How much gain is needed in a Phono Preamp for a 0.2 to 0.3mv low output moving coil?
The obvious assertion in this thread (so far) is that ''any'' phono- pre has just two amplifications , say, 40 dB for the MM and + 56 for the MC kinds. But I own two phono-pres (Basis Exclusiive) and Klyne 3.5 with 4 amplification stages for the MC 's. The lowest possible are recommended for the given cart. The reason being ''the higher the amplification the higher distortions''. So , say, 70 dB is recommended for low output cartridges. Before I become member of this (analog) forum I deed not think to need more than just one single cart. But because I also become member of the so called MM thread I collected more than 60 carts, 40 among them of the MC kind. I never bought any high output MC cart but my collection ''range'' from 0.05 mV (MC 2000) till 0,45 mV (Sony XL 88). So, I assume, the contributors to this thread own just one LOMC (grin). |
i went with the RCM sensor II which worked well with my ZYX Universe II lomc. I had been using the ZYX artisan as my Phono preamp, but it just did not have enough gain(it is fixed). Mehran suggested (similar to another person on this thread) the stepup by ZYX and the RCM for me to tryout. After using both, i preferred the RCM. |
Juke, probably least expensive way to find out what correct loading and gainwill mean to you is to buy or borrow an ifi 2 Phono stage. Plenty of load settings and 72db gain not to mention sound that will embarrass many Phono pres in the sub $3k. Don't buy or borrow the original ifi which won't get you the gain you need. In fact, buy one on amoney back deal from Music Direct. I don't think you will send it back. Yes, there is a meaningful interplay between load and gain. |
I use a Dynavector XX2 MKII (.28 mv) with the ARC PH-7 (57.5 dB). My line pre is the ARC REF 3 (11.6 dB balanced) and the amp is an Ayre V5xe (26 dB). Noise and gain are not an issue. When the volume control gets past 50 (out of 104) my Vandersteen 3A Sigs (87dB) are at party. Normal levels for me are 25 -45. Even though the DV works well, no complaints, I can’t help but wonder if could work better with more gain. I would recommend carts from .4 to .6 mv. There are outstanding carts in that range. |
I have the Chinook and upgraded the tubes to Phillips NOS. Just bought my second Soundsmith Cart - the original Zephyr is on my VPI Scout 1.1 now (Zephyr is made for unipivot arm) and it sounds great. Have Primaluna pre and Dialogue Premium power amp, Martin Logan ESLs. Got the Zephyr MIMC Star MC at .4 output but have not mounted it yet. Hope it all works out. Not sure what output the PL pre and power amp provide. I did notice a little more gain when I replaced the Chinook stock Electro Harmonix tubes. I may be asking you some questions sbank. Juke4u let us know what you end up doing! Great thread. |
Thanks again, I keep reading all the good words regarding the AT Art9. When I owned audio stores years ago we sold AT cartridges along with Grado, Denon, and Shure. The best one AT made was $150 and had a Shabata stylus. Compared to the others we sold and got in for demo the AT sounded the worst. I would prefer a LOMC most are around 0.3mv and 60 db of gain is max on most phono preamps and you have no room to upgrade to a cartridge with lower output. I emailed VPI and Marc sent me back a nice email about cartridges on the Prime. He said the Ortofon, AT, or Dyna are good matches for the TT. There are probably others but I only asked about the 4 mentioned. Didn't have any experience with the Benz on the 3D arm. I wish the Manley had more ourput. One just popped up for $1500 for an older one. It might end up being the Herron only because it gives me more options. |
How much gain for 0.2 mv MC ? It depends on the gain in your line stage and your amplifier, but I would say 60 db is a good starting point....I wouldn't go any lower, unless your line stage has 15 db of gain or better itself. If you use a buffer / unity gain line stage (First Watt B-1, etc.), then you need more like 75 db. The Pass Phono (XP-15 and XP-25) stages can provide that much gain with very low noise. Most toob phono stages give 50-60 db, and the quietest ones either use a step-up transformer or JFET's on the input stage (like the Pass solid state designs). 55 db is enough for a normal 0.5-0.6 mv MC, but marginal for a lower output cartridge. |
If the noise floor is low enough 57 db might be fine. But the phono gain isn't the whole thing. The gain in the line section, the gain in the amp and finally the efficiency of the loudspeakers all make a difference! So if you have 57 db, a passive volume control and 89db speaker it won't work in most cases. So you need to add up the gain in the electronics and see if that will give you enough sound pressure. |
Thanks, Analogluvr. Good to know. What I was recalling may have been the second of the two posts dated 4-22-2013 by member Czbbcl in this thread. Apparently he was wrong. Best regards, -- Al |
With the Herron you have the added advantage of being able to easily switch from 64 to 69 Db of gain just by swapping out two tubes.I'm not sure that is true, Analogluvr. I believe I recall someone stating in a thread some time ago that he was told by Keith Herron that there are circuit differences between the two gain configurations, in addition to the differences in tubes. In any event, as you, I, and just about everyone else who has heard it and posted about it has found, it is a remarkable performer. Best regards, -- Al |
With the Herron you have the added advantage of being able to easily switch from 64 to 69 Db of gain just by swapping out two tubes. And I've not heard a phonostage that I like the sounds of better yet. It's one of those things that you may not regret spending a little extra on as you will not get upgraditis later. |
I have a Dynavector 10X5 on a REGA P3 with the Manley Chinook Phono Pre, 45db is more than adequate for the 10X5! (this is my goto backup rig) I also have a Pro-Ject Xtension 10 with a Dynavector 20X2 Low .3mv and 60db is plenty for that cartridge as well. I use the Manley for both and switch cables around (when needed). I love both these setups, very satisfied. Matt M |
Lots of good suggestions in the last day or two here. I agree with the brief comment that a solid state phono stage will give you a lot higher chance of quick success. It hasn't been discussed much in this thread(but plenty elsewhere!) that low level phono signals are most susceptible to picking up RFI(ie. radio)/EMI noise. Tube phono more so. Go with a ss phono stage with plenty of gain and you will high probability of quick success without headaches. The Art9 sounds lovely and balanced, great with classical, perhaps a bit on the sterile, detailed, cool side vs. Dynavectors which also are frequently mated with VPI arms and tend toward warmer, punchier, more relaxed sonic profile that appeals to many. Either is a great choice. Cheers, Spencer |
I try hard to make a good decision, so I don't have to go thru a bucket of cash trying to get things correct. That is why I started this post. I read reviews just to get a feel for the products but hearing from everybody on Audiogon that have the same interest, means a lot. Sincerely thank you all. I know the end result is my system and my ears. I have been told by many that synergy is important. Partly the reason I went with the ARC amp and preamp knowing they would mate well and when I want to upgrade they seem to have a good following. I had checked out the AT Art 9 in the last post I did regarding pre and power. I think they were the first to use a nude Shibata tip many moons ago. It seems they have come a long way. I checked the web for an Art 9 and they are no longer made. I saw the Art 1000 and figured it was the replacement for Art 9, but I quickly realized I was completely wrong. Please keep the comments coming. As you can see I need help but i am getting there. |
Personally I would avoid the Transfiguration/VPI combo. I tried both a Temper Supreme and and Spirit III on my Classic and still got some IGD on hotter records. Tried all manner of alignments and protractors and eventually sold both carts. It was particularly hard to do because they sound so damn good most of the time. I have an AT ART9 now and that is what I would recommend you start with. Will sound great with most any standard (60db) MC preamp gain. |
"I like everything I read about the Benz (lowest $1800) and after reading about the Transfiguration cartridges (lowest $2450) I was very impressed. That being said, I am very concerned that with the VPI Prime I may be spending more on a cartridge than I should considering my TT. Please honest opinions, you will not hurt my feelings.Opinions help you learn." Reading and listening are 2 completely different things. Carts that you read about will probably sound different in your system (how much can vary). Synergy is much more important than price. Your TT is fine. I wouldn't make plans to upgrade before you listen to it. Keep it simple. A LOMC is fine. Match it to a phono pre that can handle the output and don't worry about an SUT. Also, at this level, I wouldn't fool with tubes either. |
"Thank You" everyone for the help. I have been away from this so long I will probably never catch up. I am constantly learning things and finding new products. I had looked at the Herron and the ARC Ref. but the price set me back a little. I had never heard of the Orpheus (Transfiguration) cartridge and had to check it out. I like everything I read about the Benz (lowest $1800) and after reading about the Transfiguration cartridges (lowest $2450) I was very impressed. That being said, I am very concerned that with the VPI Prime I may be spending more on a cartridge than I should considering my TT. Please honest opinions, you will not hurt my feelings.Opinions help you learn. Not sure if anyone tried this. I went to the store that sells Granite counter tops and got the cut out for a double sink for $1.00 (yes a dollar). I had them cut it to my size and edge it for $45.00. All I have to do now is find some feet for isolation. Is sorbothane still a good isolation damper? Thanks Everyone, Zuddie |
Lots of good comments, many of them cautiously worded...I hope your takeaway is that you could do better. I have recently troubleshooted a friend's Chinook/Prime setup and before we got things sorted out had to get replacement tubes for the Manley and properly functioning junction box from VPI. Even after working through that, with his Ortofon Qunitet Black(0.3mv) his Primaluna linestage needed to be cranked up very high and while generally musical, I wouldn't call it a quiet presentation, nor one that I could live with. IMHO, 60db gain in the phono stage would be better matched with a cart >=.5mv. There are plenty of nice phono stages that offer 65 or 70db gain. When dealing with small phono signals an extra 5db of quiet gain is nothing to sneeze at. Contrary to some here, I would suggest staying away from adding a SUT at this level of system, as most of them will take away from the purity of the signal, add more cabling and related susceptibility to incremental RFI/EMI. When considering adding a Kondo SUT to your 6figure table setup, then maybe you can convince me otherwise. Cheers, Spencer |
As usual Larryi makes an excellent point, in this case about the relevance of line stage gain and amplifier sensitivity. I see in one of the OP’s recent posts that he has recently purchased an ARC REF 5SE line stage (12 db gain for its balanced outputs) and a REF 75 amplifier (1.4 volt sensitivity). Based on the relation... db = 20 x logarithm(Vout/Vin) it can be calculated that 60 db of gain corresponds to a voltage multiplication of 1000 times, and 12 db of gain corresponds to a voltage multiplication of about 4 times. Therefore 0.2 mv into a 60 db phono stage and a 12 db line stage will provide an input to the amplifier of 0.2 mv x 1000 x 4 = 0.8 volts, ***when the volume control on the line stage is turned up all the way.*** Since the amp requires 1.4 volts to be driven to full power, with a 0.2 mv cartridge and a 60 db phono stage you would therefore only be able to drive the amp to full power on particularly high volume peaks that are present on some recordings, that exceed the standard test conditions upon which cartridge output ratings are based. And even then you would find yourself turning the volume control up to close to the top of its range, especially on recordings having wide dynamic range. With excessive hiss possibly also resulting. FWIW, I use a 0.5 mv cartridge (the Audio Technica AT-ART9) with a 64 db phono stage (the Herron VTPH-2, which is also offered in a 69 db version BTW), in a system having particularly high gains and sensitivities further downstream, and that works out well. Finally, I suggest caution in using the KAB calculator. Note the following statement in the text above the calculator: The optimum gain is based on achieving 325mV rms output at 5 cm/s. For the current crop of CD recorders, 300mV is required for 0dB recording level with the recorder’s level control set at max. Aiming for 325mV gives a little margin.325 mv multiplied by the 4x gain of your line stage would result in 1.3 volts into your power amp when the volume control is at max, which would still not be enough to drive the amp to full power. Good luck. Regards, -- Al |
Battery powered ZYX CPP-1 headamp (pre-preamp) designed for 0,24mV MC cartridges and compete with the finest suts ever made according to Arthur Salvator’s info. It has additional 26db step-up ratio for your MM input to drive LOMC cartridges. This is a very special device! ZYX own input resistors made of cryo purified chrystal copper wire (they use the same in material for their mc coil). The resistor is made by winding the wire to a coil that has no inductance in a special process. No noice and no infuctance at all. With this device all you need for LOMC is just MM stage. So in addition to regular MM stage +26db with headamp for 0,24 mV MC is enough. I owm Zyx CPP-1 and never had probs with LOMC. |
Hi Larry, Congrats on your Orpheus L. Your inputs elsewhere on this forum helped me to decide on buying mine. Much appreciated. I get enough volume with the Ayre set at 60db, but think that it would be optimal to have my preferred listening volume occur at the unity gain position or below on my pre's volume control rather than above, thus my comment on wishing I had a bit more gain from the phono stage. Going to a 0.2mV cartridge would make this even more of a challenge. Dave |
I also run an Orpheus L with a phonostage with 60 db of gain. I have enough gain from the phonostage. However, I don't know about the amount of gain provided by my linestage or the input sensitivity of my amp, so it is hard to translate my experience into how anyone else would fare with 60 db of gain. If I had an additional 3-6 db of gain, that might be desirable, but, as with anything audio, that would probably come as a tradeoff in some other area of performance. |
"Most of the cartridges I have looked at are 0.3 or less so I need to find a Phono with at least 60db output. " The 10x5 is a high output cartridge. But if you are going to use a low output card, I wouldn't use a tube phono pre unless you can afford a really good one. If you want something that's foolproof and sounds really good, get a Dynavector P-75 phono preamp, and a Dunavector 20x2 low output cart. I have the same setup on one of my VPI TT's. |
