Phono Amp Spec’s

[No Regrets]

The key word is "tube." In our case, a solid-state device.

Yes. This distinction is why I am concerned using my 1mV Ruby ZH into the Accuphase C-47 phono amp.
I am able to use my 1mV Ruby ZH into my all vacuum tube 62dB phono amp with no problems at all.
Is this because the designer of my vacuum tube phono amp has allowed for higher overload margins than what the Accuphase c-47 does?
Or, is it because my record collection is in Near Mint condition and therefore the overload margin isn't as important???

Best wishes,
Don

 

[SVS]

Yes. This distinction is why I am concerned using my 1mV Ruby ZH into the Accuphase C-47 phono amp.
I am able to use my 1mV Ruby ZH into my all vacuum tube 62dB phono amp with no problems at all.
Is this because the designer of my vacuum tube phono amp has allowed for higher overload margins than what the Accuphase c-47 does?
Or, is it because my record collection is in Near Mint condition and therefore the overload margin isn't as important???

Best wishes,
Don

NM is a very important factor. But over time it becomes VG, then G...
All tube RIAA preamps have better overload capability if the designer did everything right.

 

[SVS]

The design of tube MC preamps has its own peculiarities. Preamps made exclusively on tubes are quite noisy. I believe that the best way to eliminate this problem is to use a solid-state input MC amplifier with a low noise level. If this amplifier is SE and does not have general feedback, then its presence does not spoil the overall result.

 

[No Regrets]

The design of tube MC preamps has its own peculiarities. Preamps made exclusively on tubes are quite noisy. I believe that the best way to eliminate this problem is to use a solid-state input MC amplifier with a low noise level. If this amplifier is SE and does not have general feedback, then its presence does not spoil the overall result.

Thank you Serhii for your reply!

I don’t know if the Accuphase C-47 is single ended or if it has general feedback.

According to “AI” I found the following…
he specific gain devices employed are:

• MC Head Amplifier: Low-noise bipolar transistors configured in a 9-parallel, current-feedback arrangement.
• MM Head Amplifier: Low-noise JFETs (Junction Field-Effect Transistors) also configured in a 3-parallel, current-feedback arrangement.

It does also say in their manual that it is a fully balanced design, but I don’t think that is what you are referring to.

Do you think this solid state Accuphase would be a good choice for my 1mV cartridge, knowing that I’ll only have 15dB of overload headroom or should I look for something else?

I truly appreciate your thoughts and comments as well as the time you’ve devoted to helping me.

Best wishes,
Don

 

[Salectric]

The design of tube MC preamps has its own peculiarities. Preamps made exclusively on tubes are quite noisy. I believe that the best way to eliminate this problem is to use a solid-state input MC amplifier with a low noise level. If this amplifier is SE and does not have general feedback, then its presence does not spoil the overall result.

The statement about tube preamps being noisier than solid state is often repeated, but is not always true. In fact, in my experience it hasn’t been true at all. A good tube MM stage with a good SUT can be super quiet.

My tube phono preamp (my own design) is a simple 2-stage with Siemens D3a and 5687. For a LOMC, I use it with a SUT and there is no audible noise at any listening volume. In contrast, the solid state phono units I owned years ago all had audible hiss. These include Threshold FET-10E, Audio Research PH-1, Emotive Audio Circa, Lehmann Cube and one other I can’t recall right now. Granted these were 20 to 25 years ago, but the same claims about solid state being quieter were being made back then too.

Please note I am not referring to tube phono units with a 12ax7 input tube. Good noise performance starts with a good design.

 

[SVS]

Thank you Serhii for your reply!

I don’t know if the Accuphase C-47 is single ended or if it has general feedback.

According to “AI” I found the following…
he specific gain devices employed are:

• MC Head Amplifier: Low-noise bipolar transistors configured in a 9-parallel, current-feedback arrangement.
• MM Head Amplifier: Low-noise JFETs (Junction Field-Effect Transistors) also configured in a 3-parallel, current-feedback arrangement.

It does also say in their manual that it is a fully balanced design, but I don’t think that is what you are referring to.

Do you think this solid state Accuphase would be a good choice for my 1mV cartridge, knowing that I’ll only have 15dB of overload headroom or should I look for something else?

I truly appreciate your thoughts and comments as well as the time you’ve devoted to helping me.

Best wishes,
Don

Don, in this case I am biased: I do not like the sound of semi-conductor RIAA preamps. Almost all of them have feedback and PP amplification. In addition, I believe that the balanced input worsens the noise characteristics of the RIAA preamp (I ask you not to confuse noise with hum).
For these reasons, I would not buy this Accuphase for myself. You will have to solve this problem for yourself.

 

[SVS]

The statement about tube preamps being noisier than solid state is often repeated, but is not always true. In fact, in my experience it hasn’t been true at all. A good tube MM stage with a good SUT can be super quiet.

My tube phono preamp (my own design) is a simple 2-stage with Siemens D3a and 5687. For a LOMC, I use it with a SUT and there is no audible noise at any listening volume. In contrast, the solid state phono units I owned years ago all had audible hiss. These include Threshold FET-10E, Audio Research PH-1, Emotive Audio Circa, Lehmann Cube and one other I can’t recall right now. Granted these were 20 to 25 years ago, but the same claims about solid state being quieter were being made back then too.

Please note I am not referring to tube phono units with a 12ax7 input tube. Good noise performance starts with a good design.

I completely agree with you about the noise of a tube MM preamp and a SUT. But I have not yet heard a single SUT that would not "edit" the sound. SUT "loses" part of the sounds. I have already written about the reason above. I had the opportunity to compare the sound of a SUT and a MC preamp in one listening session, which is why I say this.

Modern MC preamps have slightly more noise than SUT, you can hear it only when you put your ear to the speaker. From the listening position, you cannot hear the noise at all. In my RIAA preamps, I use 16 bipolar transistors connected in parallel at the input of the MC preamps. I make MM preamps three-stage.

I do not like 12AX7 at all, even its top version, the ECC808. They have a small plate current and do not provide good sound dynamics. IMHO.

 

[Salectric]

I am not going to argue the point with you @SVS since it's been argued both ways for as long as I can remember reading about moving coils. I haven't heard your preamp so I can't say how it compares. What I hear with a good SUT is improved dynamics, a more solid, tangible sound with more weight and body, and excellent detail. If a good SUT sacrifices a little inner detail compared to a high-gain phono stage without SUT (and I am not admitting that it does), it is a minor amount and a compromise I am willing to accept.

 

[mtemur]

Solid-state phono stages are lifeless, dull, and unless you’re in the very top echelon, they sound plastic. I also keep seeing the usual comments that SUTs have their own “sound signature” and that tube amplification stages are noisy. I’m on the same page with @Salectric here—those comments only show that you haven’t experienced top SUTs and tube amplification, and you also haven’t recognized the plastic sound signature your favorite solid-state phono is engraving into the music.

Dear Don,

Your Benz cartridge has a 1mV output. IMHO you should look for a SUT with a 40Ω tap (the most common option) and stop worrying about output voltage. Once you have that, you can pair it with any MM stage you like—I’d recommend a tube MM—and set the gain around 40dB. Overloading won’t be a problem if it’s not a low quality phono. I’m using a 1mV MC to 1:10 SUT and 34dB tube MM for years without problems.

 

[DasguteOhr]

Thank you Serhii for your reply!

I don’t know if the Accuphase C-47 is single ended or if it has general feedback.

According to “AI” I found the following…
he specific gain devices employed are:

• MC Head Amplifier: Low-noise bipolar transistors configured in a 9-parallel, current-feedback arrangement.
• MM Head Amplifier: Low-noise JFETs (Junction Field-Effect Transistors) also configured in a 3-parallel, current-feedback arrangement.

It does also say in their manual that it is a fully balanced design, but I don’t think that is what you are referring to.

Do you think this solid state Accuphase would be a good choice for my 1mV cartridge, knowing that I’ll only have 15dB of overload headroom or should I look for something else?

I truly appreciate your thoughts and comments as well as the time you’ve devoted to helping me.

Best wishes,
Don

Hello

Can someone please help me understand the following…

*Maximum Input Voltage
64dB = 5.7mV
70dB = 2.9mV
34dB = 180mV
40dB = 90mV

I would be using a Benz Micro Ruby ZH moving coil cartridge with this phono amp.
It’s output is rated at .7mV@3.54cm/sec which I believes equates to .998mV @ 5cm/sec.

1. Am I understanding this correctly, that my roughly 1mV cartridge would be fine going into this 64dB MC input?

2. Is there a way to know what the dB overload margin would be with 1mV @1khz as well as the low, mid, and high frequencies going into this 64dB MC input?

Secondly,
As you can see, I’m concerned about over driving/clipping the phono amp.

* Input sensitivity
64dB = 1.26mV
70dB = .63mV
34dB = 40mV
40dB = 20mV

1. Can you please help me understand how the input sensitivity of 1.26mV for the 64dB MC input relates to my Benz Ruby ZH with a roughly 1mV output.

What exactly should this mean to me?

After suffering 5 major strokes, my memory of many things have been lost. So, if anyone could please help me better understand how the above spec’s would affect me, I would truly appreciate it.

Best wishes,
Don

i would use the accuphase mm input 40db with 1: 10 sut= 60db gain with 470ohms that works good with benz cartridges.( much better SNR)

 

[Salectric]

I still have a vivid memory of an after-hours listening session at the 2011 RMAF in the Galibier room. Thom Mackris was using a Herron phono preamp that had an internal FET head amp for moving coils. At somebody’s request, he swapped in a S&B SUT going into the Herron all-tube MM input. It was a night and day difference, and all in favor of the SUT. The FET head amp had a bleached sound, lacking in color, dynamics and detail.

Perhaps today’s solid state head amps are much better than the Herron’s. I really don’t know. I do know there are SUTs that sound much better than the S&B. For my money, a very good SUT coupled with a very good tube MM preamp is the way to go.

 

[DasguteOhr]

I had use a scheu ruby 3 with the klyne px 7.3.5 mm 1: 10sut amazing sound
a big recommendation from me to try it out.

MC Scheu Ruby 3 • Tonabnehmer • Scheu Analog

MC Scheu Ruby 3, für uns entwickelt und gefertigt bei Benz Micro in der Schweiz. Dieser Tonabnehmer basiert auf dem Benz Ruby mit dem Generator des Benz LP.

www.scheu-analog.de

Exsample Klyne phono with silvercore pro sut ( ortofon vienna)

 

[SVS]

I still have a vivid memory of an after-hours listening session at the 2011 RMAF in the Galibier room. Thom Mackris was using a Herron phono preamp that had an internal FET head amp for moving coils. At somebody’s request, he swapped in a S&B SUT going into the Herron all-tube MM input. It was a night and day difference, and all in favor of the SUT. The FET head amp had a bleached sound, lacking in color, dynamics and detail.

Perhaps today’s solid state head amps are much better than the Herron’s. I really don’t know. I do know there are SUTs that sound much better than the S&B. For my money, a very good SUT coupled with a very good tube MM preamp is the way to go.

Bad sound could be heard not only in 2011, there is enough of it now.

In Ukraine they say that from the same products different cooks get different tasting borscht. We have a similar situation. But it is difficult to argue with the fact that double energy conversion cannot occur without losses and it is clearly audible. Some perceive it, others do not like it. We are all different and different tastes are the norm.

We periodically produce an MC preamp that has autonomous power supply and has more functions than SUT. Most of those who have heard them prefer them. But 10-15% of listeners like SUT, it's hard to argue with that.