Phono Amp Spec’s

@tablejockey  Thank you for reminding me about the the Benz site stating the ZH was ideal for tube stages with 50-60dB of gain.  I'm embarrassed to say that I had forgotten about that piece of information.

However, with that being said... each phonostage design can be different in how they deal with their overload margins.  

I realize that using my .7mV@3.54 (equating to 1mV@ 5cm/sec) may be pushing the overload limits of some phono amps that are pushing 60-64dB of MC gain.

Therefore, I am trying to learn as much as I can about the parameters of some various phono stage before buying them.  Sadly, if seems virtually impossible to demo anything in home now-a-days, even when buying new.  Let alone if you want to entertain purchasing a used item.

I'm looking at costly pieces, and I'm trying not to take an unnecessary bath, so to speak if it doesn't mesh with my cartridge and system.

Thanks again,

Don

@viridian Hello and thank you again for your reply!

I wish I could know how much overload margin I would have when using my .7mV@3.54cm/sec or 1.mV@5.0cm/sec cartridge into the 64dB MC input.  

I've reached out to the distributor; they didn't give me any answers. Instead they pawned me off to a dealer; which sadly, still hasn't given me any answers.

Hence the reason I decided to implore the wisdom of my fellow forum friends here 

I totally agree... listening will be the only way to tell.  However, I haven't been able to arrange an in-home trial as of yet.  The piece is quite expensive and I don't want to step into this completely blind just to find out I made a huge mistake and then take a huge loss trying to sell it off.

You brought up a great point about how the higher the gain, the lower the voume control will be.

The nice thing about my line stage is that it is using a very high quality ladder stepped attenuator that only uses two resistors per step and the excellent sound quality has remained the same throughout it's range.  I have used several different power amps with this line stage that had widely varying input sensitivities which required me to have the dual mono volume controls to be set very low on some amps to very high on other amps and the sound has been truly excellent.  Also, when going thru the range of volume with any of my amps, the quality of the sound has been really great... only the volume seem to change.  I wonder if it has to do with the design of the "ladder" vs using a "pot"?

Yes... good catch :)  I am indeed, one and the same - No Regrets from WBF.  Thank you so much for loving my dog!!!

Many thanks to both you and tablejockey again for trying to help me better understand these things.

Best wishes,

Don

If you are contemplating a new Phone Stage, I can recommend the Sutherland Duo.  There are other Sutherland options in various price ranges; given the impedance of the Benz ZH the "Loco" Sutherlands are probably not right.  In reviews their phono stages are noted for having large headroom.

The Duo (and 20/20) offers five gain settings (40, 46, 52, 58, and 64 dB) and five loading options (100, 200, 475, 1k, and 47k ohms).

The 52dB or 58dB with 475 ohms would seem to be a good match.

Upscale Audio (e.g.) offers 60 day auditions.

I have the Duo, paired with the Koetsu Rosewood Platinum and am delighted with the sound.

Best wishes to you.

I think you got most of the info you need already, but let's put it in context.  An amp has a maximum output level it can provide. Think of it as an electrical volume.  The larger the amplification factor -- (multiplies the input signal to get output, for example 1V input with 2X gain (amplification) means 2V output) -- the smaller the input must be so the output is not exceeded.

So this is stable of "gains" whcih is the amplification factor expressed in decibels.  At various gains they provided the largest output voltage in mV it can handle. You cna look up your cartridge's output max and make sure it is lower (bro not too much or the volume will be low).

Phono amps are a tradeoff of gain, noise, and overload all the time. Drove me nuts until I got my few recipes.

To put real numbers on this, one listing is 40dB, which is 100X.  The maximum input they list is 90mV (0.09V). We can then infer the overload output level is 0.09 X 100 = 9V. 

I agree with the other @retiredaudioguy…your preamp jumps from 40 to 64 dB while your cartridge’ sweet spot is in the middle. I have used Pro-Ject PhonoBox DS3B and it has a 55 dB setting. They make a TubeBox version as well.