I have the ARC SP-8 preamp with a MM phono section for years. I have gone through many step-up transformers including the last one I had (Counterpoint SA-2 Tubed pre-preamp) which I thought was the best of them all. In my opinion, even the best step-up will deteriate the sound quality to a certain extent. The best sound is the most direct path from your source to your speakers. Anytime you add another piece of component and interconnect you will loose in sound quality. I had the Benz Ruby (0.35mV) and had experimented with or without any step-up. The results have always been better in sound quality without step-ups but without the proper dynamics. I love the SP-8 and don't want to replace it with a MC phono stage which could be very expensive. I have always liked the details coming from MC cartriges and don't want to use a MM catrdge. The problem was just about all MC cartridges are low output. In recent years, there are many very good quality HO MC cartridges coming onto the market. I finally sold the Ruby low output and bought a HO MC cartridge. Now, the sound quality remains and the dynamics is there too. To me, the best step-up should be right at source. Most MC phono stages have built-in step-up transformer as well as tubes to reach the gain they need. Most tubed MM phono stages use only tubes for the gain. I think that makes a difference. Before, we didn't have too many choices but now we have choices of many good quality HO MC cartridge. Good luck.
What cartridge and phone amp are you using?
Sidssp: currently I am using a Dynavector 17D-II and a Herron Audio phono pre. I have tried the Coph Nia and Rega Fono.
Blptwp: I like the Dynavector very much (I have never heard any cartridge with the detail it translates) and would rather not change cart's. However, I am afraid that if I add a step-up, I'll get the volume I want but will lose the detail. What to do - What to do?
Odd, i have a Dynavector xx-2 (same output as the 17d) and the herron, an I have no problem at all with volume. the herrom has 65 of gain, which is right for the .23 output. I feed the herron into a Kora Eclipse pre, andplay one of the new rega p9 turntables. The volume at relaxed listening is around 9 o'clock, froma starting point of 6 o'clock. I have cranked it to 11 or 12, and do not hear any backgound noise until 3 or so (not playing any music). does your pre use balanced interconnects to you amp(s), and is you turntable isolated?
Herron phono amp has two versions one for MM and one for MC. The MC version has about 66db gain that should be enough for the Dynavector unless your preamp is very low gain also. Are you using the MC version?
a good step-up costs pretty-much the same as a good phono $1k or higher. there could be a-bunch of different contraversal issues in this case since high-gain mc sections tend to have more than one amplification stages and/or a step-up transformer as well. also all-tube phono preamps either very costly or have not enough gain to handle super-low output cartridges.
cary audio came up with inexpencive solution and i'm sure that there are more brands that have electronic approach for a step-up that for the money is more efficient than step-up transformer.
in general for this issue i tend to partially agree with Blptwp for the MC cartridges not higher than 2mV on the output used with phono-sections 50...55dB since the coil length does affect pretty-much as amplification stages or step-up transformers.
for herron phono preamp you can use as low as 0.5mV output cartridges and mainly you need to step-up another just 6...8dB. if you go for step-up passive device you should probably research Quicksilver or EAR step-up transformers that will minimize any losses and boost the volume. Also less expencive Ortofon T1000 can just do that job. In high quality transformers you can select the gain or even use the unity gain just to match impedance with no headache. If minimal gain is used on the high quality step-up device you should hear no difference in terms of details.
I believe you won't be satisfied with step-ups. However, many audiophile use them with satisfaction. I guess it all depends on your expectations. I was not satisfied with step-ups because I knew what the sound quality was supposed to be like without step-ups even though without dynamics. The sound did changed for sure. I never liked SS step-ups. I had tried 4, including the one made by Benz Micro. Tubed step-ups are very difficult to perfect because of different tubes have different sonic characters, trying to get the sound you want to match tubed step-up and your tubed preamp and phono section means endless tube rolling. I did all that and through with it.
Your choices are, if you don't want to change cartridge, to try different step-ups. Based on 0.23mV output, your phono must already be a high gain phono. Be very careful when you add a step up. Too much gain will really be a bad thing, I have tried that, it sounded aweful. Or, get a phono stage with even high gain. If your phono stage is already high gain, do not use a step-up period.
G_m_c and Sidssp are right. 65 db gain in your phono should have enough gain for your cartridge.
Okay, look, we have 2 situations here. Standard MM input with a gain level for about 4mv cartridges, and some type of MC input with higher gain for a low-output MC cart. There is no free ride. Either you have a step up transformer into the MM stage, or you have extra gain stages in the MC section. Pick your poison. The additional gain stages in the MC section are at least as objectionable to signal quality as a step up transformer. Personally I use a step up transformer because I think it is less problematic than additional gain stages. Others think differently. If you have a decent step up transformer, or a decent MC stage, you should not be corrupting the signal in a real bad way. My Cotter transformer passes a nice clean step up, that sounds real good to me into my MM stage.
And you can't get around the issue with a MM cart or a high output MC, because they have heavier moving structures than a low output MC and so you have a very likely possiblility of losing something there.
If you are looking for what the "experts" say, Kondo, the total "audio guru" who makes some of the most musical gear in the world, specifies only a transformer is to be used to step up his top of the line cartridge. A step up transformer does not have such a limitation like an amplifier output transformer, because very low level signals are being used and saturation is really not an issue. And if you don't use a step up transformer, and your MC stage has insufficient gain, then you raise the noise floor by turning up the volume, and obscure low-level detail that way. You have to use one method or the other to use a low-output MC. You have to choose one. I chose a good quality step up transformer, and I am happy with it. I would dare say that if you heard my system playing, you wouldn't be talking about any lost detail.
Step-ups require one more set of cables, right? factor the cost in.
G m c,
most of the times, the step up just does the trick being passive voltage amplification device connected to the minimal amplification circuit having less length of a higher gauge wire than it would be in the cartridge coil with the high output and moreover matching impedance with no additional adjustement to the load section of the phono.
MM phono-stage(especially stand-alone) coupled with step-up transformer can do about the same trick as it would the whole MC phono but and again but depending on the quality of the transformer which might be even more sophisticated to build than an electronic stage. Currently if the author uses MM version of Herron I believe that the cartridge is not properly loaded as well.
Dynavector as far as I know also produces step-up tranny with built-in set of wires. Ortofon T1000 has built-in set of wires as well. If you will order brand-new Quicksilver you can also request built-in set of wires thus you will avoid extra connection.
Marakanetz, i understand what you and TWL are saying, but in my mind, (following the mantra of Keith Herron (Why am i thinking of Kieth Herring?)), more interconnects, more connections, more wobbles, are not good. Is less better? I would sell the mm, and buy an mc, let the connections be solder, silver solder, I hope, and eliminate variables.
Thanks' to everyone for their responses. In answer to some of the questions from above:
Yes, I am using the Herron MC Phono-pre. I had it set-up at the factory to match the recommended loading of the Karat cart. at 100 Ohms. In discussions with Kieth Herron regarding my wish for more volume, he suggested I clip the leads to the resistors which gave me about 6db and un-loaded the cart. Truthfully, the volume is very close to being acceptable now, but I prefered the sound with the cart. loaded. The mids and highs lost some extension and sweetness, solo strings do not have the immediacy they had.
My Pre-amp is a Mark Levinson 380S, which if I remember correctly, adds about 17db gain. My digital front end plays at a reading of 55 to 58db on the 380S, my Rega P-25 through the Herron, plays at 65 to 68db on the 380S, to get the same perceived volume and detail. Unfortunately, I start getting noticable background noise from the Herron at a reading of 60db (lower starting point and louder noise from the Coph Nia and Rega Fono). From that, I have concluded that I need a boost of at least 10db.
Yes, I am using balanced interconnects between the 380S and my amp, and the P-25 is isolated. FWIW, I get no background noise from the digital front end (Levinson 37 Transport and Chord DAC 64) when played at any level.
From the responses above (and I really appreciate your help!) it looks like my choices are 1) get a good transformer at +$1K; 2) get a higher out-put cart for the same or more $'s; or 3) re-solder the resistors and live with the noise (least acceptable alternative).
Thanks for everything, David.
Make sure phono preamp and preamp are physically
separated from one another. This will lower noise floor.
The problem with most step up transformers is the the bass gets softer. And in my experience, a low output moving coil is better sounding than most high output models. It is best to get a preamp that has enough gain in the phono stage or get a line level preamp and get a stand alone phono stage that will have enough gain for low output cartridges. The Reference Phono that Audio Research makes uses a Jensen step up transformer to have enough gain with low output coils. While I have not heard this preamp, and Jensen makes some of the best transformers available, I feel that they are charging a lot of money for something that only costs a few hundred dollars and anyone can order from Jensen on their website. I realize that the transformer is not the only thing about this preamp and that it is highly regarded.