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Increasing gain for your vinyl front end when pre-amp doesn't quite have enough juice

Hi Folks, just wanted to get your thoughts on what route you would go if your pre-amp (I’m talking about a normal pre-amp, not phono preamp) doesn’t quite have enough gain for very high listening levels for my turntable set-up. Now, on my phono-pre amp, there is a setting for maximum gain (schiit Mani) up to 59db, but the S/N ratio takes a hit and goes down to 70db, however, it does pump out the needed volume. What about the idea of putting in a good (inexpensive headphones amp/preamp - one of those $99 guys - like schiit Magni, JDS Labs Atom or Monolith Liquid Spark) between the phono preamp and the regular preamp? Does this have the potential of producing the needed gain while at the same time not degrading the signal too much (perhaps not as much as full gain on the Mani?) Just wanted to see what you all think. To me it seems like less items in the signal chain the better, but if it has a higher S/N ratio could be a better option? (with the added benefit of listening to vinyl through headphones, which I’ve never done before.)
bstatmeister
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almarg
9,670 posts
 
@uberwaltz,

I'm sure there are online calculators that can be found which when either number is entered will provide the other number. But I do that calculation manually, using a hand-held scientific calculator.

As you may be aware the ratio of two voltages, expressed in db, is:

db = 20 x log(V1/V2)

where "log" is the base 10 logarithm.

So to convert in the opposite direction, from db to the corresponding voltage ratio, I divide the number of db by 20, and then raise the number 10 to "the power of" that result. (For example, 10 raised to the power of 2 = 10 squared = 10 x 10 = 100).

In this case:

42/20 = 2.1

10^2.1 = 126 (rounded off to three digits).

Best regards,

-- Al
 

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yogiboy
5,556 posts
 
@almarg 
Hi Al,
I thank you for that information. I never knew that!
Yogiboy
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uberwaltz
13,381 posts
 
As usual Al comes up with the goods!

Thank you, exactly what i asked for and gives me better understanding.
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tyray
568 posts
 
@bstatmeister

Please, please, please (a little James Brown here) don’t put those Vandersteen Model 2C’s out to pasture! There may be a speaker recone kit made specifically for those babies. To save money you could buy the kits and do it yourself or have a speaker tech do it for you.

Go ahead and take the speaker covers off and you’ll know right away if the cones are ripped, dented or decomposing in anyway. This way is far less expensive than buying new speakers and if you did decide to put them out to pasture you could at least sell them as they have been rebuilt, and not just sitting in your old hi-fi tech closet that we all have. Hope this helps.
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