The question is a bit rhetorical. No preamp is the best ever, and much depends on system context. I am starting this thread beacuase there is a lot of info on this preamp in a Music First Audio Passive...thread, an Slagle AVC Modules...thread and wanted to be sure that information on this amazing product did not get lost in those threads.
I suspect that many folks may give this preamp a try at $450, direct from Australia, so I thought it would be good for current owners and future owners to have a place to describe their experience with this preamp.
It is a passive preamp that uses light LEDs, rather than mechanical contacts, to alter resistance and thereby attenuation of the source signal. It has been extremely hot in the DIY community, since the maker of this preamp provided gernerously provided information on how to make one. The trick is that while there are few parts, getting it done right, the matching of the parts is time consuming and tricky, and to boot, most of use would solder our fingers together if we tried. At $450, don't bother. It is cased in a small chassis that is fully shielded alloy, it gets it's RF sink earth via the interconnects. Vibration doesn't come into it as there is nothing to get vibrated as it's passive, even the active led's are immune as they are gas element, no filaments. The feet I attach are soft silicon/sorbethane compound anyway just in case.
This is not audio jewelry with bling, but solidly made and there is little room (if any) for audionervosa or tweaking.
So is this the best preamp ever? It might be if you have a single source (though you could use a switch box), your source is 2v or higher, your IC from pre-amp to amp is less than 2m to keep capaitance low, your amp is 5kohm input or higher (most any tube amp), and your amp is relatively sensitive (1v input sensitivity or lower v would be just right). In other words, within a passive friendly system (you do have to give this some thought), this is the finest passive preamp I have ever heard, and I have has many ranging form resistor-based to TVCs and AVCs.
In my system, with my equipment, I think it is the best I have heard passive or active, but I lean towards prefering preamp neutrality and transparency, without loosing musicality, dynamics, or the handling of low bass and highs.
If you own one, what are your impressions versus anything you have heard?
Is it the best ever? I suspect for some it may be, and to say that for a $450 product makes it stupidgood.
This thread has had 18 million views... that is nuts.
I had a lightspeed years ago. Should have never sold it. They are the best preamp for the $ no doubt. It really does just get out of the way of the signal. You do need proper gain matching but if you have that, a good dac and a good amp, the lightspeed is just awesome.
Got one of George's Dual Vol units a few weeks ago. Been doing some casual and a little critical listening (don't do much of that anymore, can't enjoy the music) over the last week.......what can I say....there is sooo much detail coming from my system with this unit, it is certainly highlighting ordinary recordings that I thought previously were ok. On good recordings bass seems tighter and more detailed and in particular vocals and drum kit are crystal. As George mentions above, this is about as "straight wire" as you can get. Currently running with a JOB225 power amp; Audioengine streamer and pair of Elac B6 speakers. Seems a good match for the JOB. Am going to switch out my MF tube X-Pre and run the X-A50 momoblocks with the Lightspeed and see how it goes. Thanks George. Cheers, John
ledoux1238 Does it come in a dual volume pot arrangement?
Yes it does, it’s a $35 option, and is good for recording, room or system imbalances, also great for vinyl, as I never seen cartridges that have perfect channel balance. It’s all in the sales/pricing info I send in emails to customers, if you want it send me an email to georgehifi at optusnet dot com dot au
I am late to this thread and I have not gone through all of it. But I have just one question which might have been covered, so please excuse me for repeating:
Thank you Sean for the very favorable mention of the Lightspeed Attenuator. I just had a good look at these highly regarded Linkwitz Labs speakers of yours, very elaborate for a diy'er to do, one needs to be on the ball to make these. (and have some time on their hands). https://www.linkwitzlab.com/LX521/LX521_4.htm
The best preamp I have used.
I thanked Georgehifi from the bottom of my heart for the Lightspeed passive preamp. It really elevated my system which comprises Sony HAP Z1ES for transport and LX521.4 speakers. His preamp is the best thing that I have ever done for my system. It has made my system so transparent, clear, and luxurious. I cannot imagine any better preamp ( my experience is obviously rather limited but I just cannot imagine anything better) and I deeply thank you. I certainly do not need to upgrade my preamp.
brewmasterdon Reading this makes me want to stick a finger down my throat. There are probably some people after the first comment who might consider me a troll. If I continued making many comments over and over with no relevant experience to offer to the original poster’s question, I’m sure there would be more and more people who would think that I’m a troll
Self confessed troll, you need to be banned. Maybe you should stick your active preamp down your throat instead, it probably fits.
1. I think Lightspeed Attenuator is not an accessory, but a MANDATORY component for most audio systems because the difference is unbelievable.
2. I believe that DUAL volume control is a MANDATORY. It is very useful not just for vinyl records (which half of audiophiles don't use), but nearly for EVERYTHING: to compensate room settings; to compensate your sitting position; to compensate inferior audio recordings (common); inferior sound recording in movies (very, very common).
I
am so impressed with Lightspeed Attenuator. HUGE
sound improvement!!
With
80-85% of regulated analogue output on Oppo UPD-205 player and around
11-12 clock on Lightspeed, I am getting MUCH more balanced, realistic
and pleasant sound. This is with mild to medium speakers' loudness
which I use 95% of the time. Improvement is very obvious across all
sound spectrum, but is extremely obvious in the voices.
I
always pay paramount attention to the voices. To me, if the voice is
compromised, nothing else matters.
In
comparison, without Lightspeed (or with only 20-25% of regulated
analogue output on Oppo UPD-205 player and max volume on
Lightspeed), the sound is MUCH less articulated, less pleasant and less
realistic. This is very obvious in all sound spectrum, but is
extremely obvious in voices. Again, this is with mild to medium
speakers' loudness which I use 95% of the time.
Blue label on the Lightspeed box is a great match to other
blue lights in my audio. Very thoughtful, George.
Audio
system:
Voltage
stabilizer: Line-R; Cawsey
power cleaner;
Aurealis:
speaker cables and copper interconnects Litz Dragon;
One thing that I didn’t mention, was that xrl only sounds better than se over very long distances. In many cases se actually sounds better, if an opamp was used to make the xlr circuit in your equipment, and you’d be very surprised to know just how many do it that way in many hiend products. .
lordcloud Has anyone made a balanced version? Is it possible to purchase a balanced version?
I've tried many different ways all a compromise, or not reliable over time. I don’t do them and I suggest you don’t use them. It can’t be done reliably in the "purest" way of making the Lightspeed Attenuator circuit that gives it it’s magic, and also ask it to stay in calibration over time. https://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-passive-preamp.html
It can only be done with active force matching circuitry that’s a compromise to the sound in itself, and "can" damage one or more of the 8 led/ldr’s in the long run from over driving them to keep up with the stronger ones. Your better off using xlr to rca adapters as my customers use when they have no rca connections, only xlr, these works great.
roddek6 Non c est bien un des vôtres c est moi qui est rajouté une plaque de bois de chêne pour changer le look, le son est vraiment superbe Bien à vous Rodolphe
OK I understand, each to his own for the look. I’m just glad it wasn’t another clone ripoff on the market, and even using the Lightspeed Attenuator front logo.
Non c est bien un des vôtres c est moi qui est rajouté une plaque de bois de chêne pour changer le look, le son est vraiment superbe Bien à vous Rodolphe
Hi roddek6 From what I’ve been able to understand with the translator, you bought this used and are very happy with your sound. What you purchased is not one of my production Lightspeed Attenuators, but looks to be diy unit that has been made that I posted how to do it many many years ago. https://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-passive-preamp-post924... But it looks to be a close copy of my artwork logo, which makes me wince.
https://www.dropbox.com/s/jjnbp4n98hsovjv/IMG_20181121_174855.jpg?dl=0 Bonjour excusez mon anglais je viens d'acquérir un Lightspeed et j en suis ravi il est alimenté : 100VA Ultra faible Bruit LPS SALUT-FIN R-core Linéaire alimentation/100 w PSU pour audio DC12V En Option Avec affichage. J écoute Qobuz Hi-res avec un bluesound node2, câbles rca maison argent, sur ampli classe D N-core, sur des klipsch Rf7 lll., j arrive difficilement à dépasser midi, les RF7 ont 100dB de sensibilité. Un gars de Cassis en provence en France
I have now had a good listen to my dual mono version of the LSA. To my ears (and friend's and family's) It has bettered the pre-amps i have had in this system so far, including ARC Ref5se (the Ref 5se was nice with the ARC amps i had previously, (perhaps at a disadvantage due to an impedance issue with ARC & Current SS amp ??). Among other great tube pres, I also compared an older SS Pass X2.5 and Bryston BP20.
George was extremely helpful; not just in confirming impedance compatibility with my current equipment, potential PSU upgrades, but also general audio advice and a friendly approach to my many questions.
My Current system is: 0.25mV MC Cart > Herron VTPH2 phono stage > LSA > Gryphon Antileon Signature > Wilson Sasha.
Herron is configured to lower gain 64dB.
Levels are fine, i am running at 12-2 o'clock, or just past half way for comfortable to strong levels. Although my room is not large, there is still plenty of gain available (not from the LSA of course).
I wont go into its sound too much other than to say it seems to have no sound, very neutral and balanced. When i placed other preamps back in to compare it became apparent what colourations those other pres contributed to the sound, some aspects of which were enjoyable of course but ultimately there was too much trade off. I prefer the clean, open, neutral, balanced sound I am getting with the LSA.
Perhaps eventually I will discover a Pre that betters the LSA in my current system, (I'm sure when i do it will be in excess of 20x the price) or i may change a component and find it an impedance mismatch with LSA. However at this stage, with my current setup it is very impressive and very good value sonically.
To go remote, you need the remote, a receiver, the motorised pot and power supply for it. You
need a dual 100kohm Logerithmic pot, and this one is just that, you
could use it in the Lightspeed. (no need to use the input board with the
6 relays, just the remote and motorised pot board with receiver)
I
won’t use them myself because the reliability factor is not there, and
with supply is not there either for me over a long period of time, but
there’s nothing stopping owners from doing it themselves.
As for the used Lightspeed, I’ll PM the owner and see if it’s still for sale.
Glad a search led me to revisit this thread today, had not received notice of replies. Fortunately they had one left lol. Thank You @georgehifi for the info. I will mount it externally, use the same size or larger knob and a rubber band or belt without having to take the LSA out of the chain to work inside of it and risk losing the sound I have now.
Thanks to some feedback, I put an iTube 2 in front of the lightspeed a couple weeks ago and have to say I'm liking it so far! Switched to +9db pure tube buffer mode today and think I'm liking it more. I'm curious if it's best to use it before or after the LSA and if there is an ideal LSA volume position. Without the added gain, I varied between 11:00 and 2:00 for the most part.
Was not looking for another LSA but what a great offer. I use a Teradak LPS with mine, BTW.
Wow, your reference to my post is from the deep archives. I recall trying the Lightspeed schematic together with battery-powered monolithic Nat Semi buffers. I ended up (and still employ) the Lightspeed schematic as a volume control in a tweaked-out AtmaSphere MP-1 tube preamp. TX2575 series resistors and Silonex LDR shunts in a differential balanced circuit. It sounds fantastic relative to the stock Shallco series attenuator.
hat i don’t like is even more limitation with Lightspeed to have just ONE input.
It meant to be like that on purpose, because it eliminates the "source selector" switch which is another lightweight potential distortion causing contact taken out of the signal path. The Lightspeeds all about no contacts in the signal path.
A couple of customers use these external "source selectors switches" if they want to switch multiple sources and couldn’t be bothered changing over interconnects for non serious listening. That way they have the option of still hearing the best without it when they want or to impress their friends by going back to direct into the Lightspeed. with no source selector.
The Goldpoint one is the better, it also seems it has the option of bypassing the source selector switch (see they know), BUT!! with what? another contact inside, so they take the nasty away but replace it with a not so nasty pin plug jumpers? http://www.goldpt.com/sw4.html
Here is a picture of my opened B1, and this is another view on this beauty. Sadly, even 2 inputs is not enough for me as i normally use two turntables with 4 tonearms (different cartridges and phono stages). On my tube amp i got remote control, sadly there is no remote on B1, but dual volume control is a nice option to adjust the balance if needed.
Always a trade offs :(
Yes, the input impedance of by First Watt F2J power amp is 50k Ohms.
What i don't like is even more limitation with Lightspeed to have just ONE input. BUT has anyone with the same problem ever tried Luxman Line Input Selector AS-4III which is easy to upgrade ?
Nelson designed a buffer for the Lightspeed Attenuator over 10 years ago on diyAudio so my Lightspeed customers could drive some of his low impedance (10kohm) amps with it, here it is. Later he called the B1 buffer.
If you have a high impedance amp (>30kohm) the buffer (B1) is not needed and the Lightspeed will sound better without it. The best buffer is still no buffer.
I expected to hear sonic trade-offs, with the passive winning on treble resolution & overall sonic purity, and the active winning on dynamics and LF control. In actuality the hybrid buffered approach won on every point. As a result I opine that if the impedance match is anything less than perfect(and who really knows for certain what is perfect?), a passive would benefit by being equipped with an active buffer on an A/B switch. There are several simple & inexpensive buffer designs(including one contributed to the Lightspeed DIY thread by Nelson Pass) that will do justice to a top-quality passive. In this scenario the comparison of LSA to other preamps becomes more of a contest between volume controls-- which is a critical and oft-neglected determinant of a preamp's performance.
Well I see no reason why either of those sources would pose a problem for the Lightspeed. Glad to see the JLTi is still around as well. Listened to one a while back and enjoyed it quite a bit. Great bang for the buck.
@georgehifi not sure how anyone can judge by the picture (and it’s a bit off topic), but the picture of WLM you have posted is unfinished unit.
1) This is the actual picture of my WLM Phonata made when i opened it to upgraded load resistors to Vishay Naked Foil 100k Ohm for MM input (i prefer 100k over 47k for nearly all MM cartridges): https://pbs.twimg.com/media/DaEOa5DXUAA892A.jpg
Technical Data: MC-Input Impedance Range: < 100 Ohm to 50kOhm MM-Input Capacity: 100pF THD (Total Harmonic Distortion) @ 1kHz: 0.01% SNR (Signal to Noise Ratio) MC: >72dB SNR (Signal to Noise Ratio) MM: >85dB Max. Input Voltage for MC-cartridges (theoretical value): 1200mV @ <1% THD High Performance, Professional Type Step-Up Transformers
The PHONATA offers utterly precise RIAA equalization: • RIAA equalization is implemented across two amplification stages (within current amplification), providing a frequency expansion from 10Hz to 50kHz (Subsonic cut below 10Hz). Selected components (1% tolerance) are used. • RIAA equalization can be selected from two positions with a switch at the back of the unit (position “high” for records produced before 1965 or to improve the performance of somewhat “darker” sounding cartridges at higher frequencies. This position provides +3dB equalization as from 5kHz and +6dB as from 10kHz.) • Position “low” for all other records.
The unique feature of PHONATA is automatic adjustment of Load-Impedance for MC cartridges, but i use this phono stage mainly for MM cartridges nowadays, sadly a few units were made before the company closed the business, WLM speakers were quite nice, their tube apms were made by Trafomatic Audio (and i have one of them - WLM Minueta).
2) Phonata has much better bass response than Joe’s JLTi phono stage, the difference is huge (but the price difference is also very big). I like JLTi phono stage too, RCA plug load resistors on the back is such a great feature! If you want to look at the JLTi you will see it’s even simplier and smaller. This is the actual picture of my JLTi (inside).
For LOMC cartridges i use ZYX CPP-1 Pre-Preamp favorited by Arthur Salvatore (his name has mentioned in this thread many times).
And Luxman AD8000 with 8030 silver SUT for LOMC with extremely low impedance.
None of the mentioned phono stages can handle LOMC as good as the LUX silver SUT or ZYX CPP-1 headamp. So for MC i use those phono stages as MM mainly to connect my SUT or Headamp.
P.S. I hope i will find the right phono stage or sut to handle my 0,05mV Ortofon MC2000 cartridge, maybe now when i have so much power with First Watt B1 + First Watt F2J i have to try it again with my existing phono stages. We will see.
I have various phono stages, but Austrian (out of production) WLM Phonata Reference and new Australian JLTi is what i use the most. Funny, but the cabinet of my JLTi prono stage looks exactly like the cabinet of the Lightspeed device.
@chakster, what phono sources would you be using? I think this will have some bearing on the result. I have heard the B1 but have not been able to compare it to my Lightspeed. I have compared my Horn Shoppe Truth buffered preamp to the Lightspeed and there is a thread here that discusses the results. Quite frankly, of all passive, buffered, and unity gain devices I have tried, the Lightspeed is the one I still use. Your input impedance on the FW amp is on the cusp, but I have used my Lightspeed with a solid state amp with a similar input impedance and had no issues.
In the beggining of this thread @clipsal mentioned that First Watt B1 killed his Lightspeed Attenuator in terms of dynamics.
This could be true, in most systems the Lightspeed is a great match just like many tube pre's are, this could have been an instance where it or a tube pre's was not. clio09
and the originator of this thread (rip)
pubul57
asked
clipsal
what were the other components, alas he was never to be seen/heard of again???
Great thread, i'm on it. Well, i want to read an opinions from the users of both products like First Watt B1 buffer preamp (original, not a clone) and Lightspeed Attenuator with analog source only (not digital).
After years of using several tube pussh-pull integrated amps with vintage NOS tubes i put First Watt B1 buffer preamp with First Watt F2J (current source power amp) in my system last night. Now i have to learn more about deviced i have never heard before.
The input inpedance of my First Watt F2J current source power amp is 50k Ohms, gain 15.6db.
My speakers are Zu Audio Druid mk5 (101db)
My source is MC and MM cartridges with different phono stages, headamps, suts.
After my firs listening session with First Watt B1 and FW F2J
i've noticed that i use 10% of the volume control on buffer preamp. I could live with only 20% of volume forever as it's already pretty lound for an evening sessions.
In the beggining of this thread @clipsal mentioned that First Watt B1 killed his Lightspeed Attenuator in terms of dynamics.
I hope someone else compared those two products, i hope to hear from you guys.
You sent me a PM for info PDF's ect, but for some reason I can't return to you via Agon PM with my email address in the answer as this is the only way I can send you all the info. So you have to email me on [email protected].
stray_cat Now I just need to rig up a motor with remote control to control the volume knob externally with a belt. Has someone diy this before on anything?
To go remote, you need the remote, a receiver, the motorised pot and power supply for it. You need a dual 100kohm Logerithmic pot, and this one is just that, you could use it in the Lightspeed. (no need to use the input board with the 6 relays, just the remote and motorised pot board with receiver)
I won’t use them myself because the reliability factor is not there, and with supply is not there either for me over a long period of time, but there’s nothing stopping owners from doing it themselves.
As for the used Lightspeed, I’ll PM the owner and see if it’s still for sale.
Anyone who wants a used late model Lightspeed Attenuator, one has popped up very cheap here for $250aud which equates to $196usd and I know it only costs around $40 post to send as I send heaps to the US.
Just found a new cheap well made linear 12vdc power supply for you guys to power your Lightspeed Attenuators with. just make sure you tell him the mains voltage in your country.
It’s $58aud, this equates to around $45usd. It has the right voltage 12vdc has plenty of current, has the right size 2.1mm plug centre possitive and looks to be well made, with a sexy digital readout of the voltage.
Hi clio09, I've purchased two U9 Teradak power supplies from the same seller and link you posted. They both work great with the two Lightspeeds that I've recently acquired.
Batteries??? Yes as I measured above they are 20uV quieter on test bench, but you’d have to be a "super bat" to hear that sort of difference.
But all including myself hear something different that we can’t put a finger on, but we all prefer it (maybe physiological).
And for the money, $20 for a 12v rechargeable Li-Ion one that lasts a good two weeks before a recharge is needed, well worth having. Here is the ebay links. Just make sure with the seller, that it has a 2.1mm plug, and that centre is positive.(I like the black ones, as they look better.)
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