aboulang@BBN.COM (Albert Boulanger) (07/02/90)
I am posting this for a friend. Replies should go directly to Kevin Kennedy (see his address at end of newsletter). This is the second in a series of audio news-letters, let's hope there are fewer mistakes than in the last one. Please bear in mind that these are my opinions and are obviously subject to my relative objectivity or lack thereof.... I somehow stupidly managed to scramble the order of Apature's name and product in the last letter. Apature makes Signature 500 speaker cable not the other way 'round. You can contact them at: 1-800-APATURE, this is an unsolicited endorsement of the 500 cable only. It's good stuff, try it as an alternative to some really expensive cable. I recently discovered that the relatively inexpensive Radio-Shack MEGACABLE OFC 8mm A/V cable PN#278-1272 makes a good interconnect cable in systems having fairly low source and load impedances between components. I noted improvements in depth, imaging and detail over the previous cable I was using. High impedance may result in a rather audible roll-off. (My pre-amplifier output Z is under 100 ohms and the power amplifier's input Z is 100K ohms, but some amps. with 1M ohm input impedance sound rather dark.) Now with that out of the way, I've discovered that the Tungsram 12AU7A sounds pretty decent in Scott tuners and MPX-335 stereo adaptors. It seems quite good, in fact it is the best I've heard lately- clean, open and quick. Those small Tungsram 6CA7/EL34 sound good, but aren't as sturdy as some of their Western counterparts. A noted English manufacturer is rebranding them (in England) and selling them under their own label. If you want to try them give me a call and I'll tell you where to purchase them. More talk about 6DJ8's, I definitely agree that 6922's and particularly JAN 6922's are significantly better than the 6DJ8 in many respects-but don't use them in RF applications because their internal construction differs markedly from the 6DJ8, and this will probably mean a realignment will be necessary in most tuner circuits. (Some Fisher tuners use them.) If you intend to purchase Chinese KT88/6550 output tubes, do shop around, to my knowledge they are ALL the same, except for getter and envelope designs, so let the price be the deciding factor. (As low as $10.00 each on sale.) Buy several extra so that you can select ones that exhibit about the same transconductance (near identical bias settings...) as consistancy isn't always good. I have recently encountered a number of bad Yugoslavian 12AX7's sold as premium types that were supposedly tested and sold under certain brand names. They were extremely noisy!!! Normally these tubes are among the quietest I've encountered... Buy a few extra in case you get a bad one. As promised Andrea and I intend to share some of our observations at the Stereophile show in NYC at the end of April. For convenience we stayed in the Penta hotel, venue of the show, which made visiting the show extraordinarily convenient, my only advice would be not to eat in the hotel restaurants..... We are in basic agreement about the best sound at the show, and that Paul Heath Audio walked away with the honors for most neutral, dynamic sound with good depth, imaging and instrument specificity. The system consisted of a pair of Merlin Signature IV loudspeakers driven by four Megavox M75's by Ray Lumley, the source amazingly was a Philips LHH-1000 CD player. The Dutch made Audio-Stats were a major disappointment to us when they were substituted for the Merlins. (Rather like the early Eminent Technology LFT III's before they were revised.) The English made Lumley amplifiers were quite wonderful sounding, and were very nicely constructed with a black anodized front panel designed for rack mounting. Our second choice was the Swan Speaker Leda/Gemini combination which featured particularly accurate imaging and adept handling of transients, with good neutrality somewhat marred by an excessive bottom end. The combination consists of two satellites and two sub-woofers and features very extended response, but not quite as smooth the Merlin Signature IV. Bass response was copious, but easily controlled with the optional electronic cross-over. The sources were also CD based, (Mod Squad Prism I think) but the details of the rest of the system are unknown to us. Our third choice was the Infinity Modulus satellite and sub-woofer combination driven by the Threshold SA-3.9 power amplifiers. Interconnects were the Monster Sigma M1 speaker and interconnect cables. The speakers feature razor sharp transient response, perhaps the best of the show, with really excellent imaging, good depth, bass response was extremely over abundant probably due to the preference of the Infinity sales people. Both CD and LP were used for the demo. Our fourth and final choice among the contenders for best sound at the show was Audio Concepts, with their excellent and pretty reasonably priced (compared to all of the above which cost at least twice what the Premiers do) Premier I satellite and sub-woofer combination for under $2000.00. The sound was transparent, imaging solid and predictable, good depth, dynamics and extension. I think this design is exceptional in that it provides a lot of the performance of the best designs for less money. We both liked the new Vandersteen 3 loudspeaker, it seemed to be very neutral and essentially without significant character - a good thing in loudspeakers. I also liked the Quad ESL-63 pro monitor combined with a pair of Velodyne subwoofers- they seemed very well integrated, and you really can't beat the Quad for imaging and transparency. If this show is any indication, the days of the LP's availability are very numbered, the only true High End turntable at the show was the Basis, with an SME V arm and Micro Benz 3 cartridge. The sound was not quite as I expected.... We also looked at the Ariston and Linn table offerings, all quite reasonably priced, but not used in conjunction with very ambitious systems, making judgement of merit especially difficult. The Esoteric P2/D2 CD transport/converter really impressed us with its musicality, depth and imaging as well as its freedom from "digital glare" if this is the future of digital sound, then there is hope that this format may get really good .... At $8000.00 for the combination though I wouldn't be too fast to rush out and replace my LP's with CD's. My other personal favorite was the Philips LHH-1000, which at $4000.00 is not too affordable either. The Kinergetics KCD-40 was a distant third, but at substantially less money. We also heard the Barclay transport used in conjunction with the Wadia 32 processor, which was also quite good, but was not used in any of the systems we preferred, making it difficult for us to tell how they sound in comparison to the other units we heard. I want to emphasize that I don't feel anyone should rush out and replace their LP's with CD's. A lot of material will never be reissued on the new format and further, I think that the digital "remastering" many CD reissues are subjected to results in reduced detail and much increased coloration.... Another matter concerns the aging of the original masters themselves, and the early pressings made from a fresh master tape may be of greater quality than the CD reissue due to subsequent deterioration of the master tape, assuming of course that you were able to take good care of the disk over the years..... Good quality turntables are still available and significant improvements in cartridge technology are still ongoing. At the highest performance levels analog technology still offers better performance in the areas of detail, imaging, depth, timbral accuracy and musicality, but digital technology is closing the gap, and commercially has already killed analog sound. For those of you on a serious budget I have found that the Radio-Shack V15 Type RS (A Shure) cartridge, Cat. #42-2800 can be modified to provide relatively decent performance in view of its low sale price. Normally listed at $79.95, it is frequently on sale for $39.95, and at this price it's an OK cartridge. The cartridge is best used in low mass arms like the Mayware, etc. The mods consist of the following changes; Carefully remove the dynamic stabilizer by cutting it off, glue the stylus assembly to the cartridge case (plastic part only) with RTV red and then carefully coat the whole case with a thin layer of RTV red to damp its bell like behaviour. This cartridge is extremely VTA sensitive so be sure that it can be adjusted either with shims under the cartridge body or by adjusting the arm itself. Tracking force should be around 1.5 grams to 1.75 grams for best results. If the cartridge sounds really bright and obnoxious this indicates that the VTA is probably too high. Recommended loading is around 100pf excluding arm wiring. (no more than 300pf max.) So modified and installed this cartridge can provide a surprising amount of detail with solid imaging and pleasant tonal qualities. Obviously it is not by any means an ultimate cartridge, but it can be decent.... For those of you on the net please feel free to print and copy this file as much as desired. Comments and suggestions are encouraged, but please don't ask for copies of the letter unless you have no other recourse.... I was quite swamped after the last newsletter! Letters on audio are greatly appreciated. Thanks, Kevin Kennedy Kevin R. Kennedy d/b/a Kennedy Audio Laboratories 273 Barker Ave. #5 Lowell, Ma.01850 Tel:(508)441-1010