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    SP9 Preamp Impressions

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    TMadden

    Posts : 99
    Join date : 2011-12-22

    SP9 Preamp Impressions

    Post by TMadden on Thu Dec 29, 2011 4:46 am

    Hello All,

    I have been listening to my Vacuum Tube Audio SP9 preamp with PH6 phono stage now for a week or two or so and wanted to share my impressions of it. Short story is: I have rediscovered the magic of vinyl! sunny
    Here is the system I have put together: Hitachi HT-561 turntable with Shure V15 type 4 cart. with JICO SAS stylus (awesome stylus), Roy's SP9 preamp with his PH6 phono stage, "Cantilena" loudspeakers (a highly regarded DIY design with Scan Speak 8" woofers, Morel dome mids and ribbon tweeters and a fantastic crossover), and currently a Jungson JA-88D class A amplifier. Sweet, sweet sounds! Anyway, I wanted to focus on the preamp. I was looking for a kit, and Roy's designs really appealed to me, they seemed to offer alot of value and high end design features. The build is straight-forward, but you would be best off to have some experiance building electronic kits. It's hard to convey in words how a component sounds, but you know when it's right, and this pre sounds superb to my ears (after rolling some tubes and finding the right cartridge and stylus!). Solid, well defined, deep bass, very natural (you-are-there) mids, extended sweet highs. I had a friend over who plays guitar in a band ocassionally, he said the drums sound real, the guitars virtually perfect. He said he had no idea vinyl could sound so good, and he has a decent system with a turntable. Cymbals ring, I had forgotten how nice and sweet analog highs can sound! Vocals float in space between the speakers. Hum and noise level is very low, nearly undetectable with the high level inputs, way below the vinyl noise floor on the phono input. I can easily hear master tape hiss deep in the backround on Alan Parsons "I Robot", Pink Floyds Dark DSOTM, and Fleetwood Mac "Rumours", all of which sound amazing on vinyl. With this pre you can easily hear the quality of the recording and the pressing. I have rolled some tubes, the character of different tubes is extremely evident. The difference in cartridges is also easily discernable, sylus' too. Currently I am using Baldwin labled Sylvania 12AX7's in the phono stage and 12AX7EH's in the line stage. Got some Telefunkens coming, I am confident that this preamp deserves them, and will bring out their legendary sound. A little note on grounding, ground loops:
    I wired the pre exactly as Roy lays out in the instuctions to avoid ground loops. I added a toggle switch that optionally connects the signal gound to the chassis ground as needed. I have tried the preamp with a Sumo Andromeda, a Sumo Polaris, a Sumo Polaris chassis with Aussie Amplifiers boards in it, Bob's M125's, and the Jungson amp, and in all cases hum was either virtually nonexsistant or barely audible with no music playing and the volume way up. Never does hum detract from the system. In short, I am very pleased the preamp, it has reignited my passion for fine vinyl. One warning, always turn the amp off before the preamp, probably common sense to most of you, but I got to see how much travel my woofers had before I figured this out!
    I can't wait to hear a PH14 and SP14 with octal tubes, I'll be talking to Roy about getting at the top of his list! What a great hobby, especially with good people like Roy and Bob helping us out! Almost forgot, I also tried a Marantz Model 7 style phono stage in the pre, it sounded a little warmer and richer, but in the end I prefer the PH6 stage, much more open sounding. maybe I'll put the marantz clone in a case with a power supply so I can use it on some of the poorer sounding albums, it seems to gloss over their faults.

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