Problem with phono stage


Hello Fellow Audiogoners,

I need help with my Phono stage. It is Lehman Audio Black Cube from Germany.  It was recommended from Simao, a very respected Audiogon member who helped me a lot when I was building my stereo. It costs 450$ brand new which I bought used from this site. Michael Fremer considers it one of the best steals in phono stages. I get a little bit better detail and bass extension BUT it also much noisier. I can hear the pops and any other noises  on the records much more then with the phono stage of my Arcam FMJ 28 which turned out to be a surprisingly good one considering it is an integrated one.
I also switched the cables but the noise is still there.
Is this a common problem with added phono stages as opposed to integrated ones or something is wrong with my phono and needs to be checked.

All help will be greatly appreciated.
Emil


emilm

Showing 9 responses by lewm

But shielded cables per se do not have low capacitance, compared to unshielded wire of the same type and length. So the shielding can be a trade off if you are looking for the lowest capacitance. But let’s hear what Ralph has to say to the OP. My question would be what is the phono  gain of the Lehman black cube?And for that matter, what is the additional gain of the line stage to which it is connected?
If the Black Cube accepts up to 4.5mV officially, I doubt that 5mV from the Nagaoka would overload it to the degree that it would cause the problems mentioned.
ncdogdoc (a vet who lives in NC?) is right.  The issue is the phono cables, defined as cables from cartridge to phono inputs.  And someone else mentioned that MM cartridges are relatively insensitive to capacitance; it depends in part on the load resistance in side the Lehmann.  It's probably 47K ohms.  So one needs to estimate the capacitative load vs the recommended capacitance. It's MC types that are relatively insensitive to capacitance, in part because they usually have very much lower inductance compared to MMs, about 10,000X lower, commonly.  But there are exceptions to every one of these generalizations.
Ummmm...  I am as lazy as the next guy about looking up facts before leaping to criticize or correct someone else, but according to my research (3 internet sources), the Nagaoka MP110 is a MM cartridge (Moving Magnet), as asserted by Atma, not an MI (Moving Iron) type.  Furthermore, Nagaoka do not make or market any MI cartridges in their current line-up, according to at least one website and contrary to Raul's claims.  I would also assert without further research, because I have done the research many times for many cartridges in the past, that the value Atma-sphere used in his example, 500mH, is very typical for the inductance of any MM cartridge.  It can be a bit higher or a bit lower in individual cases, and variation in the value would of course affect the resonant frequency when combined with cable and input capacitance. I think Atma made that very clear in his analysis.  Further, many if not all of the cartridges that Raul lists in his vitriolic response are MI types in fact, not like the Nagaoka.  MI types do indeed tend to have much lower inductance than MM types, as Raul shows us, but that is irrelevant to the OP's issue.  It is unlike Raul to make such a factual error, but there it is.
https://www.vinylengine.com/turntable_forum/viewtopic.php?t=72159&start=15https://forums.stevehoffman.tv/threads/nagaoka-mp110-cartridge-loading.364498/https://www.vinylengine.com/turntable_forum/viewtopic.php?t=116237
Info at the above sites might help the OP to think about capacitance for the MP110.  In searching, I also found one other site where the cartridge is said to be an MM type, but I tend to agree with the owners manual, per Raul.  However, whether MM or IM, the inductance of this cartridge is quite high, higher even than a typical MM.  In 3 instances I found inductance quoted as 600mH or more than 800mH.  Thus, whether it is an MM or an MI type, it is even more subject to capacitance (and load R) than is the typical MM.  So Atma-sphere's analysis of where the resonant peak might fall and effect the audio band is reasonable and even conservative, regardless of the transduction method.

As I carefully noted, I am going on information obtained from a few internet websites, one of which was LP Gear. As I have learned not to trust LP Gear for accurate information on cartridges they sell, I verified the information on another site. If I am nevertheless incorrect, good for you. I will do some more searching to verify your claim. By the way, the Vinyl Engine page you quote says the output is 5mV, as mentioned by others here on this thread. I will have to sign on to VE in order to view the owners manual, but 5mV is rather high output for any MI in my experience; I suppose it’s possible. Accessing the actual owners manual regarding the transduction method will require me to sign in on VE. I’ll get back to you. I guess the point I was really trying to make by inference is that your insults directed toward Atma-sphere are uncalled for. If you think he (and now I) erred, then just say so. There is just no need for your vitriole.
EDIT. OK, I just found the owners manual.  You are correct.  IM type.  Mea culpa. Nowhere do I find a quote for the actual inductance.  Do you know it?
Chakster, I guess the "operating principle" of the MP cartridges is not being used to "decrease inductance", per JCarr's summation, because the MP110 has very high inductance according to any info I can find on the internet.  The operating principle seems to be used to increase output, because the output of the MP110 is MM-like, even if it's not an MM cartridge.  So we have an IM cartridge that measures like an MM, both in voltage output and (high) inductance.
Raul, if the MP110 has inductance of ~800mH, as per VE discussion groups, then its resonance can fall well below 20kHz, if capacitance and R are not adjusted to prevent that.  And Mijostyn, if the foregoing is true, then it does help the OP to understand why ticks and pops may seem prominent, and it gives him some idea what to do about it.
To paraphrase Albert Einstein, it's good to keep things simple, but not so simple that a valid hypothesis is ignored.
Ironically, even though Raul hates me, I will admit I own a 3160, and it is indeed superb in its performance.  As a tube aficionado (one reason Raul likes to attack me), I find myself not thinking about whether the 3160 uses tubes or transistors, when I am listening to it. Raul's business partner, Jose', also should be credited for the success of the design and its build.  I suspect Jose' has an EE background. When Raul says "we", he must refer to Jose' and himself.  Funnily, much like a tube preamp, the 3160 to my ears gets better after it has been in use for at least 30 minutes to an hour. It's excellent from the get-go but gets even better when it warms up.  So, Raul, how far off topic do you want to get?
Have you referenced your value for the inductance of the MP110?  I did so in one of my posts above.  If you have not done so, please enlighten me.  I am always grateful to be corrected with correct information.  800mH does indeed seem very very high for an IM cartridge. The owners manual pdf that you provided does not mention inductance, so far as I recall.
This from a German magazine, measurements on the MP150, a close cousin to the MP110, gave inductance of 630mH. Note also the frequency response graphs for the given load R and C. They also mentioned the MP300 in this test, and it gave near identical value for inductance, which suggests that the MP110 would measure similarly.
http://www.nagaoka-deutschland.de/pdf/TESTBERICHT%20AUDIO.pdf
This information is offered to help the OP, not to further or provoke any arguments with Raul. Other sites do quote >800mH for the MP110.


But this article may be of more help to the OP, since it does not involve understanding how inductance affects the high frequency peak that is characteristic of all MM or MI types. Here they show how the capacitance load affects the frequency response of the Nagaoka MP11, evidently a precursor to the MP110. Just know that the "capacitance load" must include the capacitance of the phono ICs + the capacitance of the phono input gain stage + any added capacitors for loading. After all this reading and researching, I am inclined to agree with Atma-sphere that the emphasis on ticks and pops which the OP experiences might be cured by changing load R or C. And this article is sort of a guide how he might do that. For sure, all these sources give high marks to the overall SQ afforded by the MP110. So high in fact that I am about to recommend it to my nephew, a budding audiophile.
http://www.tnt-audio.com/sorgenti/nagaoka_mp11_e.html


emilm, Do you mean to say that after all that, you found you could cure your problem by changing the physical location of the Black Cube?  I hope that simple solution continues to please you.  In the meantime, I don't think the discussion was a waste of time.  If you pursue the content of the responses you got, you will have learned something.