Passive Attenuator/Pre amp: EVA 2 LDR
Time for a little play: I have an NVA power amp, so I have to use a
passive pre. That's fine, I like them in general & the NVA ones are
super. But in order to upgrade my P90 to the uber stepped attenuator
version I need to shell out over £300.....
I keep hearing whispers about another kind of passive pre: not
passive pot, not stepped attenuator, not TVC....Jason (Figlet108) first
mentioned LDR (light dependant resistor) passives a while back, and I
have been doing some research. The original is the 'lightspeed' - here:
http://members.optusnet.com.au/~georgehifi/
I've got hold of a cheaper model, from Malaysia. It has three inputs
(I only need one) and a remote control - in fact it uses the apple
remote!
I'll try & post some more tomorrow - perhaps I'll figure out how to post a picture!
Comments
Have you got a link to where you got it from? What was the cost if you don't mind saying?
I JFGI'd it and there's a lot of info on the DIY boards - I'll have a read later.
http://www.hifiwigwam.com/showthread.php?48230-For-sale-EVA-II-LDR-passive-pre-amp
This is the product page for version 1 & 2:
http://diyparadise.com/shop/index.php?main_page=index&cPath=18
I gave 200 squid for a minty one. The single input version is £150 new - when it is in stock. George (of lightspeed) reckons the EVA is as good as his lightspeed mk I, but the newer version of his is far better. and about £350 delivered.
Thanks Alan
Alan
Great spot !
These seem to tick all the required boxes for passives - ie very simple so nothing gets in the way. And a remote !
Intrigued to hear how you get on.
Mervyn
The EVA I, which is exactly the same as EVA II but has only a single input. I would have rather had this - quite apart from anything else I like the wooden case, and they are a paltry £150 or so new - but they are made slowly so there is always demand.
But it reminded me of two interesting ideas I've heard about.
One guy I know builds and generally fiddles with valve amps. Problem is he uses very un sensitive panel speakers so he often just hooks a low powered valve amp he's been working on up to his CDP and straight to the speakers - i.e. no preamp or attenuation at all. Sounds amazingly clear, dynamic and just right but limited in volume. The trick would be to get the right speakers and/or right amp output I suppose.
Another guy has chosen 3 volume setting and measured the necessary resistance values and replaced the pot with high quality switches and very good resistors. He makes do with with just 3 volume settings. Haven't heard this but he reports that it's fantastic.
Jason has said he has hooked up the TFS direct into the amps cutting out the pre and reported good improvements. Easier with a PC of course where you can use the computer's own volume settings.
I think Dave should give that a go, being an iUglyTunes kind of guy.
I don't see why this LDR attenuation shouldn't be built into a power amp - the only power source that is required is an LED, and my NVA has four of them, despite it's minimalist design ethos. I wouldn't be surprised to see an LDR in an NVA statement amp sometime soon, especially with Jason around.
My EVA II Pre-amp arrived this morning, at 8am sharp! Well done parcelforce (for once) - it was only sent yesterday. There is another one on wigwam (or there was yesterday afternoon).
It is ice cold, so it has been gently warming today. It may get it's first outing this evening after the children are in bed, if the mod so takes us. It's actually starting to feel like a slobby telly evening already though...
(:|
I wasn't calling you Shirley...
>:p
Funny you should mention that Alan but there is a recent thread 'AP20' on the Subjectivist forum where Richard has asked someone to build an LDR circuit into the amp and let him know how it sounds !
Interesting times ahead maybe ( or maybe not !)
Now I may have:
Is not being bit-perfect the same as losing some information?
Just got it in, with the usual NVA owners near heart attack on power-up....no smoke yet, watching telly through it now. I'll see if Mrs wants a bath later so I can have a listen...Interestingly, I had heard you can't fully mute the volume with LDR attenuation, but I can get it right down to nowt.
My initial thoughts are that it loses nothing to my P90, so on convenience grounds (ie size, remote control, and frankly - coolness) it is a winner. Assuming Richard Dunn makes a decent passive pre to match his own amplifiers (a very safe assumption IMO), there shouldn't be a substantive difference as both pre's are designed to add nothing.
My first concern had been the soundstaging & imaging, but in fact the soundstage was as wide as ever - even seeming slightly outside the speakers as before. I had half expected that a pre with a single stereo volume control rather than two single channel pots would impact this, but not at all. In fact it was a blessing to not have the ever present slight channel mis-match you get with twin controls...
I had a nice session on Saturday evening, when I was convinced more low level detail was present, in a very non-forced way. In fact it was rather like having a new DAC (or so I imagine, Keith....), as the whole presentation was just slightly different. I enjoyed hearing some things I hadn't caught before - notably things like subtle acoustic rhythm guitar hiding near the bass. As I would expect from a passive, the timing of the music was spot on; I was enjoying that aspect more than usual, but I am not sure there is a real difference. I most certainly cannot be faffed to swap the two pre's in and out, what with these rigid interconnects!
Sunday evening we had a few round, and surprisingly they wanted to skip through my music collection & hear the system. We played an eclectic mix & things were great, but I couldn't help feeling there was something missing; feeling the bass in my bones even at low volume, the liquid midrange, sparkling treble (see - I'm a HiFi reviewer mum!) - a cliché, but true. I haven't listened since, but there are two conclusions. Perhaps the quality of the unit isn't up to the NVA after all, what with the box design, the specific type of wiring Richard uses. Or, perhaps more likely, having so many bodies in the room sucked some of the life out of the rooms acoustics.
There is more listening to be done for sure, and not so many opportunities with the three children off now. But I will keep you posted.
This is a bit of a heavyweight, this little box! Every doubt I had the other night has evaporated - the textural detail that has surfaced since putting the little LDR pre into the system is gorgeous, the timing is infectiously groovy at times, the staging & imaging has just slapped me around the chops!
@-)
I was listening to Prelude 'N Blues played by the Matt Catingub Band, which is a track I have literally grown up listening to on my Dad's system & my own - and I am suitably awe struck at the perception of the alto saxophonist standing 8-10 feet closer to the mic than the trombone player - just one example. Imaging has never been top priority for me, though I've always enjoyed it when it's been good - but this is rather excellent!
I recommend further investigation!
(*)
I should be interested if anyone ever compares an LDR pre to a P90sa.
It sounds like money well spent and to work so well with the TSS is a good omen.
Is the remote user friendly ?
Mervyn
ps totally understand heart-stopping effects of plugging the amp in again after any system change especially with SSP interconnects. Lack of any on/off switch simply compounds the cardiac arrest potential !
Jerry is da man when it comes to swapping gear, he & others like him have helped me innumerably when trying to decide whether to act on a whim or not. He assuaged my doubts over both Beresford & NVA - about 4-5 years ago now, as I was procrastinating badly. My first forum postings were on wigwam asking whether I should consider NVA seriously.
I think trying out loads of gear, and broadcasting your views in a balanced way can be helpful to the larger community, as awkward as I feel when I share my views. No-one's opinions should ever be taken too seriously (in particular mine) as tastes and systems are too different, but amateur reviews have their place on the net for sure.
You never know, the LFD rig might offer something very special in it's own right. I find gear that is just different in character is often as good as gear that is an incremental upgrade.
This little EVA is a gem, no doubt at all. I will try a lightspeed attenuator in the new year and if it yields an improvement I will move the EVA on, but I think I will be sticking with LDR passives for now.
I have used the BNC - RCA adapter before & it was sonically 'invisible', but that was for a digital connection.
& There. http://www.maplin.co.uk/Module.aspx?ModuleNo=1593
This is the original lightspeed, now mkII: (this has no remote control).
:-D
Loving this! I don't think I will be going back to conventional pre-amps again...
I mentioned (slightly tongue in cheek) the "ever present slight channel mis-match" I get with twin volume pots on the P90, but funnily enough there is a slight mis-match with the EVA! It is apparently a labour intensive - and wasteful process - to match the LDRs that go into these units, and it isn't uncommon for there to be a slight balance issue. It is very slight though, just nit-picking really, but I do want to know if George (who builds the original Lightspeed) pays more attention to this aspect of QC than the folks who built my EVA.
I can't help but think (dangerous - a subjectivist trying to understand why something might work....) that little EVA II is missing a trick by having three selectable inputs - and a mute funtion via remote. The whole idea as I understand it behind an LDR passive is to eliminate the contact points that potentiometers & input selector switches introduce to the signal path - these were previously unavoidable. My guess is the EVA I would be marginally better, and I would hope the Lightspeed attenuator would have tighter QC wrt LDR matching. It is also single inout, and doesn't have remote control (I think), so the hair shirt minimalist approach would then pervade my whole system.
Is there a way to put a PDF up on the board here? Lightspeed sent me some info over email that I could put up if it's easy.
:-))
On a related note, Keith is expecting the M2Tech DACs to arrive Monday or Tuesday, so I suspect we will have much to talk about.
I like mine a lot, and it seems happy with NVA, although the input impedance is just out of recommendation. I believe the lightspeed may be better, but it is dearer & has no remote. Now I have had a remote it is hard to imagine sacrificing it!