A little background on SAE. The SAE Two are OK, but not highly regarded, as it SAE was sold to DAK, and production standards were lowered and production went to Asia. I, personally, think the prices you stated are a little high.
High End Series
>
> Mk series: Two Tone style. Black and Champaign/Silver or Black or
> Silver. Rack mount and Analog Meters optional.
>
> *1st generation: 1970-1972
>
> MK2 & 2B, MK3 & 3A, MK4 & MK23
>
> (Very limited sale of the MK23...always in the shop....thing. A
design
> ahead of the technology needed to make it really work.)
>
> *2nd generation: 1973-1975
>
> MK31B, MK3CM, MK4DM Note: MK31B lasted till 1977
>
> Marketing/Engineering: Simple next generation product line taking
> advantage of all the rapid new semiconductor advances that had
ocurred.
> It replace all the older MK series products. SAE also offered
> professional rack mount versions of these amplifiers on special
order.
> (I have yet to find a MK4D in rack mount).
>
>
> *Early 3rd generation: 1975-1976 Replaced MK3CM and expanded.
>
> MK24 & MK25 (The MK25/2500 was what the MK23 was intended to be.)
>
> Marketing/Engineering: Home audio two tone versions of next
generation
> of 00 amps. They did not have the rack mount option of the 00 amps
but
> they kept the new fan cooling system which later would be a bad
thing
> for home audio market.
>
>
> ======
> 00 Series: All black and rack mount & LED or Analog Meter Standard.
> Units 200W/chan and above had fans.
>
> Marketing/Engineering: Simple next generation product line but ONLY
> available in black rack mount profession look which was the "in
thing"
> and a very hot seller in Japan. Also of note is in 1978, SAE
expanded
> into the consumer market with the SAE TWO series clearly saying
this is
> the high end.
>
> *Early 3rd generation lineup: 1975-1976 Replaced MK3CM and
expanded.
>
> 2400 & 2500
>
> Marketing/Engineering: Professional all black versions rack mount
> versions of MK24 and MK25 amps. New fan cooling system.
>
> *Standard 3rd Generation: 1976-1980
>
> 3100 (197
, 2200, 2300(197
, 2400L(1997-), 2600
>
> Marketing/Engineering: Two tone home audio version now completely
> dropped. Pro version only. Fan cooling became a selling problem in
> high end home audio market (2400L, 2600) which would not be
addressed
> until 01 series with its wide scale adoption of the non fan turbo
flow
> heatsink technology introduced with the 2200! The future adoption
was
> foretold by the 3100 and 2300 introduced in 1978. The LED meter
system
> introduced on the 2200 migrated to the 2400 becoming the 2400L. The
> 3100 and 2300 were also introduced with LED meters along with a new
> splashier boxy LED meter scale silkscreen markings that introduce an
> additional new color...blue. The new LED meter marking style
migrated
> to the 2200. Thus you can find two styles of 2200's out in the
market
> place. Later in production, internally most of the amps had their
> transformers upgraded to the more efficient toriodal (round) design.
>
> ======
> 01 Series: All black rack mount, no fan and rectangular LED meters
> only. Except for the SAE logo, text was now in a new font.
>
> Marketing/Engineering: Due to the X series introduction, the 01
series
> became, dispite the fact model 01 series was better than the 00
series
> in many regards, a midrange product line. It held the same pricing
> structure the former "high end" 00 series had. It hard to say if
this
> was 4th generation or not. It circuits were designed in parallel
with
> the X series. 100% turbo flow heatsink design eliminated fans for
home
> audio applications.
>
> *Early 4th generation: 1980 only. Replaced 2400L and 2200.
Transition
> models only.
>
> 2201 & 2401
>
> Marketing/Engineering: The 2401, and later higher power levels,
showed
> that turbo flow heatsink was great for home audio applications, but
> would not cut it under true professional audio (rock concert)
> applications. SAE had to introduce a seperate rack mount fan
cooling
> system accessory.
>
> *Standard 4th generation: 1981-1986 Replaced the entire 00 Series
and is
> black panels and rack mount.
>
> A201, A301, A501 & A1001
>
> Marketing/Engineering: In 1983, SAE broke out into the true PRO
Audio
> market with the P-50, P250 and P500. The P250 and P500 were based
on
> the A501 and A1001. Fan cooling system were not integrated since
there
> were no mechanical changes to the chassis and thus the rack mount
fan
> cooling system used by the 2401 was still offered. The P-50 was
unique
> in that it came with a built in fan and squeezed into a 1U rack
chassis.
>
> =====
> X Series: Silver/metallic gray? Rack mount sharing mechanical's of
01
> series.
>
> Marketing/Engineering: Introduced at the end of the 00 series and
> promoted as being the new ultra high end. This instantly pushed
the 00
> series into midrange status which later was picked up by the 01
series a
> year later. Some say the literature had a hard time explaining,
from a
> technical point of view, how much better the X series was above the
01
> series such that it's higher price could be justified. It also
looked a
> lot like the 01 series except not in black. Not a big seller from
what
> I can figure out dispite it having the longest production life. It
also
> created a 3rd product line for SAE. Potentially very confusion for
a
> market used to only two product lines.
>
> *5th Generation?: 1979-1989
>
> X25A, X15A and X10A
>
>
> =========> Consumer Line (Asian circuit design or influence)
>
> SAE TWO Series: 1878-1984 All black with analog meters when
needed. No
> rack mounting.
>
> A7 and A14
>
> Marketing/Engineering: Address mainstream consumer market place
using
> SAE name as leverage. 100% Asian design.
>
>
> ======
> 02 Series: 1985-1989 All black rack mount with LED meters.
>
> A202, A502
>
> Marketing/Engineering: Replaced SAE TWO series. Lower Cost Asian
version
> of 01 series design. Initially held the consumer space product
line but
> sold side by side with some of the 01 series. It later replaced the
> entire 01 series in 1987 as the last of the 01 series products were
> withdrawn.
>
>
>
> Best Regards,
>
> Mark Gurries
> Linear Technology
> Power Supply & Battery Charger Applications Engineer/Manager