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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.
Ag insider logo xs@2xscottwsmith
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rauliruegas
13,084 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
oregonpapa's avatar
oregonpapa
4,867 posts
 
Scott ...

Here's another thread on the AT ART-9:

https://forum.audiogon.com/discussions/pani-new-art-9-up-and-running
jperry
2,450 posts
 
Oregonpapa, I agree with you. If I were the OP I would get a different cartridge. The Denon is a great price performer, but in most cases needs to be used with a SUT to perform at its best. Audio-Technica,  Shelter as well as others make cartridges with more compatible output.
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rauliruegas
13,084 posts
 
Dear @oregonpapa : Did you listen in your system the Ortofon A-90 and then compared against the ART-9?

I did it vs ART 7 and 9 ( both from an audio friend. ) and even that the AT are very good performers IMHO the A-90 is better.

Now, if you did not listening yet the A-90 then make no sense to me your advise.

Anyway, the ball is in the OP field.

regards and enjoy the music,
R.
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