Yes I have noticed that one is recommended a lot. Looks like a move from PH-5 to Herron could cost about $ 2K. Will have to consider whether that is "reasonable" or not. But for me, swapping gear and upgrading is part of the fun. It seems that used versions of the Herron are hard to find. I guess those who have them, keep them. Did you purchase yours new?
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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Yes, I purchased my VTPH-2 new, directly from Keith after speaking with him on the phone. You would want to confirm with him that the lower gain version is the optimal choice for use with a 0.27 mv cartridge. I suspect that it will be, though, in part because he recommended that version for use with a 0.3 mv cartridge I was considering at the time. I ended up going with an Audio Technica AT-ART9, though, which is rated at 0.5 mv. Best regards, -- Al |
This has two gain settings. Take a look, it just might fit the bill ! https://www.youtube.com/watch?v=RfpJYJv3ddo |
I have had no luck with using a SUT with the ARC-5. The gain of 57.5 is difficult to work with. Almarg is correct. However, if you look at the signal to noise ratios of active MC/MM phono stages, you will find that the signal to noise ratio using MM is higher than the signal to noise ratio using MC. Additionally, increased distortion results from using the MC active stage. That is why many manufacturers using SUTs in their phono preamps to accomodate MC cartridges. The challenge is making different gain adjustments to accomodate different cartridges. ARC makes this easy by only offering one option and designing the phono preamp for only one gain setting. It is great for a cartridge of about .5-.6 mV, but lower output cartridges don't work as well. |
In the ARC world, you can move to the Reference product line, which does offer different gain levels, but they are pricey, I don't think I am too interested in that solution. For those phono preamps that really do have an MM/MC switch -- I think you are saying using the MM setting with an SUT, instead of the MC setting might yield better results for a MC cartridge with output in the .25 range, such as mine. For example, on the Manley Chinook, there is an internal setting to set the gain at around 45 dB, " for MM cartridges". With my SUT's of 1:13 and 1:7 and that gain setting, what would be the input levels to the REF3, and given your suggestion of possible lower noise and distortion, is this a good upgrade? Same set of questions for the Herron, if you would indulge me?? |
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