Grant Fidelity Shuguang Treasure 6CA7-Z Grade A
12/5 - 12/30/10 Preliminary matters. In order to determine the trajectory of the break-in of the 6CA7-Zs, I used the time before the arrival of the Grant Fidelity Shuguang Treasure 6CA7-Zs to treat the sound room with acoustic foam panels. Properly treating the sound room will permit hearing small sonic differences attributable to cable switching, adjustments to component menu settings, cartridge tracking force, power plug polarity and the like. With the RAM NOS Siemens EL34s output tubes in the Music Reference RM9 mk ii amplifier, there should be a latitude in bias current of about 20% (that’s according to its designer Roger Modjeski, who stated that within the + or - 20% in bias current for the NOS Siemens, there should be no effect either on the sound of the EL34s or on the tubes’ life-spans). I did, however, notice a strong effect of bias current on the JJ KT77s’ tonal structure, although not so much on the EH EL34s. The best bias setting for the JJs in the RM9 was to reduce the bias led lights on the RM9 to just nil and then add the smallest amount of bias back.
On Benjamin Britten Ceremony of Carols, recorded in Chapel of St. John’s College, Cambridge, on Argo label, one can hear distinctly moving car engines in the recording background. At this point the soundstage was so large and the sound so satisfying, that I questioned the need to spend more money on the Treasure 6CA7-Zs. The JJ KT77s had about 500-600 hours, the Amperex Bugle Boys driver 6DJ8s had 60-80 hours on them, the Grant Fidelity Shuguang Psvanes 12AX7s, 12AT7 and 12AU7 in the Hovland HP-100 preamplifier had about 100-120 hours and the Clearaudio Discovery cartridge had about 250-300 hours on it.
I did not want to choose the currently popular KT88s, since like other amplifier designers such as for VTL and VAC, I believe, Roger Modjeski does not recommend replacing the stock Chinese EL34s with the 6CA7-Zs, 6550s, KT66s, KT77s or KT88s, despite the manual’s text allowing the substitutions (in that order) without having to make any physical changes to the amplifier. Yes, the KT88s may give you more powerful bass or dynamics, but at the likely expense of adversely altering the timbral structure and other qualities of the sound. The RM9 was designed and voiced around the Chinese EL34s, and I believe the user should stick with that tube (RAM recommends their NOS Siemens EL34s and Shuguang does not make a Treasure EL34s, but the 6CA7-Zs do have similar albeit not identical electrical characteristics to the EL34s - see Wikipedia). I bought the Grade A versions of the Treasure tubes, since Grant Fidelity does extensive testing and screening for the best samples for its Grade A label. See http://www.audiocircle.com/index.php?topic=89231.0. I am reasonably assured that the 6CA7-Zs are a close match to the NOS Siemens EL34s electrically.
12/30/10 Eight Grant Fidelity Grade A Shuguang Treasure 6CA7-Zs were installed. Within the first hours, a lean sound became bass heavy, then hollow-sounding. I balanced the driver tubes and re-biased the output tube current to slightly past a dimly lit led. By the 3rd hour of break-in, the Treasures produced a clearer sound with less smearing and better balance and I wrote in my notes that I could not go back to the JJ KT77s or the EH EL34s, if the these tubes were priced the same.
By the 4th hour, the harmonic structure relaxed and there was a spooky realism to the vocals on Paul Simon Graceland and the low level resolution combined with less masking and smearing contributed to a beautiful natural sound, with clearly delineated music lines and instruments with nice sonic reliefs on Handel Messiah with Charles Mackerras on Angel record side 6. Messiah is not a particularly good recording, and I can see how some people might use the KT88 or 6550 to bump up the bass or dynamics for a more exciting sound from this recording, but at what cost to timbral neutrality on other better recordings and pressings ?
1/1 - 1/15/11 As the sound changes with each passing day due to 6CA7-Z break-in, I could make minute adjustments to the system because of the improvements to the sound, like more cable switching and switching the power plugs to different outlets. By the 25th hour of break-in, the sound was slightly more dynamic with more of a 3-dimensional sense than what I remember the Siemens EL34s to sound like. There was a grunt and grittiness and punch in the drums on Saint Saens Danse Macabre Charles Dutoit on London ffrr label, and Riccardo Muti’s Tchaikovsky Romeo and Juliet Fantasy overture on Angel label, which do not seem compressed.
By the 40th hour of break-in, the Treasures gave a glimpse of what a world class system might sound like, when reproducing the sound of a large orchestra at full tilt. There were dynamics stronger than I have heard before on my system with remarkable decay on piano tones. The soundstage can be wide and somewhat deep with an almost piercing vocal presence within a distinctive soundstage acoustic, as in Jill Steven Desert Rain or Bruce Springsteen’s vocals and the harmonica in Ghost of Tom Joad or Chabrier Spanish Dances with Ataulfo Argenta. The volume of the soundstage varied with each LP, so the Treasures did not sweeten or embellish the sound, nor did they obfuscate recording flaws or venues.
By the 50th hour, the Treasure 6CA7-Zs were producing the kind of prominent, full-bodied midrange that I remember the Siemens produced, to the point where they appeared to depart from tonal neutrality. But although the bass was satisfactory, the Treasures at this point were bested in both bass and dynamics by the JJ KT77s. On the other hand, the low level resolution and lack of smearing and masking with the Treasures combined to expose the flaws in each recording, pressing or musicianship, as well as laying bare the missteps, timing errors and sour notes (part of which may be due to the weaknesses of my modest analog source). Nevertheless, on LP after LP such as Jimmy Rogers Blue Bird side 2 on Analogue Productions, the sound is confirmed as to dynamics, clear, full and large harmonic tones, contrasting with more focused piano tones and more focused still guitar tones within a larger acoustic soundstage, as if the tones were being cushioned against a larger acoustic envelope. Although the JJ KT77s and possibly the Treasure KT88s might exhibit better dynamics, there is much to be risked and lost in using a tube different from the ones around which the amplifier is designed.
By the 60th hour, the midrange and the upper bass are more pronounced, although I would hesitate to call the overall sound warmer than what I remember the Siemens EL34s to sound like. The treble of the Treasures are not equal to the sound of the EL34s, which reproduced violins with a delicate almost gossamer quality, resembling, as an analogy, shifting cloud formations. The tonal colors of the Treasure 6CA7-Zs, on the other hand, are more solid in the upper frequencies and denser in the midrange, as in the Eagles Hell Freezes Over side 4, where the sound including the applause have greater body and the better sense of separate individual pairs of clapping hands, aggregating to the applause of a crowd. The vocal timbres may be similar between the Siemens and the Treasures, but the Treasures have the more solid bass tonal colors and definition, while the Siemens had the ecstatic upper frequency qualities.
Through the 100th hour of break-in, there was still some harshness in the mass violin passages and the tonal purity heard during the soft passages were masked during the more complex musical passages, a condition that persisted after the normal ½ to 1-hour warm-up period for the 6CA7-Zs. Various LPs such as George Frederic Handel Watermusic with Trevor Pinnock, Ataulfo Argenta El Sombrero de Tres Picos, Nirvana Nevermind on regular pressing, Johan Sebastian Bach Konzerte on DGG Archiv side 10 and The Who Who’s Next side One all exhibited a slight tipped up condition.
1/16 - 1/31/11 While the Treasures were breaking in, I took advantage of the increasing low level resolving powers of the tubes to make further micro-adjustments to the system, including reducing the bias current to a barely lit red led and moving the speakers backward and forward, and side to side, toeing in and out, to a final adjustment of 1/4 inch to 1/8 of an inch precision in the final positions. Some of the tipped up condition I found with the Treasures is due to improper or sub-optimal speaker positioning. If the speakers are too narrowly placed, or too near each other, or if resonances are too great due to sub-optimal speaker positioning, then there is a smearing of tones, resulting in among other things, a tipped up condition. I noticed this effect in treating the room with acoustic foam panels. On removing some of the bass resonances, the tipped up condition improved simultaneously as well. With the removal of excessive bass resonances, there was greater detail in the harmonics, greater timbral accuracy, better focus, less high frequency distortion and slightly greater dynamics, although there may have been slightly diminished left-right spaciousness in the soundstaging.
I also played with DVD soundtracks, using Dolby Digital 5.1, Dolby ProLogic 2, and DTS bitstream. The sound improvements tracked those heard in LP playing. If I had to assign a number to the changes in sound, I would say that the tonal density of the DVD sound had nearly doubled and that the sound tones took on a life and animation of their own. There is a deep and rich soundstage, very dynamic at times with thunderous bass, and in DTS (digital theater sound) format, as in Steven Spielberg’s War of the Worlds (2005), the sound can be menacing. Yet playing Cat Stevens Teaser and the Firecat on Mobile Fidelity recording side 1, there was presence and delicacy, as well as tonal density. At this point I believe that the use of KT77s, 6550s or KT88s in the RM9 for the sake of augmenting bass slam or adding explosive dynamics to the sound runs a serious risk of injuring the overall timbral accuracy and possibly other parts of the 6CA7-Zs’ sound. See also Erick Lichte’s review of the KT88s’ sound compared to the EL34s’ sound in the Mystere ia21 report in Stereophile vol 34 no 3 March 2011, and Dick Olsher’s report on the slight sonic change from EH 6CA7-Zs to Mullard reissue EL34s in Van Alstine Ultrawave power amplifier in The Abso!ute Sound issue 204 August 2010.
According to my notes, at about 110 to 120 hours of break-in, the sonic presentation had so many dimensions/parameters/indices of sound qualities all working in cohesion and simultaneously that I could not point to any single parameter as the focus of improvement due to break-in, such as the warmth or the dynamics or the image focus. At that point I thought that the room was now too small, as the sonic presentation was improving along all these parameters simultaneously and almost overwhelmingly in my small room, suggesting that the 6CA7-Z break-in was splintering into a number of different directions.
What started out as a luxuriant 6CA7-Z sound turned into a lively sound, characterized by independent instrumental sounds, some soft and rounded, and others detailed and resolved with their warts and flaws exposed - all at the same time and within the same sonic presentation.
On Beethoven Piano Concertos with Solti and Ashkenazy on London label side 3, the piano notes sounded cushioned and wrapped in their own acoustic envelope, much like the sound of the front door slamming shut in a Cadillac car, that satisfying thud, as opposed to the sound of a car door closing in a lees expensive car. This would differ from the presentation, for example, in Gustav Mahler Symphony of a Thousand (8th) George Solti on Japanese pressing, which sounded harsh, compressed and uninviting and that in Joni Mitchell Court and Spark on DCC Compact Classics, title track and Help Me, the all-vacuum tube cutting for which resulted in delicate overtones and cymbals, contrasting with the solid electric guitar tones, all in a near grainless sonic presentation.
At about 150 hours, there has been a substantive shift in the sonic presentation. Whereas prior, the individual elements of the presentation appeared to have been taking their positions, much like orchestral musicians taking their seats, now the Treasures seem to be entering the stage and performing their intended work - making music.
At about 175 hours, the sound elicited emotional responses. Whereas the Siemens EL34s highlighted the beauty of the high frequencies of the spectrum, producing gossamer mass violin string sounds, the Treasure 6CA7-Zs produced just as gorgeous midrange-treble colors with slightly less of the gossamer treble qualities. The apparent timbral accuracy, moreover, is compelling, similar to but not the equal of what the better solid-state amplifiers can achieve, which solid-state seemingly can achieve so much more effortlessly.
At about 200 hours, the Treasures permit and almost demand the adjustments and re-adjustments of your system components, integration and tweaks. I was adjusting the turntable matting, the bias current on the output tubes yet again, the azimuth by altering the tonearm counterweight rotation position, to the point where the tonal sustain was gorgeous, the equivalent of the Siemens EL34s, and where the pre-echo sound that you hear on vinyl, during that otherwise silent leader space immediately preceding a loud cut, itself had some tonal color - which I had not heard with the Siemens. That was surprising.
2/1 - 2/28/11 As the Treasures continued to break in, the sound changed daily through the 300th hour on 2/19/11. The sound became more liquid, less harsh, more even, rounded and balanced in timbral structure, with a deepening soundstage. By the 300th hour, the Treasures matched the Siemens as I remember them in the above qualities, but with more incisiveness, vivid vocals, dynamics, less smearing and masking, better low level resolution and colors and better bass control and better harmonic colors in the sustain and the decay. On the other hand, the Siemens bested the Treasures in the delicacy and nuance of applause and mass strings. Even if I forego the Siemens’ gossamer strings and the subtle rendition of delicate piano notes recalling the image and sound of raindrops, the Treasures nevertheless approximated the Siemens in this regard and bested them in the other qualities mentioned above, and I still would wish that the Treasures rendered a deeper and taller soundstage with better transparent layering; but in all fairness, that may be the fault of the rest of my system not being up to par, rather than the fault of the Treasures.
Several friends stopped by with their Benchmark and Art-Dio DACs, and two weeks later another brought his Eastern Electric Minimax DAC. Although cursory in review, the digital sonic presentation confirmed the resolving, dynamic and tonal qualities heard with vinyl.
I would recommend the Shuguang Treasure 6CA7-Zs, as tested and screened by Grant Fidelity, as a substitute for the EL34s. The additional cost is well worth the better Grade A. I noticed that the heat from the Treasure 6CA7-Zs is substantially and significantly less than the heat that emanated from either the Siemens or the JJ KT77s or the EH EL34s. That thermal difference could well mean a longer life-span for the Treasures. Additionally to avoid undue stress on the output tubes, for the nominal 8-ohm Waveform speakers which dip to 4 ohms, I used the 4-ohm taps on the RM9 mk ii, as recommended by Roger Modjeski, who advises in general not to use a tap higher than the minimum impedance of the speaker.
Current System
VPI HW-19 mk iii, Rega RB600 tonearm, Clearaudio Discovery cartridge
Hovland HP-100 preamplifier with Grant Fidelity Shuguang Psvane 12AX7, 12AT7 and 12AU7 tubes
Music Reference RM9 mk ii amplifier refurbished with new capacitors, tube holders, etc and Amperex Bugle Boys 6DJ8 driver tubes and Grant Fidelity Shuguang Treasure 6CA7-Zs Grade A tubes
Waveform Mach Solo speakers
Meridian 568.2 sound processor for its digital crossover at 80Hz and low pass filter at 90Hz to dual Electron Kinetics Eagle 2 and 2c solid-state amplifiers to the Waveform Mach Solo woofers
Kimber Select 1030 interconnect, Wegrzyn Silver Slam speaker cables, Walker Audio Reference Speaker Links and assorted power conditioning gear
Prior System
Same as above except :
Rega RB300 tonearm, Clearaudio Virtuoso Wood cartridge
Audible Illusion Mod 3 preamplifier with RAM Sovtek tubes
Music Reference RM9 mk ii amplifier with RAM Sovtek driver tubes and NOS Siemens EL34s
Kimber 8TC speaker cables
Room Size 18' x 11' x 7'
Speaker-listener physical boundaries 12' x 10' x 4' height
12/5 - 12/30/10 Preliminary matters. In order to determine the trajectory of the break-in of the 6CA7-Zs, I used the time before the arrival of the Grant Fidelity Shuguang Treasure 6CA7-Zs to treat the sound room with acoustic foam panels. Properly treating the sound room will permit hearing small sonic differences attributable to cable switching, adjustments to component menu settings, cartridge tracking force, power plug polarity and the like. With the RAM NOS Siemens EL34s output tubes in the Music Reference RM9 mk ii amplifier, there should be a latitude in bias current of about 20% (that’s according to its designer Roger Modjeski, who stated that within the + or - 20% in bias current for the NOS Siemens, there should be no effect either on the sound of the EL34s or on the tubes’ life-spans). I did, however, notice a strong effect of bias current on the JJ KT77s’ tonal structure, although not so much on the EH EL34s. The best bias setting for the JJs in the RM9 was to reduce the bias led lights on the RM9 to just nil and then add the smallest amount of bias back.
On Benjamin Britten Ceremony of Carols, recorded in Chapel of St. John’s College, Cambridge, on Argo label, one can hear distinctly moving car engines in the recording background. At this point the soundstage was so large and the sound so satisfying, that I questioned the need to spend more money on the Treasure 6CA7-Zs. The JJ KT77s had about 500-600 hours, the Amperex Bugle Boys driver 6DJ8s had 60-80 hours on them, the Grant Fidelity Shuguang Psvanes 12AX7s, 12AT7 and 12AU7 in the Hovland HP-100 preamplifier had about 100-120 hours and the Clearaudio Discovery cartridge had about 250-300 hours on it.
I did not want to choose the currently popular KT88s, since like other amplifier designers such as for VTL and VAC, I believe, Roger Modjeski does not recommend replacing the stock Chinese EL34s with the 6CA7-Zs, 6550s, KT66s, KT77s or KT88s, despite the manual’s text allowing the substitutions (in that order) without having to make any physical changes to the amplifier. Yes, the KT88s may give you more powerful bass or dynamics, but at the likely expense of adversely altering the timbral structure and other qualities of the sound. The RM9 was designed and voiced around the Chinese EL34s, and I believe the user should stick with that tube (RAM recommends their NOS Siemens EL34s and Shuguang does not make a Treasure EL34s, but the 6CA7-Zs do have similar albeit not identical electrical characteristics to the EL34s - see Wikipedia). I bought the Grade A versions of the Treasure tubes, since Grant Fidelity does extensive testing and screening for the best samples for its Grade A label. See http://www.audiocircle.com/index.php?topic=89231.0. I am reasonably assured that the 6CA7-Zs are a close match to the NOS Siemens EL34s electrically.
12/30/10 Eight Grant Fidelity Grade A Shuguang Treasure 6CA7-Zs were installed. Within the first hours, a lean sound became bass heavy, then hollow-sounding. I balanced the driver tubes and re-biased the output tube current to slightly past a dimly lit led. By the 3rd hour of break-in, the Treasures produced a clearer sound with less smearing and better balance and I wrote in my notes that I could not go back to the JJ KT77s or the EH EL34s, if the these tubes were priced the same.
By the 4th hour, the harmonic structure relaxed and there was a spooky realism to the vocals on Paul Simon Graceland and the low level resolution combined with less masking and smearing contributed to a beautiful natural sound, with clearly delineated music lines and instruments with nice sonic reliefs on Handel Messiah with Charles Mackerras on Angel record side 6. Messiah is not a particularly good recording, and I can see how some people might use the KT88 or 6550 to bump up the bass or dynamics for a more exciting sound from this recording, but at what cost to timbral neutrality on other better recordings and pressings ?
1/1 - 1/15/11 As the sound changes with each passing day due to 6CA7-Z break-in, I could make minute adjustments to the system because of the improvements to the sound, like more cable switching and switching the power plugs to different outlets. By the 25th hour of break-in, the sound was slightly more dynamic with more of a 3-dimensional sense than what I remember the Siemens EL34s to sound like. There was a grunt and grittiness and punch in the drums on Saint Saens Danse Macabre Charles Dutoit on London ffrr label, and Riccardo Muti’s Tchaikovsky Romeo and Juliet Fantasy overture on Angel label, which do not seem compressed.
By the 40th hour of break-in, the Treasures gave a glimpse of what a world class system might sound like, when reproducing the sound of a large orchestra at full tilt. There were dynamics stronger than I have heard before on my system with remarkable decay on piano tones. The soundstage can be wide and somewhat deep with an almost piercing vocal presence within a distinctive soundstage acoustic, as in Jill Steven Desert Rain or Bruce Springsteen’s vocals and the harmonica in Ghost of Tom Joad or Chabrier Spanish Dances with Ataulfo Argenta. The volume of the soundstage varied with each LP, so the Treasures did not sweeten or embellish the sound, nor did they obfuscate recording flaws or venues.
By the 50th hour, the Treasure 6CA7-Zs were producing the kind of prominent, full-bodied midrange that I remember the Siemens produced, to the point where they appeared to depart from tonal neutrality. But although the bass was satisfactory, the Treasures at this point were bested in both bass and dynamics by the JJ KT77s. On the other hand, the low level resolution and lack of smearing and masking with the Treasures combined to expose the flaws in each recording, pressing or musicianship, as well as laying bare the missteps, timing errors and sour notes (part of which may be due to the weaknesses of my modest analog source). Nevertheless, on LP after LP such as Jimmy Rogers Blue Bird side 2 on Analogue Productions, the sound is confirmed as to dynamics, clear, full and large harmonic tones, contrasting with more focused piano tones and more focused still guitar tones within a larger acoustic soundstage, as if the tones were being cushioned against a larger acoustic envelope. Although the JJ KT77s and possibly the Treasure KT88s might exhibit better dynamics, there is much to be risked and lost in using a tube different from the ones around which the amplifier is designed.
By the 60th hour, the midrange and the upper bass are more pronounced, although I would hesitate to call the overall sound warmer than what I remember the Siemens EL34s to sound like. The treble of the Treasures are not equal to the sound of the EL34s, which reproduced violins with a delicate almost gossamer quality, resembling, as an analogy, shifting cloud formations. The tonal colors of the Treasure 6CA7-Zs, on the other hand, are more solid in the upper frequencies and denser in the midrange, as in the Eagles Hell Freezes Over side 4, where the sound including the applause have greater body and the better sense of separate individual pairs of clapping hands, aggregating to the applause of a crowd. The vocal timbres may be similar between the Siemens and the Treasures, but the Treasures have the more solid bass tonal colors and definition, while the Siemens had the ecstatic upper frequency qualities.
Through the 100th hour of break-in, there was still some harshness in the mass violin passages and the tonal purity heard during the soft passages were masked during the more complex musical passages, a condition that persisted after the normal ½ to 1-hour warm-up period for the 6CA7-Zs. Various LPs such as George Frederic Handel Watermusic with Trevor Pinnock, Ataulfo Argenta El Sombrero de Tres Picos, Nirvana Nevermind on regular pressing, Johan Sebastian Bach Konzerte on DGG Archiv side 10 and The Who Who’s Next side One all exhibited a slight tipped up condition.
1/16 - 1/31/11 While the Treasures were breaking in, I took advantage of the increasing low level resolving powers of the tubes to make further micro-adjustments to the system, including reducing the bias current to a barely lit red led and moving the speakers backward and forward, and side to side, toeing in and out, to a final adjustment of 1/4 inch to 1/8 of an inch precision in the final positions. Some of the tipped up condition I found with the Treasures is due to improper or sub-optimal speaker positioning. If the speakers are too narrowly placed, or too near each other, or if resonances are too great due to sub-optimal speaker positioning, then there is a smearing of tones, resulting in among other things, a tipped up condition. I noticed this effect in treating the room with acoustic foam panels. On removing some of the bass resonances, the tipped up condition improved simultaneously as well. With the removal of excessive bass resonances, there was greater detail in the harmonics, greater timbral accuracy, better focus, less high frequency distortion and slightly greater dynamics, although there may have been slightly diminished left-right spaciousness in the soundstaging.
I also played with DVD soundtracks, using Dolby Digital 5.1, Dolby ProLogic 2, and DTS bitstream. The sound improvements tracked those heard in LP playing. If I had to assign a number to the changes in sound, I would say that the tonal density of the DVD sound had nearly doubled and that the sound tones took on a life and animation of their own. There is a deep and rich soundstage, very dynamic at times with thunderous bass, and in DTS (digital theater sound) format, as in Steven Spielberg’s War of the Worlds (2005), the sound can be menacing. Yet playing Cat Stevens Teaser and the Firecat on Mobile Fidelity recording side 1, there was presence and delicacy, as well as tonal density. At this point I believe that the use of KT77s, 6550s or KT88s in the RM9 for the sake of augmenting bass slam or adding explosive dynamics to the sound runs a serious risk of injuring the overall timbral accuracy and possibly other parts of the 6CA7-Zs’ sound. See also Erick Lichte’s review of the KT88s’ sound compared to the EL34s’ sound in the Mystere ia21 report in Stereophile vol 34 no 3 March 2011, and Dick Olsher’s report on the slight sonic change from EH 6CA7-Zs to Mullard reissue EL34s in Van Alstine Ultrawave power amplifier in The Abso!ute Sound issue 204 August 2010.
According to my notes, at about 110 to 120 hours of break-in, the sonic presentation had so many dimensions/parameters/indices of sound qualities all working in cohesion and simultaneously that I could not point to any single parameter as the focus of improvement due to break-in, such as the warmth or the dynamics or the image focus. At that point I thought that the room was now too small, as the sonic presentation was improving along all these parameters simultaneously and almost overwhelmingly in my small room, suggesting that the 6CA7-Z break-in was splintering into a number of different directions.
What started out as a luxuriant 6CA7-Z sound turned into a lively sound, characterized by independent instrumental sounds, some soft and rounded, and others detailed and resolved with their warts and flaws exposed - all at the same time and within the same sonic presentation.
On Beethoven Piano Concertos with Solti and Ashkenazy on London label side 3, the piano notes sounded cushioned and wrapped in their own acoustic envelope, much like the sound of the front door slamming shut in a Cadillac car, that satisfying thud, as opposed to the sound of a car door closing in a lees expensive car. This would differ from the presentation, for example, in Gustav Mahler Symphony of a Thousand (8th) George Solti on Japanese pressing, which sounded harsh, compressed and uninviting and that in Joni Mitchell Court and Spark on DCC Compact Classics, title track and Help Me, the all-vacuum tube cutting for which resulted in delicate overtones and cymbals, contrasting with the solid electric guitar tones, all in a near grainless sonic presentation.
At about 150 hours, there has been a substantive shift in the sonic presentation. Whereas prior, the individual elements of the presentation appeared to have been taking their positions, much like orchestral musicians taking their seats, now the Treasures seem to be entering the stage and performing their intended work - making music.
At about 175 hours, the sound elicited emotional responses. Whereas the Siemens EL34s highlighted the beauty of the high frequencies of the spectrum, producing gossamer mass violin string sounds, the Treasure 6CA7-Zs produced just as gorgeous midrange-treble colors with slightly less of the gossamer treble qualities. The apparent timbral accuracy, moreover, is compelling, similar to but not the equal of what the better solid-state amplifiers can achieve, which solid-state seemingly can achieve so much more effortlessly.
At about 200 hours, the Treasures permit and almost demand the adjustments and re-adjustments of your system components, integration and tweaks. I was adjusting the turntable matting, the bias current on the output tubes yet again, the azimuth by altering the tonearm counterweight rotation position, to the point where the tonal sustain was gorgeous, the equivalent of the Siemens EL34s, and where the pre-echo sound that you hear on vinyl, during that otherwise silent leader space immediately preceding a loud cut, itself had some tonal color - which I had not heard with the Siemens. That was surprising.
2/1 - 2/28/11 As the Treasures continued to break in, the sound changed daily through the 300th hour on 2/19/11. The sound became more liquid, less harsh, more even, rounded and balanced in timbral structure, with a deepening soundstage. By the 300th hour, the Treasures matched the Siemens as I remember them in the above qualities, but with more incisiveness, vivid vocals, dynamics, less smearing and masking, better low level resolution and colors and better bass control and better harmonic colors in the sustain and the decay. On the other hand, the Siemens bested the Treasures in the delicacy and nuance of applause and mass strings. Even if I forego the Siemens’ gossamer strings and the subtle rendition of delicate piano notes recalling the image and sound of raindrops, the Treasures nevertheless approximated the Siemens in this regard and bested them in the other qualities mentioned above, and I still would wish that the Treasures rendered a deeper and taller soundstage with better transparent layering; but in all fairness, that may be the fault of the rest of my system not being up to par, rather than the fault of the Treasures.
Several friends stopped by with their Benchmark and Art-Dio DACs, and two weeks later another brought his Eastern Electric Minimax DAC. Although cursory in review, the digital sonic presentation confirmed the resolving, dynamic and tonal qualities heard with vinyl.
I would recommend the Shuguang Treasure 6CA7-Zs, as tested and screened by Grant Fidelity, as a substitute for the EL34s. The additional cost is well worth the better Grade A. I noticed that the heat from the Treasure 6CA7-Zs is substantially and significantly less than the heat that emanated from either the Siemens or the JJ KT77s or the EH EL34s. That thermal difference could well mean a longer life-span for the Treasures. Additionally to avoid undue stress on the output tubes, for the nominal 8-ohm Waveform speakers which dip to 4 ohms, I used the 4-ohm taps on the RM9 mk ii, as recommended by Roger Modjeski, who advises in general not to use a tap higher than the minimum impedance of the speaker.
Current System
VPI HW-19 mk iii, Rega RB600 tonearm, Clearaudio Discovery cartridge
Hovland HP-100 preamplifier with Grant Fidelity Shuguang Psvane 12AX7, 12AT7 and 12AU7 tubes
Music Reference RM9 mk ii amplifier refurbished with new capacitors, tube holders, etc and Amperex Bugle Boys 6DJ8 driver tubes and Grant Fidelity Shuguang Treasure 6CA7-Zs Grade A tubes
Waveform Mach Solo speakers
Meridian 568.2 sound processor for its digital crossover at 80Hz and low pass filter at 90Hz to dual Electron Kinetics Eagle 2 and 2c solid-state amplifiers to the Waveform Mach Solo woofers
Kimber Select 1030 interconnect, Wegrzyn Silver Slam speaker cables, Walker Audio Reference Speaker Links and assorted power conditioning gear
Prior System
Same as above except :
Rega RB300 tonearm, Clearaudio Virtuoso Wood cartridge
Audible Illusion Mod 3 preamplifier with RAM Sovtek tubes
Music Reference RM9 mk ii amplifier with RAM Sovtek driver tubes and NOS Siemens EL34s
Kimber 8TC speaker cables
Room Size 18' x 11' x 7'
Speaker-listener physical boundaries 12' x 10' x 4' height
