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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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rauliruegas
12,862 posts
 
Dear @scottwsmith : I owned the A-90 that's one of the finest ( still ) today cartridge performers and I can tell you that for the cartridge can shows at its best  it needs a very good matching tonearm and the finest phono stage/phonolinepreamp we can get and with all respect your PH5 can't do it.

The gentlemans that posted in your thread are not a little " concerned " on the  A-90 cartridge needs and IMHO this must be the first " parameter/premise " to judge what to do.

Regards and enjoy the music,
R.
czarivey
5,750 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.

bobsdevices
99 posts
 
I refuse to get into a pissing contest with a skunk.  Done here.
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rauliruegas
12,862 posts
 
Dear @bobsdevices : Well, I understand feelings when some person has no facts in a discussion. I posted facts that goes per se against your opinion and that’s all.

Maybe you think that in audio SUTs are a perfect device and I think diferent: that in audio nothing is perfect not even near the perfection, all in audio has its own trade offs.

Regards and enjoy the music,
R.
oregonpapa's avatar
oregonpapa
4,867 posts
 
Scott ...

" So a PH-5 and REF 3 are really only good for LOMC?  Yipes."

I've owned the ARC phono stages from the PH-5, PH-7, PH-7se and now the PH-8. I use a REF-3 preamp also.  

According to the techs at ARC, their phono stages, including your PH-5 are designed to operate best with a cartridge output of between .4 to .8 ... with .5 being the ideal. Get the cartridge right, and these phono stages really sing. 

 Instead of investing in a new preamp, why not take a look at a new cartridge?  The Audio Technica ART-9 is a wonderful cartridge and works perfectly with your preamp. The ART-9 has an output of .5. Its available from LP Tunes at the moment for $1197 with free shipping. Here's the link:

http://www.lptunes.com/Audio-technica-AT-ART9-MC-phono-cartridge-p/atart09.htm

The ART-9 is a true over achiever competing with cartridges in the 3-5k price range. Here's an entire thread on the ART-9:

https://forum.audiogon.com/discussions/audio-technica-at-art9-phono-cartridge

Hope this helps.

OP
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