May 14, 2012

• Electro-Harmonix KT88EH

  The Electro-Harmonix KT88EH can be widely purchased from online tube vendors such as Upscale Audio for $34.95 each and the Tube Depot for $59.95 per pair.  The KT88EH is a top getter only, three-hole grey plate tube with a chrome-colored collar and black base.  Two of the tubes in this matched quad have a decidedly greenish cast to the glass bottles.  To my eyes, the KT88EH looks remarkably similar to the Electro-Harmonix 6550EH, differing only in bottle shape.  I would assume, however, that there are electrical differences between the two.  Whether these differences extend to how these two output tubes sound, will remain an open question until the 6550EH review.   

   KT88EH Front view                                                                               KT88EH Rear view
          

  KT88EH Close-up                                                                                 6550EH and KT88EH side by side.  Note the greenish cast to the KT88EH
           

  
  

  The quad of KT88EH in this review, although in my possession for years, had only a little use on them and continued to improve for the first day and a half (approximately 12 hours) of my audition.  My comments are based on how they sounded to me after they were fully broken-in.  Total playing time was about 27 hours.  .

   

  Listening Impressions:

  • Lacking in deep bass
  • Average (good) treble transients and a bit closed in on the very top of the range (that I can hear).
  • Very  good midrange with clear dialogue and vocals; realistic in portraying clapping and crowd noises.
  • Macro-dynamics are somewhat reined in and I find myself turning up the volume two or three clicks from its normal position (so about a 1.5 to 2 dB boost in level is needed).
  • As I have found to be typical of most output tubes in the KT88 family, soundstage width, depth and height are a borderline 4 out of 5 (where fair = 1, good = 2, very good = 3, 4 = excellent, and 5 = reference level).
  • Image specificity is very good with more going on behind the speakers than typically the case.
  • In general they are pleasant sounding, although ultimately just competent and somewhat uninvolving.

   

  In the final analysis, I would place these on par with the Shuguang KT 88-98 at the bottom of the output tubes reviewed so far during this phase of auditions.

   

  Sidebar:

  A reader’s review in Upscale Audio has the statement that “the KT88EH and Gold Lion are virtually the same tube, with the Gold Lion recieving (sic) more QC/QA and a really spiffy paint job.”  Now, the KT88EH that I have are from October, 2002 and January, 2003 but I’ve also looked at the picture of this tube from Kevin Deal’s web site and his tube is from July, 2006 and the New Sensor Gold Lion KT88 and the KT88EH are most definitely structurally not the same tube. 

  The differences I noted, from top to bottom:  The KT88EH has a single top getter ring while the Gold Lion has two top getter rings;  the KT88EH has six support rods while the Gold Lion has four; the KT88EH has a circular getter splash shield while the Gold Lion’s started as a circle but had its two opposite sides squared-off plus it has a large hole in its center that the KT88EH lacks; the KT88EH has no side getters while the Gold Lion has a centrally located side getter on either side.

  I think you can tell from this description that while the same parent company, New Sensor, may produce both of these tubes, they are, in fact, quite different in appearance and, in my opinion, are nowhere near in sound. 

  The lesson to be learned here is to not take everything you read, including my own ramblings to be the gospel truth.  Remember Sturgeon’s Revelation (usually mistakenly referred to as Sturgeon’s Law):  “ninety percent of everything is crap.” 

  • 10:08 pm
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