Ohm Loads for cartridges

And Albert, I just listened to "Balalaika Favorites" and "Bartok: Concerto for Orchestra" ON 45 RPM....and sheesh, am I NOT interested in DVD-A, SACD, or anything digital for a while....I bet these would just make you die of delight on a "real table" with all those separate dedicated power supplies...heh heh.

In general, the preamp load setting should be 10x,or greater, the cartridge's internal load. This last number can be obtained from the cartridge manufacturer.

Hi Carl. I have experimented with cartridge load in the Aesthetix IO phono, and the hand trimmed resistor provided by Lloyd Walker (Walker audio) was an improvement over the standard one. As far as other places in the circuit, I agree that any resistor that parallels the signal path will effect the sound. On subsonic filters, the IO does not have one. My previous unit, the Elliott Magnum Opus Phono (previously the Counterpoint SA-9, less the Infinity caps and tweaks), did have a subsonic filter, and it was adjustable in two positions. I think it was 30 HZ and 10 HZ, but I may well be wrong on those numbers. My experience with the subsonic filter (either position) was negative in my system, but that could be due to the design of the filter in that particular preamp. I previously used a 28K Vishay for loading the Benz Ruby in my system, when it was my reference cartridge. The specifications had called for the Ruby to load at 49K. My Koetsu Rosewood Platinum Signature is running at 1K Ohms, and was determined by the (selectable) choices on the rear of the IO. After that load number was determined, I tried the hand trimmed resistor provided by Walker. The improvement was very nice, considering the little money and time spent for the change.

1000 ohms seems very high for such a low output mc like that Koetsu. According to the Guide, it's output is .2 millivolts at 5 cm/sec rms lateral velocity. My Lo4 is much higher at .85 millivolts, and seems to sound best at 384 ohms. Again, Fremer never sways from his experience, that very low output cartridges sound best when loaded (even well below 100 ohms). I don't doubt that you are getting excellent performance from your Platinum Signature, though. I also don't doubt that a subsonic filter would have a signature on the music, but feel that it'd still be nice to "switch one in", when needed, otherwise you're unnecessarily straining the power amplifier, asking it to reproduce a noise artifact that isn't part of the recording...and a very loud artifact it can be, even with slight warpage that's common in the pressing of brand new records.

For what it's worth here are my observations. I am running a Koetsu Onyx Platinum (.2mv, 5ohms) into a BAT VKP10 phono stage into a BAT VK5i into VK60 monoblocks biamped with Llano Trinities. The P10 has gain settings of 50 and 55 db in its direct all tube mode (6 6922 for gain) and gains of 67 and 73db if you switch in the stepup transformer. Loading of 100, 1000, 10,000 and 47,000 is builtin. To me the Koetsu sounds best at 55db all tube loaded at 47k. I believe there is some ringing at the higher frequencies which can be cured by going to 10k but with the loss of some dynamics. Going under 10k turns everything to mud and syrup. The volume at the preamp is generally at 50 I(unity is 62) so there seems to be sufficient gain and no loss of dynamics. The bass is satisfactory but see below. My guess is that the best loading would be around 25k. When I switch in the steup (sounds best at 73db) the sound to me takes on the characteristics of a CD: fast, dynamic, and a bass with terrific extension and control; however I lose all the midrange delicacy and air and timbre and so I go back to the all tube mode. This is loaded at 100 ohms and the sound would probably improve by going even lower. At 47k it is unlistenable. However the volume setting on the P10 is now around 30 which probably is not a good thing--losing music to the resistor. So all this means to me is that loading is very dependent on whether or not you are going into a stepup or all tube. I noticed that the Rowland phono stage only offers loading of 200 and 400 and I believe this is true of other solid states and hyrids. Now if I could only incorporate the stepup bass with the all tube mids and highs....