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I’ve been searching for a preamp, so for a Google giggle I searched for “best preamp ever audiogon” to see what would happen. I thought the Americans would have tackled the subject that way, and I wasn’t wrong. The top hit was for tube preamps, but I didn’t want to limit my search to tubes. The second-top hit was not it either – just preamps for sale. But the third and fourth hits were more like it. They came from the same thread, which began in in 2010 and – 36 pages later – is still going (just). I started reading. My reading extended over two nights. My interest had turned to intrigue when I twigged that the preamp they were talking about was Australian. Users were claiming that the Lightspeed Attenuator, a US$450 passive preamp was the best they had heard. They were saying this little preamp had bested the likes of Cary, a bunch of Audio Research (SP22, SP10, LS3, LS8, LS2), Mark Levison 380S, NuForce P8, Gryphon MKII. The names went on. Now besting another amp in a get-together is one thing – but actually getting rid of a very expensive/very good/very respected preamp and replacing it with something cheap (by comparison) and (at the time) unknown is an altogether different thing. And that’s what some of them were claiming to have done. Like ditching a Supratek hand-made triode tube amp. (Which also happens to be Australian.) The Lightspeed Attenuator, which will be well familiar to some people here on stereonet. My intrigue turned to astonishment when it became apparent that the creator/manufacturer is someone active in this forum – @georgehifi. So what is this thing? The Lightspeed Attenuator is, as the name suggests, an attenuator. A passive preamp. All it does is transfer the signal – and give you the capacity to turn the volume down (attenuate). Also as the name suggests, attenuation is done by the use of light. Turning the volume control up or down decreases or increases the resistance of the internal light-dependent resistor (LDR). All I had ever heard about passive preamps was that they ultimately lack bass punch, transient attack and big soundstage – three vital elements of music IMHO. I’d always thought no, I don’t want a passive. But I kept reading this thread. Users kept saying the same thing – that this thing was as close to the proverbial straight wire with gain as you can get. Except there is no gain – and no wire either. And they kept saying that the common complaints about passive amplifiers (see above) did not apply. What made this especially intriguing was that some of these users were big fans of tube preamps. Now I like tubes too, but tubes are as far as you can get from the ‘straight wire with gain’ aesthetic. All of that was impressive, but the clincher for me was that the thread had gone on for years – and some of the users were still using the Lightspeed. Now we all know how people who are interested in this stuff will turn over components, either out of curiosity, the desire for a change, FOMO, because the grass is always greener, or just for the hell of it. So the fact that they had stuck with the same preamp for years… So I had to try, didn’t I? Now, the OP in that thread had made it clear that the Lightspeed needs the right environment in which to work. A source ouputting 2V or more, which is pretty much everything these days I believe, a short interconnect to the power amp (three metres or less), low capacitance interconnects – and a power amp whose input is preferably the industry standard of 47K ohms or more. Hmmm. I checked the specs on my Halcro DM38. Only 10K ohms on the RCA input. The Lightspeed outputs RCA only. That might be a problem. Theroetically, it really should be problem. But I wasn’t going to stop now, was I? Just to test before shelling out, I plugged my passive Schiit Sys into the Halcro. The Schiit ouputs up to 5K ohm. So we are a long way from the ideal 1:10 ratio, which would have us up around the 47K standard on the power amp. But the Schiit provided enough bass and volume to make me push ahead. It worked, at least. But I thought I was probably going to need a buffer, so as to fix the impedance mismatch between the Lightspeed and the Halcro. While I think of it, it’s worth adding that as well as having only one output, the Lightspeed also has only one input – and no remote control. It runs from a supplied wall wart. And I should detail contextualise the rest of the system. Speakers are a massive pair – Be-One, The One. Five drivers per cabinet, about 100 kgs each, sensitivity 89db. Streaming via an Auralic Aries Mini, listening to 320 MPs, CR rips, hi-res files and DSD. Switching between DACs – the Aries, an Emotiva and an R2R Audio-GD 11. Preamps on hand for comparison were the Aries Mini again, a Xindak XB 8250, and the Geiseler preamp, also made by someone active here. (There were two tube preamps, an Audile using Jan Philips 5814a tubes tubes, and a SoundMaster Mk 23 using 2A3, but the tubes were so different, I didn’t make comparisons.) And I listen to most genres of music (except opera). So the Lightspeed arrived. One great thing about it – no burn-in. Because there really is nothing to burn it. That’s a relief. Just give it one minute to get warm. We’re off. First impressions: this is good. It was clear. Like water. There was no shortage of bass. Or slam. Highs were clear. Volume – more than enough. I had it playing around 2 o’clock to play it loud (90db, sitting four to five metres from the speakers.) There is no sweet spot on the volume dial – the sound is the same all the way. That’s what it sounded like – which is to say, it had little sound of its own. It was dead silent – which I suppose is a function of no gain and no mechanical parts to speak of. I really like a silent preamp. Whenever I get a new component, I make a point of listening to it. By which I mean, not comparing, but just listening to it. (And I only change one thing at a time – so I can be sure where the difference is coming from.) But it sounded not quite right. Hard to pinpoint, but it just felt like it was struggling. There was nothing i disliked, and what was there was good – but it just felt a bit lifleless. So after a few days I compared. Yep, the Lightspeed was approaching the weaknesses commonly attributed to passive preamps. The attack on notes wasn’t quite there. That one thing meantthe music losing life and shine. But what was there was all good – it just felt it was pushing the music uphill. But it was good enough that it deserved a proper chance – so let’s get a buffer. I got a Musical Fidelity X10v3. (not XD.) It puts out just 33 ohms. It deploys two military-spec tubes – which Musical Fidelity says are designed to withstand the radiation of a nuclear war. Pity the rest of the system won’t. And, voila. Now we’re talking. If the taste was water before, it was water that wasn't quite flowing freely from the cup. Now it’s water out of a perfect glass. Transparent. Delicious and pure, as water can be. Absolutely none of the usual criticisms generally aimed at passives apply. All the life and dynamics were there. Transients had zing. Slam had slam. It just sounded like I was hearing the music. So, there you go. This will be old news to some – George apparently made his first version as far back as the 70s. And that Audiogon thread where this journey began started back in 2010. But I wanted to share it – this thing really is ingenious. I like the fact that theoretically, it’s the ideal preamp. As far as I can see, adding nothing, subtracting nothing. (Used in an appropriate context, as explained.)

Item: Meixing MD6 Passive Pre (Amp) Location: Brisbane Price: $450 Item Condition: As New Reason for selling: Originally sent for review, now surplus to requirements. Payment Method: Pickup - Cash, Paypal Only. Courier to anywhere in Australia for $25 in addition to purchase price. Extra Info: Inputs: L/R Balanced and L/R Unbalanced Outputs: L/R Balanced and L/R Unbalanced Distortion: < 0.09% S/N: 96 dB Freq. Range: 5Hz - 25kHz Voltage Gain: 9.6 dB Other: Silver contact gain controls A low cost opportunity to try a passive preamp. If you have a high output source (e.g. CD transport) then this will suit nicely. Some people warn/worry about the length of interconnect with a passive pre-amp. This unit uses transformers to provide enough "drive" to effectively run over long interconnects, should you require same. The lower the interconnect capacitance, the better, but you knew that already. I have used this device with 8 metre interconnects (12.5pF/ft) between it and the power amp (near the speakers). This will work well with an impedance ratio between source and amp between 50:1 and 100:1 Performance is at a very high level for this expenditure, comparing to active preamps costing a couple of thousand. Gary Jacobson The Quad ESL (www.quadesl.org) Pictures:

Item: Sonic Euphoria Passive Preamp / PLC Location: Melbourne Price: $500 + shipping AUS wide Item Condition: Excellent Reason for selling: Need funds for Reno Payment Method: Pickup - Cash, Paypal, COD Only Extra Info: Shame to see this go. Purchased back in March from another SNA'er here: https://www.stereo.net.au/forums/topic/281378-sold-fs-sonic-euphoria-passive-preamp-plc/ This preamp was the heart of my system. I couldnt have found a more transparent preamp with use on sources that output at least 2v's. This unit is very solidly built, and near bulletproof and sonically 'invisible' as the previous owner has mentioned. The dial on the left is for the source switch, middle is for volume attenuation, and the one on the right is to fine tune the volume, essentially giving you control to around 48 independant volume steps. As it's passive, it doesn't even plug in to the power, and its main parts are 2 switches, a high quality volume control, and 2 tapped, hand-wound transformers. The tape out RCA's bypasses the volume control totally, so you can use it as a switch. The volume dial is very robust and locks in to the taps solidly, unlike other cheap clicky sounding relays. Comes with a grounding cable if needed, but sounds best without. It weights about 8kgs. No remote (not that type of preamp) Review: https://www.stereophile.com/solidpreamps/106sonic/index.html Donation to SNA upon completion of sale.

Item: Luminous Audio Axiom II passive preamp Location: Canberra Item condition: As new in original box with paperwork (few months old, barely used) Reason for selling: Surplus to needs Price: $170 Description: Up for grabs is a Luminous Audio Axiom II passive volume control. The Axiom two is a brilliant device for attenuating volume. Signal runs through a single resistor (which you can easily change to what ever flavour you prefer). Excess signal is sent to ground via an Alps Blue carbon pot. The Axiom II is very transparent and can be easily configured to your system or taste as desired, or just use it as is...simple. For most systems this is all you will ever need and will outperform many active preamps. And it looks great, my wife actually loves the look Payment: Direct deposit Postage: Buyers pay postage (the unit is very light) Thanks for looking

I'm currently wondering if a high quality passive pre is what I am after for my next up/side/change-grade. I was thinking about picking up a Schiit SYS and maybe replacing the volume pot with a more upmarket one but I'm not sure if that would fill my needs. I assume there are other options out there but I don't know of any ATM. Does anyone have any comments or alternative suggestions?

Item: StereoKnight Silverstone B&R passive preamp Location: StKilda, Melbourne Price: $1200 firm Item Condition: almost excellent. Bought Jan 2011 Reason for selling: already upgraded to a valve active preamp Payment Method: Pickup - Cash, Direct Transfer, PayPal + 3% Extra Info: see below Pictures: see my thread here This is a great preamp, to my ears as good as a Music First Mk II and at a great price. It's extremely detailed, has good sound staging and 6dB of gain. Like all passives it doesn't quite have the dynamics of an active, but that is the trade off in return for the detail unless you want to pay x5 more in order to get both from an active preamp (I just have!) It's complete dual mono with independent volume adjustment (both channels controlled simultaneously from the remote). It's fully balanced and transformer coupled so contains 4 transformers. The transformer coupling allows it to be used with low impedance loads like active speakers without bandwidth constraints, or with long interconnects, unlike many passives. It has 3x RCA inputs and 3x Balanced XLR inputs, so a total of 6 sources can be accommodated, it's rare to get that many input options these days. You can use RCA inputs and XLR outputs so this is a very versatile preamp. It has 2x balanced XLR outputs so that you can run a powered sub with your 2 channel setup. There are 2x RCA outputs although these have never functioned from the day the amp arrived new. This may be simple problem to fix, I don't know, however I'll supply 2x XLR->RCA adaptors in case your cables are RCA only. I've only used the XLR outputs anyway so never bothered to get it fixed. The reviews claim that the XLR balanced outputs sound better than the RCA outputs. New price from Osbourne (the Aussie distributor) is $2700. The amp comes with a full function remote control that adjusts volume, mute, input and output selection and adjusts channel balance. The amp is quite heavy and very solidly constructed, it's made from solid aluminium plate and weighs more than my new valve preamp! Some reviews: 6moons review the non-remote control version - identical sound. Dagogo reviews the B&R

Item: fidelity research as 1 passive preamp Location: nsw Price: $1000 + postage Item Condition: very good Reason for selling: surplus Payment Method: Pickup - Cash, Paypal, COD Only Extra Info: ridiculously good passive preamp superior to most available, recent sale o.s. U.S. $2500 Pictures:

Item: B&K PRO-10MC preamplifier Price Range: Negotiable Item Condition: Used Extra Info: I am looking for the version with the silver handles to match my B&K St-140. I have the Pro-5 preamp but would like to try the model above. The later PRO-10MC Sonata isn’t as desirable for me but I may be interested if I can’t find the earlier one. Thanks