My understanding is, I am not a very technical person so I might have gotten this wrong, that the voltage gain of the phono stage needs to match the voltage output of the cartridge. In my experience the KAB calculator is very accurate and this is the tool that I am using to determine gain for my cartridges. I have heard many catridges that are mismatched with higher that needed gain and the sound is edgy and harsh. I can tell right away, when I hear that sound, that there is too much gain. I have no technical knowledge to know why specifically this happens, (I am guessing spikes in amplitude due to higher voltage?), but is unmistakenable in my ears. I have heard wonderful cartridges to sound unbearble because the gain was too much. I remember that there was a thread here when a forum member was trying a Lyra with the JC3 and the gain mismatch made the cartridge sound horrible. New toys: Parasound JC3 phono preamp & Lyra Delos cartridge
Thank you! A very good reply. I'm still a bit confused though: When you see the specs of the Parasound JC3+ phono stage (Model Halo JC 3+ « Parasound ) it says: Input Sensitivity at 1 kHz MM: 4mV for 1 V output MC: 600µV for 1 V output Total Gain MM: 48 dB MC: 64 dB If you apply the math to these numbers, they match: 4mV + 48dB = 1V and 0.6mV + 64 dB = 1V (aprox). Of course I can use cartridges with lower outputs which will result in less than 1V. But wouldn't these specs above mean that the designer thought it was optimal, or at least good, to this phono stage to deliver 1V to the line stage? Maybe it is. Remember that the TAS article referred in the thread used 1V as a standard too. Let's consider for a minute that the designer of the JC3+ (John Curl) though it was good for this stage to deliver about 1V to the line stage. If it does mean that, and if an 1V output from the phono is unsuitable for a 300mV input sensitivity line stage, than the weird result is that this phono stage would be a mismatch with every integrated amplifier and preamp made by Parasound, because all of them have input sensitivity rated at 300mV or below, if used with 4mV and 0.6mV output cartridges as pointed in the specs. We would have to use lower output cartridges to have 300mV or 500mV output from the phono stage. But how much? Let's do the math and the results are even more bizarre: If the JC3+ needed to deliver only 300mV to the line stage of Parasound integrated and preamps, its MM input would be totally useless, because 48dB would be optimal only for MM carts with 1.2mV output at maximum, but that doesn't exist. To deliver about 500mV, 48dB would be optimum for 2mV MM carts, and I don't know any. This would exclude all Nagaokas, Ortofons, and AT cartridges for example. So John Curl made a completely useless MM entry in his very famous phono stage. Should we admit that? The results for MC would be not so bad but also puzzling: its MC output has 64dB gain. It would be optimal only for 0,3mV carts to deliver 500mV and for 0,2mV carts to deliver 300mV. This phono stage would be useless for every MM cart in the market and for a lot of MC carts when paired with the line stage of integrated amplifiers and preamplifiers designed by... the same John Curl! The same guy designed line stages with 300mV and 200mV input sensitivities, for the same company, in all of their integrated and preamplifiers. So if you're right and 500mV would be the maximum input the Halo would accept, Mr. Curl designed amps that won't work with his phono stage and designed a phono stage that won't work with his amplifiers. I'm not quite ready to assume that. So I believe that the line stage of the Halo and of all other Parasound integrated or preamplifiers are able to receive more than 300mV or 500mV in their line inputs. 300mV would be the minimal but somehow it can handle more than that up to 1V. Maybe, as you said, "the line stage of your HALO, which has an additional 10 dB of gain, will be applying very little of it to that incoming signal, or may even be attenuating it". I understand that the 2M Black I'm using now is too much with its 5mV output. It delivers 1.25V to the line stage when paired to the 48dB MM stage of the JC3+. I'm not sure it's distorting but the volume knob is very sensitive. I'd be better off with a 4mV output cartridge, this should be a good match, delivering 1mV. And a 0.5mV MC should work great with the 64dB gain of the MC stage. In this thread there are people, like the OP, who uses 66dB with 0.5mV cartridges and enjoys it.
I see two possibilities here: a) they may mean that the 1V output comes out of the line stage, not phono stage - then it would make sense, they just did't make it sufficiently clear; or b) with a 1.0 - 1.25 V coming out of the phono - the line stage may be attenuating that signal instead of amplifying it, or, that signal may just be passing through straight to the power stage - it certainly would be sufficient. In my desktop system, I have a Parasound Zphono USB with an AT-120, for vinyl drops. The gain of the Parasound unit is not listed, but I assume it to be around 40 dB - MM "standard". The cartridge is AT95XE, with 3.5 mV. So, the resulting output from the phono is about 350 mV. That 350 mV output from the phono goes directly into Audioengine HD-3 powered speakers, with a 50 WPC on-board power amp (with volume control), and is sufficient to drive them with no issues - with no line stage in between. Now, just imagine 3V (!) coming out of the line stage into the power stage... Put it in perspective: 1W output to the speakers is achieved at 2.83V coming out of the power amp (the standard formula for speaker sensitivity 1W = 2.83V). Depending on speakers' sensitivity, one may be getting 88,90 dB or even above in SPL at that 1W. Hell, there are SET amps that put out a total of 2W! With 3V out of the line stage, I believe the volume control would have to be close to zero, and the music would still be louder than you want, and you'd have no way of lowering the volume. So, while giving us the nominal numbers, John Curl and Parasound are not telling us everything that's happening inside their unit. I'm almost sure that either it's NOT 1V coming out of the phono, or, if it is, the line stage is attenuating it, rather than amplifying it. I think the 1V figure is coming out of the line stage, instead. KAB believes that the optimal output from the phono is 325 - 350 mV. I think it is around 500 mV or a little above. I can hardly believe in output 2 to 3 times higher being even suitable, let alone optimal.
If this is right, than John Curl designed and Parasound made a very expensive, award winner, editor's choice of The Absolute Sound phono stage that is completely useless for every single MM and most MC cartridges in the market. This sounds very strange to me.
Good explanation. I do disagree the "rule" that 56db of gain is too much for a .5mv cartridge. It truly depends, I have had .5mv cartridges that thrive on 66 db and some that do not. My current .5mv Ortofon does not like to go above 58 db for example yet my Audio Technica sounded amazing at 66db.
What is mystifying (to me) are the phono preamps that have really high gain for MC cartridges- Parasound JC+ (64db) Ear 834P (68db) Jolida JD9 (85db- 95db) Are these limted only to low / very low output MCs? which by rights could have to much gain for .3mv cartridges. I don't think so but I would hesitate to use any of them with a .5mv cartridge.
I guess it might depend on the cartridge and on the phono stage too. When Fremer reviewed the JC3+ he used, among others, a Lyra Etna, a $9,000 MC cartridge, with 0,56mV output. He played it at the 64dB setting of the JC3+, which would give an output of almost 1V, and didn't register any problem.
another thing is the renown BAT VK P6 preamp. It has a max MC gain of 55db. I would hesitate to use this one for .3mv cartridges and would proceed with caution for .5mv carts.
Wait, I said 66 dB is too much for 0.5 mV, not 56 dB. But it's not really a rule, as you've said, it depends on cart/system synergy. I've replaced my integrated amp with a pre/power pair. Because the preamp has an additional 12 dB of gain, I find that I can easily get by with less phono gain than I normally would need with an integrated. My chain now is Denon DL-301 (0.4 mV) into Lounge Copla (around 14 dB at +/- 220 Ohm on the transimpedance dial) into Pro-Ject Tube Box S2 at the 43 dB setting, for a total of about 57-58 dB. Normally, I would have preferred around 61-62 dB gain for a 0.4 mV cart, but the line stage preamp compensates for it easily with its added gain, and the resulting chain is actually quieter than the former integrated with a phono at a higher gain setting.
Nope, John Curl simply isn't telling us everything that happens inside that box. I'm sure it sounds wonderful, so - he must have found some ways around the conventional math. My guess, as I've said before - the line stage is attenuating the signal from the phono, there must be some sort of sensor in there which tells it to, when the incoming signal is too strong. EDIT: Tell you what - let's ask @morinix. He designs and builds phonos for a living, I'm sure he can shed some light on this situation better than you or I can.
I've used up to 66 dB on a 0.3 mV cart (Zu Denon 103) - no issues whatsoever. The resulting phono output is only 598.6 mV - no cause for concern. I now feed that cart into 64 dB, resulting in 475.5 mV - also sounds great, I just have to crank up the line preamp a notch or two higher when playing it.
I can't at all, I understand nothing about this. I'm just a puzzled consumer. Sorry if I sounded like a Smart Alec, not my intention. What puzzles me is that I'm pretty sure that the JC3+ was not designed to work only with the HINT, so the fact that it delivers much more than 300 or 500mV with any of the common MM cartridges in the market suggests that values higher than these shouldn't work only with the HINT but with any good integrated / preamp. It can't be due only to internal tricks in the HINT. Anyway, I don't have an answer, it's just that the answers I've read haven't satisfied me so far.
The "proper" gain setting for a given cartridge output spec is a complex question. The answer is dependent on other components in the system besides the phono preamp. Line stage gain available is one consideration, input sensitivity of the amp(s) is another. Sensitivity/efficiency of the speakers is also a factor, then add in room size and listening distance. Try to pick a setting that gets your volume control to between 12 and 3 o'clock at the very loudest you'll ever play the system.
Another intriguing example: http://boulderamp.com/products/508-phono-preamplifier/ 70dB MC and the guy loved it with a Kiseki Purple Heart, a 0.48 mV output cartridge: I found a giant killer phono stage today - by by Parasound
Circling back on the reason for the thread in the first place that "conventional wisdom" with respect to ballpark gain requirements for a given cartridge output may not yield the best sound. Unfortunately many variables enter into the mix as we have read. Choose your phono preamp with care and ideally a degree of gain adjustment that begins with the minimum needed gain- yet allows the option to increase it to reach the gain match in the TAS calculation. I have only had one case where the gain for a cartridge needed to be between the available settings- my MM 2M black sounded weak at 36db gain yet harsh at 46db. MCs seem to be better at sounding dynamic with less than ideal gain- most likely because they are more dynamic by design. My current MC puts out .5mv and conventional wisdom calls for 56db. It sounds optimized on my system at 58db and overdriven at 64db, possibly because of the 2v output of the preamp. No one way to skin the cat but with the level of investment these devices require, not getting the best out of them is not acceptable!
What I learned from this thread and further research is that the results of the KAB calculator are very conservative and don't give you automatically the maximum or the best gain for a given cartridge output. It gives you the minimum needed for a 300mV input sensitivity line stage, which should be enough for more sensitive line stages as the 200mV ones. This minimum could work just fine for some cartidge/phono stage/system combinations but may not be enough for optimal sound for others. It might be the case to have more (sometimes much more) gain. A combination that results in 1V or something around it, as in the original post of this thread, might be the best. It's usual to high end phono stages to work with high gain specs. However, too much gain can also give you bad results. I suppose that anything within the KAB calculator (300mV) and the TAS (1V) should be safe to try, but one can't really know how a system will sound only by doing math. While researching before buying a cartridge or a phono stage, looking for a good match, one should not make a definite choice considering only the KAB calculator. It may prevent one from finding a better combination.
The proof is in the pudding. There is no substitute for listening to a specific cartridge into a specific phono preamp. Gain calculators are generalizations at best. A lot depends upon the quality of sound a phono preamp can deliver and of course the quality of its input, the cartridge. Some phono preamps just don't sound as good as others, and it isn't just about their gain or their loading. If it were that simple, no one would ever bother listening to different designs over the course of years, they would just read specs and buy something and be done. That's why I don't like the arguments of many engineers who seem to think that it is only about the numbers and that they can select products based on published specs and that they will be equal to anything else. That just isn't true, and you will discover that only after you have heard several other systems. In general, I prefer to use as little gain as is necessary to amplify any signal, including cartridges, hell particularly cartridges, because all amplifiers have some sonic impact. Using less gain in a particular circuit lowers the sonic impact of that circuit. If you start out with a great cartridge and thus a great signal, you don't want to squash it with an amplifier that has high gain and self noise. Some systems may benefit slightly from a really well designed higher gain preamp, but there are trade-offs. -Bill
It's that those transient peaks may overload the circuit. Either they do or they don't. Also, I think gain is very seductive and is very commonly heard as more is better. As you improve the accuracy of playback, you'll probably find that to be false. A little too much has always been the issue with me, and the choices in 3 to 3.5 mV output MMs is pretty small.
Something like that might be going on. If I had a CD player with an average of 2V output, I'd plug it in the same line stage. So it must be able to deal somehow with this amount of input.
Are you sure a line stage is supposed to put out 2V tops? Isn't that what the line stage might receive from a CD player for example, and in this case it will put out much more than 2V (2V plus 10dB) to the amp stage?
Same experience here, in terms of 3mv output. I am fortunate to have the abilty to chose 46db and it sounds just right.
I do 3 mV @ 44 db, and that's really a pretty good match. I'd like to have a 43 db setting, though. Thing about the specs, that voltage is at a certain frequency so it only describes a tight window. Cantilever resonance and other factors like loading can damp or boost, so you've really got to listen, IMO.
My phono stage has 48dB and I'm using a 5mV 2M Black. I'm pretty sure it's too much, not sure if it distorts but it surely makes the volume knob too sensitive. I'm planning to buy a new cartridge in November and if MM one of my targets is the Nagaoka MP-500 (3mV). It would be a better match. I wonder if I should choose MC though, but I'm not comfortable to send it overseas from Brazil for a future retip.
Don't know what to tell you. I like the Denon DL-110 but not the stylus shape so much. Nagoaka is moving iron. I'd like to try one at some point. Should be nice at 40 db gain. Pretty expensive stylus replacement, though, as I go through them.
