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Phono Pre-Amp

I think you'll appreciate it even more when you hear it! A good phono-pre can make a BIG difference. And, from all I've read, the Vincent is a very good one. Be sure to let us know what you think, it shouldn't take long to determine if it's an improvement!
 
In reply to our esteemed Mr. Rothwell,

FauxHall said:
Very high efficiency speakers are more sensitive to tube hiss maybe pointing towards SS if that's what you use.
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"The efficiency of the speakers is irrelevant. The tubes in a tube phonostage are before the volume control, therefore any tube hiss in the phonostage is attenuated by the volume control. With more efficient speakers the volume control is turned down for the same SPL, hence tube hiss is no louder than with less efficient speakers."

Correct me if I'm wrong, but my presumption is that a front end of a modern op-amp or selected discrete solid solid state devices should have lower noise than an ECC83S or 12AX7 tube front end at the same gain. Hence the SNR of a solid state phono pre-amp would be better (higher) than a tube pre-amp at the same gain to the output.

My current tube Luxman CL-38uC looks like a 60+ dB SNR at output with a low MC input while the Schiit Skoll phono pre-amp with discrete JFETs, even at 70dB gain claims over 70 dB. The Luxman has internal transformers for the MC input. Not quite apples-to-apples, but suggestive that tubes are noisier. Once the signal is made noisy BEFORE the volume control, I know of no way to de-noise it from further amplification.

High efficiency speakers in my experience are more prone to presenting noise through the tweeter for any giving input.
 
FauxHall said:
In reply to our esteemed Mr. Rothwell,


"The efficiency of the speakers is irrelevant. The tubes in a tube phonostage are before the volume control, therefore any tube hiss in the phonostage is attenuated by the volume control. With more efficient speakers the volume control is turned down for the same SPL, hence tube hiss is no louder than with less efficient speakers."

Correct me if I'm wrong, but my presumption is that a front end of a modern op-amp or selected discrete solid solid state devices should have lower noise than an ECC83S or 12AX7 tube front end at the same gain. Hence the SNR of a solid state phono pre-amp would be better (higher) than a tube pre-amp at the same gain to the output.

My current tube Luxman CL-38uC looks like a 60+ dB SNR at output with a low MC input while the Schiit Skoll phono pre-amp with discrete JFETs, even at 70dB gain claims over 70 dB. The Luxman has internal transformers for the MC input. Not quite apples-to-apples, but suggestive that tubes are noisier. Once the signal is made noisy BEFORE the volume control, I know of no way to de-noise it from further amplification.

High efficiency speakers in my experience are more prone to presenting noise through the tweeter for any giving input.
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Yes, as a general rule tubes aren't as quiet as modern op-amp or transistor circuits, so it's reasonable to assume that a tube phonostage won't give as high a signal-to-noise ratio as a good SS phonostage would. However, loudspeaker efficiency has no impact whatsoever on the signal-to-noise ratio of a phonostage. For a given position of the volume control on any particular system, using higher efficiency speakers will give you louder sound. Yes, the noise from a tube phonostage would be louder with the higher efficiency speakers, but so would be the music (ie the signal), so the signal-to-noise ratio would remain unchanged.

The noise from a noisy power amp, or from output stage of a preamp (ie, after the volume control), certainly would be louder with high efficiency speakers. In both those cases it's the noise generated after the volume control which is exacerbated by the high efficiency speakers.
 
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justjed2 said:
a TCC TC-750. Leave it on all the time. After a week of being powered up, it sounds quite good for a cheap preamp.
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I have one of these but I'm curious about this. What is it about leaving it on that changes the sound of this pre-amps? Does it lose this change if you power it back off later? Mine is some years old now but I don't have it on all the time.
 
With Nad having a smoothness and yet defined sound I would just stick with what you have. If you want to try a different sound add a program EQ or change cartridges. Now if your NAD is having technical issues, maybe its time to update the NAD rather than adding a phono pre-amp.
 
twiiii said:
With Nad having a smoothness and yet defined sound I would just stick with what you have. If you want to try a different sound add a program EQ or change cartridges. Now if your NAD is having technical issues, maybe its time to update the NAD rather than adding a phono pre-amp.
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The OP has already ordered a Vincent Audio PHO-701. It's supposed to arrive tomorrow, and it will be interesting to hear his impressions of it once he's had a chance to listen to it for a while.
 
Well, I am having issues. The firt unit arrived and worked beautifully for 20 minutes then shut down. I got a replacement and it worked fine, but then today same thing, power is on, tubes are lit but no sound. I am guessing there is somrthing wrong with my pre amp. If its not one thing it is an other. Does anyone have have any idea what it could be?
 
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