Lightspeed Attenuator - Best Preamp Ever?
I just saw in your previous posts that the capacitance you have is so small on both cables it does not even factor in which goes after the Lightspeed. As the Blue Jeans at 2ft you have at 13pf per foot will be -3db at 874khz!!! And the Bryston cable you have at 3ft at 21pf per ft will be -3db at 541khz!!! As you can see it will not matter as far as the -3db roll off point, just what you prefer the sound of in which position. Cheers George |
Bought mine at Sears: http://www.sears.com/diehard-gold-portable-power-950-with-jumpstarter-dc/p-02871987000P They have less expensive ones too. I bought this one because it powers my LSA and phono stage. You need an adapter cable but they cost around $5. Lasts for weeks without a charge. |
You could for comparison against the wall wart use one of those small square Duracell 9v Alkaline batteries, or even a rechargable one, it will probably last for 24hrs. Just wire up a 2.1mm dc plug to it (but please make sure + positive goes to the centre of the plug) Anywhere between 9v-18v dc is fine, as inside the Lightspeed Attenuator there is a second regulated supply that regulates everything that comes into the dc socket down to 5vdc. Cheers George |
If anyone is a little put off because George says the LSA is sensitive to the length of interconnect I can state that my 20 ft interconnect doesn't present a problem. There is no lack of clarity, no loss of treble or bass and no loss of volume. It sounds like the 1 mtr Nordost I had been using. So if you think you need to invest in a special interconnect to get the most out of the LSA,give it a try with what you have. I don't know what George will have to say about this, but a long interconnect going out of the LSA to the amps is not a problem for me. |
I'm very conservative with that statement just in case the interconnect is poor quality high capacitance. I call it like it is and don't try give best possible scenarios only. Here is a simple semi technical explanation. In your case with 20ft, lets say that the cable is good quality and low capacitance, a nice low capacitance figure would be 10pf per ft, with your 20ft that is total 200pf. 200pf connected to the output of the Lightspeed Attenuator makes a high frequency filter of -3db at 114khz. No problem as you can see way higher than our best human limit of 20khz Double that 20ft of cable capacitance to 20pf per ft and the -3db is then at half the above at 57khz still no problem even 20ft of interconnects. Halve the length to 10ft and then your back to -3db at 114khz way out of the audio band. Halve the capacitance to 10pf and your at -3db at 228khz!!! bat territory Cheers George |
Thank you George,my intent is to let people know that your volume control isn't going to do nasty things if someone uses cables that are a different length from what you suggest. I admit I was hesitant to try this configuration,but I wanted to remove all the gear from between my Acoustats,and long interconnects was the only way to do it. The results have been terrific, nothing was lost and more was gained. So, if interconnect issues and cable lengths are holding you back from trying the LSP,don't let that stop you from giving it a try in your system. I run an Esoteric cd/sacd into it with short DIY silver/copper interconnects and out to the power amps with 20 foot quasi balanced RCA DIY interconnects,the type of wire is unknown to me,made for me about 20 years ago.Nothing fancy,especially the RCA's. The LSP is not a component that requires the owner to only use a specific type of cable as some gear specify. Nothing will be damaged,treat it with the same type of wiring and respect as any other pre-amp. Now I am left with the audiophile's curse of wondering how much better it could get with some name brand 20 foot interconnect. Fortunately/unfortunately, there's not a lot of the good stuff out there to try in 20 ft lengths. |
King, The LAS did a way better job of letting me hear my Lamp L5 than the Placette. My goal here is for the VC/pre amp not to alter the sound of this great 3D sounding Dac. I am sure an active pre would give me a more .... Sound and add to the mix but the L5 has enough of all that so there is no need to add any other ingredient to the system. The LSA is noise free and simply passes the L5 sound to my amps. I have a 3D sound stage if it's recorded as such. Not flat or 2D as that is not what the L5 is about. So the LSA guy is giving me the Lamp sound I know so well that the Placette just couldn't do. So I hooked up some ASI LL SC/IC's to my system and it was an ear opener. I will keep them hooked in as they work well with my amps/speakers. |
UPDATE: New Amplifier in my rig So on a whim, I decided to try out the Nelson Pass First Watt J2 amplifier at 25 wpc. I was concerned about the volume levels but no problem watt so ever with the J2. Actually, the LSA works smoother than with my Bryston 4b SST amp. It is a great combination and I could not be happier. Th J2 itself is such a nice amp, so smooth yet detailed and 3D imaging and the sound at low volumes is so much better than with the Bryston. |
Those who have a Lightspeed Attenuator and wishing to try a different power supply instead of going battery. I've been shown this quite reasonable priced one which is a nice linear regulated product. 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. http://www.ab-system.hk/index.php?route=product/product&path=73&product_id=64 Cheers George |
No I have not tried it, but I have compared pure battery power to the standard supplied power supply, and the difference is subtle, you can't put your finger on it, that subtle that you forget which is on. I posted this power supply as it looks impressive for the cost, and looks to be very very well made both in circuit and appearance for the money. And you get a bonus with it, a well regulated linear USB 5v supply. But no I have not tried it, but you know what audiophiles are like, especially with power supplies and plug in tweaks that don't cost the earth. http://www.ab-system.hk/index.php?route=product/product&path=73&product_id=64 Cheers George |
Thank you George,I have just ordered one. Compared to the walwart I've been using, this looks like a very well made piece for reasonable money. I have been very pleased with the performance of the LSA as it is,this looks like it should improve things even more, and if so I'll be quite the happy camper. |
It is nice to hear ones having success with a passive. I think it takes time and patience to adapt it to a system. This might be quite contrary to what one might think but I think I have found that the more neutral and clean sounding cables are(or I should say what I consider a neural and clean cable because I don't pretend to be a cable expert), the more warmth and fullness in a recording comes out(I am supposing that only if it is on the recording because the LSA doesn't add anything right?). At least that is kind of contrary to what I thought. When I say neutral I don't mean lean or edgier or brighter, I mean what I perceive as a cleaner signal. In fact is seams like the cleaner the signal (less distortion?) you have from source to speakers the better the passive's strengths show. I guess I am saying when a signal doesn't get as muddied up? Just my take but I thought I would share, it may help someone else. |
$59.00 US dollars to my door. $15.00 of which is shipping. I used Paypal so a little extra charge on my final bill. Isn't this hobby all about improvement? That's why I ordered the unit,hoping it will improve the sound of the LSA. I am pretty sure it will do something,comparing this to the wallwart I was using is like comparing a model T to a modern Bugatti. The power supply improvement is not denoting a flaw in the LSA. The owner has to provide his own PSU for the LSA unit,and a 10 to 20 dollar walwart will work,like I said. THis robust little beast hopefully will unlock the full potential of the LSA. If adding a little salt to the soup makes for a better meal than I am willing to go that route. Nothing in this hobby is perfect. Everything can be made to sound better or worse than it is. Doesn't matter who built it, where it's built or for how much it cost to build it. Please,just allow me the option to try to make an improvement. Thankfully the LSA allows one to experiement with PSU, and doesn't tie you into what one fellow feels is the only way to go. |
The LSA arrived a few days ago. I had high hopes, as it appeared that my new DAC (Lampizator L4 with USB and native DSD) sounded strained with my (modified) Cayin A-88T integrated amp. The problem appeared to be the incompatibilty (soundwise) with the its preamp. I found this out by taking a flac file, reducing its volume using Adobe Audition, and playing the low-volume file directly from the DAC to the Cayin power stage. Everything resolved, everything opened up! Now with the LSA it sounds just like that: open, musical, detailed and non-fatiguing, but with the added benefit of a volume control. It does not only sound good, but also feels good, knowing that the LSA does not mess with the signal... A wonderful addition to my sound world... And doing business with George was a pleasure! Dennis |
Just wanted to say that I'm still happy with my Lightspeed Attenuator. I plan on never getting rid of mine, and in fact, I'll probably buy another one when I build a second rig. Thanks again George, you're a trooper to still be active in this thread as I'm sure you've answered every question 3 times! If you quit, I'm sure no one would blame you and I'm sure you'd still be selling Lightspeed Attenuators, as they kind of sell themselves. Incredible product, ridiculously low priced for what you get! |
I guess I'll go first. I received the TeraDak power supply today and played with it for 3 hours or so. The first thing to note is that it works as it should. That's more than can be said for the battery I ordered for the LSA when I first got it years ago. That died within minutes. The unit comes well packed and looks decent enough. Mine came with 3 wood isolation cones and corresponding supporting wood disks. That was either a mistake or a surprise New Year's gift, because I didn't order them. The cones are quite nice so I stuck them on the unit with some blu-tac. It doesn't come with a power cord so I used one that was just ready to hand. The second thing to note is the retina destroying red indicator light on the front panel. Damn that thing is bright! That thing needs to be covered up. I left the unit powered up but unused for about an hour as I acclimated to the sound of the LSA with wallwart. When I switched over there seemed to be a significant attenuation of volume. I checked with my trusty radio shack db meter and, as far as it can detect, there was no change. Puzzled, I continued to a/b the two power supplies for the next two hours. Looking back, I believe the sense of volume attenuation was due to the decrease in distortions caused by the wallwart. The teradak smoothed out distorted peaks and thus gave the appearance of being softer in volume. It gave me the desire to turn up the volume. Another thing I noted was an increase in transparency. This was evidenced by how much more clearly enunciated were the words of songs. There were possibly other changes as well, e.g. in dynamics and soundstaging, but I didn't have a chance to fully explore those. Obviously, a couple of hours is insufficient to draw any definite conclusions. Nevertheless, I'd be surprised if someone said they couldn't hear the difference between the teradak and the wallwart. Unlike with reports involving battery supply/wallwart comparisons, the differences noted here are not at all subtle. And I am not in any way a power cord guy. My few forays into after market power cords have ended in disappointment. For $60 this thing is a no brainer in my book, if only to mess around with a new toy. I believe it improves on the already stellar sound I was getting, so it is for me better than just a new toy. YMMV. Needless to say, I have no affiliation with the Teradak's maker. |
Hi Banquo363, that's great to hear, but I am a bit shocked at the amount of difference you heard. Are you in the US or Canada? Is it possible the 110v wall wart you have is a SMP (switchmode)? As I cannot supply 110v wall warts to the US. I only supply my own linear wall warts to 220-240v countries. If your 110v wall wart is a smp (switch mode) then this would explain the big difference you heard, as they are very dirty, even though regulated, and can radiate their crap right through the system, even via the air. Cheers George |
I'm in the US, George. I have no idea what kind of wallwart I have, nor do I remember how I came to acquire it (or whose advice I sought). I certainly had no expectations going in, so I myself am surprised by the differences I heard. But I used it for only a short bit of time; and, who knows what psychological forces are at work when auditioning cables and whatnot. I will be fully prepared to see it as an illusion, albeit a delightful one, if this weekend's scheduled round of testing reveals it to be so. I'll see. And thanks for making us aware of the product, George. It's a nifty piece of gear. |
Hmmm, Interesting. I'm a believer in upgraded power cords, power supplies and outlets but I can't see how this could make the lightspeed sound better. Correct me if I'm wrong, George, but the light in your Lightspeed Attenuator is really only controlling volume, right? I don't see how there could be "dirty" light.... I'm confused, but if Banquo continues to hear a difference I'll give it a try also. |
Banquo363, you can tell a smp wall wart a couple of ways. One is they are half the weight of a linear, but if you don't have a linear to compare it to then that's hard. The other way is to get an AM radio and go near it tuning up and down the am dial, you will hear it if it's an smp. Another way is that they have nearly 2 or 3 times the amperage ratings for the same given size of linear wall warts. Cheers George |
B_limo hi, the smp high frequency rubbish gets into everything even the grounded chassis, interconnects, input and output, even your amps and source can get it via the wiring or even through the air, especially if it's a bad designed one. The AM radio trick (above) will really give you a big shock about the run of the mill smp wall warts and why the high frequency rubbish is like a cancer for hiend audio. Cheers George |
Banquo63: I did a quick search, very hard to find linear ones as they never state if it smp. These are the parameters you should look out for. 1: 9vdc-18vdc linear 2: can be regulated or unregulated as the Lightspeed Attenuator has it's own internal 5v regulator. 3: 200mA or higher 4: plug has to be centre positive and 2.1mm x 5.5mm. I quickly found these in the US via a Google search. http://www.jameco.com/1/1/51493-adp2108gt-2-1-9v-dc-unregulated-wall-transformer.html http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_2192712_-1 http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_null_2197484_-1 And these from Part Express, but they don't say if they are smp or linear. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=120-1055 http://www.parts-express.com/pe/showdetl.cfm?Partnumber=120-1100 http://www.parts-express.com/pe/showdetl.cfm?Partnumber=120-1095 Cheers George |
I got my TeraDak just a few minutes ago. No special surprise footers, but the cord they sent to attach to the LSA looks very nice in a retro toatser cord type covering. I'll probably get a lot of guffaws over this next revelation, but the power cord I will be using is a Shunyata Annaconda Helix,which was sitting here doing nothing but collecting dust. I'll report back in a few hours with the initial impression, and no I won't be doing any power cord comparisons, just the sound I hear compared to the wallwart. Getting back to that connecting cord from TeraDak. This by itself is very reassuring compared to the wallwart. |
I've only listened for about 45mins,and just to my vinyl, but here are my intial impressions- More slam,more dynamic, increased bass,increased treble(some sybilance on Graceland I never heard before),a no brainer for the money investment.Perhaps the sibilance has always been there on the Graceland LP,but I've just noticed now with the TerDak. I think this unlocks the real potential of the LSA and anyone who is using a cheap wallwart isn't getting the full measure of their LSA investment. Granted I use a Shunyata power cord and the unit is plugged into a Hydra 8 on dedicated 20 amp line. Some may question the sanity of plugging an expensive power cord into the TeraDak,but until you do you'll never know for sure how much you maybe compromising its potential, just as you are compromising the LSA with a cheap wallwart. I think sometimes the common sense of audiophiles can be a stumbling block.Accepted wisdom is that we should always spend the big bucks on the amps, pre amps etc, and shell out the small change on the stuff that shouldn't make a difference like power cords. I think many a fine low cost upgrade is compromised by the use of even cheaper ancillaries. I think the combination of the LSA powered by the TeraDak justifies something better than a generic cheap power cord. I'll leave it to others to expereiment and post their findings, I'm over the hill with the sound of my set up as it is and have no desire to try somethingelse. The pieces fit and please me more so than I had expected. It's almost like I've added a solid state turbo charger to my tube Acoustat servo amps. In fact I never heard them clip before on the Dafos lp, but clip they did on the big drum crash,eventhough I didn't have the volume any higher than normal, nor did it sound any louder. I think more of the dynamic slam that is on this recording was unleashed for the first time ,so watch out if you have low powered SS amps that might not clip as harmlessly as my amps did. If there is any downside so far it's back to that solid state attack that this power supply adds to my sound. It's very clean,crisp, and fast ,perhaps I'll have less of this when I put the cd player into service and I've run a few days on the unit, so I'll report back then as I said I would. But I would gladly trade this bit of edge if it doesn't go away for the increase in all the good things this unit has done for my sound.Easily worth the trade off, and perhaps just a sign that I need to fine tune my cartridge a bit more. Did I mention the TeraDak is more revealing? Well it is, so make sure your system is up to snuff, because you will not have those nasties buried in the muck a wallwart gives you. That sounds harsh. I really was quite pleased with the LSA and the wallwart. Like most things in this hobby, it's only when you go outside the comfort zone of "good enough"that you find how good can go to great, and in this case, how such a small cash outlay($60.00 CDN)can make such a big improvement. In my system the TeraDak ,cold out of the box,was better than I had anticipated, and I had anticipated an upgrade, but not to this extent. Anyone with an LSA has not heard what their unit can really do if they are using a cheap wallwart. Thanks for bringing this to my attention George,I would put this at the top of your list of power supply options for your volume control. In fact, if I were you I would make it part of the package for North American consumers from you as a low cost option. If you haven't tried it you should. |
