If Preamp Gain is Set to High-What Consequences?


I can turn the gain on my Joule Electra LA100 mk2 preamp to about 25-30% with 2 of my sources (transports). With my other sources (macbook pro and Don Allen Marantz changer) I can use up to 40% of the gain without the dbs getting too loud. (Bryston 14B SST amp/Mirage OMD28 speakers/ Krell SACD MK3 transport/ Jolida JD100 transport- W4S DAC2)

What if any are the consequences to the sound quality of the system as a result of the gain of the preamp? (measured by a technician at 15db)

Any effects on midrange-highs-bass weight-resolution-soundstage-imaging?
foster_9
Thanks for the information Newbee, but I'm not confusing anything. The gain of the Joule can be set internally from lower to higher by changing the position of jumpers on a circuit board. The Joule technician set "gain select" at the highest setting, a measured 15db. This leaves me with much less play in the volume control (Joule calls it "gain" on the faceplate). I'm wondering if the gain-select jumpers had been set to a lower setting and I had more play in the volume control than I currently have, if that would improve the sonics or make no difference. For example if I had the ability to turn the voulume as high as the 50% point rather than being limited to 25-40%.
Newbee, I don't see that Foster_9 has confused anything, given the clarification provided in his second post. He is saying that the gain of the preamp has been set internally to 15 db. Nothing has been set to 15v or 15 volts. Which means that when the volume control of the preamp is turned all the way up, its output voltage will be 15 db greater than its input voltage. That corresponds to a ratio of about 5.62x, meaning that the output voltage at any instant of time will be about 5.62 times as great as the input voltage at that instant, with the volume control at max.

And, yes, reducing the volume control setting from its max position will reduce the actual gain provided by the preamp from the specified number, since the specified number is based on having the control at max.

Concerning whether or not reducing the internal gain setting would result in improved sonics, IMO it's anyone's guess, as there are many preamp-dependent variables that are involved. Anecdotal evidence seems to suggest, though, that having a gain structure which results in running the volume control in the upper part of its range often (but not always) provides best results. Personally, though, my instinct under the circumstances would be to leave it as is.

Best regards,
-- Al
Foster 9 and Almarg, Obviously I had a brain fart - posted before coffee! :-)

But, changing the measured fixed gain of the pre-amp from voltage to db I think is the extent of my error ( :-)) unless I do not understand how most pre-amps work.

In pre-amps with which I am familar, in the basic circuitry the attenuator is placed before the amplifing stage of the pre-amp. Rotating the VC only changes the strength of the signal from the source to the pre-amp. It does not change the strength of the pre-amps amplifying stage which remains as it was set by Joule at 15db.

Am I wrong? How so?

Foster 9, FWIW and I don't know why it should be worth anything after my first comments, many pre-amp manufacturers suggest that the preferred VC position rests between 10 and 2 o'clock. Something to do with impedences I think, depending on the design of the VC, which makes some sense to me. If there is any validity to that it seems to me that it can be obtained by controlling the pre-amps fixed gain by reducing it internally, by reducing the gain as seen by the amp by attaching incased fixed value attenuators, reducing the strength of the signal of the source, either by initial selection or addition of inline attenuators (incased fixed value resistors). Personally I think there are too potential many tradeoff's trade offs to bother unless one is trying to minimize pre-amp noise, typically seen in a tubed unit.

Al, I always respect your comments and I'll look forward to you edification! :-)

Foster 9, Oh, the value of a re-read of your original post. :-)

To answer your specific question, I would not change the pre-amp gain from 15db unless Joule feels the changes it would make in the optimal position of your volume control (as suggested as possible in my last post) would make it worth while. It seems from your description of your VC's position that you only use it from about 9 to 11 o'clock. If your pre-amps gain as set by Joule were further reduced you would get more use of the VC, presumable a finer gradiation of volume changes and perhaps impedence changes. Al is much smarter than I on these matters, so he can advise or Joule can help.

FWIW. :-)