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Audio Research PH5 Phono Preamplifier Input Clipping Problem

I have an ARC PH5 phono preamplifier and most of the time it sounds fine.  But on a few of my favorite LP's with wide dynamic range, it will clip and distort on loud sections, especially those with lots of bass content.  This only happens with use of a step-up transformer, without the SUT in line, there is no clipping. I do prefer to use the SUT, as without it I have to turn the volume setting on my ARC REF 3 preamp to a very high level.   I have to conclude that the PH5 is distorting because of high input signal levels, due to the gain of the SUT.   I have tried two SUT's, one with 13:1 and the other at 7:1, both exhibit the same problem (although the lower gain SUT is much better).  The cartridge is Ortofon A90 with .27 mv output.  Given this, would you expect clipping or do you think there is something wrong with the PH5?  I have talked to ARC about this issue, and they seem to think that there is a chance the PH5's maximum input of 70 mv is being reached on these loud sections.  Would appreciate opinions from those that have experience with a similar setup.  Thanks.
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Showing 2 responses by czarivey

czarivey
5,946 posts
 
you can destroy phonostage by overloading it. input devices weather transistors or tubes are very easy to ruin by overloading.

the simplest solution is to use cartridge with sufficient enough output to use it without SUT.
many above had mentioned that.
using low-out cartridge just because it has great parameters, but requires extra gain, won't bring performance up.

czarivey
5,946 posts
 
raul,
no matter how sooper-dooper-good Ortofon A-90 sings, the PH5 ain't enough. 
oregonpapa offers the most reasonable solution to preserve the best sound of whole system. 
forget about your little piece, it's too small no matter how good it is compared to the whole system synergy.

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