Are You Happy With Your Phono Preamp?
I have been gradually upgrading my analogue components. Which presently consist of: SME 20/2 turntable (old but good), Kuzma 4Point Tonearm, Soundsmith Hyperion (MI) cartridge (love this), Dynavector (MC) DRT XV1, PS Audio Stellar Phono Preamp (connected to ARC Ref 6, Pass Labs 160.8, Avantgarde Uno). I have to say that I am very happy with the analogue sound from this system. That said, high end audio being what it is I can’t help wondering if I am leaving some better sound on the table with the PS Audio phono preamp … though I know I should not judge by price alone. I have been looking alternative phono stages: the VTL 6.5i, ARC Reference 3SE, Boulder 508, Pass XP17 … this price range. Those who are long experienced analogue lovers … do you think I am leaving any sound quality on the table by sticking with the PS Audio phono stage? Do you believe that I would see a meaningful change in sound quality by moving to a phono stage in the price range I have been looking at?
You are completely mistaken. The ARC Ref preamps are fully balanced/floating and the ground floats separately from the signal itself, even on the Ref Phono units that use RCA inputs. (The line stages offer RCA and XLR connections on each input.)
It isn’t clear what you mean by "artificially balanced." How would you design a balanced preamp without differential circuits? Transformer coupling? That’s what many would consider to be "artificially balanced," @clearthinker. |
Thank you. But I still cannot see how it can be fully balanced if it has only phonos for inputs. If phonos can be balanced, why does it need XLRs for outputs? And why do ARC included XLRs in and out on the Ref pre-amps? And on earlier phono amps like the PH2 that I used with pleasure for 20 years. All fully balanced phono amps offer XLRs for both inputs and outputs. And, as you say, the ARC Ref preamps (I use a Ref 6 and have favoured ARC preamps in the past) include XLRs for input and output that I use as I want to run fully balanced throughout. |
@clearthinker The tonearm cable from turntable has a separate grounding wire. Instead of duplicating the ground wire per L+R channels (dual 3-pin XLRs), here it’s common for both channels. That’s what the grounding lug next to the input RCAs is for. So IF they wired the tonearm RCAs with "+" and "-" balanced signals on pin and barrel, with ground on the separate grounding wire, and with the ARC taking it in this way (isolating the barrel signal carrying "-" from the chassis), it could be fully balanced over RCAs. There are enough separate conductors. BUT I have no idea if this is how it’s actually setup; it depends on your tonearm cable’s wiring, and I’m not sure this is even a good idea - exposing the "-" signal on an exposed RCA barrel kind of defeats the purpose of common mode noise rejection. Even if it’s NOT a balanced signal coming in, there can still be benefit from using a differential input stage and running everything downstream fully balanced, IMO (like Stax headphone amps). |
