Preamp Noise with High-Efficiency Speakers

I agree. He should have to use it. I liked the sound of a past system and the
only way I could keep,same components was to use a Jensen ISO tranny.

It rid the system of a buzz I could not tame in any other manner. Not ideal
as you say, but it worked and did not change my sound. In my case the
issue was between the amp and preamp. It was a buzz.

Just an idea.

The OP can call Jensen as they are very helpful and they can help
determine if this would be a strong potential fix. I bet they would be open to
letting him try and return it if it does not,cure the problem.

Almag here is the one who turned me onto the idea as well as another
Agoner who had the same issue and the Jensen worked wonderfully.

I assume here a nice tube preamp would deliver better sounding music and
this step is thus worth it.

Charles1dad said:

My point is don`t be condescending and dismissive to those listeners who chose an active component rather than his.

I agree completely. I think that you have to look at the LSA in terms of value. It's an outstanding value and a very good pre-amp. George, I second Grannyring's accolades for your DIY support (this from someone whose DIY skills pretty much end at crimping spades and rolling tubes ;-)

Worth a try if it doesn't cost him even more money and time to rid the noise.
I believe he maybe just hearing the noise from too much amplification with 104db speakers and when he OMITS the active pre (and he has tried 4 different ones solid state and tube) he is reducing his overhaul system gain by maybe 40db or more, and this also equates to the reduction of the active component noise as well when he goes direct, remembering every 6db of added gain is double the voltage.

Cheers George

... when he OMITS the active pre (and he has tried 4 different ones solid state and tube) he is reducing his overhaul system gain by maybe 40db or more...

George, note that he is talking about a line level signal from a DAC, not a phono level signal. I am not aware of any preamp that comes remotely close to providing 40 db of gain from its line level inputs, even with the volume control at max. Typical numbers these days are in the teens, or even less. And with a DAC or other digital source, commonly the volume control of an active preamp will be set such that its gain, from input to output, is less than zero in terms of db.

Bill (Grannyring), thanks for the acknowledgement. Glad I was helpful with that issue.

Regards,
-- Al

Yes you are right Al, my bad, I was including the phono, but up to 20db for the line level is not unheard of.

eg:
The CAT line stage: 15.0dB of gain set to Low and 25.8dB set to High.
Balanced Audio Technology line preamplifier gain was slightly higher than the published specification, at 18.7dB

It only takes the OP's power amp 1.4v to clip and he has over 2v from the dac so he does not need and more gain from the output stage of a preamp which in 99.9% of cases comes after the volume pot.

Cheers George