aboulang@BBN.COM (Albert Boulanger) (12/05/90)
Reply to Kevin Kennedy, *NOT* me. Just posting for Kevin ;-). Kevin R. Kennedy d/b/a Kennedy Audio Laboratories 240 Barker Ave. #8 Lowell, Ma. 01850 Tel:(508)441-1010 10/90 Yep, its definitely time for another of Kevin's notorious newsletters, this one being the fourth in an ongoing series of letters on tube high end audio and related topics. I think that a bimonthly schedule fits my available time fairly well and is in fact a precursor to a formalized subscription newsletter. I will continue to make newsletters available for as long as I have access to the net. This time I'm going to share some of the joys of setting up a decent analog front end (?!) among other items. This is not for the faint hearted and frankly CD's can provide a good level of fuss free performance for those who are not inclined to tweak things on a regular basis... I recently acquired a Pink Triangle turntable and would like to share some of my experiences with the table, arms, cartridges and establishing synergy between them all. Oh, what a nightmare .......... (Un)fortunately the Pink Triangle is no longer available here, due to the importer's gun running operation and the resulting seizure of an entire consignment of turntables a few years back.... Originally, they cost about $700.00 new, but are available used for a song.... The manufacturer still provides excellent support for current owners of their tables. To preface my remarks I think I should provide a little background on the Pink Triangle. The Pink Triangle is one of those weird English turntables of extremely doubtful reliability in that the original drive circuitry and motor can be counted on to fail within a few short years, if not sooner... The motor is a Matsushita FG Servo type (cheap) and the electronics by PT are not good at all. I replaced the whole assembly with a new one brought back from England by a friend and this is when I discovered that the design doesn't actually operate closed loop due to some unresolved design error. To make a long story short I beefed up the power supply and motor drive circuitry and will eventually design a proper servo controller for it. Inspite of the above flaws, wow and flutter are extremely low and the pitch stable once the motor breaks in. The table features a variant of the old AR suspension, but is easily adjusted for different arms, weights and platter matts. Isolation is excellent and the acrylic platter is dead and non-resonant. Arm boards are easily exchanged. Speed change is fuss free and electronic. Belt drive is employed along with a novel inverted ruby center spindle bearing for platter support - this is one quiet bearing.... The original arm, a Helios Scorpio seems to leave quite a lot to be desired, and consequently was replaced by an Ultra-craft AC-300 MKII uni-pivot arm on a new arm board. This arm features variable arm damping as well as interchangeable arm wands and weights allowing it to provide a good match in terms of mass versus cartridge compliance for most cartridges out there. VTA, tracking force, anti-skating bias and azimuth are also easily adjusted. I have a Shure V15-RS on a low mass arm wand and a Monster Alpha II high output moving coil cartridge on a high mass arm wand. I prefer the Monster Alpha II to all the other cartridges in my possession which currently also include an Ortofon LM-20 and a Denon DL-103D. I have spent many hours tweaking this combination (and I HATE tweaking) and my experience as well as that of others indicate that VTA, azimuth (stylus perpendicularity) and stylus overhang are perhaps the most critical and difficult parameters to optomize. I cannot emphasise this enough: ANY ARM WORTH ITS SALT MUST BE EASILY ADJUSTED FOR VTA AND AZIMUTH. You cannot even begin to approach the state of the art in analog sound if you don't have these features. In addition the arm must have low friction bearings entirely free of play and chatter otherwise image specificity will be lost. Good rigidity (stiffness) is also important so that any energy coupled from the cartridge into the arm will be transmitted into the subchassis rather than reflected back into the cartridge where it will result in a loss of transparency. It also goes without saying that the arm should not exhibit any pronounced resonances in the passband, and cartridge choice should be such that the arm/cartridge resonance falls between 10-15 Hz to avoid problems tracking warps. A simple rule of thumb: low mass arms need high compliance cartridges and high mass arms need low compliance (most moving coil) cartridges. The turntable should also be leveled as closely as possible and this should be done with a disk on the platter as well as any record clamp you may be intending to use. I have also learned just how long it can take for a cartridge to break in properly and I would suggest you give it at least 30 hours of playing time before making any judgements about the overall performance. VTA should be adjusted periodically as the cartridge breaks in, and azimuth should be rechecked simultaneously if you are using a unipivot arm. I will try to make some suggestions about potential arms, turntables and cartridges that I have found to be good or cost effective or both. The new comer is often faced with a bewildering variety of choices, but I do recommend allowing the dealer to install a matching arm on a table if purchased new. New arms from Morch (Danish), Rega (English), ET (Eminent Technologies) Linn and SME are all good to excellent. I particularly recommend the Rega RB-300 at approx. $300.00 and the lower cost Morch at about $400.00 for their high levels of performance. Used arms can represent good value also and here I recommend the Ultra-craft AC-300/400 MKII, and used versions of all the above brands. Linn and Ariston both offer good and complete record players for widely disparate prices. The Ariston can be had for as little as $450.00 including a Sumiko Blue Point cartridge. AR offers the AR-ES1 for about $400.00 without an arm (don't buy the AR arm), but for about $1700.00 the Merrill turntable is hard to beat - infact it compares rather well to much more expensive tables. All these tables are good bets used also, and in addition those of you on a serious budget can purchase a used AR-XA/XB for under $50.00, install a Merrill subchassis and the arm of your choice, (you furnish the arm) and all for under $400.00 including a good used arm and a new moving coil cartridge.... ( One caveat about used arms - it would be best if the arm was demonstrated to you prior to purchase, and do check the bearings carefully for play if not a uni-pivot type.) Cartridges are a different matter, few used ones will provide good long term service unless you personally know the previous owner and his habits. (Low hour cartridges purchased for 10-25% of their original purchase price from friends or acquantainces who are upgrading to even more expensive cartridges are a good risk.) Cartridges I like are the Monster Alpha Genesis 1000/2000, Alpha II high output, the Virtuoso Boron DTI, the NEW Koetsu Rosewood Signature, the Micro Benz 3, and the real bargain of the group - The Sumiko Blue Point costing under $100.00 and only $85.00 with trade - in at the Audio Advisor. TEL:(800)942-0220. USUAL DISCLAIMER: I have no connection commercial or otherwise with this outfit.... On an unrelated subject, I have ranted about the quality of the Chinese 12AX7A before, but recently I started testing them in various amplifiers that were here for service and I have found that in some applications such as in the Heath W-6A power amplifier the distortion generated by this tube is about three times higher than a Philips ECG 12AX7A. ( 0.7% versus 0.25% THD ) Admittedly this is a rather small sample, but it does tend to corroborate my negative sonic experiences with this tube in various other applications. I plan to build some test jiggs and perform further measurements once my spectrum analyser is refurbished... Next time I'll relate some more experiences in my quest for improved sound at something close to affordable prices.