Phono pre suggestions?

[NiagaraPete]

Disclaimer:
I sold all my phono gear after collecting for 40+ years and “I’m free”. Now I’ll probably have to give away 1000+ CDs away as they have no value.

 

[dougi]

I don't think a schematic of the RIAA preamp circuit in the Kenwood receiver was ever posted, so who knows what the answer is to the OP's question.

The Audio Technica cartridges mentioned are moving magnet types, so will be affected by any capacitance load presented by tonearm cable and preamplifier input stage. The optimal loading will be dictated by the output impedance of the MM coil and its inductance, with the added capacitance from tonearm and interconnect cabling. The AT carts are made in such a way that they should not be loaded with any more than 250pF total parallel capacitance. Keep in mind that the tonearm wiring may have 30pF capacitance, and the interconnect cable 100pF to 150pF (sometimes more). That leaves only about 100pF maximum input capacitance allowed from the RIAA preamp. An FET input discrete RIAA preamp may have higher input capacitance than this. A 12AX7 based tube RIAA preamp is practically guaranteed to have input capacitance of >150pF, which will cause a resonant peak centered around 8kHz in the cartridge's electrical output. This can be perceived as overly aggressive sounding upper-mid and/or treble response and/or exaggerated surface noise. Opamp based RIAA preamps will have extremely low input capacitance, which is a good thing in the case of these AT MM cartridges.

However, some opamp-based RIAA preamp designs have additional parallel capacitance added for 'tuning'. If this additional capacitive 'loading' can't be defeated, then that could be a downside for these AT MM cartridges that work best into a low capacitance load of 100pF to 200pF total.

Yep, you need a pre with low capacitance for your carts and short, low C cables. Some of the project pres have a "no C" option, which is 50pF in reality they say.

 

[rongon]

Yep, you need a pre with low capacitance for your carts and short, low C cables. Some of the project pres have a "no C" option, which is 50pF in reality they say.

The relatively high inductance and coil resistance of an MM cart means any capacitance in parallel will cause a resonance up in the 5kHz to 15kHz range. In the old days they'd use that to tweak the HF response to taste. Shure recommended a 450pF load for some of their MM carts. These days, MM cartridges are made to run into a very low capacitance load -- typically 150pF, 3X lower than in days of yore -- so you're better off just making the input capacitance as small as you can, as you described.

On the other hand, moving coil cartridges have very low inductance and coil resistance, so are not affected nearly as much by input capacitance loading.
But if you use a step-up transformer for your MC cart then the input capacitance of the RIAA preamp very much does matter (loading the transformer).

As usual... It depends.

 

[mhardy6647]

Sorry - Rookie ASR question. Where is Amir's list of top phono stages? Can somebody post a link or copy/paste the top 10?

I don't think ASR's looked at ten of 'em.

 

[rongon]

Disclaimer:
I sold all my phono gear after collecting for 40+ years and “I’m free”. Now I’ll probably have to give away 1000+ CDs away as they have no value.

I hear you!

But I still have my LPs. I do enjoy a rainy Sunday afternoon spinning vinyl. It can be very relaxing....

 

[rongon]

Sorry - Rookie ASR question. Where is Amir's list of top phono stages? Can somebody post a link or copy/paste the top 10?

Click on Review Index tab (upper left), then Audio Electronics in the brown menu, then type "phono" in the search box. Click Search and then sort by Price Each USD.

 

[AaronJ]

SINAD is arguably the least important factor for measuring a phono stage when you consider that the noise floor of the LP medium itself is always going to exceed it. More important measurements are RIAA eq (easy to achieve a flat response) and overload headroom. Almost all budget phono stages fail at the second one. Truth be told the 2 best measuring budget phono stages when all things are considered are probably the Schiit Mani 2 and the Darlington Labs.

 

[mhardy6647]

Click on Review Index tab (upper left), then Audio Electronics in the brown menu, then type "phono" in the search box. Click Search and then sort by Price Each USD.

View attachment 238721

Well done!
You beat me to it!
I had opened the database... but then I had to go eat dinner

 

[rongon]

I agree!

I would also suggest that super-tight RIAA EQ accuracy is not that important considering the frequency response errors introduced by most cartridges. I mean, it's important, for sure. But do you need +/-0.1dB accuracy from 20Hz to 20kHz? Or would it be just as good to have response that's +/-0.1dB from 50Hz to 15kHz, and down by -0.5dB by 20Hz and 20kHz? Remember, these are records. Can any LP playback system play 20Hz cleanly? Can any needle trace a 20kHz sine wave cleanly? Can it really?

That leaves headroom.

A good click on your LP is going to clip any phono preamp. You don't want it to smash the circuit so hard that you get what's called blocking distortion, where a momentary overload causes a few cycles of absolute silence while the amplifying circuit regains its equilibrium. You also don't want the circuit to slew limit on high frequency surface noise. That can cause a vague kind of 'harshness' to the sound of worn LPs. And you also don't want the amplifying circuit to scrunch on every tick and pop, causing them to sound louder than they actually are.

You know what's funny? That means vacuum tubes begin to look like a decent option. They are high impedance, sure, so they're going to be noisier. They age, so frequency response errors are sure to increase in magnitude as the tubes age. But, they operate at high voltage, and can swing lots of volts (relatively) cleanly. That means, if properly designed, they can give you lots of... headroom.

Everything is a compromise. Maybe in the case of playback of LPs, it's worth trading away noise and super-low THD for lots of headroom (and SINAD be damned).

I wonder if this is going to be controversial... We shall see.

 

[NiagaraPete]

I hear you!

But I still have my LPs. I do enjoy a rainy Sunday afternoon spinning vinyl. It can be very relaxing....

No man it was stressful. Taking such care holding the lp, cleaning with a deca brush, cleaning the stylus only to be disappointed with whatever I chose. Then I looked at the cost and value. Neither made any sense.

But have fun if you enjoy it. Now I just listen to music without the fuss. Oh and if I decide I didn’t really want to hear that track or album I can change it without any more fuss.

 

[rongon]

But have fun if you enjoy it.

Thank you. And you as well! I mean, that's the whole point, right?

 

[NiagaraPete]

Thank you. And you as well! I mean, that's the whole point, right?

That you need to decide yourself. I found it tedious. Plus I really don’t enjoy listening back in time. I enjoy finding new treats and now there is so much to find.

 

[rongon]

Are you trying to convince me?
It's OK, really.
I understand. Really. I do.

 

[mike70]

People needs to understand that their decisions are ... their decisions ... and others can do different things.

So, we can try to justify our smart decisions ("what they do is silly") or simply accept the different opinions / "flavours" / ways to enjoy music and help in a positive way. I choose the second option.

There's no risking life or something in this hobby.

 

[NiagaraPete]

Are you trying to convince me?
It's OK, really.
I understand. Really. I do.

If you’re replying to my post ??

No I’m not.

 

[levimax]

The "headroom" issue is an interesting topic. For clicks and pops do you really want to send 6 volts to your pre-amp? Can it handle that? If it can do you really want to clip your power amp? As mentioned "graceful recovery" from overload is one of the most important characteristic of a phono pre-amp but I don't think any of the measurements shows that. I don't even know how you would test for that... some type of bust or impulse and watch how the amp reacts?

 

[dougi]

The "headroom" issue is an interesting topic. For clicks and pops do you really want to send 6 volts to your pre-amp? Can it handle that? If it can do you really want to clip your power amp? As mentioned "graceful recovery" from overload is one of the most important characteristic of a phono pre-amp but I don't think any of the measurements shows that. I don't even know how you would test for that... some type of bust or impulse and watch how the amp reacts?

It would be really interesting to test the different types/places in the chain of clipping and see what appears worse in measurements and what sounds worse. I run my phono pre (Quad Atera PRE) pretty hard into an ADC (RME ADI-2 PRO) by adjusting the PRE volume on the fly. On really bad records a pop may throwup an ADC over, but it never sounds too bad to me.
I was thinking clipping of phono pre vs preamp vs ADC vs digital vs amp.

 

[sq225917]

You want an output that doesn't smash into the limit of the rail voltage whenever you trace a click, how this is achieved, soft clipping, lots of headroom.or by another method is a matter of choice. Personally i prefer headroom, and lots of it

 

[Fontie]

Click on Review Index tab (upper left), then Audio Electronics in the brown menu, then type "phono" in the search box. Click Search and then sort by Price Each USD.

View attachment 238721

funny that the Cambridge solo has the highest SINAD rating and is not recommended, yet the Emotiva , UTurn and Schiit are recommended

 

[AaronJ]

funny that the Cambridge solo has the highest SINAD rating and is not recommended, yet the Emotiva , UTurn and Schiit are recommended

Edit and completely rewritten…

The Solo wasn’t recommended based on its RIAA implementation. By all other metrics it’s very good, but for similar $ or only a few dollars more you can get something that aces the RIAA implementation.