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Current or former owners of ARC PH2 and/or LS5

I know these products were intended to be used together. But, no matter how hard I web search, I cannot find out which product contains the RIAA compensation circuitry. "LS" usually means line stage only, but I see a “Phono” input on the back of LS5 photos. The PH2 appears to be intended to be used as a MC head amp which usually has no RIAA EQ, but maybe this one does have it . I would like to archive some of my LP collection as 24-bit 192kHz audio files and may potentially use one or both of these units to front end a professional analog to digital converter. I see some contributors in past forums have owned these products, so thanks in advance for anyone that can help me out.
128x128icewater_7
icewater_7's avatar
icewater_7 OP
3 posts
 
Thanks to both Mofimadness and Dgarretson for your kind responses. I would be especially interested, Dgarretson, in the modifications you performed (best caps and resistor brands/specs). I used to make very extensive modifications to my ARC and Quicksilver tube gear. I routinely completely rebuilt and redesigned tube gear from the ground up. I did phase out of the DYI audio hobby years ago, but still have some esoteric quality parts and can handle that kind of thing very well. I do happen to own a used PH2 and was intending to use it with the Pure Vinyl SW to apply RIAA in the digital domain for LP conversion to 192K 24-bit .WAV files, so now I know that option is out. However, if the modifications that Dgarretson performed can upgrade the quality of the PH2, maybe I would be happy digitizing its balanced output straight into my Digidesign 192 I/O converter and be perfectly happy with the results. I will be retiring in few months, maybe it would be fun to get out the old soldering iron, study schematics and get back in the DIY game!
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dgarretson
2,599 posts
 
Icewater7, the factory manual included schematics. First step is to replace four 5uf and four .01uf/600V coupling and bypass caps at output. The stock unit uses entry-level MIT/Multicap PPMFX. The 5uf caps should be better MultiCap PPFXS film/foil or similar ClarityCap MR, Mundorf, or others rated at least 400Vdc. The .01uf bypass caps can be inexpensively replaced with eBayed Russian SSG silver mica. Replace the loading resistors and series resistors at input(R1,2,3,4) with Texas Components TX2575(available factory-direct) or Caddock TF020 from Parts ConneXion. Add a 3uf-10uf/400V-630Vdc film cap to filter B+ at ingress on channel board. Other suggestions via PM.
icewater_7's avatar
icewater_7 OP
3 posts
 
Kind thanks again to all that responded. This is my first foray into the Audiogon forums. I am pleased to see that it is a nice community of very friendly and helpful enthusiasts. After being absent from the world of high end audio for several years, and now slowly getting back into it, I’m encouraged by your support. I hope I will be able to eventually help other Forum users as well as you have all helped me.
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