Review #5 - January, 1996
By JP Singh
Following is a review by JP Singh, an audiophile who is not afraid to trust his ears.
I was particularly interested in JP's use of speakers which do not really fall into the Audiophile approved category.
The review is sparked off by JP's enthusiasm for finally tracking down that "ultimate amp" for his system.
JP definitely sticks to his convictions!
JP Singh's PIECE:
Education: BS in Electrical Eng., MS in Computer Science and MBA.
Work Experience: Worked for a multinational process control instrumentation company in India.
In the US, I have worked for U S WEST Advanced Technologies, a unit of USWEST which is a regional Bell operating company (RBOC or Baby Bell). Currently working as a systems engineer at AT & T Bell Labs.
Audio and audio gear have always interested me since my childhood. From pre-canned tube kits to design of my own stereo, I have built a few audio systems. For some stereos, I went as far as etching my own Printed Circuit Board (PCB)and drilling holes in them.
Currently, my focus is more towards assembling different components and building my own system that will perform great at a reasonable price.
I also advise my friends about what components to buy based on their budgets and preferences. I get called by my dealership off and on to "discuss" technology with the sales representatives of Krell, CJ etc.
Besides audio, I have very strong interests in investing and I am watching my money grow slowly.
My system consists of the following components:
CD Player: Sony 69ES.
The ES series has a transport that is very stable and has quite a few metal parts instead of cheap plastic. The transport will compete head on, if not better than the CAL transport. However, since the DAC of this player cannot compete with hi-end DACs, its overall performance is lower than the CAL.
The 69ES has a digital out, which allows a bypass of its in-built DACs. Therefore, I can simply add an outboard DAC to greatly improve its performance.
Hot on my DAC list is the Theta's Pro Gen V.
My preamplifier consists of Conrad Johnson's PV12L, the cost of which is $1950.00 retail.
This is a hybrid (tube + solid state) line stage pre-amplifier and can be upgraded to phono. The preamp is very musical and transparent. It is a very well built piece with premium parts like 1% tolerance resistors in the critical sections., and no electrolytic capacitors.
The default color is champagne gold brushed aluminum. One can also obtain it in black for a slightly higher price.
I am using Music Interface Technologies (MIT) MIT2s. My interconnects are the MIT 330 series.
Cost: MIT2- $20.00 a foot.
330s : $140.00 a meter.
Prior to the MITs, I had tried Monster Cable which I didn't like at all. Then I tried AudioQuest Midnight. Though they were good, they didn't match with my system very well, and I had to return them.
A word of caution. Whatever cables and interconnects you choose, keep the following guidelines in mind:
Velodyne 1215X. I do not use it for music. It is for home theater use only. This is because of its active speaker/passive radiator design. The sub is slow to respond and therefore cannot keep up the tempo with fast music. But, on the other hand, the unit can provide really thunderous bass in movies. The unit can deliver 250 watts of power.
My speakers are Bang and Olufsen (B&O) RL140 ($1100 a pair). They are concave shaped speakers with no parallel surfaces to muddy the sound. The sensitivity of the speakers is 87 dB/w/m. These are now superseded by B&O 7000 series with a sensitivity of 93dB/w/m. Speakers related to this series are the 6000 (smaller version of 7000) and 8000 (same as 7000, but active - i.e., it has an built in amp).
Remembering that power doubles every 3 dB (200 watts is 3 dB louder than 100 watts), a 93 dB/w/m sensitivity speaker is going to be driven effortlessly by smaller wattage amplifiers, thus making it ideal for tube amps.
A word about B&Os. B&O designs are regarded more as a piece of art than performing equipment. For some reason people think that pleasant aesthetics and great sound cannot be found in the same equipment. I beg to differ.
However, I do agree that B&O itself is also responsible for this perception, partly due to their product line and partly due to their advertising strategies.
From their product line, my B&O RL140s (and the current 6000, 7000, 8000 series) are the only speakers that offer both "art" and "performance" . From my point of view, the rest of their product line leaves a lot to be desired with respect to performance.
I was able to dispel the myth of thinking at my dealership that art cannot be blended with performance.
I accomplished this by comparing the B&Os with Thiel speakers. The testing was both blind and direct and the following equipment was used for the setup:
Cal transport, Cal DAC, CJ PV12/Premier11A (and also with Spectral DMA180 and Spectral 20 preamp).
MIT SH750 cables and 330 series interconnects.
We started with Thiel 0.5s and RL140s. Everyone was able to pick up B&Os immediately as a better sounding speaker.
The results were the same with Thiel 1.5s. But when replaced with Thiel 2.2s, the staff could not determine one way or the other. This led to the conclusion that the B&Os and Thiel 2.2s were at par.
However, Thiel 3.6s definitely outperformed the B&Os. But then they cost a whopping $3600.00 as compared to B&O's $1100.00. Even with Thiel 2.2s, B&Os win because 2.2s cost in excess of $2400.00 a pair.
The same steps were repeated in a non-blind fashion with same results.
An equal performance at less than 1/2 the price and together with an "arty" looking design, definitely seems like a better deal. Therefore, I suggest that people should use their ears rather than price-expected-performance perceptions to evaluate equipment.
The soundstaging of B&Os is excellent, and with the MIT cables and the PV12L/Premier11A combination, the sound emerges with uncanny detail and transparency. The speakers are very neutral. With well recorded material, they become invisible, and get replaced by a three-dimensional stage in front where I can accurately pinpoint the instruments and the singer.
Like any other speakers, the positioning of B&Os is important. The RL140 has an optional stand. It also has a built in screw which changes its angle of fire towards the listener. I have found the speakers work best when placed away from the walls. Near the walls, the bass deepens, but its soundstaging gets lost due to wall reflections. Away from the wall, the speakers become invisible after some experimentation with toe-in.
I used Radio Shack's sound pressure level (SPL) meter and Test CD2 (Stereophile) to calibrate the ideal location of B&Os.
My search for "the ultimate amplifier" for this system has lead me on the following test/search path:
Bryston 4B NRB, 4B ST series (30 day trial), Krell video series 5 channel amp (don't remember its model, 30 day trial, horrible), Conrad Johnson Premier11 (30 days), Conrad Johnson MF2300A (bought but kept for a month), Premier11A.
I will discuss only a few.
First, I used the Bryston 4B NRB. The 4B is simply a muscle amp good for tight and powerful bass. It had the sharpest snap of all the amps I tested, but its tinny mid-range always drew my attention to the fact that I had an amp sitting on my shelves. In retrospect, I *think* the snap was artificial, but I still liked it.
The 4B has excellent soundstaging capabilities though, and is really well built and rugged. However, personally, I would rather use it as an amp that drives passive subwoofers.
Then I tested the Conrad Johnson (CJ) MF2300A. This new and improved MF2300A in the CJ rep's word was "going to blow me away". Well, it was an excellent piece and the best so far in the CJ line of solid state amps, but it was still a far cry from the Premier 11A. I recommend it highly for anyone who likes solid state amps though.
The 2300A was significantly smoother and silkier in the mid-range as compared to the Bryston and its own predecessor (MF 2300), but the electronic glare was still present.
At 57 lb., it is extremely well built using premium parts including Vishay caps. The sales rep from CJ showed me all the that went into the making of the MF2300A. He thought that this amp could compete with the premier 11A. I was able to prove it the other way around. However, if anyone is looking for a good solid state amp, especially at a similar price point ($2800.00 retail vs. $2200 for Bryston), I would recommend this over Bryston.
Finally, I ordered the Premier 11A for my home. This was because I already liked the Premier 11 and the 11A was just a few mods to the 11.
|Conrad Johnson Premier 11A Technical Specifications:|
|Hum and Noise:||98 dB below full power output.|
|Weight approx.:||50 lb.|
|Power:||70 Watts RMS per channel driven into 4 ohms.|
|The unit is a Vacuum Tube Amplifier and uses 8 tubes - two 5751, two 6FQ7, and four 6550s.|
So here it was, at my home, the neatly packed Premier 11 which had undergone modifications and was now labeled Premier 11A. The unit was re-reviewed in the "Follow Up" section of the Stereophile in 1995 and got even better reviews than its predecessor, Premier 11. It is listed as a Stereophile rated Class A amplifier.
Opening the box revealed a neatly packed unit. The base unit was champagne gold brushed aluminum. It was accompanied by separately packaged tubes and grille to cover the tubes. The unit looked beautiful without the grille, so I decided not to use it altogether.
I followed all the instructions in the manual and plugged in the tubes. The output tubes have adjustable bias and CJ requires the user to bias the tubes before operating for the first time.
CJ provides a plastic screwdriver to adjust the bias. Bias adjustment is done by switching on the amp, letting it warm up a little (2-3 mins) and turning the screws next to the tubes clockwise until the red LED next to the screw lights up and then turning the screws counterclockwise just enough to switch off the LEDs. After the amp warms up another 30 mins, the same procedure needs to be repeated.
I really like the biasing feature because now I do not have to be dependent on CJ to get matching tubes. I can buy tubes anywhere on the market, and I can match the tubes myself through bias adjustment.
The amp is quite heavy with three transformers mounted in the back in a row. The tubes occupy the front of the unit with three huge polypropylene capacitors sandwiched in between. The champagne gold finish of the amp enhances its looks significantly.
The rear of the amp has hexagonal nuts so that a spade connector can be tightened properly. That is really thoughtful. A loose connection can definitely reduce the performance of any amplifier significantly. I used pliers to tighten the connection with slight pressure.
There is a large switch on the front of the unit to switch it on and off. There is no LED to indicate that it is powered, but then the 8 tubes lighted up are more than any indication anyone will ever need!
When powered, the unit is really quiet. Despite the three transformers, there is simply no transformer hum, pointing to an excellent transformer design.
I played the unit for a long time. It was quite musical, but after the unit had broken in (60 hours of play), the amp became extremely detailed, more musical and accurate. Of course the transition was gradual.
The Premier 11A has no graininess in its sound and can really bring out details that one had never envisioned. The music is vibrant and gives the listener a very good feel for live music.
Other amps with such accuracy and detail run into thousands more. A good example is CJ's own Premier eight ($6600.00) and Cary audio ($8000.00). At this price point, the Premier 11A is a steal. No wonder Stereophile keeps on rating this amp as Class A.
Panamax 1000+. It has 8 outlets and jacks for cable to totally isolate the whole system from the electrical mains of the house.
This unit does an excellent job of line conditioning.
Now to the full system review:
We generally hear a system perform well in dealership's studio only to be disappointed with the same system's performance at home. This is because the dealership's demo rooms are conditioned, offering excellent performance even for mediocre systems, while our homes are not, unless one goes about constructing a quiet room for music only.
Let's face it; we may have an audio room which is relatively quiet but may not be totally anechoic. Therefore, to me, a real test of a system is in the "normal" home condition. I define a normal room as one that an audiophile has put in some effort to remove/reduce wall reflections and has followed the basic steps in making the room tend towards ideal conditions.
Therefore, I use the dealership's demo room to get a feel for the system, and I test it out in my environment to see if it can meet my needs.
For my system, the interconnects and speaker cables were MIT2 initially. The interconnects were replaced by MIT's 330 later on. My initial amp was Bryston 4B NRB before I replaced it with Premier 11A. The rest of my system is already described above.
In the whole setup, only the Premier 11A was new and not broken in. I switched on the unit and left it on for an hour. I decided not to use the XLO test/burn CD and wanted the amplifier to break in on its own. I calibrated the system with Stereophile's test CD2 and with Radio Shack's sound pressure level meter. I kept the level at 70db SPL.
I started the listening sessions with Linda Ronstadt's "Like a Rainstorm" CD. Frankly, I wasn't impressed. The sound was good, but this is not how I had heard the Premier 11 at my dealership. I felt as if the guts of my system were lacking. The voice was mellow, but the highs, I thought, were less than normal. I attributed the whole thing to the fact that the amplifier wasn't broken in. Eventually, I yielded to the XLO test/burn CD. During the period (20 hours) of break-in, I did not listen to the system at all. After the burn in period, I was ready again.
I started again with Linda Ronstadt's CD. This time through, the bass was much tighter and there were highs that I had not noticed before. The voice was rich, and the amp sounded really nice.
While playing, my system faded into the background, and was replaced by a feeling of three dimensional stage where I could pin point the location of the individual instruments. The depth of the system sounded accurate. The music was forward to midway - that is, as if I was sitting 2-4 rows away from the singer. There was no edginess to the sound.
The voice of the singer was palpable, and I could even hear the singer breathe in some of the passages. This is something that I had never noticed before. I could hear the guitar strings being plucked, and I could visualize the motion of the performers as they struck the percussion instruments or as they plucked the strings of the guitar. This was sheer magic. The whole system was so "alive".
Yet, despite all the magic, I felt that I was missing something. I couldn't put my finger on it, and was totally mystified since I liked every aspect of the sound of the amp. The clarity was there, so was the punch and liveliness of music, excellent soundstaging, details of the music, and the instruments sounded correct! You name it, and it was there and still I felt like there was something that I knew existed before, but I just could not identify what! I had to find out!!
In the meantime, I got a chance to attend a live concert by an Indian singer (Jagjit Singh) where I got a good chance to gauge individual instruments covering the full spectrum of sound. The singer was accompanied by five musicians (low frequency "tabla" through high frequency "sitar") thus offering a chance to audition each instrument closely. I was in the front row, and therefore, I got a chance to listen to these instruments "live" instead of listening to processed signal.
After the concert, when I reached home, I decided to play the same singer's CD which contained some of the performances from the concert.
I warmed my system for an hour and then played the CD. I was stunned! It sounded as life like as the live performance that I had just attended. The output was remarkably close to the live performance, and I could not believe that my system could reproduce it that faithfully. I could hear the strings plucked, I could hear the resonance of the percussion instruments, I could "see" the singer performing and appreciate his deep rich voice, I could perceive the depth of the stage etc. The playback was uncannily realistic.
Suddenly, the whole issue of "missing something" got demystified! The amp was so accurately producing the music, that what I was **missing** was the electronic glare and other artifacts so common among other amps, especially in solid state amps!
I was so used to listening to inaccurate sounds from other systems that I saw an accurate reproduction of sound as a problem with the amplifier's capabilities.
So! my system **was** accurately able to reproduce what was recorded. This was further tested when my friend who works at the dealership mentioned above, decided to bring in an "excellent" recording to listen to on my system. We played it and he asked me how I liked the recording.
I told him that it sounded somewhat metallic as if it was recorded from an old style microphone. He then revealed to me that the "excellent" recording was a 1963 recording, digitally remastered. So the amp WAS capable of accurately reproducing its input signal. The final test came from the well recorded Chesky record's "Ultimate Demonstration Disc". The third song on the CD (Spanish Harlem by Rebecca Pidgeon) was very palpable. The CD indicates what to look for in that song, and all the aspects described were present.
Once I realized that the amp was faithfully reproducing the input source, I really appreciated the engineering finesse accomplished by CJ. Of course, I am glad that I am "missing" something - that something being the artificiality of the sound reproduction.
The Premier 11A is not only faithful at reproducing the original sounds, but is also very infectious. It grows on you. Once hooked to its sound, it is very hard to like the sound of any other unit. The PV12 pre-amp augments the performance of this amplifier.
Finally, when I replaced my MIT2 interconnects with MIT's 330's, the sound blossomed even more.
By this time, the amplifier has also seen about 70 hours or so of playing and is truly broken in. Now, the more I hear the system, the more addicted I get to listening to music. The Premier 11A/PV12L combination really makes the technology invisible and allows a listener to concentrate on the music instead of the underlying technology.
I think the Premier 11A could sell for significantly more, given its performance. I also think that CJ has deliberately kept its cost low in order to avoid competing with Krell. The unit is really well designed and well built. There are no cheap components in this amplifier. . . period. Even the storage capacitors are polypropylene instead of electrolytic ones which have a tendency to change their characteristics significantly with temperature and time, and tend to leak.
If anyone thinks the best tube amps have to cost above $6000.00, take another peek at Premier 11A. Do a blind test with equipment at that price and see if you can easily discern the difference between this $3500.00 amp and a $6000.00 amp.
Finally, remember that a tube amplifier is always "on", unlike transistor amps which is a switching circuit (except class A amps where the transistors are always on and hence the huge heat sinks). Therefore, a tube's 70 watts is much more than a transistor's wattage. There is no hard and fast conversion criteria, but I would **guess** (read again, guess) Premier 11A's power rating as 140 watts/channel of class AB/B solid state amps. So there is plenty of juice to drive hard loads.
The Premier 11A and PV12L combination is one which I intend to keep for a long time to come in my system. The tubes are rated to last 1500 hours on an average, making them almost as convenient as solid state units.
Improvements? I mentioned that even though I am using the SONY 69ES CD player's internal DACs, I have every intention of replacing them with a better DAC. I have tried Theta's Pro Gen V, and it improves the transparency of the system greatly. The improvement is very discernible. Therefore, when I have the money, I will buy that or an equivalent DAC in the system.
© Copyright 1995, 1996, 1997 Secrets of Home Theater & High Fidelity
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