Phono amp gain too high? (EAR 834p)

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!

Hi Scott,

Yes, an excellent question, and as usual an excellent response by Bdp24.

I couldn’t find relevant specs on the LFD LE V either. I note, btw, that while the Clearaudio site indicates the cartridge’s rated output is 3.6 mv as you mentioned, at NeedleDoctor.com it is stated to have a 4.2 mv rating, both ratings based on standard test conditions of 5 cm/sec & 1 kHz. Not a big difference, in any case.

FWIW, 49.2 db is a voltage gain of 288x (i.e., 20 x logarithm 288/1 = 49.2), so 4.2 mv would be stepped up by the 834P to 288 x 4.2mv = 1.21 volts. Some recordings having particularly high volume dynamic peaks may cause the cartridge’s output to exceed its rating under standard test canditions by several times, to perhaps 5 or 6 volts or so. That may be helpful to know if you can eventually find specs on the LFD.

While the caution Bdp expressed about the overload margin of a phono stage that provides more gain than is usually provided for a given cartridge is one that should always be considered in such cases, looking at the overload points indicated in Stereophile’s measurements of the EAR 834P I don’t think that would be a problem in this particular situation.

As you realize, though, without further information about the LFD integrated amp we can’t say anything with certainty about the possibility that it may be overloaded. If its volume control precedes any of the gain circuitry in its signal path, as is the case in many designs (but certainly not all), that won’t be a problem. But even in that event there could still be a problem of having to operate the volume control too low in its range to be desirable, depending on the gains and sensitivities of everything that follows, including the speakers, and on the characteristics of the volume control at low settings.

My guess, fwiw, is that the odds are **somewhat** in favor of neither of those issues being a problem. However, in addition to significant uncertainty in that regard I’ll mention that many reports I have seen of the support and service EAR tends to provide are suggestive of it being, um, not in the same league as that by provided by Keith Herron, who is an absolute treasure to deal with, as well as being someone whose designs receive virtually unanimous acclaim. I would therefore take Bdp’s suggestion to heart. Or better yet, if $3650 might not be a show-stopper consider a new VTPH-2.

Good luck. Best regards,
-- Al

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.