Krell KBL DUAL MONO Preamp Stack with Dual Power Supplies

We've managed to assemble the holy grail of Krell Preamps from the 1990's across two  different purchases after lots of looking!

We started with just a single stereo KBL. A few years later we finally came across another KBL which almost completes our stack.

You see, there are switches inside the KBL allowing you to reconfigure it to a fully balanced mono preamp! Ganging two together gives you the best reference configuration possible. Yes, you do end up with two volume controls but thats the best you can get. 

Be sure to watch our video below detailing the setup and design.

Best of all, we have two power supplies so each KBL will have its own power source. So essentially you end up with a FOUR chassis system!

Complete this setup with a pair of Krell MDA-300 monoblocks that we just listed for an outstanding Krell system. We've included pictures in this listing with the amps, but they are obviously not included in this listing.

Back in the 1990's Stereophile gave the KBL a Class A rating in stereo configuration. Had they reviewed the Fully Balanced version we have here, it would have been off the charts. 

Click below to add our recommended matching cables from Kimber Kable, all brand new as SkyFi is an official Kimber dealer.

Kimber Kable - RCA Interconnects

Kimber Kable - XLR Interconnects 

Kimber Kable - 14AWG (Gauge) Power Cords

From a review written by Lewis Lipnick for Stereophile:

"The KBL is undoubtedly the finest preamp ever to come from Krell. It's priced in the same league as the No.26 ($4500 for the Krell vs $4850/$5450 for the Levinson unbalanced/balanced), is a "line-level only" component which can be combined with a matching phono stage (Krell KPA vs Levinson No.25), and offers balanced operation (as does the No.26 with its optional input card). It can also be mated with another KBL for dual-mono operation.

...I feel the KBL belongs at the top of Stereophile's Class A. As did Krell's KSA-250 power amp, I feel the KBL to redefine the term "neutrality." Dynamic and transparent, this preamp is faithful to the musical material, revealing a recording's best and worst aspects."

Specifications - KBL Preamplifier:
Solid-state, class-A, DC-coupled, line-level, stereo preamplifier
S/N ratio: 100 dB (A-weighted)
Input impedance: 10k ohms
Output impedance: 0.5 ohms
Frequency range: 0.1Hz-250kHz
Voltage swing: 65V peak-peak (23V RMS)
Voltage gain: 3x (approximately 9 dB)
Dimensions: 2.25" H by 19" W by 12" D (preamplifier) and 2.5" H by 9" W by 12" D (power supply)
Weight: 27 lbs
Year: 1990

Click here for a PDF copy of the Krell KBL & KPA Owners' Manual 

Our Testing Process for Preamplifiers at SkyFi:
We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and transistors are checked for signs of stress or damage. Special attention is paid to the power supply which is the most common source of failure for preamps. We then power up the unit and run a simple 1k sine wave while monitoring the low voltage output on an oscilloscope for signs of distortion or noise to get a baseline.

At this point we will lubricate and clean all switches and potentiometers (that are not sealed) with a high quality contact cleaner, and then re-test all functions for any signs of noise or scratching.

Final testing involves putting actual music through the preamplifier We have learned over time that some issues are only noticeable to a trained ear while listening to a familiar source material. Our test bench has reference vintage Kef speakers that we are super familiar with which will quickly reveal any discrepancies. Some preamps will then move into the listening room where they will be tested with our in-house reference system.