Pani, Yes, I think there would be a sonic difference between those two alternative strategies. Ralph (Atma-sphere) posted on the subject of loading the primary side of the SUT, recently on the Analog thread, but I cannot recall where. In any case, his reasoning would lead one to expect that loading the primary would not be optimal.
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Or add a resistance in parallel with the 300K resistor that would bring the net resistance down to 100K. 150K ohms would do it.
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Pani, You could replace the 300K ohm resistor with 100K ohms, or have Dave do it for you. Then the cartridge would "see" a 250 ohm load. Easy, peasie.
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Cool_jeeves, When you went from 100 to 30 ohms load, was there a subjective loss of gain from the cartridge, which is to say, did you have to turn up the volume a bit in order to get the same sound pressure levels in your room? I ask because I think at a 30-ohm load, you may be attenuating the treble frequencies, and overall, as you drop the load impedance, the cartridge gets less and less able to drive the phono stage, which loses gain; some of the signal voltage is lost to ground. You yourself mentioned that the treble was too energetic at 100 ohms and is more tame at 30 ohms. You may like this effect, but it is an artifact of the impedance mismatch. I bet that as the cartridge breaks in, you will grow to prefer the 100 ohm load or higher. On the other hand, some prefer the Denon DL103 at very low load resistances, where that cartridge should not really work well. So sometimes theory does not predict personal preferences.
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Pani, I find the correlation between goodness of sound and price, when it comes to cartridges, to be unreliable at best, if not totally non-existent. Thus, if I find a cartridge that is "special", no matter what the cost, I would use it on the best turntable I could afford, regardless of cost. Among the MM/MI cartridges in my stash, I adore the SS re-tipped Grace Ruby and the Acutex LPM320STRIII. Neither is worth more than $500-$600, but I would use either on any turntable with any suitable tonearm regardless of cost. And they do respond to better and better equipment downstream. |
Thanks for that review. I own a first generation ZYX Universe with low hours on it, and I just bought an ART7. I plan to compare those two, and if anyone is interested, I will report here. The ART7 is very different from the ART9 in terms of construction, and, of course, voltage output. The difference between how two stereo cartridges play mono LPs is kind of beside the point, because it may have as much to do with the phono stage as with the cartridges themselves, but I assume you had the Dolshi in mono mode when you made that comparison. Yes?
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I agree with sbank that the 17D to D3 series (I own a D3) has or did have a reputation for being a bit "clinical" sounding, which usually indicates a "rising top end". But I think we all have to be careful how we use the term I put in quotes. Almost none of us has a hope of hearing a rising response in the range above 15KHz; so none of us could hear the gradual rise in amplitude above 15kHz shown on the graph that Oregonpapa referenced. In fact, there are not even any common musical instruments that can produce a primary tone in that region, only harmonics. If we really hear a rising top end, it would likely mean we are hearing a deviation from flat response in the 2kHz to 5kHz region. |
Also, it seems based on the appearance of the various graphs that in the case of the Lyra cartridges vs the Dynavector Karat 17D3, you are comparing measurements done at least two different ways; the Karat graph looks exactly like the package insert that comes in the box with some cartridges, i.e., a straight line from 20 to 20kHz. The evaluation of the Lyra cartridges cannot have been done in the same way using exactly the same methods. So, at least those 3 graphs (Atlas, Dorian, Karat) are not scientifically comparable. I have not looked at the rest of the data, but I am betting that the same caveat applies.
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Oregonpapa, Can you say how "Robert" is making those measurements? What equipment, what test LPs, what load resistance, etc? I am not necessarily a big fan of Lyra, but those reported deviations from flat response seem oddly extreme. Also, Raul is a fan of Lyra, and it hardly seems likely that he could tolerate such "distortions" without noticing the problem.
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I have a great deal of respect for Joe Rasmussen and for Allen Wright before him. It is ironic to note that Allen espoused the idea of using a 47K load on LOMC cartridges (which I too have found go be worth trying). Now here we have Joe espousing a much different sort of heresy, in fact a more controversial one. Frankly, it is a physical fact that using a 2K load on most MM cartridges, which typically have about 1000X more inductance than a typical MC, would result in a high frequency roll-off well within the normal range of human hearing and well below 20kHz. So, if your MM cartridge has some really annoying hf characteristic that you would like to "damp" or tame, then maybe you'd like a 2K load. Otherwise....NOT. And where the heck did he get "1.6" as the multiplier in his little formula for selecting a load resistor for an MM? Since I know JR knows more about this stuff than I do, I have to wonder how he justifies his advice. It is not sufficient to talk about "damping".
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Chakster, Thanks for the response. The circuit looks very simple, which is good. I have no idea why they call it a "Diamond" transistor, but that's marketing-speak anyway.
I wonder a little bit how they achieve two different gain profiles (one for MM and one for MC) in such a simple circuit. |
Dear Pani, My apologies. I knew full well that it is Chakster using the JLTi. That was just a bit of brain fade. Perhaps Chakster will respond to my question: What happens if you don't plug anything into the load jacks on the JLTi? Does it present no load or some standard value?
Pani, I did wonder what resistive load you are using with the ART9. Mainly because I have found with my Atma-sphere MP1 that 47K works well with several of my MC cartridges, giving a slightly more open top end, and a "bigger" sound, compared to using the more typical LOMC loads, e.g. 100R to 1000R. Perhaps the overall tonal balance is better, as well.
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There are many, many other phono stages (besides the JLTi) that also allow the user to tweak the resistive loading by one method or another. In my opinion, this is an essential feature of any "high end" phono. If one only wants to convert from a 47K load to 100K for MM cartridges (which I agree mostly do sound best with 100K), then the more purist approach is to de-solder the 47K load resistors where they are mounted and replace them with 100K (nude Vishays, of course). Other very neutral resistors for this purpose are the Caddock TF020 (available from M Percy) and the tantalum types, if you're reluctant to pay for the Vishays.
So what about the ART9? Are you running it also with a 47K or 100K load? In my fully balanced Atma-sphere MP1, I am finding that MCs can sound excellent with a 47K load. (I am not going to say they sound best this way, because that would be a subjective judgement, but I do think they sound a tad more open at the top end than they do with the more classic 100R to 1000R resistive loads. Like someone else said, the load R is really a load on the phono section, rather than on the cartridge.)
Pani, I am unfamiliar with the guts of the JLTi. If you have no resistor plugged into the aux phono inputs, is there then no load at all in place? In other words, is it designed such that one MUST plug some resistance into those inputs? |
I don't think my throwing one more set of subjective opinions into this mix would do anyone any good, least of all the OP. However, Chakster, because you've got a ZYX 4D, do not assume you know how a UNIverse sounds. I don't own and have not heard the UNI II or the newest iteration, the UNI Premium (I think), but I do own a plain Jane original UNIverse, and it's a truly great, exceptional cartridge. This is coming from a guy who mostly loves MM and MI types, too. Here is why: It does piano better than any MC I have owned. While accurately re-creating the believable timbre and decay of a piano, it also separates out instruments in space; there is no congealing of the violin section, for example. And bass definition is better than with other MCs I have mounted in the same tonearm now sporting the UNI. (10.5-inch Reed 2A on Technics SP10 Mk3 in 100-lb plinth.) I also have a new ART7, which I intend to compare to the UNI, next.
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I like what Pani said. My Ortofon MC2000 is relatively new to me and my system. I got that thrill of discovery when I first auditioned it (without a SUT into my modified super hi-gain Atma-sphere MP1 loaded at 47K). And I think I reported my results here, to credit Raul with his citation of the MC2000 as one of the greats. Now here it is at least a year later. I have spent a lot of time in the interim listening to my other (Beveridge) system, which runs with either an Acutex 320STRIII or a Grace Ruby. However, whenever I go back to the MC2000, I feel the same giddy thrill. Proof of its enduring excellence (to my ears and brain).
There is a paradox with very LOMC cartridges. If one must use a SUT, then one cannot effectively experiment with "infinite" (very high resistance) phono loads, because of the effect of the turns ratio of the SUT upon the impedance seen by the cartridge. Thus it may be the case that one cannot fully experience the best performance of the cartridge, if in fact infinite loading is the ultimate. I really don't know and don't claim that this is always true. It seems to be true for the MC2000, however.
Can anyone explain the differences among AT7, AT9, and AT50? Are they available in mono versions? |
Now you can move up from Nancy to Frank. |
Thanks, Al. I am in need of a mono cartridge. Based on that table and other information, I gather that AT make at least two mono cartridges of interest. Has anyone here auditioned an AT Mono? I started reading this thread with a bias toward the AT7 vs the AT9, but based on what is written here and elsewhere, the AT9 may be a real winner in terms of bang for the buck, and is said elsewhere to be superior to the AT7 for jazz and similar music that I favor. |
So far as I can tell, 50ANV is no longer available, and I could not find that anyone is selling NOS ones these days. I got the impression, right or wrong, that ART7 replaces the 50ANV, in effect. |
Hi Almarg, I was very interested to read your remarks comparing the ART9 to your SS re-tipped Grace Ruby. I use an SS re-tipped Ruby (top of the line OCL stylus) regularly on one of my two systems. What struck me is that your list of the ways in which you perceive that the ART9 ("considerably increased detail and better
definition in the treble region, cleaner and more accurate response to fast transients, and improved dynamics") surpasses the re-tipped Ruby would also be MY list of the strong points of my OCL Ruby, as compared to the qualities of the original OEM elliptical version. IMO, these virtues come at the expense of a more romantic mellow sound with the elliptical.
So, my first question to you is whether you have the CL or the OCL stylus on your Ruby. If you have the OCL tip, I am really puzzled, because if I had my 'druthers, I would want my Ruby to be slightly LESS strong in the very same areas you mention. Mine has only 20-30 hours on it, so I do have reason to expect that it will mellow out a bit as the hours of use accumulate. But I would not want to go from the current flavor of my OCL to another cartridge that was similar only more so in the areas you mention. My Ruby is driving the phono section of a vintage Quicksilver preamplifier with a load of 47K ohms and no added capacitance. The Q is highly tweaked in terms of parts, but I have left the circuit topology as Mike Saunders designed it. Speakers are Beveridge 2SW plus home-made Transmission Line woofers below 100Hz.
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I heard from one Grace Ruby user who is also apparently a dealer that he has come to the opinion that the CL re-tip is to be preferred over the OCL re-tip, when it comes to SS re-tip choices. His opinion was based on an N=3 of samples, his own Ruby plus those of two customers (or two friends; I'm not sure which). My OCL re-tipped Ruby is coming around, in terms of a decrease in edginess and a subjective increase in mid-bass response, to be a favorite of mine. Albeit, like I said, I would not want it to go the other way and become more "clinical" sounding. I also think I read that the original spec for the Ruby recommended adding a fair amount of capacitance, at least 300pF if not more. This was a factory recommendation in parallel with 47K ohms. I don't know if such recommendations apply after a re-tip.
You say that the Herron gives "near infinite" input resistance if no resistor is in the jumper position. Is there no resistor between the gate of the FET and ground, in such a case?
Re load resistance: Ever since I accidentally listened to my Ortofon MC2000 with a 47K load, I am routinely using 47K with it and most other MC cartridges. (This is into my Atma MP1 balanced differential phono section.) The MC2000 sounds about as good at 1000R but loses something at 100R, which by usual practice would be the "correct" choice. We've been brainwashed.
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