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Phono amp gain too high? (EAR 834p)

Hi everyone,

I have long been interested in trying the EAR 834P, and I recently came across the old Stereophile review of it.  In the measurements section, the gain for MM carts was 49.2db and 68.2 for MC.  That seems to be an inordinately high gain if I'm not mistaken.  I don't  know how to determine whether this would overload my integrated amp.  I am running an LFD LE V and a Clearaudio Maestro V2 (3.6mV).  I can't find specs on the integrated as far as gain and input sensitivity.  As I understand it, there is no active preamp in the LFD, but I can't even confirm that.  Is there someone with better technical understanding who can help?   

Thanks for your thoughts,Scott
smrex13
almarg's avatar
almarg
8,673 posts
 
Hi Scott,

"o/p" presumably means "output."  If 2 mv in results in 0.5 V out, since 0.5 V = 500 mv the gain is 500/2 = 250x (i.e., 250 times).

The ratio of two voltages expressed in db equals 20 times the logarithm of the ratio.  So 250x is a gain of:

20 x log(250) = 48 db

Best regards,
-- Al
 
smrex13 OP
423 posts
 
Gracias :)

randyhat
138 posts
 
If I may resurrect this thread a year later...

I am having some cartridge/EAR mis-match issues of my own.  First of all I have an EAR 834p and it has worked wonderfully with my low output Grado Reference cartridge (.5mV).  Since I've had the Grado for nearly 15 years I decided it was time to get a new cartridge so I sent it back to Grado in exchange for there current version of the same exact cartridge. This seemed like a safe move.  One of the differences between the older version of this low output cartridge and the newer is that they increased the output from .5mV to 1mV.  I had no idea how much difference this would make if any at all.  Well it now seems that playing the new cartridge using the MC setting on the EAR results in too much gain.  I get distortion, particularly on highly modulated musical peaks on many records.  Even if I turn down the volume on my line stage to almost it's lowest setting it is still very "hot" and the distortion frequent.  When I change the setting on the EAR to MM I then have to turn the volume way up on my line stage and it just doesn't sound as lively or dynamic as my old cart.  So, after talking to Grado support it seems I am caught in the middle where the output of the cartridge is too high for MC and too low for MM.  Grado suggested that I switch to their high output version of the same cart (4.8mV)...I am considering that but am also considering abandoning the Grado and move to a true low output cartridge like the Dynavector XX2 for instance (.28mV).  Seems I am having to move either up or down.  Any suggestions or ideas how I can get my new cart and EAR 834p to work better together?
yogiboy's avatar
yogiboy
2,678 posts
 
@randyhat
You can lower the gain of the EAR if you relpace the 12ax7 with 5751 tubes. The 5751 has 30% less gain than the 12ax7. I had the same problem (too much gain) with my Quicksilver phono and the 5751 did the trick!
randyhat
138 posts
 
Thanks for the suggestion.  I need new tubes anyway so I may just try that.  Think it would be best to replace all 3 with 5751s?
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