B& K Reference 7250 mkII 5 Channel Power Amplifier - 200 Watts Per Channel

I purchased this B & K Reference 7250 Series II
amplifier on eBay in 2012.  I could not
ascertain the history of the unit as the seller was not the original owner. I
used the amp sparingly in a downstairs home theater system (along with another
7250 which I am also selling) driving a 9.2 system.  It has performed flawlessly.  Regrettably, the wife’s current lower level
remodeling plans do not include a home theater system.  Cosmetically, the amplifier is somewhat
scuffed up and a little dinged up.  I
would describe its external condition as “below average”.  Again it works perfectly.  The amp weighs 70 pounds and is built “like a
tank!”

Open http://www.audioreview.com/cat/amplification/amplifiers/b-and-k-components/reference-7250/prd_124170_1583crx.aspx
for user reviews.

Open http://data.manualslib.com/pdf/2/143/14245-bk/7250.pdf?2896097d259f64998d578dff1664c924&take=binary  for owner’s manual.

True to B&K's long tradition of offering high quality at a
reasonable price, the 7250 isn't just another big amplifier. It's built to
audiophile specifications for clean low level detail and sweet, non-fatiguing
high frequencies, but will drive any loudspeaker you care to mate with it to
deafening levels. Engineering highlights include a Class AB MOSFET output
stage, 1% metal film resistors for ultra-low thermal noise, computer grade
capacitors, toroidal power transformers, and discrete circuitry throughout.

Each channel has its own level control, making system calibration
a breeze, especially in systems where the front and rear channel speakers are
different brands. The 7250's five channels of amplification are identical,
unlike some amplifiers that skimp on the rears by using a monolithic output IC
and cheap connectors. Conservatively rated at 200 watts/8 ohms, the B&K has
enormous dynamic headroom, capable of 375watts/4ohms or 75 ampere peak current.  The B&K retailed at $2498.

FEATURES:

• 200 watts X 5 channels at 8Ω, 375 watts X 5 channels at 4Ω (20Hz
to 20 kHz) at .09% Total Harmonic Distortion

• Class A Pre-Driver circuitry improves low-level detail for a
smoother and more musical sound.

• Class AB MOSFET Output stage delivers efficient, linear power.

• Differential input stage with a current source load assures DC
stability and wide bandwidth linearity.

• Use of 1% Metal Film Resistors in the entire active circuitry to
reduce noise for greater purity of sound.

• Use of Toroidal Transformers and Computer Grade Capacitors to
provide high current for superior dynamics and extended low frequency control.

• Capability to operate at full power with a square wave input
signal.

• Individual External Fuse Protection prevents damage from
accidental shorting of output devices, while preserving the highest level of
integrity to the original signal possible.

To maximize amplifier performance consider upgrading the power
cord and acquiring a power line conditioner (This is a VERY high current
amplifier).  Beware that all Class A amps
(particularly high current ones!) run warm even at low volumes.  Therefore, do not stack any equipment on top
of the B & K and allow at least 2 to 3 inches of clearance from the top of
the amplifier to the next shelf.  Room
temperatures in excess of 80 F will result in amplifier overheating.  Do hook up the 12 volt trigger to turn the
amplifier on and off using your processor or preamp, for example. Over time the
front switch sees wear as the switch bounce creates mini arcs wearing on the
plates which could negatively impact the life of the amplifier.

As B & K is no longer in business, amplifier service/repair
(unanticipated, but the future is ALWAYS uncertain and the prudent will prepare
a contingency plan) will require a competent, high- end audio shop.  The service manual is available and parts for
class A, MOSFET amps are also available. 

Local
pickup (Detroit area) is preferable, however I will pack it extremely carefully
and ship it within the CONUS by FedEx/UPS at the buyer’s expense.