Phono amp gain too high? (EAR 834p)

Frank Van Alstine used 5751's in his redesign of the Dynaco PAS 3, preferring it's gain structure, low noise, and distortion characteristics to the stock PAS' 12AX7.

And his usual great advice from Al! I haven't heard anything about it's sound quality, but Mike Moffat (Theta designer) offers a phono amp with only 30dB of gain, the Schitt Mani. It'll cost you only $129 to give it a try.

Excellent question! I dealt with this issue recently, but from a different angle. My concern was the amount of gain inherent in the mm section of a phono amp, rather than the amount of signal it presents to the following line stage. The reason for that concern is, the higher the gain, the lower the overload margin, generally speaking. A cartridge with as high an output as yours does not need as much gain as the EAR (and most other phono amps these days, optimized as they are for low-output cartridges) provides, and that high gain reduces it’s overload margin. I also use a high output cartridge (5 mV), so I looked around for a phono amp with a lower amount of gain, thereby increasing my chances of getting one with a higher overload margin. I found that in the Herron VTPH-1mm, which offers 42dB of gain, and a pretty healthy overload margin characteristic. It’s a discontinued product, but Keith had an mc version of the VTPH-1 in shop, and reconfigured it for me. Give him a call!

By the way, most of the difference between the VTPH-1mc and the -2 is in the mc section, which was significantly revised and improved in the -2 version. The difference between the -1mm and -2 when using a mm cartridge should be minimal.

Unless I’m mistaken (a real possibility), the setting of the volume control does not infact determine the gain of the amp, but instead attenuates the phono amp’s full output---not the same thing of course. I believe the gain of the amp is set, the full output of the circuit is sent to the volume control, which attenuates it to varying degrees depending on where it is set. The volume control doesn’t decrease the gain of the circuit, only attenuates the full output of the amp. A look at the schematic will provide the answer---look for where in the circuit the volume control is located; if it’s before the amplification is achieved, then yes, it may lower the gain of the amp. But I doubt it that’s where it is. If it was, EAR’s published specs for the amp would show variable gain. The variable output would provide a solution to the problem of the phono amp overloading the line stage, however.