Best phono stage?
- Thread starter awsmone
- Start date
Please go to audition the Soulnote E-2 too.
I consider it a very good-buy, although less famous than Accuphase.
http://www.kcsr.co.jp/detail_e2.html
https://www.whatsbestforum.com/threads/soulnote-e-2-phonostage.27765/
https://www.hiendy.com/hififorum/forum.php?mod=viewthread&tid=125237&highlight=Soulnote
The Lyra cartridges don't need anything less than 47K.
If you find that you need to load them to get them to sound right, the issue is the preamp, not the cartridge! There has been a good deal of discussion on this site about cartridge loading, on which Jonathan Carr (@jcarr) has participated (he's heavily involved with Lyra). In a nutshell, the inductance of the cartridge interacts with the capacitance of the tonearm cable to create a radio frequency resonance and that resonance messes with the input of the phono section. If the phono section designer didn't know about this phenomena (and a lot don't) then the phono section will need 'cartridge loading'. The loading resistor detunes the resonant peak, eliminating the RFI. Essentailly the loading resistor 'flattens the curve' so the resonance can't go into excitation (IOW, get energy from the cartridge and use it to make Radio Frequency energy, otherwise known as RFI).
The downside of loading is you make the cartridge do more work; its a lot harder to drive 100 or 500 ohms as opposed to 47,000 ohms! That energy has to come from somewhere and that somewhere is the stylus in the groove; IOW the cantilever of the cartridge gets stiffer. This has the ability to mess with high frequency tracking and the mechanical resonance the cartridge has in the arm.
A side benefit of not needing the loading on the preamp is you get less ticks and pops. This has to do with the RFI being unable to mess with the input of the phono section. Since that resonance I mentioned can be a 30dB(!) peak, the RFI from it can overload the input section- and there's your ticks and pops. If the phono section is designed with sufficient overload margin and RFI stability, these ticks and pops go away.
So try it without loading! If its too bright on that account, your preamp is upable to cope with the RFI coming in; just my opinion but that isn't what I would call 'best'. And if you are wondering if there are a lot of phono sections with this problem, you would be right; nearly all of the phono sections in Japanese amps and receivers from the 1960s and 1970s have this problem. A lot of 'high end' preamps do too- I'm sure this is part of why digital got going. Many people don't like ticks and pops.
Very informative, Ralph.
I recall you commenting that phono sections using loop feedback in their RIAA curve circuitry can 'enhance' ticks and pops. Is that the case just for RIAA or is it anywhere in the phono stage?
Yes! I can give you an example, which is how I found out about this, about 35 years ago. An employee of mine and I both bought the same Mobile Fidelity UHQR (Tea for the Tillerman). He got his home and called me almost right away- 'Is you copy noisy? Mine sure is!' He brought it over, but oddly it was silent and played fine on my system. We had the same cartridge, arm, amps and speakers; the preamp was the only variable. The next day he brought in his preamp and there were the ticks and pops, on my copy too. It took me a while to sort out why that was so, and in the decades since I've seen this play out many times!
I did used to think that the feedback loop had a role in this but it does not. You can build a phono section with RIAA EQ in the feedback and it can be perfectly stable (I like to use 'stability' as there are issues in the circuit design that can excite small oscillations) with no added ticks and pops. The key is to understand how a cartridge works- there is far more to a phono section than just gain and EQ! Unfortunately most phono section designers don't seem to recognize this problem; we have an entire generation of audiophiles that grew up with induced ticks and pops.
Hi Ralph. with respect, in your opinion.
Even Jonathon has changed his view on Lyra's being loaded at only 47k.
47k does not get bright in my system, but it does lose control in the bass with almost every phono stage I have ever heard or used.
I prefer my Lyra cartridges loaded lower than 47k and that is backed up by J Carr's quite detailed manual that includes the capacitance of the tonearm cable and the phono cable calculations in recommending a loading value.
I have tried Lyra's very low capacitance Lyra Pipe phono cable and in my system I preferred my Nordost Valhalla.
In the end, I rely on my ears to what sounds best to me. That is why I thought out aloud about having a 500ohm load as a nice to have.
cheers
Shane
These simulations from JCarr are interesting.
https://www.whatsbestforum.com/threads/cartridge-loading-a-misnomer.15077/page-2#post-258578
The cartridge signal itself provides the energy. If there is electrical energy in the system, if there is an acute resonance like the 30dB peak we're talking about and its 'Q' value is high enough (and a 30dB peak qualifies) then it can go into self-excitation. Note Jonathan's comments about IMD; this is the audio signal intermodulating with the frequency of that peak (see link in the quoted text directly below).
Yes. And shows what I'm talking about. Jonathon and I discussed this at Munich a few years ago; he was concerned about low resistance loading was doing to the compliance of the cartridge. It probably doesn't affect bandwidth insofar as the audio band is concerned, but it can affect the mechanical resonance of the cartridge in a given tonearm.
Either way if the phono preamp is simply designed to take this stuff into account, it will perform as I described earlier.
Jcarr's theoretical simulations have wide bandwidth, but @Atmasphere are you telling us that a real MC cart is capable of exciting 5 Mhz? Have you seen measurement data to corroborate this because it doesn't seem plausible. And if the cart isn't capable of creating 5 MHz, then what in an audio signal chain is??
Thanks.
Thanks.
It needn't be the cartridge. Provided the resonant circuit exists all sorts of radio induced noises can excite it. Whether this matters depends on how upset your system gets by Rf. All very hypothetical to me and certainly not a reason to play mc carts into 47k. Ymmv.
No cartridge can do 5MHz! But the the peak doesn't need that to resonate; that is the nature of self-excitation. A brief pulse of DC could set it off. However, this is easy to take into account when designing a phono section and IMO its a bit of a crime that so many designers don't. But I've found that many of them lack an actual education other than just the school of hard knocks.
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