LINN's "Classic" Klimax System Hub (2018 Variant) Gets A Surround Module

The recent introduction of the new Linn Klimax System Hub (reviewed here) means there are a few of the previous versions appearing on the used market - a small glut means great pricsd so the 'Musings system has had a nice upgrade to the "front end".

As usual with Linn, the ability to process surround sound is an option and requires a module to be installed into a System Hub (nee Exakt DSM).  Unfortunately for me, the module from my existing Akurate EDSM is not compatible with the Klimax System Hub, so a visit to the dealer was necessary to install the new unit. 

Being a 2020 version of the classic Klimax System Hub, this example has been built on Linn's newest component placement machines and their vapor-phase soldering machine.

Below are some photos of the install steps.

The System Hub is flipped upside down for access to the circuit boards - lifting off the heavy alloy baseplate reveals the Dynamic PSU on the left, an alloy wall for sepration, the main board across the rest of the unit and the HDMI daughter board bottom left

 

 

Here the HDMI daughter board has been removed to allow access to some of the mounting components.  The metal stand-off in the centre of the board is replaced as it now needs to support 2x boards and the screws centre and right along the bottom edge of the picture need to be replaced with new stand-offs

The new surround processor module is positioned on the newly installed stand-offs

HDMI daughter board re-installed and the ribbon cables reconnected.  Time for a last check on torque of the mounting screws and for the baseplate to be refitted.

For contrast, the install in the Akurate Exakt DSM (System Hub) is quite different as it uses a multi-pin connector to sit directly on to the HDMI board. One picture below for comparison, full series of pictures here.

Linn's Akurate Exakt DSM / System Hub - Adding Surround Functionality

Linn's Akurate Exakt DSM (AEDSM - the main source in the 'Musings system) has always had lots of HDMI inputs and an output, since it was launched in 2014.  Later versions and the otherwise identical re-branded System Hub has an updated HDMI board to support later protocols.  If I remember correctly, the update was introduced in 2016, but there must have been some forward thinking going on back then...

At the end of 2018 it became apparent that a surround sound upgrade was available to be retro-fitted to the AEDSM  / Akurate System Hub (ASH), for Exakt systems.  I would say "announced by Linn" but that would be overstating the case as the stealth marketing continues...

To add the new surround board, the later HDMI (2.0) board is needed - we'll see why in the pictures below.  So back in 2016 the board was designed with the ability to add a surround module which wasn't mentioned at the time.  So later AEDSM / ASH products can have the surround module added to the HDMI board already installed, earlier AEDSM products need an update to the HDMI board before the surround can be added.

But surround capability has been available for some time in Exakt right?  Well kind of - if you have a disk player or movie / tv streamer that can decode the signal and then send a multi-channel digital output for the AEDSM to translate that into Exakt and send it to multiple Exaktboxes or Exakt equipped speakers.  So the major change here is that it is possible to connect multiple sources to the AEDSM / ASH where the processing will be carried out inside the DSM, not in the source component.  Also, in previous Exakt surround implementations, as in stereo Exakt, an Exaktbox channel and a power amp channel is needed for every drive unit in every speaker.  Now it is possible to set up an Exaktbox to supply a full range signal to centre, rears and sub, whilst the main left and right channels continue with the normal approach to Exakt.  So that massively reduces the cost of going Exakt surround for those who already have Exakt main front left and right solutions.  For example, in a Linn Akurate system using a 225 centre channel, Akubariks as rears and a sub, and additional 13 channels of Exakt and power amplification is required.  And those Exakt channels would have to be across 2 full Exaktboxes and one Exaktbox sub.  Now those additional centre, rear and sub channels can be driven out of one Exaktbox and 3 amp channels (plus the sub amp).

This will be first of 2 (or possibly 3) parts - in the next I'll get to setting up the system, but for now, this is about the boards that are fitted into an early DSM to get surround up and running.  The pictures below show before and after:

Original HDMI board - The front of the DSM is at the top of the picture: 

It's not easy to spot in this picture, but there are 2x main board layers - HDMI is on the upper board - the lower board contains the pre-amp and Exakt boards.  This upper board ends where you can see the 2x light blue ribbon cables upper left

The Newer HDMI (2.0) Board.  Main interest here is the new long multi-pin connector in the centre of the board:

Surround Module Still in Anti-Static Bag.  It's quite a small unit:

Surround Module Underside:

Note the board copyright on the lower edge in this picture - its not a Linn designed board - it looks like a product of Momentum Data Systems based in California, US. No surprise that it would be an outsourced supplier - Linn won't want all the expense and complication of testing and managing the licencing of this kind of functionality - it changes far too frequently to make sense at Linn production volumes:  http://www.mds.com/wp-content/uploads/Datasheets/Audio/DAE82_rev8d.pdf  Looks like it may be a 4 year old design already.

Surround Module Installed into the Multi-pin Connector on the HDMI Board:

 Next post in this short series will consider connecting up the Exakt system implications.

Digital vs Analogue? But Not Streaming vs Vinyl.

Its already been raised in a couple of posts.

Linn have discontinued their analogue pre-amps.  So its digital volume controls all the way now, with the streamers and pre-amps being combined into the DSM streamer/pre-amp products.

Linn announcement covered here

Initial thoughts on a first listen to a digital volume control (DVC) are here

So how is this relevant to the main system at Audiophile Musings?  Well, it has the following streamer and pre-amp:

Klimax DS/1 (KDS/1) streamer
Klimax Kontrol/1/D (KK/1/D) analogue pre-amp

So Linn are now, effectively, advising customers that combining these 2 products into one Klimax product and using a DVC is an improvement on separates.  They still sell a separate streamer - the Klimax DS/2 (KDS/2) which features a new circuit board layout and an improved clocking system. Said to sound better than the KDS/1, of course.  The alternative, and what Linn seem to be recommending is the combined streamer and pre-amp in one box, the Klimax DSM/1 (KDSM/1) which features a DVC.  Of course, the older, KK1/D separate pre-amp features an analogue volume control.

The analogue vs DVC debate is lengthy on the Linn forum and there's the usual conjecture, assumptions and actual experiences recorded there.  Some are vehemently against, some are accepting, many are still on the fence, probably not having listened yet.  Linn themselves have produced technical information proving that the DVC introduces less distortion into a system, and is therefore, according to them, a good thing.

Why is this currently relevant?  Well, as the KDS/1 has been superceded by the (supposedly) improved KDS/2 streamer, then there's an option to consider upgrading the KDS/1 in the main system.  In typical Linn style, its possible to upgrade an existing KDS/1 to KDS/2 internals.  But it's also possible to upgrade the KDS/1 to the combined streamer and pre-amp, the KDSM/1.  So upgrade to KDS/2 or to KDSM/1 and sell the KK/1/D pre-amp? Or neither and stay as-is, or stay as-is to try and work out what Linn will do next - the myriad changes in the last 18 months or so is probably de-stabilising customers' system development plans, to say the least.  These upgrade options also come with Linn's proprietary Exakt digital outputs which allow the use of Exakt digital crossovers or Exakt enabled Linn active speakers in addition to traditional analogue output. This decision combines the following:

- commit to DVC (or not)
- upgrade the DS (or not)
- upgrade the DS to a DSM (or not)
- open up the option for Exakt at some point in the future (or not, but upgrading doesn't mean this has to be the future)
- are any of the upgrades good value (in the context of a Linn Klimax system)
- consider how any of this works with or without the KK/1/D pre-amp and the multi-channel cinema processor (or not, possibly leading to lots of other considerations / expenditure)

As you can probably see, lots of options for Linn's existing customers (although, as a new customer, things are very much simplified now), and, consequently, lots of confusion.  Change to new Linn? Move to a different manufacturer? Do nothing? Wait and see - for how long?

So, down to the dealer to have a listen, as that's the only way to resolve a few of these questions.  But with the demise of the analogue pre-amps, even that's not so easy now.  In order to listen to the KDS/1 against KDS/2 through a KK/1 pre-amp, its necessary to take along both the DS and the KK. But this does at least allow comparison of the 2 separate products compared to the combined KDSM/1.  A time was sorted out and about 2.5 hours was spent working through the options and making a decision.

At House of Linn, we used a Majik power amp into passive Majik 140s in the upstairs front room - so similar to my own system, but not identical as there weren't enough Majik power amps on hand to run the M140s in active mode.  The shop's pair of Solo power amps were out on demo, so they weren't an option either.  Linn Silver interconnects and one half of K400 speaker cables were used.  All the source and pre-amp components were placed on the top shelf of a Quadraspire Sukono Vent rack with a bamboo top shelf supported by their latest bronze spikes. Control was through Linn Kinsky on iPad and we used volume levels in the 60-65 range. We listened to the following combinations:

KDS/1 and KK/1/D
KDS/2 and KK/1/D
KDSM/1

These were swapped in and out of the system to enable A to B comparisons.  The KDSM/1 was used with the HDMI ports switched off and the KDS streamers with their internal volume controls disabled.  SPACE was disabled and the speakers had been positioned in the room using Tune-Dem by Brian and Trevor of HoL.  We used tracks familiar to me such as Nils Lofgren Live, Malia & Boris Blank, Blues Company, Peter Alderton, Yello and FAC15.  May be a few others over the 2.5 or so hours.

Top Shelf: Left to Right - Shop KDS/2, my KK/1/D and my KDS/1
Second shelf: Majik Power Amp
Rack: Quadraspire Sukono Vent with Bamboo Top Shelf and Bronze Spikes
KSDM/1 not shown in this picture

So first up was the most straightforward option - KDS/1 versus the newly released KDS/2, both playing through the KK/1/D and therefore using analogue volume control. Given that the KDS/1 is the most musical digital source I've heard to date, its surprising to find that Linn have, again, managed to deliver another notable upgrade.  The new clocking and circuit layout has been a spin-off from work done on the Exakt versions of these products, and the changes are more significant in the sound than I was really expecting.  I was thinking (maybe hoping?) that the improvements would be negligible and I could use the cash elsewhere, but no, this is another step forward.  Listen to the KDS/1 and you would think there was no noise floor, no hash in the music, until you hear the same track through the KDS/2 which sounds cleaner - its hard to describe, but there's more definition in the instruments and vocals, there is less "background" for want of a better phrase.  Imaging is more precise (again, I wasn't really aware of a lack of precision in the KDS/1, its still an excellent product) but the biggest change for me was the intonation and expressiveness of vocals.  There's just so much more texture to the way the singer is interpreting the words and providing the feel of the song.  Good stuff.  Is it worth the upgrade price?  No, its not.  However, when factoring in the ability to use the old KDS/1 electronics to create a new streamer (the DS Renew option) and then selling that onwards, then the upgrade becomes much more affordable and worth the extra (IMHO of course).

So, within about 30 minutes it was clear (after discussion around Renew values etc.) that the KDS/2 was something that interested me.  But how will that compare to the KDSM/1?  Will the combined streamer / pre-amp outperform the separates?  The KDS/1 was replaced on the top shelf of the rack with the KDSM/1 and we got started.  Some of the same tracks were used and we swapped between KDS/2 with KK/1/D and then to the KDSM/1 and back.  And here's the thing - its pretty easy to hear the difference between these 2 options, but which you will prefer, I think, will come down to individual choice.  In terms of detail retrieval, then the KDSM/1 is a marginal improvement on the separate boxes.  There's definitely more fine details resolved and there's a little more in terms of the acoustic space of the venue (on live recordings).  So that's it then, choice made?

No, its not that simple.  If I were a new buyer and only heard the KDSM/1, there's every chance that I would enjoy it and want to buy.  It plays tunes, it sounds good.  There are a couple of things I didn't like though - one is a very slight sharp edge to the lead of the notes and vocals - it doesn't sound like distortion, it's just a bit too abrupt.  But more importantly, there's less coherence and flow to the music.  The KDSM/1 plays a tune, but the separates play a more coherent and flowing tune - its easier to follow, to remember and enjoy.  Is the KK/1/D rounding the edges a bit?  Is it softening the spikes to make the music more "comfortable"?  Quite probably.  But when the music needs to shock or excite or thrill, its all there with the KK/1/D - this isn't about slowing the music or softening the impact, its about music sounding like music rather than a hifi.  The KDSM/1 is more hifi, the separates more musical.

So, is the KDSM/1 no good?  Not at all, its very good, and would be fine, and an improvement on the KDS/1, if I hadn't heard the KDS/2 and KK/1/D combination.  Which is superb and sounds like something I can listen to for hours.

KDS/1 is now back at Linn HQ, and a KDS/2 with a Renewed KDS/1 should be back in a couple of weeks.  Really looking forward to the KDS/2 in the system :-)