I was trying to eliminate a humming sound that was coming through my system whenever the cable was connected to my Comcast cable box.  Unlike times past, no amount of finagling with the cable connection could eliminate the 60Hz hum and it was driving me crazy.  The temporary solution was to disconnect the cable feed whenever I wanted to use the system but that meant I could no longer watch a cable TV broadcast and hear it through my stereo system.

Every time I even touched the F-connector on the coax cable to the cable box, the hum would immediately come through the stereo.  I began to wonder whether changing the coaxial cable itself, that was feeding the cable box, might be a solution.  I saw a used video/digital cable terminated with F-connectors for sale on an online audio forum, and decided to take a chance.

The coaxial cable I purchased was a 10 foot run, terminated on both ends with the necessary F-connectors, made by Straight Wire and is called the Silver Link II Video/Digital Cable.  If purchased new, a 10 foot length costs $82, but in used (although apparently like new) condition, it only cost me $25.  If it solved my humming problem, it’d be money well worth spending.

Straight Wire Silver Link II Video/Digital Cable                                         Silver Link II F-Connectors
     

Silver Link II Logo                                                                                F-Connector Close-Up
      

It did stop the hum, but only for five days and then the system began to hum even louder than it had before installing the Straight Wire cable.  However, immediately upon its installation and for those five days, there was a dramatic improvement in the sound quality coming from Cable TV-sourced programming.  I found the largest changes for the better were in bass response, dynamics and a wider sound stage.

Alas, on the sixth day the hum returned and was worse than ever.  The solution took the shape of a TII model 220 Isolation Transformer purchased through Amazon.  Once this was installed (in less than a minute’s time) between the Straight Wire Silver Link II and the Comcast cable box, the hum totally disappeared.  Even better, the improvements that the Silver Link II has brought to the system’s cable-sourced sound, have remained.

TTI 220 Isolator                                                           Needless Warning
      

As a point of information, I did not, and still haven’t, noticed any improvements to the video quality of cable TV broadcasts since the introduction of the Silver Link II.  Nor has the TT-220 resulted in any degradation of audio or video quality.  How much of this lack of improvement to the picture quality is attributable to Comcast, my Samsung LCD TV and/or the Silver Link II, is unknown.

As regular readers of these ramblings will know, I had my conrad-johnson Premier 140 repaired and upgraded with CJD Teflon capacitors by the manufacturer (see Part 1 and Part 2).  For almost a year, while the Premier 140 languished, I was using my trusty Premier 11A amplifier and many of the reviews that appear in these pages and this update, were written during that time period. 

What I have found is that a good deal of my impressions regarding the tubes used in my system, including both the Premier 140 and to a lesser degree, the Premier 16LS2 preamplifier, have changed since the 140 went back into service on July 18^th.    

I thought it was time, therefore, to revisit some of my power tube evaluations in light of the Premier 140’s return.  During this three month period, I have auditioned the following baker’s dozen of output tubes.  NB:  Many of the review links are from when the tubes were used in the 11A, and while my general impressions may remain the same, there has been a distinct shift in my preferences based on how the tubes performed in the 140.

Ei KT90 Type 3
General Electric 6550A
New Sensor:  Genalex Gold Lion KT88, Tung-Sol 6550 , Tung-Sol KT120  
Penta Labs KT88SC
Philips ECG 6550
SED =C= 6550C
Sovtek KT88
Tung-Sol 6550:  black plate, solid grey plate, three-hole grey plate
Valve Art KT88

It is difficult for me to state unequivocally that this or that particular tube is my favorite because so much of what goes into that decision process is dependent on ancillary equipment, source material, and quite honestly, my mood.  That having been said, what can be done is to break out these various output tubes into a general system of tiers.  These tiers represent, at this point in time, my overall preferences.  Within each tier, the output tubes are cited alphabetically and are not necessarily an indication of actual preference in that tier. 

For comparison purposes, I’ve indicated in parentheses how I informally ranked these same tubes when evaluating them in the Premier 11A.

Tier 1:   

SED =C= 6550C  (#6)

Tung-Sol 6550 three-hole grey plate (#3)

Tier 2:   

New Sensor Genalex Gold Lion KT88 (#4)

Tung-Sol 6550 solid grey plate (#2)

Valve Art KT88 (#13)

Tier 3:

GE 6550A (#8)

New Sensor Tung-Sol 6550 (#9)

Tung-Sol 6550 black plate (#1)

Tier 4:

New Sensor Tung-Sol KT120 (#10)

Penta Labs KT88SC (#14)

Philips ECG 6550 (#7)

Tier 5:

Ei KT90 Type3 (#11)

Sovtek KT88 (#19)

There are a good many tubes that were reviewed in the Premier 11A that I haven’t tried as yet in the Premier 140.  And so there may be some additions and changes over time, but at this point, these are the standings.  

The sample set of 6922 dual triodes under review is branded National and was made by Matsushita, Japan with tooling obtained from Mullard.  Their exact vintage is unknown but most probably date from the late 70’s to early 80’s.  They were purchased from TubeMonger for $40 apiece.  An average, brand new E88CC/6922 scores between 10500 and 11500 mmhos on the tester used by the vendor and this sample set measured an average of 12150 mmhos, or, about 10% higher than typically the case.

One 6922 was used as the input tube in my c-j Premier 140 amplifier and the remaining six were placed in the Premier 16LS2 preamplifier.  They replaced a set of GE grey glass 6DJ8’s (review one of these days) that had occupied the same seven positions.

The Matsushita 6922's physically resemble their Mullard forbears right down to their seamed tops.  Th review set was auditioned for 46 hours and did not change character through break-in.  They were used almost exclusively with Valve Art KT88 output tubes in the Premier 140; a match that I thought was particularly good.

Matsushita 6922 front view                                                                   Matsushita 6922 rear view
     

Matsushita 6922 top view showing seams                                                Matsushita 6922 getter ring
     

 Listening Impressions:

• Frequency balance is leaner than the GE 6DJ8 but manages to maintain an organic sound indicative of the Mullard/Amperex pedigree.
• The cello work in the first-rate String Quartets SACD on the 2L label, an area where the GE grey glass excelled, is not quite as prominent.
• Conversely, the deepest bass on the Prometheus blu-ray disc was cleaner and managed to be forceful without any boominess.
• The sound stage is sometimes box-like, rather than a triangle with its apex at the listening seat.
• Fine detail within the acoustic was readily apparent and upper treble response is superior to the GE grey glass 6DJ8. 
• The increased high frequency energy gives the impression of more detail with sharper leading edges and a cleaner sounding bass line.
• The Chet SHM-CD released in mono was dynamic with excellent tonality and detail.

I found the Matsushita 6922 dual triodes to be very much in the Amperex camp, in general, and in particular, reminded me most of the Mullard PCC88, with a little less treble emphasis.  Given their lineage, this is not much of a surprise.  If you would like to investigate what all the fuss is about regarding NOS tubes, these may be a relatively affordable way to accomplish your goal.

I thought it might be of interest to compare and contrast two sets of Telefunken branded PCC88/7DJ8 tubes that I have on hand.  One set was actually manufactured in 1968 by Telefunken although I don’t know whether at their Berlin or Ulm plant.  They all bear the telltale Telefunken diamond bottom and their tops are seamless. 

The above sample tubes were purchased from the TubeMonger at a price of $50 apiece and are, unfortunately, no longer in stock.

The second sample, although labeled as Telefunken, were in fact manufactured by Siemens at their Munich plant.  This is evidenced by their production codes.  Additionally, the tubes have the hallmark four-seamed top and lack the Telefunken diamond molded into the glass on the tube’s bottom between the pins.

The Telefunken branded Siemens tubes in the 16LS2 tubes were most likely produced in 1973 (DJ8 ≠3I), the one in the 140 is Platinum grade ($85) and made in 1970 (DJ8 ≠0K) while the other six used in the 16LS2 are Gold Grade at $65 a piece and all were purchased from Upscale Audio.

Upscale and TubeMonger Boxes                                                              TFK/Siemens on Left and TFK on Right
     

TFK/Siemens on Left and TFK on Right                                                    TFK/Siemens on Left and TFK on Right
     

TFK/Siemens on Left and TFK on Right                                                    TFK/Siemens PCC88
     

TFK PCC88                                                                                          The Entire Ensemble
      

Both of these “Telefunken” PCC88 tubes are among my favorites and will see periodic rotation in my system going forward.  The Siemens manufactured version is still readily available and interestingly, of the two, they sound just a bit more organic and sweet than the TFK manufactured tubes.  This is a definite about face from what I normally find when listening to other tube types made by these manufacturers.

The subject tubes were used simultaneously both for the conrad-johnson Premier16LS2 preamplifier and as the input tube for the Premier 140 amplifier.  They were purchased as used but test as new tubes, from a private seller for $20 a pair.  The tubes were manufactured in 1980 at the Voskhod plant in Kaluga, USSR (at the time) and were originally sourced from BOI AudioWorks.  The original source continues to carry these tubes where they retail for $17 each.

The 6H23π-EB (also known as the 6N23P) is a direct replacement for the 6922 twin triode.  The tubes under review are imprinted with a stylized rocket, the Soviet Star and the CCCP designations in gold lettering.  These were most likely manufactured for military use.  They replaced a set of AEG CCa and Siemens E188CC/7308 in the Premier 140 and 16LS2, respectively.

Voskhod 6H23π-EB with Military Imprints                                                Voskhod 6H23π-EB with Saucer Getter
      

Listening Impressions:

• Playing the Twelve Tribes CD, the album sounds harmonically richer with denser and more specific imaging spread nicely over a very wide sound stage.
• Bass guitar has a distinct growl while cymbals are finely filigreed.
• The sound is snappy and peppy without being irritating.  This is not always the case with other tubes which seem to force the detail onto you.  
• The Voskhod 6H23π-EB mate particularly well with vintage Tung-Sol solid grey plate 6550 output tubes yielding a comfortable and organic sound.  The match, however, does not sacrifice detail for richness and manages to accomplish both.
• Images are round and palpable with texture and substance with the overall sound capable of being hard or soft depending on the source and the recording.

As may be easily seen, I was very taken with these tubes and especially so in combination with the Tung-Sol 6550 solid grey plates.

Tung-Sol was the first company to develop the 5687 tube and it was introduced in 1949.  The original version was tall (similar in size to a 12AU7) with black, ribbed plates and a square getter ring.  Tung-Sol 5687’s are generally considered to be the best of this type with a sound that is characterized as smooth, sweet, punchy and as having the most detail.

The 1956 vintage subject pair was purchased as a set of four on April 1, 2005 for $66 at an Ebay auction and was not listed as NOS.  For comparison purposes, a basically identical pair of these tubes is currently being offered on Ebay by a Hong Kong seller for $39.  It would seem that I either overpaid seven years ago or, this type has appreciated at just about the inflation rate during the intervening period.  The review pair is a triple mica design, with smooth black plates, copper posts and a D-shaped (sometimes called a U-shaped or horseshoe) getter ring. 

  Tung-Sol USN 5687WA                                                                         The Pair
      

  Close-Up of D-Getter                                                                          Response Audio RAM Signature CD25
     

I use tubes from the 5687/6900/7044/7119 family in my Music Hall CD25 disc player where they serve the function of Class A gain/output buffer.  The CD25 was sold c. 2003 by Response Audio and is technically called the Response Audio RAM Signature CD25.  The player started life as a Music Hall CD25 and was then extensively modified by Dan Wright’s company ModWright Instruments.  The stock tubes in this unit are cryo-treated Tung-Sol 5687WB of apparently identical construction.

The Tung-Sol USN 5687WA replaced a pair of Philips Miniwatt SQ E182CC/7119 tubes (review forthcoming).  Many of my comments below are actually in direct comparison to both the Philips tube and the GE 7044.  My one pair of Bendix 6900 had one tube suffer infant mortality years ago.  I’ve never replaced the 6900 because they are virtually unobtanium and therefore very expensive, if you can find them.

Listening Impressions:

• Gain was lower than the Philips E182CC/7119 which makes sense since the Mu (amplification  factor) for a 5687 is 17 while the corresponding value for a 7119 is 24 (7044 = 21 and 6900 = 18.5).
• Frequency response is more midrange-centric and classically “tubey” in nature.
• The most holographic sound stage of any tube I’ve heard in this family.
• Treble response is sweet with less of a leading edge to transients.
• The antithesis of a “hi-fi” presentation resulting in a relaxed sound with the emphasis on the music rather than Technicolor effects.  The Breathless CD by Kenny G (okay, there’s no accounting for taste) never sounded more beautifully musical, smooth and sweet with evocative tone (so, I’m dating myself).
• Switching output tubes in my Premier 140 from vintage Tung-Sol smooth grey plates to SED 6550C resulted in better extension at the frequency extremes, greater clarity and a more punchy sound as evidenced when listening to Twelve Tribes by Richard Souther.

Depending on how your system is presently “voiced” and what your sonic goals may be, this Tung-Sol 5687WA may be just the ticket.  However, if you prefer your coffee black and nothing in your scotch except the glass it’s in, you may want to look elsewhere.  

The subject of today’s review is DIY cable elevators.  There are a variety of products commercially available that address this topic ranging in price from a few dollars each to $30 apiece, or more.   

I’ve gone the Do-It-Yourself route using 7-ounce plastic drinking cups.  You could also use toilet paper rolls with notches cut out of them and painted any decorator color you wish, three chop sticks tied together wigwam style, etc.  The limiting factor is your imagination. The plastic drinking cups were purchased at a local supermarket at a cost of 3¢ each.  I buy them periodically anyway for home use, so no special purchase was required in this case.  I used 8 cups to elevate my current set of Sanders ESL speaker cables, for a resulting total investment of 24¢.  While these may not be very attractive, they are functional.  

There is also the question of whether this approach might be susceptible to an electrostatic charge build-up on the cables being suspended.  As a result, I may be substituting one problem, namely the dielectric effect of having my speaker cables resting on my synthetic fiber carpeting, for another.  

According to one cable lifter manufacturer, Shunyata, this is a problem with all products of this type other than their own Dark Field Cable Elevator's and Dark Field Mini Cable Elevator's.  Readers interested in these technical aspects, are directed to the links provided.

Left Channel                                                                                       Bridge to Right Channel
     

Although it isn’t clear in the photographs, the speaker cables do not touch the ground and the apparently coiled portion is also free standing with no contact between the wire.  

Waterfall

The set-up of the Waterfall is not optimal and when I play LPs, there will need to be some adjustments made, but for the moment, this is what it looks like.
 

How does it work?  Surprising well, actually.  There is a subtle but noticeable increase in clarity.  Lower level detail comes to the fore and as a result, the sound stage benefits as well with images embedded a little more solidly.

Do these plastic cups work as well as the more expensive elevators?  I don’t know as I’ve never tried them but this may be a good place to start, and, if you’re satisfied with the results, it could be a good place to finish.  They’re certainly not as attractive as some of the commercially available elevators but if aesthetics aren’t of much importance to you, and you just want to experiment and discover whether there’s a difference in your system, then give them a try.

NB:  If you'd like to read my impressions of the Sanders Sound Systems ESL speaker cables, you can find it here:  review.

Today’s review takes us to Germany and, specifically, to small signal tubes manufactured by Siemens.  The subject tubes are the AEG CCa 6922 which was used as the input tube in the Premier 140 and six Siemens ECC188/7308’s in the Premier 16LS2 preamplifier. 

AEG is an acronym for Allgemeine Elektricitäts-Gesellschaft which is German for “the General electricity company” and the competing radio companies AEG and Siemens & Halske merged back in 1903 to form the subsidiary company Telefunken.  On January 1, 1967 AEG and Telefunken merge to form the not very originally named AEG-Telefunken.  Sound confusing and more than a bit incestuous?  In any event, based on its construction which includes a four-seamed top and a silver production chad bearing the imprint:

A6 (Siemen’s designation for a 6922)
0B (1980 production)

I’m going to say with some confidence, this is a Siemens 6922.  The CCa is a subgroup from general production (typically around 15% of a batch) that was selected for low noise and close triode matching and ear-marked for the German postal service (telephone, telegraph, telex, and the postal system).

The Siemens E188CC tubes in the 16LS2 also bear a silver chad with the imprint:

G6 (Siemen’s designation for an E188CC/7308)
8B (1978 production)

                                             AEG CCa                                                                                     AEG CCa Rear View
     

                                     Siemens E188CC                                                                             Siemens E188CC Rear View
     

                             Siemens E188CC Bottom View                                                             Siemens E188CC Top View
     

As a point of information, some vendors say that the later production Siemens ECC188/7308 (late 70’s and 80’s) sound nothing like earlier production and should be avoided because they sound harsh. 

You take what you can get.  One other bit of information, the Siemens E188CC’s produced a tinging sound out of the left channel speaker at times (especially when cold) when volume changes were made on the preamp.  As far as I could tell, however, they were not microphonic while music was playing.

This set of seven tubes replaced an Amperex pinched-waist 1958 US production 6922 that had been in the Premier 140 and Amperex small O-ring 6DJ8’s from Holland that were marked HP (Hewlett-Packard) in the 16LS2.  In other words, they had their work cut out for them.

Total playing time for this configuration was 54 hours.

Listening Impressions:

• Bass is tight and well-defined with no booming qualities.
• Impactful sound with reference level macrodynamics.
• The overall sound quality leaned towards the analytical with a lack of the Amperex’s vaunted smoothness and refinement.  It could almost be described as more solid state than tubular.
• Frequency response is even across the spectrum but with a little glassiness in the lower/mid treble.
• The sound stage started in a plane farther behind the speakers compared to the Amperex configuration, although it projected well into the listening room as is characteristic for my system.

Changes made to the system which included power cords, speaker cables, aftermarket fuses, and new phase splitter tubes in the Premier 140 while this configuration was in place were consistently audible.  I take that as a very good sign.

If your system currently leans a little to the dark side of neutral, these tubes may offer you a useful fine-tuning option.

The subject of this review is the HiFi Tuning Supreme fast blow, 1.25 Amp fuse that has been recently placed in the rear receptacle of my Modwright/Music Hall CD-25 disc player.  The reader is directed to my previous entry on HiFi-Tuning-Gold 38mm Special Fuses and Fuse Directionality for additional information.

The Supreme fuse replaced the stock, glass fuse that came with the CD player when I purchased it approximately nine years ago from Response Audio.  I use the modified CD-25 for Red Book and HDCD playback.  In those applications, I prefer this player over the Oppo BDP-95 universal player, which does many things well but not always as well as players dedicated to particular purposes.  The CD-25 is currently outfitted with a pair of Philips Miniwatt SQ 7119 small signal tubes sans dampers, no footers of any kind, and Shunyata’s Antares interconnects and Venom3 power cord.

HiFi-Tuning Supreme in Box                                                                   Supreme Standing on Its Own
     

Supreme and Stock Fuses                                                                      Music Hall CD-25
     

As a point of possible interest to readers, Oppo is discontinuing production of the BDP-93 and -95 models and will be introducing their newer counterparts, the BDP-103 and -105 in October.

The fuse was placed in the preferred position, which is with the directional arrow pointed away from the body of the unit and towards the end cap of the fuse receptacle.  I’ve found that in this position, the full benefits of the aftermarket fuse are realized.  I encourage anyone purchasing this type of fuse to experiment and see which orientation is preferred.  The common wisdom is that the fuse should be oriented, as is the case with directional cables, in the direction of current flow. 

As soon as the CD-25 was played after the Supreme fuse was introduced, there were easily audible differences in the sound.  I played a variety of music during the evaluation including Twelve Tribes by Richard Souther, Bach Concertos with Hilary Hahn on violin, and the Mercury Living Presence recording of Janos Starker performing Italian Cello Sonatas. 

I’ve owned the last disc close to 20 years and thought I’d been very familiar with it.  Let me give you the following as an example of how the Supreme fuse has affected the playback abilities of the CD-25.  While reading and listening to this album as background music, track 19 (the Vivace movement of J. S. Bach’s Sonata in G Minor) began to play and immediately drew my attention away from my book.  This album is a somewhat dry recording but one I find reveals changes in my system handily.  This track and the following two portions of Bach’s sonata just sounded better than the previous ones.  The music was more immediate, lateral separation and the depth of the sound stage were markedly better.  I don’t think I’d ever noticed this before so I checked the liner notes after the CD finished playing.  I’d pretty well stopped reading as soon as track 19 commenced.  Anyway, Tracks 19 -21 were not recorded by the same people as the previous material.  The Chief Engineer and Technical Supervisor for these concluding tracks was C. Robert Fine and the Recording Directors were Wilma Cozart and Harold Lawrence. 

It may have been just chance, but I don’t think so, it was only after the Supreme fuse was added to the mix that I became aware of these differences in the recording.

You kind reader, may take this installment on its own.  The recommendation, however, is that it’s read as an introduction to the following installment on the HiFi-Tuning Supreme fuse.  You may also wish to take a gander at the HiFi-Tuning Gold 38mm Special Fuses entry for further fusile reading.

I’ve been spending a lot of time recently listening to fuses.  For those of you who may believe that fuses cannot affect the quality of sound coming out of your sound system, I recommend that you read no further.

Okay, those of you still here, let’s continue.  Not only do fuses affect how my system sounds, the direction the fuse is oriented is just as important.  To my ears, when the fuse is oriented improperly many of the benefits of the aftermarket fuse you’ve forked over your hard-earned cash for are never realized. 

Compared to a properly oriented fuse, the one pointed in the wrong direction just doesn’t sound right.  It gives less detail, dynamics and there’s something definitely not kosher with the sound stage.  In other words, when it’s not pointed properly, you’re going to get some, a little, benefit when compared to most stock fuses but you’re going to definitely consider whether your funds might not have been better spent somewhere else.  Like a tasty single-malt scotch, or some new music, or a decent meal out.

All of the literature in the field I’ve read appears to be unanimous in that the fuse should be pointing in the direction of the current flow, just as your cables that are directional should also be pointed.  In order to do this properly for an internal fuse, you’ll need as schematic and also the ability to read one.  That’s why I haven’t replaced any of the internal fuses in my system:  because I have neither.  The outside fuses, though, that are held in place by an end-cap that fits neatly into a fuse receptacle, is something I can handle.

How to orient the fuse in this case, however, is not an open and shut case.  There are those who believe that the fuse should be pointed with the directional arrow oriented towards the body of the component and therefore away from the end cap and those who believe just the opposite.  In the two cases (on my conrad-johnson Premier 140 amplifier and Music Hall CD-25 disc player) where I’ve tried it both ways, I prefer it pointing towards the end cap. 

When I first received and installed the HiFi-Tuning Gold 38mm Special fuses in the Premier 140 back on August 1^st, I placed the fuses pointing outwards.  This morning, I reversed the fuses prior to warming up my equipment to see what I thought.  After about 45 minutes warm-up, I played the Twelve Tribes CD by Richard Souther on the Narada label on my CD-25.  I immediately wanted to take the fuses out and reorient them because the system now sounded less dynamic, less clear, not as extended at the frequency extremes, and there was something wrong with the sound stage. 

I persevered and listened to the entire CD.  My thoughts were that perhaps because I now had the fuses in the amplifier pointing inward and the one in the CD-25 in the outward position, they were somehow out of sync.  I then reversed the orientation on the HiFi-Tuning Supreme fuse in the CD-25 so it was pointing inward just as its golden brethren were in the amplifier.  I played the Twelve Tribes CD again, and things were even worse.  Everything I didn’t like before was still there, except more so.

What direction is going to work better for you in your equipment, only you can determine.  I urge you, however, to try the fuses in both directions and judge for yourself.     

Interested readers may wish to check out the following thread regarding fuses.  Part of the discourse covers fuse directionality and it was interesting to me that the author, Darqueknight, who did an amazing amount of research into fuses both stock and aftermarket, feels that in almost all cases, external fuses should be oriented outwards towards the end cap.

Here’s the link:  Studies On Residential Power Line Noise, Part-7:  HiFi-Tuning and Isoclean Fuses