January 1, 2013

• conrad-johnson CA200 Control Amplifier, Part 3

  The CA200 now has 222 hours of playing time accumulated and, during this period, quite a few changes were made to my system.  I’ve broken a number of audiophile rules in the process, including making more than one change at a time, but, life is short.

  This installment covers those changes and the trials and tribulations experienced along the way.

   

  HiFi-Tuning Fuses

  12/19/2012:  at the 73 hour mark, a small (20mm) slow blow HiFi-Tuning Supreme T6.3A fuse was inserted into the drawer under the mains/IEC receptacle.   Four large (32mm) fast blow 6.3A HiFi-Tuning Gold fuses replaced the stock glass body B-/B+ rail fuses.

  Immediately upon reconnecting the power cord, the Supreme fuse popped and the unit failed to power-up.  Although I realized it was the mains/IEC fuse that had blown, this highlights an issue with HiFi-Tuning fuses, in particular, and aftermarket fuses that use opaque bodies, in general:  you cannot determine by looking at the fuse that it has failed.  It is immediately apparent that a glass body fuse has failed when you look at it because you can see that the metal wire is broken and the fuse has a silver flashing on its sides similar to the getter flashing on a vacuum tube.  Opaque body tubes look exactly the same whether they are intact or have failed.

  After replacing the failed fuse with the original fuse, I proceeded with the audition.  Right from the get-go, detail was better, bass was both stronger and more taut, and the sound stage projected more into the listening room.  Spoken voice was more clear and singers more realistically in the room due to the increased detail.  Throat and mouth sounds predominate over chest.  It’s easy to distinguish individual male and female voices within a chorus.  Dynamics also improved.  The overall sound is slightly smoother while simultaneously extracting more detail than before:  a win/win situation.

  There was none of the midrange predominance I find when the fuses are oriented in what is for me the “improper direction” and so I’ve left the B-rail fuses as they are pointing outwards (towards the fuse end-cap).

  The mains fuse has continued to be problematic and has blown three times in total.  As a result, I’ve only used the glass type fuses as they cost less than a dollar.  If I’m able to isolate the cause, I may attempt another Supreme fuse.

   

   

  Mapleshade Megamount Brass Footers

  12/21/2012:  after 107 hours of playing time, three Megamounts were installed under the CA200.  They remained in place for only 4 ½ hours for two reasons.  First they raised the CA200 too close, in my opinion, to the shelf above and I became concerned about possible airflow blockage although this was probably more than compensated for by the increased breathing room under the CA200.  The second, and primary, reason was the fact that, overall, I preferred how the CA200 sounded without them.

  Images were denser and the sound stage projected more into the listening room (something I prefer) but still less than the Premier 16LS2/140 configuration.  The overall sound was slightly softer with less of a leading edge to transients.  This is the only amplifier where this has happened when using the Megamounts.  Both the Premier 11A and Premier 140 have benefited from the Megamounts both in terms of a more airy presentation, as was seen with the CA200, but also with an improvement in transient response, which was just the opposite, as stated, with the CA200.  Both the 11A at 54 pounds and the 140 at 85 pounds are considerably heavier than the CA200, 42% and 124% respectively, and the Megamounts may just be too much support for the CA200.  This hypothesis runs contrary to Pierre Sprey’s comments but it is the only reason I can think of to explain their less-than-stellar performance in this application.

   

   

  Shunyata Hydra Model 8

  12/22/2012:  at the 128 hour mark, I plugged the CA200 into the Hydra Model 8 power conditioner (see Parts 1 and 2 for background information on the Hydra 8).  I tried this change for two reasons:  in hope that the power conditioner would prevent any further blown mains fuses and to note possible changes in the sound.

  The CA200 was now less airy and the upper treble was diminished – both negatives in my book.  Although detail was still excellent, there was definitely less high frequency energy and as a result, the system sounded smoother and, in some ways, the CA200 now seemed more like the 16LS2/140 pairing.  Bass response was more extended but that may have been a psychoacoustic effect of the diminished upper treble. 

  Similarly to the effect of the Megamounts, images were a bit denser, the sound stage projected a little more into the listening room and transients were softer.  My listening notes do not record the actual elapsed time, but within a few hours the CA200 was disconnected from the Hydra 8 and was back to being plugged straight into the wall outlet.  The change was immediate and positive:  the treble was once again crisp and extended.  The CA200 has remained this way since.

   

       

  Cable and Power Cord Changes

  12/22/2012:  later that day.  Fresh from their treatment on an audiodharma Cable Cooker, a Shunyata original model Taipan Alpha power cord was placed on the left channel Quad 989 speaker (so now both speakers were identically powered), a 1m XLO Signature 1.1 interconnect was placed on my cable TV box and a three foot Taipan Alpha Helix power cord replaced the stock cord on my Oppo BDP-95 Blu-Ray/universal player.  The Oritek X-2 interconnect that had been on the cable box was shifted to the Modwright/Music Hall CD-25 disc player.

  The system was smoother (due to the Taipan Helix Alpha on the BDP-95) with a more well-defined central image (due to the matching pair of original Taipans on both 989 speakers).  Bass response was more prominent, dynamics better, decay a touch longer, and detail a shade diminished due to a slight (and I mean very small) lessening in transient sharpness.

   

   

  Mapleshade Triplepoint Brass Footers

  12/22/2012:  even later the same day.  The Megamounts had been, generally speaking, a failure but how would their smaller siblings, the Triplepoints, fare?  After placing them under the CA200, background/low-level details were immediately clearer.  The overall sound was more airy and clarity went from being excellent to reference level.  This was the effect I typically get when placing Mapleshade brass footers under a component.

   

   

  Shunyata Hydra Model 8 Redux

  12/24/2012:  150 hours of playing time have elapsed.  I disconnected all source components from the Hydra 8 in a fit of what can I do now?  My Samsung LCD-TV, the Oppo BDP-95, Olive O3HD, the Music Hall CD-25, and my cable box were now connected to a PS Audio power strip that’s plugged straight into the wall.  Previously, the PS Audio power strip had been connected to the Hydra 8.  Daisy chained to the PS Audio power strip is a cheap plastic power strip that has my Netgear router, modem, telephone, conrad-johnson PV-10A, and Clearaudio Concept turntable connected to it.

  Will the madness end?  The immediate effect was an increase in “air” (although it may very well have been an electronic glaze/haze) and the concomitant diminishing of bass weight.  Musically, there is less slap on percussion and less sweetness (in a negative way) to the sound.  Increasing the volume setting over usual levels does add some weight to the bass, as would be expected.  Images are larger and more diffuse.  Certain sounds such as metal striking metal may be sharper but are also less realistic.   

  As the system settled in, percussion, dynamics and clarity all improved.  The perceived extension in the mid- to upper-treble complimented the sound of early instruments.  As good as the system is performing I can’t help but feel that the music is lacking something that the Hydra 8 lends to the equation:  realism.  The system in its present configuration is more “high-fidelity” but less musical.  There is an emotional connection to the music that’s been broken.

   

   

  CA200 as Preamplifier

  12/27/2012:  170 hours playing time have elapsed.  I now get the brainstorm to try the CA200 as a preamplifier only.  I connect it via Nordost Red Dawn interconnects to the Premier 140 power amplifier  The 140 is not resting on the Megamounts (as it had during previous use) and is connected via the stock conrad-johnson power cord (not the original Taipan Alpha as it had been) to the wall outlet (as usual).  Due to a lack of available outlets, the CA200 is plugged in (via an original Taipan Alpha) to the cheap plastic power strip.  It’s still resting on the Triplepoints and continues to sport the Gold fuses for its B-rails.

  Because the CA200 utilizes what is basically a passive preamp, I have to turn the volume level way up to get comparable sound levels out of the Premier 140.  Bear in mind that although the Teflon capacitors on the 140 are now fully run-in with over 1,300 hours on them, the amp has not been used in two weeks and the capacitors will need some time to “reform”.    

  Initial impression is that the CA200/Premier 140 pairing is not as clear as the CA200 standalone.  However, even cold, with a suboptimal set-up and the capacitors still reforming, the sound is more organic than the CA200 alone and the sound stage is both wider and deeper, which is a hallmark of c-j’s tubed equipment. 

  As more hours tick by, the sound coalesces and is richer, clarity improves and the sound stage begins to envelop me.  Bass response is superior in terms of extension but isn’t as taut.  Sound effects, such as the clinking of glasses, are superior to that of the standalone CA200.  Listening to HBO’s Game of Thrones, the introductory music is harmonically more complex and majestic.  However, I realize that while c-j’s Premier badge is well-deserved, the CA200’s merits, taken on their own, are still exemplary.      

   

  Bach (intentional) to Square One

  12/28/2012:  almost 181 hours have come and gone.  Everything is placed as it was:  the CA200 is once again standalone and plugged directly into the wall, everything else is either directly or indirectly via the PS Audio power strip plugged into the Hydra (Quad 989 speakers excepted).

  During the reconfiguration, the CA200’s mains fuse has once again popped during power-up.  Sigh.  Although I have two of the stock 20mm T6.3A glass fuses on order from conrad-johnson, they still have not arrived.  I decide to venture out of my apartment in search of replacements.  The electrical gods smile on me, for a freakin’ change, and I find the exact same fuses as had come stock with the CA200 at the much-maligned Radio Shack for less than $4 for a four pack.  I hurry home and insert the fuse, power it up, and, Lord have mercy, nothing goes wrong.  Everything is good in Mudville.

  First up, I play the Mstislav Rostropovich/Hugo Wolff Teldec recording of C.P.E. Bach, Vivaldi, Tartini: Cello Concertos via the BDP-95 from a copy ripped to my personal computer.  Parenthetically, as much as I like the AudioQuest Forest Ethernet cables (see Parts 1, 2, and 3 for the details), I prefer the sound of the BDP-95 wirelessly connected to my Netgear router.  The sound stage with the BDP-95 connected via the Forest is excellent, but for sound stage transparency and detail clarity, the wireless connection is superior, even if not quite as harmonically rich.  The bite on the cello’s string is sharp and the harmonics are richer than the system sans Hydra 8 power conditioner.

  Further listening on the cable box (Game of Thrones and Straw Dogs), on the BDP-95 via Netflix (Lost Girl), and the Olive O3HD music server (Americas), cements the deal.  For the CA200 as a standalone, this is the optimal configuration so far.

   

  For those of you still awake, I applaud your perseverance.

   

  Still to come:  the CA200 back on the Triplepoints and a new player in this game, the Shunyata Guardian Pro 6  power conditioner, as a possible replacement for the PS Audio power strip, enters the fray.       

            

  • 12:54 pm
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