I own a Monster Alpha-1. I prefer my Grado wooden body and all. If it wasn't such a pain to set up a TT I'd switch it back in and run an A/B on the HF peak, this is SO easy to measure. You and John R. both have access to the gear yet apriory assume this is another audible but unmeasureable effect.
Scott, sometimes test equipment FAILS to measure what the ear can hear under the right circumstances. It is not for me to measure something to assure you that there is something different sounding between a summing input and a real load impedance. Perhaps you Alpha 1 likes low Z. Some early phono cartridges did. Dr. Van den Hul liked low Z loading, and we added it as an optional connection to the Vendetta Research SCP-1 and SCP-2A from 1983-1990. However, feedback from serious users like Brian Cheney of VMPS and Dave Wilson from Wilson Audio, stated that the optimum loading was steadily increasing from 50 ohms to beyond 200 ohms, which was a problem for me, because my Tantalum film pots are only good to 200 ohms, because that is their nominal value. Dave and Brian would give me specific loading for specific cartridges down to 1 ohm in accuracy. This can be done with a Vendetta phono preamp by adjusting the load while listening to music.
The new Constellation Orion will have 1 ohm resolution from 10-5000 ohms, made by a precision, motor driven, 10 turn pot with graphical readout. This costs 'big bucks' and we would love to 'drop it', but we know it is audible, and that users will conveniently find it so, when they adjust the load while playing their favorite music. If they don't, well so much for loading. '-)
The new Constellation Orion will have 1 ohm resolution from 10-5000 ohms, made by a precision, motor driven, 10 turn pot with graphical readout. This costs 'big bucks' and we would love to 'drop it', but we know it is audible, and that users will conveniently find it so, when they adjust the load while playing their favorite music. If they don't, well so much for loading. '-)
if the load resistance approaches the coil R then you have 1/2 the coil current that would exist in the coil working into a virtual gnd/summing input transimpedance amp
so you are only a factor of 2 away from whatever condition is causing John's objectionable muddy sound?
Risch' comments on liking virtual gnd amp with "replica feedback" from an identical cart glued to prevent motion suggests he is canceling nonlinearity
so what is the story - Curl pointing at damping which should be largely linear and could be EQed or is it nonlinearity - and how much, what characteristic - possibly "bad" hysteresis with high output MC coil wound on iron cross in a strong bias field?
so you are only a factor of 2 away from whatever condition is causing John's objectionable muddy sound?
Risch' comments on liking virtual gnd amp with "replica feedback" from an identical cart glued to prevent motion suggests he is canceling nonlinearity
so what is the story - Curl pointing at damping which should be largely linear and could be EQed or is it nonlinearity - and how much, what characteristic - possibly "bad" hysteresis with high output MC coil wound on iron cross in a strong bias field?
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As jcx has pointed out, different load resistances affect the quantity of the current output from the cartridge.
Regardless of the different electrical damping on the cartridge and it’s effects if any, there will be a quantitative difference on the voltage output of the I/V converter.
If not trimmed at the I/V converter output, this will alter the acoustic level on which one evaluates the different loading on a cartridge (i.e. no level matching), as well as drive the subsequent amplification stages with different voltage levels, something that may - during crescendos and difficult music passages – cause these amp stages to work on unfavourable - in any case different - levels.
All these may add to perceived (or measured) differences on sound.
Regards
George
Regardless of the different electrical damping on the cartridge and it’s effects if any, there will be a quantitative difference on the voltage output of the I/V converter.
If not trimmed at the I/V converter output, this will alter the acoustic level on which one evaluates the different loading on a cartridge (i.e. no level matching), as well as drive the subsequent amplification stages with different voltage levels, something that may - during crescendos and difficult music passages – cause these amp stages to work on unfavourable - in any case different - levels.
All these may add to perceived (or measured) differences on sound.
Regards
George
It is strange that almost nobody realyses the importance of MC cart loading.
IMO there is a sweet spot for every cart/system setup. My Benz ACE M likes 2350ohms with my 48dB Riaa. (Not 2300 or 2400). So I am using Vishay 1280G trimming potentiometers: (Bulk metal foil, 15ppm, 26 turns for ultra-precise adjustment).
My Denon DL160 likes 1050 ohms on the same setup.
The load value varies with resistor type. (When using Tantal resistors I must set the value slightly lower then with carbon films for instance).
IMO cart loading is as important as cart VTF and VTA, where there is also a sweet spot for best overall spatial presentation.
IMO there is a sweet spot for every cart/system setup. My Benz ACE M likes 2350ohms with my 48dB Riaa. (Not 2300 or 2400). So I am using Vishay 1280G trimming potentiometers: (Bulk metal foil, 15ppm, 26 turns for ultra-precise adjustment).
My Denon DL160 likes 1050 ohms on the same setup.
The load value varies with resistor type. (When using Tantal resistors I must set the value slightly lower then with carbon films for instance).
IMO cart loading is as important as cart VTF and VTA, where there is also a sweet spot for best overall spatial presentation.
I know but in the real world there seems to be some people that do not believe cart loading is important
It must be a secret but nevertheless I am used to get an answer from everybody in this forum.
Still playing, on version 2 of the test rig.
So what is the difference between signal induced noise and a dead spot?
Huge, one's always in the same spot. I could be we are not talking about the same thing. Your proposal of a while ago implied near perfect rectification of microvolt signals, the radio astronomers will beat a path to your door.
Not rectification, just drop outs. You know hysteresis, doesn't want to start till it gets going and then is happy until it rests again. Direction of current does not matter. Of course I withhold further speculation until after I see the results.
The resistor loading is PARALLEL in the audio path, and therefore if it OPENS, it only UNLOADS. Hardly a big problem, but we ARE careful with what we use. We are using wirewound 10 turn oversize pots, just like the 'big boys'. Tantalum film is my first choice, but impossible to get in a high resolution variable pot.
RCruz, you are very brave to express your findings, here. Now, it might make more sense to others why Constellation is going through such an effort.
RCruz, you are very brave to express your findings, here. Now, it might make more sense to others why Constellation is going through such an effort.
Hi John
Your work has always been an inspiration for me. Years ago I read that you considered MC Rload very important. I know that now, based on my own experiences.
I even tryed to find a Tantalum variable resistor without luck.... In this case I just wanted to know what you were using in the Constelation.
Your work has always been an inspiration for me. Years ago I read that you considered MC Rload very important. I know that now, based on my own experiences.
I even tryed to find a Tantalum variable resistor without luck.... In this case I just wanted to know what you were using in the Constelation.
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