Gain on preamps and why are some so high? ...

joeinid

joeinid

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I've been looking at some preamp specs and thinking about ones that I've owned and some I'm looking at for the future.

Some have adjustable gain of 4 dB or 14 dB, some are typically around 10-15 dB and some are as high as 25 dB.

Why is it necessary for a manufacturer to have a gain as high as 25 dB?

I am finding lower gain preamps to be preferable in my situation.

Thought?
 
Joe

Usually the ones that do that like CJ or AI do it to match amps that they are selling that have input sensitivities well north of 1.5 volts. I guess they don't take into consideration that the inability to adjust from those high values eliminates them from consideration with a lot of other amps. Especially true of tube preamps where the mismatch results in tube hiss heard across the room. The Job 225 was an example where we all had issues. Years ago even companies like Anthem made preamps with adjustable gain switching.
 
Often manufacturers will design/optimize preamps to work with their own amplifiers and ancillary equipment. Thrax and NAT are two that come to mind right off, but the more you look, the more you’ll find.
 
Jack said:
Joe

Usually the ones that do that like CJ or AI do it to match amps that they are selling that have input sensitivities well north of 1.5 volts. I guess they don't take into consideration that the inability to adjust from those high values eliminates them from consideration with a lot of other amps. Especially true of tube preamps where the mismatch results in tube hiss heard across the room. The Job 225 was an example where we all had issues. Years ago even companies like Anthem made preamps with adjustable gain switching.
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Thank you Jack. That's what I was thinking, CJ and higher gain.

My LTA MZ2 is wonderful. Not sure I can better it for any reasonable money.

IAmRael said:
Often manufacturers will design/optimize preamps to work with their own amplifiers and ancillary equipment. Thrax and NAT are two that come to mind right off, but the more you look, the more you’ll find.
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I agree. I am surprised there's no "industry standard" to keep levels normalized. Even Primaluna is around 8 or 10 dB. More sane for sure.
 
Well W4S has proven that it's not necessary. Keeping it under 12 should be easily doable if they wanted to or allow some method for adjustment either through tube swapping like the LTA or switching like the Anthem had.

Just based on what I have read from people that have heard both I think the only other options I would explore for "reasonable money" would be the Rhumba 1.2 or the Don Sachs. The Sachs has variable gain for each channel so it does eliminate the too much gain issue. The Rhumba is reasonably low to start with but since it is factory direct they can lower it further if you want.
 
BlueFox said:
Stupid question here. Isn’t the gain controlled by the volume? Just don’t turn it up to 87. :)
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With too much gain, its very difficult to set the volume precisely - a slight turn can lead to more than 6db increase in volume. Also some preamps has some sort of sweet spot for their volume control at normal listening level - with too much gain in the system, the sweet spot could easily be missed.
 
Some preamps start out higher to begin with, so just barely moving the volume control gets too loud with the tiniest of movement.

It's like starting a race halfway to the goal.

BlueFox said:
Stupid question here. Isn’t the gain controlled by the volume? Just don’t turn it up to 87. :)
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joeinid said:
Some preamps start out higher to begin with, so just barely moving the volume control gets too loud with the tiniest of movement.

It's like starting a race halfway to the goal.
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Yes, precisely. My Cary slp-05 had 24db gain on their balanced output - as much as the preamp sounded excellent, it didn't go well with some amps. Now think what would have happened if it were paired with a Job amp with 35db of gain :rolleyes:
 
Plus if you are using a tube preamp with too much gain with a SS amp in particular you will have issues with noise or being able to source tubes quiet enough. Higher efficiency speakers make the issue even more noticeable. In theory if you use components from the same company you won't have a problem but that is not guaranteed either if different designers are involved.
 
I am highly intrigued with Don Sachs' preamp, as well as the Backert Rhumba Extreme and the Herron Audio VTSP-360.
 
Ayre preamps have variable gain setting to match sources.


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joeinid said:
I am highly intrigued with Don Sachs' preamp, as well as the Backert Rhumba Extreme and the Herron Audio VTSP-360.
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Does all of them comes in a balanced version ? My DAC and Amp sounds lot better going balanced (they are true balanced design as well), so I can't stick in a single ended version of a preamp in between.
 
Don's is available with balanced in/out via transformers, I think. The Backert is and the Herron, no.

Devg said:
Do all of them comes in a balanced version ? My DAC and Amp sounds lot better going balanced (they are true balanced design as well), so I can't stick in a single ended version of a preamp in between.
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Interesting thread since I wasn’t aware of these gain issues. I assumed there is a IEEE, or something, spec defining the pre/amp interface. I haven’t bought anything major since the S5s in February, and was half-ass looking at the ARC preamps I heard at Mike’s in September. But I will never, ever tolerate tube hiss, or any other noise, since my stereo is drop dead quiet. Pass just released the XP-22 upgrade, so that might be an option.
 
Even though I am gravitating towards SS amps, I do like a sweet tube preamp. Every one is different and specs seem to matter more for a proper pairing.
 
Dev

One that comes to mind though not all that problematic is with the Odyssey amps and their Candela tube preamp. The amps all designed by Rolf at Symphonic Line have 1 volt input sensitivity and the tube preamp designed in house has 15 db gain which is a bit too much with higher sensitivity speakers especially. As to the Backert, Don Sachs and Herron the only with Balanced out at this time is the Backert. Don has balanced inputs but has not committed to balanced outputs yet and it would be an extra cost add on if he does unless he just puts in the connectors only. My Modwright LS-100 is that way and it works fine with the Nord and the BHK both fully balanced.
 
Bud

Since Mike has all the gear you are dealing with in the shop he could tell you if there would be any tube noise if you paired the Ref 6 with your amp and speakers.
 
The Ref 6 is supremely quiet. You have no worry about tube noise with that one. I had a Ref 6 at one point and it was dead silent. Even heard it with a Pass X350.8 and it was superb.
 
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