What Virtues and Benefits do SS Phono Stages Provide? If Spinning Vinyl, Why not Just Do Tubes?

I read that the benefit is low noise. I lived with three phono stages in my system for a month and chose the tube one. Interestingly, it had the best qualities of each of the other two solid state stages with none of the negatives.

The primary benefit is low noise. It's difficult to generate ~ 85dB of gain from all tubes.*

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*The Aesthetix Io is the only phono stage in the world of which I am aware that accomplishes this. Every other tube phono stage of which I am aware uses a step-up transformer to generate much of the gain.

The typical way to achieve low noise with low ouput carts and tubes is to use an SUT.

So, at the end a tube phono stage will combine all sorts of interesting colourations: transformer hysteresis, low frequency core distortion, several coupling capacitors with their unavoidable flavours and of course tube microphonics.

Not all listeners appreciate such a strong combination of flavours and idiosyncrasies. And what if the SUT is silver?

The SS phono stage avoids some of these flavours. No transformers, possibly no coupling capacitors, much less sensitivity to air and structure borne vibrations.

Weirdly, after spending most of my life with tubes, it seems I can live happily without tubes. Certainty without indirectly heated tubes.

When well designed and implemented, certainly lower noise. Less heat and power consumption. No tube wear out, selection or matching (although well designed and implemented may mean transistor selection and matching by the designer). No chasing tube failure when one starts to go bad.

No fretting over sourcing replacement tubes, NOS tube prices, counterfeit or fake NOS tubes. Not needing to test tubes, clean tubes pins and sockets.

But then again, with their delicacy and beauty, why not tubes?

The main advantage of SS is reliability, tube gear seem to fail a lot. My SS phono preamp with 2 built in phono inputs has never failed in 35 years of use. My reference Io tubed phono has failed 6 times in a 4 year period, and it was sitting on a shelf needing repair 2 of those years. Personally i will not bother with tubed gear again.

Hi

I recently sold a Manley chinook in favour of a phono option for my Fls10. My main reason lay in my listening habbits. I stream and I play my old cds in addition to playing records. Wanting to play LPs required me to wait for my phonoamp/tubes to reach optimum temp. I had to plan my listening sessions.

Now vinyl delight is always ready at the flick of a switch. My Chinook served me well for several years and has gone on to a new happy owner. I play more records now, often on impulse. As a bonus a have to say i got better sound to. Very happy with my choice.

Atle

Ron Resnick said:

The primary benefit is low noise. It's difficult to generate ~ 85dB of gain from all tubes.*

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*The Aesthetix Io is the only phono stage in the world of which I am aware that accomplishes this. Every other tube phono stage of which I am aware uses a step-up transformer to generate much of the gain.

Click to expand...

Thank you for advancing an agenda item of mine.

I went for the low noise in the VDH Grail SB current phono stage

SS =Low noise, presence, & slam.
I like all solid state for analog, all tube for digital.
My current phono stage is a EAR YOSHINO 324 solid state phono stage.

Just my opinion.

caesar said:

Thank you

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Now for the downside.

While it is true that tube phono sections tend to have a higher noise floor, because of the much higher Voltage used to power the tubes, its much harder to overload them.

This is important because a LOMC phono cartridge generates Radio Frequency Interference (RFI) due to the fact that its an inductor in parallel with the capacitance of the tonearm cable (and the input capacitance of the phono section). Because the inductor in a LOMC cartridge has a high 'Q' (Quality) factor, the peak that is created has a high 'Q' as well so can be as much as 30dB higher level than the cartridge signal!

It does not matter that the cartridge isn't able to pass energy as high as the resonant frequency of the peak; it can be set into oscillation by ticks and pops on the LP surface in much the same way that spark coils energize spark plugs.

When this RFI is injected into the input of the phono section, the phono section can misbehave. It might be overloaded, in which case it will generate ticks and pops on its own. Or it might make distortion which manifests as brightness, or both. This is the reason audiophiles use 'cartridge loading' resistors. Its not for the benefit of the cartridge or the signal though; instead it calms down the phono section.

However this means the cartridge is driving a much lower impedance and therefore is doing more work. This causes the cantilever to be stiffer, in effect reducing compliance of the cartridge. This can in turn reduce its ability to trace higher frequencies or can cause the mechanical resonance of the arm and cartridge combo to be outside the ideal window of 7-12Hz.

Its much easier to design a tube phono section that does not have this problem than using solid state.

The benefits should be obvious: plug and play (no need for loading resistors), more accurate tonearm setup, wider bandwidth, lower distortion and very possibly less ticks and pops (the latter being one of the bigger complaints the digital mavens have regarding LPs). I'm very used to playing entire LP sides without ticks and pops.

Depending on the design of the solid state phono section, there may be a problem with distortion rising with frequency, which can cause the phono section to sound bright. This can be caused by a design parameter called Gain Bandwidth Product, if its insufficient in the design to support the feedback being used. This is a concern even if the EQ is passive. By contrast, tubes are so linear that zero feedback can be used (with passive EQ) so this particular demon can be avoided.