Products: Graham Slee Projects Era Gold Phono Stage and Elevator EXP Step-Up
Manufacturer: Graham Slee Projects - UK
Cost, approx: Era Gold £360/550 Euro, Elevator EXP £440/670 Euro
Reviewer: Geoff Husband
Reviewed: July, 2002
Originally this review was meant to be of the new Elevator moving coil (MC) step-up amplifier (or head-amp). I'd already done the Slee GramAmp stages and Werner had reviewed the up-market 'Era Gold' Phono stage so enough was enough. The Elevator EXP on the other hand promised to be an interesting product in a rather sparse marketplace for MC amplifiers so I thought it deserved a spin. Graham Slee had other ideas, and told me that the Era Gold had undergone major revision (see manufacturers comment) to the model Werner had reviewed and found OK but nothing special. In the end I gave in, after all I'm always keen to limit the number of variables and mismatches hi-end hi-fi is prone to, so to use the Elevator with it's matching phono stage seemed like a reasonable idea.
Going back to the Elevator - I was interested to try it because though there are a bewildering number of phono stages being launched, most capable of taking both MM (Moving Magnet) and MC cartridges, there's very little to enable MM only phono stages to take MC cartridges. Now this might seem a niche within a niche within a niche, but not so. There's now a big increase in the number of valve pre-amps and phono stages. These are almost universally MM only, primarily because high gain valve stages are often noisy. So for all these amps the owner is stuck using MM cartridges or adding some kind of step-up device to allow high-end MC cartridges to work. Broadly these devices split into two camps.
The first is the step-up transformer. This is a 'passive' device, i.e. you don't need to power it. It is simply a transformer which amplifies the MC's signal up to MM level. Proponents claim that this avoids any active devices in the process - especially the dreaded transistor - so preserving the 'purity' of the signal. What they omit to say is that in exchange the transformer forces a very small current through a lot of wire! I have good Audion step-up transformer which I like, but it has to be said that the things are 'hum-magnets' and cable runs and equipment positioning become a nightmare. Also just because these things are simple doesn't mean they're cheap, they start at hundreds and go up to many thousands of Euros/dollars.
The alternative is to use a small transistor amplifier (often called a head-amp) designed to bring the MC output up to MM level. The treaded 't' word might have rabid 'valvies' reaching for their guns but thankfully I'm not loaded with such baggage and as far as I'm concerned I don't give a 'monkey' what's in the box so long as it works... Claimed advantages are good low-noise performance and less problems with hum, but don't go away with the idea that amplifying such tiny currents accurately is easy. As with step-up transformers these babies arn't cheap either, they're also pretty thin on the ground, and the ones that do exist run at similar costs to the transformer equivalent - my own Dynavector running at well over 2000e...
So why bother? OK the Elevator is perfect for the valve brigade, but for the rest of us virtually all decent phono stages will accommodate both MM's and MC's with a flick of a switch - here the Gold is more like a valve stage being moving magnet only. The argument is that two discrete, specialised gain stages are always going to beat a 'one-size-fits-all' stage with switchable gain etc. - hmmmmm...
The test also coincided with a real avalanche of phono stages chez-nous. The Korato Reference valve stage (1500e+), the Roksan Reference (1500e+), Black Cube SE (800e), Trichord Dino (500e) and of course the phono stage of my Audion valve pre-amp (2500e). All but the Dino were still here and were used during the tests as comparison - this wasn't the original intention (hell I didn't have time for that sort of test!) but is how it finally worked out...
Thus the Era Gold was pitched against a swathe of expensive phono stages and the Elevator against my own Audion transformer and Dynavector amplifier.
I'll be brief here because a) I don't understand most of the technical stuff, and b) Graham Slee has said quite a lot at the end of this review.
The Gold is a MM only, phono pre-amp. It lifts the output of a MM cartridge to line level and at the same time equalises the RIAA response so it becomes 'flat' 20 - 20,000 Hz. As I mentioned before, serious transistor stages almost invariably offer a range of gain and input loads for different cartridges, the Gold doesn't and so is much more like a high-end valve stage (or a very cheap one:-). It comes supplied with an offboard power supply with it's own regulation housed in an ugly plastic box - best hidden... The stage now comes in an anodized, extruded aluminium, silver box - quite a change from the sticker-clad plastic box Werner was faced with originally. Worth showing off. Round the back are quality phono's for in/out and a binding post. No switches, no LEDs, just a silver box.
The Elevator uses the same power supply and the same box, it's also identical 'round the back'. The front panel sports two switches, one for impedance and one for capacitive loading. Thus as a combination the Gold/Elevator offers as much flexibility as the single-box stages and should suit all but the most off-the-wall cartridges - very, very low output MC's for example. The accessibility of the switches is handy too, rather than the usual internal or 'underneath' dip switches.
OK I'm going to nail my colours to the mast... (and I'm going to do the same with an arm next review...) Lucio has banned us from saying "best I've ever heard" "never heard anything as good" etc as it begs the question "compared to what?" and is often meaningless hype. But here I've listed the runners and riders, added the caveat "in my system and room" and finally "to my ears", so here goes. The Era Gold + Elevator EXP is the best phono combination for MC's I've ever heard - period...
So I suppose now I have to justify it...
To explain I'll go through the sequence of events that brought me to this conclusion. Originally the idea was to compare the Elevator with my Dynavector head-amp and Audion transformer, going into my Audion Pre-amps own phono input, and then through the Gold.
To my ears the Audion transformer, good though it was, just didn't cut the mustard. Lovely, natural, unforced, but a bit soft and woolly. It was also the usual nightmare to try and get the thing working without hum. There are no doubt better transformers around (at a price) but for the moment it was out of the running.
So onto the direct comparison with the Dynavector. This gave more gain than the Elevator, in fact rather too much for source matching, but its performance was superb. Powerful, organic, meaty, natural and all without a hint of strain. Remember the Dynavector was designed specifically to partner the XV-1 cartridge in use and loaded it to 30 ohms as recommended. Replacing it with the Elevator (which also has a 32 ohm setting) gave a shift of emphasis. The Elevator sounded less powerful with a lighter but tighter and faster bass. Detail retrieval was very similar but the Dynavector added more body to instruments - I'm not going to say which was better, just that they gave a different view of events. In my horn/valve system the Slee Elevator allowed the Polaris to be moved back a foot towards the rear wall, not a sonic benifit but certainly a domestic one:-)
Happy that I'd pinned down the essential character of the beast I moved on to compare the Gold phono stage to the Audion pre-amp using the Elevator in tandem. Boy were they difficult to split... The Audion stage takes a hell of a lot of beating but here the Gold was toe-to-toe, sweet, open and natural again. In fact they sounded very similar, to the point that I'd find it tough to identify them blind, but in direct comparison the Gold proved just that little bit more open, the Audion adding a little glow to events. Also the bass with the Gold was a tadge tighter and faster, the background a tiny bit darker. So I'd give the Gold the lead by a nose, but a very significant one as no other stage has bested the Audion in my current system.
So that was that, or so I thought...
At short notice Loth-x sent me their Ji300 b integrated amp. This was designed as the natural partner to my Polaris - 8000e of hewn aluminium and GE300b valves run in single ended mode. I managed to set it up without getting too much drool over it, but once installed it made its intentions abundantly clear. This wasn't a valve amp ready to gloss over and warm music, something to toast your toes in front of a fire with. The Polaris had already proved themselves viscously revealing but the Ji300b took it all one step further. The review will follow soon so I won't go too far, but it's 'hear through' midrange combined with the similarly endowed Polaris meant any harshness or distortion was ruthlessly exposed. The Audionote CD player is permanently switched on, but still needed 30mins on repeat to be listenable, but then you realised just how close you were to the mastertape...
And it didn't have a phono stage...
So you can see what's coming. The other MAJOR factor was that lust was getting the better of me and I was starting to wonder if I could afford to buy the thing. Which was why I suddenly become more interested than usual in the phono stages languishing in the loft - if I was to buy the Ji300b I needed an MC stage to go with it. So with the aforementioned competitors lined up I made damn sure I made the right choice... It's the sort of thing that concentrates the mind wonderfully:-)
First off the favourite was the Korato. Beautifully made, amazing spec - even at the price, and of course valve only. The Dynavector stage upset it big-time but with the Elevator it sounded stunning (insert here your favourite cliches), very tough to fault. In turn I tried it against the transistor stages. The Roksan was very good, open detailed, very pacey and with a 'wall of sound' image, but it was also just too pushy - I couldn't sit in front of the combination for long. It wasn't edgy at the top end like the Dino, but just wore me down in the end. The Black Cube, with it's ability to load the XV-1 at 30 ohms was more even, a little less pacey and laid back - overall as good as it's reputation would lead you to believe, but the Korato's silky top end and extra body tipped it from the top slot. Then I put on the Gold and straight away I realised that the Korato could be in trouble. From this unassuming little silver box came forth magic. It sounded very like the Korato in so many ways. Firstly it sounded like a valve stage (and I've two here so I know), in that the top end was extended, clear and yet had a silky quality that meant that when a powerful high note came it kept it's edge and force but without making you wince - just like the Korato. But where it had an edge was that it made the Korato sound as if it was subtly blurring the music, rounding off edges, tugging at highs and lows, loosing tiny acoustic clues - it wasn't night and day by any means, but the Gold had it by a head.
I'll illustrate what I mean using my notes from one record (though I used many). You are no doubt aware of how often I use Simply Red's 'Sad Old Red' because it tests just about everything, so here goes...
The track opens with the lovely fruity 'walking' bass line. Here the complexity of the note, the sound of that fat string vibrating (you could almost count the beats) was plain, the stroke of thumb audible - the Korato just didn't quite give the same definition. Then the high-hat comes in, big and shiny, with the Gold the sound was just more 'complete' than with the other transistor stages, never splashy - the 'clap' more drawn out and complex. The ridden cymbal gave a strike that the Roksan easily matched, but not the decay.
Then Mick Hucknel's voice. With the Korato and Gold it had a depth and three dimensional quality that the transistor stages struggled with. He's miked as if there's an echo off the back wall, the Korato fudged it a bit, with the Gold the 'wall' (studio effect) was almost visible it was so real - the Black Cube and Roksan picked it up too, but just not so naturally. When he belts out those high notes towards the end of the track ALL the transistor stages made me wince but not the Gold.
The change of pace and the heavier strike on the cymbal that happen midway through the song was beautifully handled, the increased dynamic range effortless.
Soundstage width was close to the Roksan, the depth better, and as a coherant whole right up with the Black Cube.
I could go through other discs but the pattern was the same. With a system this revealing only the valve stages and the Gold were in the running, and in the final analysis the Gold took the honours.
This wondrous performance took time to come on stream - the Gold/Elevator needs a week to burn in and should be left on at all times. It also seemed to sound better after 30 minutes play - no I can't explain and neither could Graham Slee and I know it worries him greatly. Personally as the transition is from excellent to brilliant I'd not loose sleep...
I'm not sure I will buy the Ji300b. I'm not sure that for the majority of my record collection I want to be that near the master tape, but the exercise left me in no doubt as to the phono stage and so I've bought both the Gold and the Elevator. It's simple, effective and has no weaknesses I can detect even ignoring it's low cost compared to most of the others (though it's still a lot of money). The other stages were all worthy contenders, but now I'm happy that no matter what direction my system goes in (and amazingly regardless of cost) the phono end is sorted...
I sent an email asking Graham Slee what changes he had made to the Gold and he came back with a long letter detailing not only the changes but also the thought behind them. As an example of how a small manufacturer thinks, and some of the problems he has to overcome, I found it very interesting and well written so I reproduce it in full here...
The original Era Gold was hard wired in the style of the pre-ornate valve era, the one that ended in the '50s with the introduction of pcbs. However, TNT's Werner Ogiers didn't think it befitted solid state and the lovingly built "boards" died a shameful death.
Take two! The MkII Era Gold was given a pcb, but Werner didn't like the plastic case. He didn't like the sound either, which came as a shock, because everyone else who'd heard it did.
Take three! The MkIII Era Gold was given an expensive metal case - alloy extrusions for base and cover, and CNC cut front and rear panels - all finished in black polyester paint (shortly to become silver anodised!). The sound was improved too. At last! Werner told me it was "a fine preamp" and worth the asking price. Then came his review...
The MkIII circuit had subtle similarities with the Gram 2, using a dual op-amp, and EQ network using the same high speed, low dielectric absorption, 1000V/µS polypropylene capacitors. The op-amp was different to the 2. It was a fast (350V/µS) Analog Devices chip, optimised due to the 50kHz cutter head compensation negative feedback pole. Werner suggested the 50kHz cutter head compensation, but I noticed how it could be used to optimise the chips performance. The chips had to be chosen by hand for their noise performance and about 11% had to be thrown away (5 quid each!) and 22% recycled for other less demanding uses.
The MkIV came about because of work on the Elevator. Early Elevator prototypes used a 1000V/µS current feedback dual op-amp in a servo assisted circuit with a precision ground generator. However, I wasn't happy with the sound. I could not find another dual op-amp having the idealised noise performance and speed and ended up using a pair of single op-amps. Because the board layout had been optimised, I decided to mount the new op-amps on a specially designed, tiny, plated through hole conversion board. The new op-amps had similar noise performance and were almost as fast, but also needed external compensation (I wouldn't want your readers thinking it's all about plugging chips in till you get it right - too many forums think this is the case). I optimised the compensation for the widest possible bandwidth (25MHz) with unshakeable stability using some very expensive silver/mica capacitors, and the result was the EXP module.
As it turned out the EXP module could also be implanted into the Gold. The result was immediately startling, sounding more engaging and with a wider soundstage. However, there was a certain hardness I didn't like, confirmed by a tiny RF oscillation in a high frequency distortion trace. The op-amps were great for the Elevator, but were a slight mismatch in the Gold. I could have optimised the compensation to get rid of the oscillation, but I was also aware that the loop gain could introduce a slight non-linearity into the input impedance, and decided to look elsewhere.
I searched both the Linear Technologies and Analog Devices databases until I found an op-amp cruelly termed "general purpose" which was far from it. I wasn't sure about it, but knew it would be ideal for the Elevator precision ground generator, and ordered a batch. After a number of calculations and measurements I built up a conversion board for the Gold using the "gp" chip. The tiny RF oscillation had gone, and the Gold sounded great - more engaging with wider soundstage as before, but without the same hardness.
I also felt the Gold was performing better partly because of the physical separation the two single op-amps were providing. Thus, I returned to examining the power supply inside the Gold. Decoupling was being taken care of by an ultra low impedance electrolytic cap, and an excellent X7R ceramic, which normally you'd never fault. I replaced them both with solid tantalums and fitted another tantalum to the conversion board (distributed capacitance as used in my earlier broadcast audio designs). The result was audible and better.
I then decided to take a second look at the EQ network and a series of RIAA accuracy tests followed. Adjusting one value (necessitating two caps instead of one) improved top end accuracy to 0.1dB. Hardly noticeable, but there.
Lastly, for the MkIV, I wasn't happy with the mechanical stability of the conversion board, and found a way of mechanically coupling the whole lot with the case. My pro audio colleagues will slate me for this, but here goes. If you vibrate any electronic component (they're all microphonic) it'll produce an electrical current (very, very tiny). If you vibrate one part of a circuit and not another it'll produce a difference current (somewhere), and that's an alien (interfering) signal. But if you vibrate the whole thing together the difference current produced will be minimised (it's a bit like the noise cancellation you get with balanced inputs). Thus little, if any acoustic feedback will result (anyway, that's the idea).
You know the Jazz Clubs is based on the Gold. I'd sent one to Stereophile and was paranoid (as usual). This made me think how I could improve the Gold further, if the unthinkable happened and I got a bad review. In the event the review was a rave, but I'd done the work by then, so you got the MkV.
Oops! Forgot to mention I'd also swapped to another manufacturer for the EQ caps on the MkIV. On the MkV I swapped back to the original manufacturers offerings for the low frequency part of the EQ network. This took away a little hardness to the sound and imparted a more tuneful bass.
What else could I try? My attentions were then drawn to the input wiring - short 3 inch lengths of coax made by VanDamme, which is considered a little bright when used for interconnects. I found some simple double screened 50 Ohm characteristic impedance coax, and used that instead.
The final mod was the addition of reverse biased signal diodes in the op-amps inverting inputs. It was debatable, but I thought this was a possible stress point during power down. They have zero effect in normal use, but should preserve the fantastic capabilities of the op-amps for many years. I inserted a couple of "virgin" op-amps and the sound seemed "fresher".
I guess that makes 7 differences between the MkIII and MkV, 3 of them being between the MkIV and MkV.
BTW, I heard all these differences with the Solo. Shame you can't review it.
© Copyright 2002 Geoff Husband - http://www.tnt-audio.com