[satiger]

I just purchased AR LS 27 pre amp and tested last night for about 2 hours. The tubes have about 110 hours and according to AR, they need 200 hours to break in.

Once the tubes are warmed up (after about 10min), the sound is fuller, warm side with more dynamics. However, I have few questions on 4BSST2 pro side.

I use single ended Cardas clear between ls27 and 4bSST2. 4BSST2 pro has two gain controls. 29 vs 23 db and being pro model has other setting called level control (0db to -14db). If I don't want to alter the input signal from LS27, should I choose 29 or 23 on gain and  0db or -14db on level setting?. In other words, I would want to avoid another round of db changes on top of LS27. I like to pass LS27 signals as natively as possible to speaker. Which setting should I use?.

A detailed review on 4BSST2 with Cardas/ AQ interconnects, Furutech fuse, PS Audio - Noise Harvester and Audio Research LS27 is in progress. Will publish soon. 

[CanadianMaestro]

^  I don't think changing the gain or level settings on your 4B will alter the signal integrity/content coming out of LS27/hitting the speakers, other than changing the loudness of the music. It's an amplifier with adjustable gain, after all. Higher gain may get you more perceived noise. Do what sounds best for you. (Are you using these in a studio for recording/mixing?)

[satiger]

Thanks CanadianMaestro for the quick response. These setup are for home audio listening.

What is the default level setting of consumer version of 4bsst2 - is it 0db or -14db?.

[James Tanner]

HI

Leave the GAIN adjust fullly up - 0 DB. 

The sensitivity switch just adjust the voltage required for full power.  Usually base it on how high the volume control needs to be at normal listening level.  If too low - Say 8 oclock set it to the 23 setting - if too high say 2 oclock set it to 29.

james

[satiger]

Thanks James, will test with those suggested settings.

[BrysTony]

Salinger,

Once you get it set up to your satisfaction you will love the combination.  I have been running an LS-27 into a pair of 7BSST² for about five years and have no desire to change equipment again.

Tony

[satiger]

I am currently running 4bsst2 sensitivity switch at 23db and will continue to observe and compare against 29db.

BrysTony, you are right. I am already liking the combination. LS27 introduces a bit warm side but highs are very detailed and transparent. Believe it or not, I am hearing more musical notes/sound that I haven't heard before LS27. More importantly staging is very very good and my speakers disappear all together...... .

[werd]

If the goal is running "natively" as possible. Use the the higher 29 dB setting.  The 23dB sees a resistor that nerfs it 6dB. I never really seen it as an issue though.