Rerurn to Romy the Cat's Site

Analog Playback
Topic: The field-coil cartridge?

Page 1 of 1 (7 items)


Posted by Romy the Cat on 09-12-2004

sertraline without prescription

cheap sertraline bc3.eu sertraline purchase

I made an experiment a few weeks ago. I took 5 cartridges that I know very well and that have thier distinctive “signature” sound signatures. I loaded my corrector into my 49K 1/12Octave, 0.25dB resolution Real-Time Spectral Analyzer and ran the inverted RIAA sweeps on the each cartridge (the phonocorrector with inverted RIAA has flat response within 0.25dB). Most of the cartridges (all of them properly loaded and with own arms having resonanses around 9Hz) produced in some way rollercoaster response, sometimes with 2-3dB jumps. What was interesting, was that the deviations of response patterns were exactly what I would anticipate by describing the subjective quality of the cartridges. All those adjectives that I would use to deferent the different models of Denons form Koetsus from Shelters from Grados and so on… were just the minute fluctuations of response… Certainly they all have many more differents then just tonal differents but still… Invigoration, isn’t it?

The Cat


Posted by coops on 05-09-2007
Romy I have read on this forum that you are not particularly keen on the very low output AN Japan ( and Uk ) cartridges, may I ask the nature  of your experience with them , have you tried the field coil versions? Thanks Keith.

Posted by Romy the Cat on 05-09-2007
 coops wrote:
Romy I have read on this forum that you are not particularly keen on the very low output AN Japan ( and Uk ) cartridges, may I ask the nature of your experience with them , have you tried the field coil versions?
Keith, I am not particularly keen on any very low output cartridges but I have nothing explicitly against the AN (Kondo) cartridges. In fact what the AN does with their low output cartridges is probably the best way to use any low output cartridges. They mapped their, I believe under 1R cartridge, with a dedicated transformer that specifically designed to work against the ultra low impedance source… I heard that cartridges but never owned it the and therefore my liking or do not liking has absolutely no rational. Still, I feel that with use of the ultra low output cartridges the gain stage (or transformer), cables and the rest become unfortunately more prominent then with high output MC cartridges. Regarding the AN UK it is a different story. I know nothing about them and generally I am not big fun whatever the do. Yes, I heard the Peter made his field-coil cartridge – I do not know if this venture has any interest. I generally not overly exuberant about any electromagnetic application as it has many “issues”… still, I do not know where AN UK stays on this progress and result with their field-coil needle. Sorry….

The caT

Posted by morricab on 05-15-2007
Hi Romy,

Interesting test you have conducted.  Were the responses mostly unflat near the frequency extremes or was there variations even in the midrange?  The reason I ask is because if you look at most of the published curve responses it is easy to see that most MC cartridges have a rise starting around 5-8 Khz and often there is a dip preceeding this rise.  This dip often is occurrring right in the presence region and could explain why some cartridges sound "spacious" regardless of the recording (many loudspeakers are "voiced" with a dip in the same region).  Could you elaborate on what the responses of each of the cartridges are like and how that correlates with what you hear from them?

The behavior of MC cartridges in this way is mainly due to resonance occurring from the cantilever assembly.  Have you ever tried a Dynavector 17D3?  This is actually the most unusual cartridge currently on the market.  Why?  First it is using a cantilever of pure diamond.  The only other one I know of is from Koetsu (but maybe they no longer make it).  Second the cantilever is extremely short, only 1.7mm long!  This is the shortest cantilever that I know of in a phono cartridge.  Third, it is using a microridge stylus, which when aligned properly, has the greatest contact surface area.  Fourth, they have gone to great lengths in understanding the magentic flux and in controlling it. 

What does this mean then in terms of performance?  Well, it has essentially no resonance below 100Khz.  This means that it is totally flat in the high frequencies without a rise like nearly every other cartridge.  Likewise, there is no dip in the presence region.  The measured specs I have seen show less than 1 db deviation from 30Hz to 20KHz.  They claim flat response to 50Khz!  This also means that it makes a very good attempt at a square wave.  The low mass of the cartridge and the cantilever and lack of resonance in the highs means that transient response is probably the best of any cartridge in existence.

How does it sound?  It is the closest cartridge I have heard to saying, "what does what sound like?"  It has essentially the character of the recording.  Close miked recordings sound very up front and naturally recorded classical music sounds deep and wide with plenty of space.  Tonality seems good because the frequency response is so flat.  I went away from it for a while because my phonostage didn't have enough gain (it is less than 0.3mV output) but now I have fixed the noise and hum problems and I will likely go back to this cartridge. 

Posted by Romy the Cat on 05-15-2007

 morricab wrote:
Interesting test you have conducted.  Were the responses mostly unflat near the frequency extremes or was there variations even in the midrange?  The reason I ask is because if you look at most of the published curve responses it is easy to see that most MC cartridges have a rise starting around 5-8 Khz and often there is a dip preceeding this rise.  This dip often is occurrring right in the presence region and could explain why some cartridges sound "spacious" regardless of the recording (many loudspeakers are "voiced" with a dip in the same region).  Could you elaborate on what the responses of each of the cartridges are like and how that correlates with what you hear from them?

Actually, I did not see any long octaves rises in my MCs I did not save the files of the sweeps and if I did I would publish them here. There is difference between the few dBs fluctuation up and down that a given cartridge might have and the fundamental offset of the RIAA filter or inappropriate loading. It is very simple to test. Popping up around here Jim Hagerman sells at his web site a ridicules inverted-RIAA filter. The ridicules of this filter is that Jim asks $50 but the filter works surprisingly good for any money. It is dead-accurate and it is very simply allows to calibrate the phonocorrector filter very precisely with no regards to needle loading. Sine I use the ease adjustable air capacitors in my corrector, to me that inverted-RIAA filter is God send. I just run the sweep of my generator via the Hagerman’s inverted-RIAA filter and turning my variable air capacitors (one for LF and one for HF) unit I get ideally horizontal line on my RTA. All further deviations would be juts to the cartridge loading. So, far I saw that various Denons do not what to be at their ideal response to sound more or less correct subjectively. However, I do not consider the Denons as interesting cartridges to begin with. However, the Shelters, Kouetsu and various SPUs that I have tested demonstrate a perfect relation between auditable and measurable and the flatter their response is the less problematic they sound. In fact my last SPU mono I did not even listen when I set it up. I just set it to the recommended 47K and running the record recorded sweep it made an excellent flat response. Sure, it has jumps all over with 12db/octave resolution but it had no long octave-wide rise or dive above 5-8 Khz. I do not know what is responsible for the rise or dips you describe. If you corrector is accurate and the loading is correct then it might be… I have no idea what. Would arms affect sound in this way? Also, do not forget that many cartridges have not stable quality of production and many of them are juts initially faulty. (I have seen those examples and even once bought a brand new Grado the turned out to be faulty, BTW, the Grado fixed it very gentlemanly)

 morricab wrote:
The behavior of MC cartridges in this way is mainly due to resonance occurring from the cantilever assembly.  Have you ever tried a Dynavector 17D3?  This is actually the most unusual cartridge currently on the market.  Why?  First it is using a cantilever of pure diamond.  The only other one I know of is from Koetsu (but maybe they no longer make it).  Second the cantilever is extremely short, only 1.7mm long!  This is the shortest cantilever that I know of in a phono cartridge.  Third, it is using a microridge stylus, which when aligned properly, has the greatest contact surface area.  Fourth, they have gone to great lengths in understanding the magentic flux and in controlling it.

Nope, I never heard nether the Dynavector 17D3 not about it. it sounds interesting, partiality the shortest cantilever part. Dynavector is strange company: they do sometimes remarkably garbage and sometimes remarkably interesting things… Go figure…

 morricab wrote:
What does this mean then in terms of performance?  Well, it has essentially no resonance below 100Khz.  This means that it is totally flat in the high frequencies without a rise like nearly every other cartridge.  Likewise, there is no dip in the presence region.  The measured specs I have seen show less than 1 db deviation from 30Hz to 20KHz.  They claim flat response to 50Khz!  This also means that it makes a very good attempt at a square wave.  The low mass of the cartridge and the cantilever and lack of resonance in the highs means that transient response is probably the best of any cartridge in existence.

How does it sound?  It is the closest cartridge I have heard to saying, "what does what sound like?"  It has essentially the character of the recording.  Close miked recordings sound very up front and naturally recorded classical music sounds deep and wide with plenty of space.  Tonality seems good because the frequency response is so flat.  I went away from it for a while because my phonostage didn't have enough gain (it is less than 0.3mV output) but now I have fixed the noise and hum problems and I will likely go back to this cartridge.

Very, good. The needles do get better and better. Unfortunately our older needles do not due as fast as new better needles get introduced. In my case of multiples arms and a strong competition from FM radio (that take 70% of my listening media-vise) I think I am all set with my cartridges to the rest of my life.

Rgs,
The caT

Posted by morricab on 05-15-2007

Hi Romy,
Look here for information about the Dynavector 17D3 cart.
http://www.dynavector.com/products/cart/e_17d3.html
http://www.dynavector.com/etechnical/dispersion.html
Cheers,
Brad


Posted by morricab on 05-15-2007
http://www.dynavector.com/etechnical/fluxdamper.html
http://www.dynavector.com/etechnical/microstylus.html

Page 1 of 1 (7 items)