Wednesday, 28 May 2014

Digital v Analogue Speakers: the Dream and Reality

So I am a huge fan of Meridian kit for digital reproduction (well Sonos excepted), key leaders in lossless processing. Pretty much the most impressive thing I ever heard whilst working in Hifi were 6 x DSP6000s run through a 568.2mm processor at a Hifi show (might have been an early 800 mule to be honest, but it were the DSP6000s that left the impression).  Despite being in probably the most dreadful possible arena for sound reproduction - massively noisy, fake walls - they sounded stupendous.  Only heard DSP6000s a couple of times afterwards and as long as you have the room always sounded epic; One of my future should-I-win-the-lottery purchases (much prefer the monolith look to DSP8000s).  The 568.2mm is a great box, and I was delighted as they came within purchase range recently, it handles all my movies and digital side.

You don't need to go as far as that as DSP5000s work in a huge variety of rooms, and with a decent digital source, and meridian processor you have to go a long way to find something sounding better.  My brother's all time favourite, and we sold a lot of them over the years.  That combination of moving the digital to the speaker, allowing a digital crossover, control of the whole package, two 24/96 (in the two later versions) DACs and 3x75W individual amplification for each drive unit, just put such power and control together in a actually quite compact, and with the DSP, very tolerant box.   It also gets rid of all the piles of power amps that you quickly end up with otherwise.  You get a neat and beautifully designed (if a little boxy for some in shape) system.   You can get them now for £1800 and when you look at what you get, that looks like a bargain to me.

So why don't I have a pair?  Well I would apart from one thing, you can't turn the digital off.  It just seems wrong to me to spend so much money on getting your turntable to sound wonderful, then digitize it on the fly.  I can understand if people want to record their vinyl to high resolution digital 24/96+ for the portability and get access to those original recordings and improved dynamic range and then playing it back digitally when they want to listen (and protecting that precious disk).  But if I am going to be getting up, opening a beautiful gatefold, cleaning a record, carefully placing the needle, I really don't want to know that it's being digitized on the fly, even if into brilliant 24/96 DSP.  I ran my turntable for a while into the 568mm which is digital only. To be honest it sounded absolutely fine, however it didn't feel right at all, and ADC change the volume digitally and then DAC as I only really listen to music on the 568mm in Direct (DSP off), seemed a huge waste.

So I'd like to be able to say that I have one dream system, unfortunately in that virtual living room - and to be fair, it would need to be a very large one, or preferably two large rooms - there needs to be two: One digital and one analogue.   As I slowly build up what I'm listening to at home, I've quickly come to the same challenge, and who has the room or the budget to maintain two?  At some point you need to compromise and pick the junction point in the system for doing that, and which (no matter how balanced you can be), gets final priority digital or analogue.  Two main positions on this one.

Digital wins: use DSP speakers, and a very high quality digital pre-amp with DAC built in of the sort I was looking at like the Mytek 192 and accept the digitization of the phono signal as high up the chain as possible then digital to as close to the speaker as possible.

Analogue wins: use conventional speakers and shorten the path directly through from the phono through a analogue preamp, then feed in the digital as low down the chain as possible with a separate digital preamp/processor, typically into the preamp, but if possible directly into the power amps and speakers.

I'm going with the latter, and next post is on trying to cut out having two pre-amps to do it.

But if space and money wasn't a constraint, and those systems could be kept separate, what would they be for me?  Well a lot of my choices are for the attachment I have to things, as well as the outright sound quality but both of these would sound awesome.

Massive room
Meridian DSP6000 x 6, custom 4x 15" cult of the infinitely baffled  style front facing subs
Second massive room for the subs to vent into behind the screen.
Meridian 800 series processing and decoding

Massive room
Martin Logan Statement E2
Krell 700 Power Amps
Some sort of Krell PreAmp
A Linn LP12 with a Woodsong plinth, probably a Peter Swain Signature

So starting to work towards those, seems like a massive room is a pre-requisite... not to mention a lottery win, ah well back to looking at how to get my Analogue and Digital to play nicely together.

Not actually Statement E2 but rather Martin Logon CLSii, from the Martin Logon site but I rather like this picture and it's using a creative commons licence allowing reuse.

Monday, 26 May 2014

Unbalanced Power: The Tyranny of Interconnects

So after getting the Cyrus 3 Power Amps happily installed I really wanted to know whether balanced XLR or un-balanced RCA connections were going to sound the best, and secretly I really wanted XLR to win.

I hate interconnects.  They are always too short, too expensive, and never enough of the same type to match. It's a complete tyranny in Hifi circles, you have to have the "Right" cable.  That cable is then ludicrously expensive, and hence short, and short is also supposed to sound better, so some are REALLY short,  then suddenly you can only plug your hifi together in maybe one or two configurations without straining any of the leads, and almost certainly that isn't the configuration which would be naturally ergonomic, or often even practical.  But it's notionally going to sound better, and you've invested all this money in shiny gold, silver, copper and PFTE you aren't going to compromise it just because it makes the the buttons difficult to reach.  By the time I've got a digital system to play nicely with my analogue system and both to play nicely with movies, that is a lot of boxes and cables and I'm fed up with them telling me how to organize my kit instead of the other way around.

So balanced is the great hope, use a technology which makes you less dependent on the type of cable, less dependent on the length.  Buy some good but not silly cable, some nice connectors and make your own the right length.  One nice soldering iron and silver solder (the states type you aren't supposed to use in the EU) and I was ready to give it a go.

So balanced is definitely the way to go if

1) You need long lengths of line level connections (say if you want your amplifier in different rooms)
2) If you have a lot of radio frequency interference (RFI)
3) You have kit which is designed from the start only to use balanced.

Balanced if perfectly implemented should be superior, but it's quite rare in kit in the UK, more common in the States, and on less than very expensive kit often it can be an added on after.

So we have the Cyrus 3 Power Amp - offering a balanced XLR imput and an unbalanced RCA input - which sounds better?

These were my creation of test cables, 2.75m long, Neutrik NC3FXXB and NC3MXXB connectors, Van Damme Tour Grade Classic XKE microphone cable, Qables 6.5mm Y-Splitters (to avoid having to daisy chaining with an RCA)  This is a spec you'll find widely on forums for instance on Hitchhikers here.  Having made a setup I can thoroughly recommend all of it - very nice kit. Probably about £35 of parts.  Most from VDCTrading apart from the splitters which are well recommended by headphone enthusiasts from Qables

These were up against my chosen RCA cable of choice from way back when, the Chord (Silver0 Siren.  Silver plated conductors, Teflon outer, nice RCAs.  I've gone through and reconditioned all of mine recently as some of the RCAs developed intermittent connections.  Taking a deep breath and cutting my limited collection of 1m pairs in order to make some really short ones for daisy chaining and linking power amps and meaning I could use them for all my power side.  Chord Silver Siren was about £65 RRP if I remember.  So expensive, short and a fetching shade of matching.purple which pleased me greatly.

So the Cyrus 3 is quite a popular model, more expensive second hand that some that came after without XLRs.  Is it worth it.

Annoyingly no.

I really wanted the balanced to sound better, but on this amp, in this test it doesn't.  The RCA option is more transparent, more open and fresh.  Not that the balanced is bad, if you weren't doing a back to back you wouldn't notice.  But not a retrograde step back I was prepared to solder a complete set of cables and switches to take.

Yes balanced *should* be better, but in this case, on this amp, it isn't and I'm not alone in thinking this.  Various threads on Cyrus forums here

So if you are buying a Cyrus 3 for the balanced connections for sound quality (rather than dealing with distance runs) don't bother.

So this isn't a hugely precise test.  Ideally it should be exactly the same length and cable type balanced and unbalanced to get a precise answer.   But for me it doesn't matter, balanced was a route to great sound with longer cables, and with more widely available cables at low cost and that I could adjust cables without such a very deep breath before cutting precious materials.  So regardless of which part of the picture, the length, the pure copper rather than silver, the insulation, the internal balancing circuitry in the amp, it doesn't matter the RCA sounds better, and I'm back under interconnect tyranny.

At this point I'd really like to state how nice the balanced materials were to work with..  If anyone is out there designing an amp from scratch, design it to have XLR end to end.  Solid, reassuring, and the right size for my fingers and level of dexterity.  RCA isn't.

The Neutrik and Van Damme stuff is made in huge quantities for stadia, studios, and outdoor broadcast.  It's lower cost because of volume at the same time as being beautifully made.  The plugs have enough space to solder and get a really nice connection on them, even if you aren't a soldering master.   They grip the cable fantastically and support the connection, with a dedicated shield stopping shorting out against the case even if you are stretching and abusing the connection.  The plugs lock in and out of components they have metal solid ends, nice tactile flexible ends.  They are in short friendly, robust and everything most hifi plugs aren't.

 The Van Damme cable is very pure, well shielded, strengthened with really nice string cord internally flexible outer insulation, stiffer inner insulation, strips nicely, cuts nicely, feels nice in the hand.  Again everything Hifi cables often aren't.

Hifi cables almost seem to have to be awkward to use otherwise you aren't sacrificing enough for the sound!

Saturday, 24 May 2014

Changing Allegiance on British Amps

I've always been a big fan of the Arcam Delta 290 (A) Integrated and Power Amps (P), and have since 1996 or so a growing stack of 290Ps until recently biamping left, centre and right, and single amping my rears for music and movies.

There has always been a great British Amplifier tradition amplifiers included and around that time there were three or four in particular which were talked about for somewhere around £500 for the integrated and then powers on top to biamp.

The Audiolab 8000 series, What HiFi raved about these, and ran a stack of 4 mono 8000Ms as their reference system, tonally a bit drier than the Arcams which a lot of people liked, and (IMO) pre the 1998 takeover by TAG Maclaren produced some really fine kit before loosing their way a bit after.

Then there was the Arcam Delta serious, bigger, more space in the boxes, warmer at the bottom and sweeter at the top, though not quite as taught.   I thought it was great, better than the Arcam 8 and 9 that followed (though the 9 is based upon the 290) and that's what I bought into.  Technically you could bridge the 290s for powerful monoblocks, but that wasn't the way they worked best, buying a 290A and then horizontally biamping with a 290P produced a really fine sound and you could argue about which one should power the tweeters and which the woofers all day (to my mind the 290P).

I never got to grips with any of the Mission/Cyrus gear.  Mainly because the shop didn't get on with the rep or the company that well, you had to run the speakers because of the awards at What HiFi but they always made it such hard work compared to the Arcam and Meridian which we were doing a lot of.  But I'd always been intrigued.

All this kit is available at extremely reasonable prices now.  You can pick up a 290A/8000A for £150-180 (watch out for the input selector on the 290As), powers for about the same, Cyrus 3 Amplifiers and Powers in good condition a bit more.  More like £180-220.  Any of these will make extremely fine noises if looked after, whilst processing, DACs have moved on hugely, good amplifiers with decent numbers of the right connections are still flexible and sounding excellent.  You just need the space to stack them up.  So something like this I had on test recently after getting each part reconditioned, really sounded beautiful,

So through April I took a plunge and replaced my set of 4 Arcam Delta 290P Amplifiers with a set of 4 Cyrus 3 Power Amplifiers.   Why?

Mainly space.  4 Cyrus (3) Powers occupy the same space as only 2 Arcam 290Ps, and I want to get everything away and in one rack and when scratching my head with how to do that, they came with a lot of additional stuff.  Flexibility to be biamp or bridged, upgradabale with a PSX-R to have two power suppliers one running the control and audio, one the main power stage which also upped the power from 50 to 70Ws, and also offering Balanced connections.

I've got balanced outputs on my Meridian pre-amps and similarly back when I was selling hifi we had one or two XLR compatibles in the shop, but never really ran an end to end balanced demo system, or had enough of the right cables to do be able to do a detailed back to back.  RCA dominated.   So I was eager to get to grips with Balanced.  Most of the DSD dacs also sport balanced, and if I upgraded I wanted to be able to go balanced end to end.

So initially purchasing 2, then another 2, what did I learn about the Cyrus 3 Power Amplifer?  Well there was quite a lot to learn, so here is a collection of useful things if anyone is thinking about them

Firstly they came with either very annoying 3mm banana plugs of slightly less annoying, but not as nice as 4mm normal banana BFA plugs (the hollow stackable type).  This was because of electrocution concerns over on the continent with 4mm bananas going into plug sockets too sweetly leading to lots of EU grumbling abouts.   There are no binding posts so you have to have the right connectors, I've ended up with an amplification pair of each type.

Moorgate Acoustics sell the best 3mm banana plugs I could find
You used to be able to get nice bananas just like the 4mm usual ones, and one seller included 2 of them reminding me, but now you only seem to be able to get 3mm bananas is nasty nickel finishes, so these moorgate ones are pricey at £27.50 but good quality.  If anyone out there has any classic gold plated 3mm bananas (socket and screw) I would be interested in buying them! So if buying a 3mm one make sure you factoring into any connectors into the purchase price.  The quality of the connection on the 3mms seems more solid and satisfying than the BFA ones, and some BFA plugs aren't very nice to solder to.  One of my amps the centre pin in the BFAs seems worn as well.   So I'd recommend if you have the choice go for the 3mm ones and plan ahead.  Some forums say you can squeeze down one of the stackable BFAs from 4mm to 3mm carefully with a crimping or pliers.  Whilst you can get something to "work" like this, the connection was highly unsatisfactory and it made a mess - I would leave well alone.  You can also try and remove the 3mm sockets and replace with 4mm, but it's an arkward place in the amp, and the de-soldering risks breaking plastic bits if you aren't precise. Again I'd leave off and buy the Moorgate plugs or similar.

Next up is that (very simple but internal) modifications are needed to use with a PSX-R so depending on how the seller has been using it may just sit and flash the diagnostic lights at you if not compatible with what you are trying to use it for.  The modification is to change around the order of 4 main coloured cables with connector clips on internally.  Taking the case apart and making the swaps is easy, however I haven't got a good guide to post with pictures.   As I had one that worked and one that didn't I changed the one that didn't to have the same order of wires to the one that did....

This was the only picture I took, a little blurry unfortunately, but you can see the 4 pins, near the transformer at the front, which run Yellow, Blue, Grey, and Brown/Red.

You also need to turn the amps off to change between states mono/stereo and balanced/unbalanced which doesn't make very quick back to back comparisons as easy as they could be, though to protect the amps it's understandable.  I have to say the self diagnosis and protection is very good.  Despite shorting on the case trying to sort speaker connections, and plugging them in in wrong modes, no blown fuses, and accurate flashing lights when reading the manual.

They also run a lot hotter than the 290Ps, not painful to the touch hot or enough to trip the protection (even after sustained loud for long), but quite enough that if you have a front on your hifi rack you notice it's getting plenty warm inside.   The classic Cyrus Hark stands with their flush open edges to the cooling fins clearly weren't shaped like that incidentally.  If putting in a closed unit worth considering.  They also seem to idle in standby a lot warmer.  Being noticably warm if not switched off at the back.

So if you press through a surprising amount of setup learning, what do they sound like?

Against the 290s.  Clearly in the same class, but slightly better.  Taughter and bigger at the bottom, not as sweet at the top, but with more overall detail, and more expansive.  Generally very nice.  I think the tone of the 290s I still preferred, but with the space saving and potential upgrade space, I was happy to trade some slight tone for the resolution and scale.

They are also really compact, although that does encourage you to get a large number of the boxes, you could have 8 just for 2 speakers (4 mono powers and 4 PSX-Rs) if you really wanted.

So all in all a worthwhile change, and at the same time I moved from horizontal biamping (one driving the tweeters left and right, and one driving woofers left and right) with the the 290s to vertical biamping (one driving left tweeter, left woofer, one driving right tweeter, right woofer).  I can't say I can notice any difference in sound quality, however that compact footprint lends itself to being place physically nearer the speaker it drives, and seems to lend itself to a vertical stance allowing shorter speaker cables.