used the Lightspeed with both MC and MM cartridges. No issues whatsoever. With MC I use 68db gain on my phono stage and the Lightspeed is at about 2 o'clock or so on the dial. With MM I use 42db gain and the Lightspeed is at 11 o'clock or so on the dial.
I have even used the Ligtspeed with an amp whose input sensitivity is nearly 3V. I even doubled the sensitivity to nearly 6V and in both cases the Lightspeed worked fine. at 6V I was pretty far around the dial, but that is what the amp manufacturer recommended having tested a Lightspeed on his own. |
09-09-10: Georgelofi
Strange? I have lots of Lightspeed Attenuator customers that use vinyl with low output moving coil cartriges, all they have is a good phono-stage like the Tom Evans and then Lightspeed Attenuator directly into their poweramps, and they are at 12o'clock on the Lightspeed for good loud level, with plenty headroom left in reserve, they say it the best they have ever heard their vinyl sound. It just so happened that my active stepup(+22dB) amp and phono preamp(+42dB) were just a little short when it came to overall gain using my Denon 103-D(0.25mV) and Grado "The Statement" (0.5mV). It was possible to use the Grado with my PX-25, but but not with my 300B monoblock amps(1.5v) and other amps. Obviously, there are other phono preamps with more gain, but I really liked the performance of mine(+TVC) with higher output carts, at the price I paid for them. |
So it seems that true to the source (or at least to the output from the CD/DAC with no impedance mismatch)has to be the standard and that any alteration caused by even the most expensive and sophisticated active preamps is an alteration having nothing to do with what is actually on the recording, not part of the music as recorded, and yet there is an enormous contingent of folks who swear that the passive approach is missing something (staging, PRAT, warmth, etc)that the actives, especially tube actives, provide. But logic seems to dictate that whatever is being heard through the actives simply is no part of the recording, it is coming from somewhere else, a distortion of the signal seems to be the only thing to call it. Any yet, many seem to prefer it, but true to the source it cannot be, or so it seems. Now maybe it is a matter of not being able to take the truth, and pleasant alterations are what people prefer. Ken Stevens of CAT once said he wanted his preamp to have the sound of water, no coloration, clear, transparent. The Lightspeed seems to meet that goal, as long as gain and impedances are what they need to be, if they are not, than an active is needed or the "direct connection" won't work. I do know it is hard to accept that a "simple" attenuator can possibly be better than a 50lb, $10,000 preamp full of stuff, and there is nothing in the LSA nearly as endearing as a NOS Amperex tube. |
09-09-10: Darkmoebius But, it did pose a problem playing vinyl w/ low output cartridges. I needed the extra gain of an active preamp or a phono pre with a lot more gain.
Darkmoebius
Strange? I have lots of Lightspeed Attenuator customers that use vinyl with low output moving coil cartriges, all they have is a good phono-stage like the Tom Evans and then Lightspeed Attenuator directly into their poweramps, and they are at 12o'clock on the Lightspeed for good loud level, with plenty headroom left in reserve, they say it the best they have ever heard their vinyl sound.
Cheers George |
09-06-10: Georgelofi
Plug your CD player or dac directly into your poweramp "this will be a perfect impedance match" As you have no volume control, first off play something that is low in level to gauge how loud it will be, doing this you are playing the "truest" form of cd/dac playback you can possibly get. Then slip the Lightspeed or any other pre active or passive back in adjust for the same level, and you will see and hear which one is "truest" to the source. Great point, George! I actually did this years back with a borrowed Museatex Bidat when comparing my TVC to some active pre's I was considering. The Bidat(300ohms/3.5V RMS max) went directly to an Art Audio PX-25(180k/700mV/6wpc) SET amp driving Cain & Cain IM-Bens(~95dB/8ohm). Obviously, I preferred the passive route. But, it did pose a problem playing vinyl w/ low output cartridges. I needed the extra gain of an active preamp or a phono pre with a lot more gain. |
Sounds like the Bolero Test by Arthur Salvatore, which also concludes that if ANY active linestage sounds better than a passive there is an impedance mismatch and the system NEEDS a an active stage. In his view, there is no better connection between a source and amp than the direct connection, and then a passive preamp. Hard to think that all those beautiful tubes in an active tube preamp does not bring beauty and flesh, etc - but it does not seem that any of that is actually in the recording (as the direct connection makes perfectly clear). |
Darkmoebius
As we all know, it is almost impossible to know which component is "true" and others are additive, or subtractive(except for truly bad components), unless one was present for the actual recording session. As to knowing what is the "true" amount of soundstage width or depth on a myriad of recordings, I think that would be an impossible task.
In reality, any preamplification is probably "truest" if it helps bring the listener a deep emotional connection to their music within the context of that listener's musical preferences and system/room acoustics. Nothing else should matter, in the end. Darkmoebius
Thought I'd chime in on this one being the manufacturer of the "Lightspeed Attenuator".
Hi Darkmoebius, welcome to the discussion, you used the magic word "truest" twice in the above reply. Having not yet heard one for yourself, can I make a suggestion to get the "truest" idea of what pre/amp passive or active is "truthful" to the original recording.
Plug your CD player or dac directly into your poweramp "this will be a perfect impedance match" As you have no volume control, first off play something that is low in level to gauge how loud it will be, doing this you are playing the "truest" form of cd/dac playback you can possibly get. Then slip the Lightspeed or any other pre active or passive back in adjust for the same level, and you will see and hear which one is "truest" to the source.
Cheers George |
I enjoyed reading that, well said, and certainly the issue of what gear will connect the listener to the music is as varied as there are people. As far as soundstaging is concerned, what I do notice with the LSA is that the apparent soundstage seems to change quite a bit from recording to recording, which I suspect is a good sign that the LSA is making and effort to "get out of the way" between source and amp. I also notice, as Clio9 suggested, that instruments do not seem to be oversized or stretched as often occurred with Patricia Barber's piano with some other very fine preamps I have owned. I don't know if you took 10 audiophiles and had them compare the LSA to, let's say, the ARC Ref5, how many would choose one over the other in blind listening, and both can certainly make for an excellent sounding system. But the fact that you could make the comparison tells you just how good the LSA (and other passives - I too have followed a similar path, Placette, K&K, Bent AVC, etc)are in the right system. Will prefer them to fine active preamps? Only listening will tell and I'm sure there will be those that walk out of the room with that Ref5 in tow. |
09-05-10: Clio09
Yes, the sound stage and imaging manipulation that active components and even some cables add to the equation is very evident after listening to a passive preamp in the system. I would agree that the LSA does not have the spatial capabilities of some other active preamps, but I'm fine with that as it does reproduce the music in a truer form. This is not meant to be to be an attack on the Lightspeed or any other optocoupler, but more a statement about overall component dedication. Almost all devotees of a particular type of component swear theirs presents a "truer" form of reproduction. I can remember the long, long, threads dedicated to Placette's passive(resistive) units and how they were the ultimate of transparency and everything else was simply distorted. Then came the Transformer Volume Control(TVC) adherents, of which I am one, swearing theirs bested all others and were the truest form of reproduction, soon to be challenged by the Autoformer crowd for that title. And all of these camps heaping scorn on solid state, tube, and hybrid active preamplification for being "colored", "distorted", etc, etc. As we all know, it is almost impossible to know which component is "true" and others are additive, or subtractive(except for truly bad components), unless one was present for the actual recording session. As to knowing what is the "true" amount of soundstage width or depth on a myriad of recordings, I think that would be an impossible task. In reality, any preamplification is probably "truest" if it helps bring the listener a deep emotional connection to their music within the context of that listener's musical preferences and system/room acoustics. Nothing else should matter, in the end. I'm not sure who it was that said this, it was a reviewer I think, but the point was that the sound stage should not extend beyond the speakers. I think I might agree with this thinking. Depth and height, as well as space between the performers are another matter though. I would think this would be an oddly distorted "view" of a recorded performance. Most live, and even studio, venues are wider than the average 8 ft that speakers are apart. Recreating a symphony into an 8 foot space would itself seem to be a artifice equal to one that extends beyond the speakers. Neither is being "realistic", but closer to scaled down versions of reality. Much like the difference between watching movies on a 40" or 65" screen. Having said that, Lightspeed attenuators have fascinated me ever since the first threads started appearing on DIY Audio years ago. I would love to hear one in the near future, but my next system will be (hopefully) all balanced/differential with sources and preamp across the room next to my listening position and the amps/speakers on the other end. This could end up being quite a long distance. |
Yes, the sound stage and imaging manipulation that active components and even some cables add to the equation is very evident after listening to a passive preamp in the system. I would agree that the LSA does not have the spatial capabilities of some other active preamps, but I'm fine with that as it does reproduce the music in a truer form.
Hanging out with a recording engineer of late, I have learned that most of what we perceive to be the sound stage created by our systems comes straight from the recording. Room acoustics play another part, as does speaker placement. I myself dislike hearing a drummer whose arms appear to be 8 feet long, or a piano that appears to be 12 feet wide, or a vocalist whose mouth appears to be a 3 foot round oval. Too much for me. I'm not sure who it was that said this, it was a reviewer I think, but the point was that the sound stage should not extend beyond the speakers. I think I might agree with this thinking. Depth and height, as well as space between the performers are another matter though.
I have a couple of compilation discs from Ridge Street Audio that offer excellent recordings where the sound stage is well reproduced. I made some copies for a friend and he commented on the improved depth of the sound stage he heard with these recordings. He seldom hears the same level of depth with other recordings. Goes to show what can happen when the recording engineer is paying attention.
The Truth awaits us... |
I meant to say not very dimensional as recorded. |
Robtn, obviously I could not agree with you more. It was interesting to hear you say, "I mentioned to Mr. Harley that when I read Jonathan Valin saying he misses the "bloom" and "spaciousness" of tubes, with ANY piece of equipment, I cringe. If I want to hear phase manipulation or harmonic distortion, etc., increasing the stage depth and image width, it ought to be on the recording, not being created by my components" because I recently heard from a well-regarded Audiogon member who told me that he has a shoot-out of sorts with LSA and 4 or 5 very highly regarded tube preamps (really good line stages)joined by a group of audiophiles. While they felt the LSA was very good in terms of clarity and transparency, the one area they felt it fell short was in this very area you mention related to spatial representation and dimensionality. But this must really be an issue of preferences as I too get the sense that what imaging is there should be real and from the source and not what you might describe as an artifact, a distortion of sorts. To me, the LSA sounds like what I am looking for, but obviously it might not be everyone's cup of tea. As you point out though, for $450 or so, it is well worth trying without too many preconceptions about tube/ss/passive and just listen, for some listeners, especially those with tube amps the LSA might be as good as it gets. Listened to SACD version of Adderly Somthing else - incredible timbral accuracy, dynamics, and resolution - but a very dimensional recording as recorded. |
I've contacted RH at "tas", and raved about the Lightspeed. I have had both SoundLab electrostatics, and Magnepan 20.1's, and I am after purity, with no added colorations. I have owned several amps of different circuit designs and preamps, tube and transistor, active and passive. The Lightspeed in the audio chain is non-existent, everything that's on the recording is there, nothing more, nothing less ... perfect. I mentioned to Mr. Harley that when I read Jonathan Valin saying he misses the "bloom" and "spaciousness" of tubes, with ANY piece of equipment, I cringe. If I want to hear phase manipulation or harmonic distortion, etc., increasing the stage depth and image width, it ought to be on the recording, not being created by my components. I see this elsewhere in criticisms of passives, and amplification in general. If someone wants to alter what the recordists have compromised, then, an equalizer is in order. The real music is At The Venue, anyway. It's pretty disturbing, as well, to think what monitoring speakers or headphones recording engineers may be relying upon to record in analogue OR digital. As an insane lover of this hobby, and an ex-musician in love with music, I know that the sound I'm getting also relies on the careful system matching of associated equipment (which is equalization of a sort, in itself, but those pieces have inherent sounds of their own, unlike this attenuator) ... interconnects, amp circuitry, speaker transducers, "wall-power" purity, transport or turntable mechanisms, server quality, ad-infinitum. The Lightspeed may have it's own system-matching limitations, but it's absolute transparency is exactly what I want any component to emulate. No sound of it's own. If I can't be at the performance, I'd like the source recording to be good enough to allow me to enjoy the music. I hope the Lightspeed gets into homes where it is understood and appreciated. This thing is a treat, absolutely incredible, and the price makes it affordable for just about anyone. |
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The battery is plug and play. The link to the connectors show several. The one I indicated is the one you want. It is center pin positive. Most are default that way, but you need to be certain as reversing the polarity on yours with a center pin negative connector will damage it. The information for the one I referenced says it is "inside positive" which means center pin positive. Buy this one with the battery and all is plug and play. |
Hi Anthony. I meant the battery and connector you provided links to. Would it be a plug&play purchased as is? In terms of the negative/positive pin issue? |
Thanks Pubul57 and Clio09. My amp has input impedence of 47 KOhms and input sensitivity of 1.27 Volts rms, my source has a output impedence of 120 ohms and output voltage of 2 Volts. It is close to what you and George S. recommend so it should work. If not it might be time for some newer items, mine is over 20yrs old. It sounds like this could be a great reviewers tool? Thanks for the input. |
Marqmike: The amp should have greater than 50k input impedance, more is better. Input sensitivity isn't as critical. Typically 1V or so would suffice, but I've run my LSA with an Atma-Sphere S-30 that is nearly 3V sensitive and it works fine. I even tried it by altering the amp to be even less sensitive (nearly 6V) and it was still fine, although I was running out of room to advance the volume control. It is also important that your source output impedance be low, 100 ohms or so, and have enough output voltage to drive the LSA, 2V or more.
As mentioned, you need to worry more about the amp/speaker combo when deciding what components to use with the LSA. Given that the above requirements are met, the LSA is benign in the scheme of things. |
If you buy this off the shelf, is it center pin positive by default? If you buy what off the shelf? |
I would say any tube amp you like with 100kohm input impedance and input sensitivity of 1v or lower. The rest is dependent on whether or not you like you amp/speaker combo. |
This kind of shared info is greatly appreciated. I am getting a LSA, and I don't even know if it will work. But I use a passive now(Sumo Athena in passive mode with a Sumo Polaris amp, it has about half the gain than the active side but sounds better), so I am hoping it will. What I would like some of you with experience with the LSA to share and keep going with this thread, what is a good(excellent sounding) amp and cd player to use with the LSA specifically? When I get mine and use it I will give my thoughts. Thanks. |
Oh yeah, and we eagerly await your The Truth comparison. |
If you buy this off the shelf, is it center pin positive by default? |
Mine was made center pin negative because the wall wart George recommended was set up this way. For the battery power supply you can find it here: http://www.sears.com/shc/s/p_10153_12605_02871486000PThis will allow the Lightspeed to run much longer than the Lithium Ion George recommended. You will need an adapter cable that plugs into the 12V DC outlet on the unit. Here is an example of one (although they are sold elsewhere too): http://www.minute-man.com/acatalog/Online_Catalog_Cigarette_Ligher_Plugs_and_Sockets_272.htmlYou need to scroll down the page and look for: Power Plug with 2.1mm X 5.5 mm Coaxial Plug with 18 AWG 8' Cord Item: CA205MCIGF8FT18AWG The cost is $5.95 Just make sure it is center pin positive. This battery power supply and the adapter cable are used to power the motor pods of Galibier Design turntables. These aren't inexpensive tables so I trust Thom's choice in parts. Thom procured my cable and wired it for center pin negative. |
Anthony, is you battery charger commercially available? Have a link? Also, what about the point George raises regarding the Center positive/negative? |
I also use a Lithium Ion rechargable sometimes, I hear a difference but cannot pinpoint what it is, even on a very hi rez system.
They say the Lithium Ion has the least chemical bubble noise of all batteries. Sometimes I forget which one I have on, the battery or the wall wart it's that close.
You can get these batteries on ebay from Asia for around $20 with international charger, do a search for Lithium Ion 12vdc rechargable usually made for cctv cameras were low noise is a must, just make sure it's center positive for all the production Lightspeed Attenuators I have made as I do not want to have to repair fried componets if I can help it. Yours Clio09 is the only one I think I made center negative I forget the reason why. They have about 12hrs constant use before a recharge of .5hr
Cheers Georgehifi |
I just started running the Lightspeed off a battery power supply. It is the same batter power supply used by Galibier Designs to power their turntable motors (Sears Diehard Portable Power 750), 12V DC and 12aH. Thom Mackris made me the appropriate adapter cable (mine needed to be center pin negative). I've been listening for a bit now and so far I like what I hear. |
Thanks George. That is pretty much what Roger Modjeski (Music Reference / RAM Labs) said and "I'll make you a preamp with a buffer, but you don't need it and it will sound better without it". Now Roger is a guy I pay attention to, he is an electrical engineer, make classic and much admired amps and preamps, and is a tube maven - he also is aghast as audiophile tomfoolery and nonsense. I've been drawing the conclusion that active preamps and even buffered or transformer based passive will sound better than a pure passive when the system needs it, and many do when the impedance and gain issues are not properly addressed, but that in a system metting the requirements for a passive (without buffer - not the Pass, The Truth, etc)something like the Lightspeed will provide the very best possible sound. It will be interesting to hear Anthony's observations of The Truth, since I do think his system is a good setup for a "pure" passive. |
About buffers, I will always say the best buffer is no buffer if your system meets the following impedance requirements. If your source output impedance is less than 200ohm and your poweramp input impedance is more than 47Kohm then the Lightspeed Attenuator is a shoe in, no buffer will sound better.
But if your source is more than 200ohms output impedance or the power amp is less than 47Kohm input impedance then you may (but not always) need a buffer, the best commercial buffer I've heard is the Burson Buffer. But the best sounding buffer is the (diy) Super Linear Cathode Follower (SLCF) buffer. But still they don't sound as good as NO buffer at all.
P.S. those who want the circuit of the SLCF send me an email
Cheers George |
George, obviously you could have made a buffered version of the Lightspeed, what are the pros and cons to that approach. What are your thoughts on buffering? Go Spain!! |
What I am most curious about is how well The Truth preamp will drive the S-30. The LSA does drive it well, but I'd like to hear if The Truth will improve upon dynamics. The bandwidth measurements are off the charts with the Truth and the output impedance is a constant 2 ohms. Apparently the input impedance is too high to measure.
No risk to try it so we'll see. |
Anthony, I've read the threads about The Truth preamp and it does seem to employ a similar "volume control" as the LSA (photo cell versus optocoupler, not sure if that makes any audible difference)along with input and output buffers. When I spoke to Roger Modjeski about his passives, as you know he has a plain Pot-in-a-box and also makes a version with a tube buffer stage, I asked him if the tube buffer version would be better, he said only if you need a buffer, otherwise the the the version without a buffer would be better. So it will be interesting to see what you find when you try The Truth. I suspect that since my system is in no need of a buffer, the LSA would like be the better choice. It does not seem like you need a buffer either, so your observations apart from "theory" will be interesting to hear. |
So we wait Clipsal for the system context for you B1/LSA "shootout". Also for Anthony's assessment of The Truth preamp, which seems to be a hybrid between some of the desing principles of the B1 and the LSA. Other passive comments (Goldpoint, BENT, Prmoethius, and other resistor, TVC, and AVC comments welcomed). In my system with Music Reference RM10 and 9, the LSA is the best passive I have heard, and I have tried most all but for the B1 in my system at home. |
We're back, thanks Audiogon support. |
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Why doesn't this link show up in the forum section any longer? I had to do a search to find it. |
Clipsal
I also would like to know the poweramp used in this shootout and also the CDP or DAC.
Cheers George |
Not joking, but of course system matching is key as Anthony. Love Pass gear, and heard the B1 at RMAF and it was very impressive. But so was the Bent TAP-x and I prefer the Lightspeed in my system since it is ideally suited for a passive with no impedance or gain issues - and far simpler device for minimal distortion. I have no doubt the B1 will perform better in some systems than the Lightspeed, but the reverse is true to, and then there is personal preference which is more difficult, if not impossible to account for. |
Clipsal, what were the other components in the system in which you heard the shoot out?
The B1 is an excellent product. Nelson Pass also has published schematics for his own version of the Lightspeed. My take on his development of the B1 is that through the use of an active buffer stage the preamp matches up much better to the low input impedance First Watt amps he designs. |
You must be joking. I've just heard the lightspeed attenuator in shootout with the Firstwatt B1 and the B1 killed the lightspeed in terms on dynamics. In fact I could not recall a single aspect where the lightspeed would be better. These are my thoughts only and do not necessarily represent others. |
Hopefully will have it in a few weeks. Ed Schilling at the Horn Shoppe builds them one by one and he has a bit of a back log right now. I'll probably start a new thread at some point in the future to provide some feedback and comparisons. |
Anthony, let us know your impressions when you hear The Truth preamp. |
I heard a Redgum integrated recently, it sounded quite good and was well built. |
06-19-10: Pubul57
With quality products like Supratek and Lightspeed coming from Australia/Australasia
For the amps list you should add: Halcro, Cymer, ME, Asaka, SGR, Redgum, Electra, Amber, Earl Weston, Aspen, Plinius (NZ), Perreaux (NZ, )
Just to name a couple
Cheers George |
We just let you guys in the Northern Hemisphere do all the groundwork ...... :-) |
