[MrSandMan]

It's becoming noticed that the pre500 isn't as special as we all had thought. It appears that the MKIII (Mark III) Transformers that were claimed to make the pre500 special, were used in later (1992) s/n Rectos. I'm trying to learn how Mesa Boogie used their components in 1992, because it's obvious some things were likely mixed and matched to some degree.

http://en.wikipedia.org/wiki/Mesa_Bo...ctifier_Series

The first 500 Dual Rectifiers are also considered to be the "holy grail" of the rectifier line. These Pre-500 rectifiers are said to have superior tone due to specific transformers that were only used on these early models. In addition these first 500 also feature a unique circuit board that was changed toward the end of 1992. You can distinguish the Pre-500 dual rectifiers by their serial number found on the back of the amp and should fall between # R-0001 to R-0500. The first 503 not only used the 100 watt output transformers from the MK III, made by Schumacher.

The Schumacher Transformers –

The digits 606 are Schumacher’s EIA manufacturer code.

Here is my pre1000 Information:
(MarkIII Trannys)

Serial: R-0929
Model: Dual Recto head
Revision: RF-1F
PT: 561136/EIA606-237
OT: 562100/EIA606-033
Choke: 550381/EI606-237
Loop: Serial
Dates: 10/27/92
Wired by: Kaydee
Other: Chrome chassis, Black diamond plate

Please complete your Dual Recto's information so we can all learn how Mesa Boogie build the earlier Rectos.

:shred:

[LnTh]

Serial: R-0812
Model: Dual Recto head
Revision: RF-1F
PT: 561136/EIA606-237
OT: 562100/EIA606-033
Choke: 550381/EI606-237
Loop: Serial
Dates: ?/?/92
Wired by: Kaydee
Other: Black chassis, Chrome diamond plate

Serial: R-0528
Model: Dual Rectifier
Revision: RF-1E
PT: 561136/EIA606-228
OT: 562100/EIA606-034
Choke: 550381/EI606-226
Loop: Serial
Dates, etc.:
Wired by Kaydee on 9/1/92
More writing by Kaydee's information that says: GM 9/92
More writing on board where power supply connects that says: 8/12/92
Other: Chrome Chassis, Black diamond plate

[reverymike]

Serial: R-0635
Model: Dual Rectifier
Revision: ???? (where can I find this?)
PT: 561136/EIA606-232
OT: 562100/EIA606-033
Choke: 550381/EI606-224
Loop: Serial
Dates, etc.:

"IVY" written on botton of tranny in red sharpie. "KP" written in black sharpie on the blue battery looking things.

"9/23 '92 Ivy" written on bottom of metal chassis.

[MrSandMan]

You can find what revision you have next to the four blue batteries.