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In Reply to: MP3 phonostage…... posted by jeagle on November 1, 2013 at 12:05:04:
We run a ZYX Universe copper here which is 0.24mV. It works well with the MP-3. However, there are a couple of variables that can be hard to predict.
One is the condition of the tubes. In plain English, if you have an all-tube phono section that is capable of LOMC operation, expect to install hand-picked tubes, that is to say, tubes that are hand-picked for low noise and low microphonics.
People like to swap tubes out for ones that they like better, but IME what this often means is that the result is a preamp that has more noise than it should. Most of the really quiet NOS tubes were sold off the shelves 30-40 years ago! So if you want it to be quiet, you will likely want to steer clear of the NOS stuff and install tubes that are in fact actually quiet.
The second variable is how much noise is OK? Our rule of thumb is that if the needle is in a silent groove, that the surface noise of the LP is the main thing you hear. If you hear the preamp over the surface noise you likely have noisy tubes. We don't really care how much noise is there when the stylus is not in the groove. People don't listen to music that way unless they are on a different input :)
Finally, we can install a set of SUTs; its been an option since the original MP-1 was introduced in 1989. With a set of SUTs you can have a considerable amount of gain, which might be tricky if you also have high efficiency speakers, as the volume control might be limited to the first few steps (noise won't be a problem though). There are solutions for this, for example we offer a jumper plug that replaces on the 12AT7s in the phono section (essentially substituting a transformer for the gain of a tube) and the result is less output out of the phono. The bottom line is there are always ways to make it work.
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Follow Ups
- RE: MP3 phonostage…... - Ralph 12:39:00 11/04/13 (0)
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