revision F on the board and pre-500 serial

[Nico]

Hi, I've purchased a Dual Rectifier many years ago and I always thought it was a rev C or D as its serial number was R026X.
It has all pre-rev. G outer criteria (power transformer and output transformer S/N, loop, covering, power chord etc.).

However I never checked the board revision, until today, when I removed the chassis and discovered it has R1-F1 printed on the mother board.

I guess either the original serial number sticker or the original mother board has been replaced...
Is there possibly another explanation?

Thanks.
Best regards
Nico

 

[Shemham]

Take some photos of the PCB, upload them and link them here. It's pretty easy to tell from the circuit details whether it's Rev C/D or later revision.

 

[Nico]

Here are the pics:
http://i21.servimg.com/u/f21/12/50/60/05/dsc07910.jpg
http://i21.servimg.com/u/f21/12/50/60/05/dsc07911.jpg

Accordig to this very interesting thread, it seems I have the rev F main board layout (and R1-1F is written on it):
http://forum.grailtone.com/viewtopic.php?f=24&t=58838&start=105

The latest transformer (choke) production date is march 1992...

 

[Shemham]

Yep, that's RevF circuit.

First I thought that the serial number sticker could've been altered for fraudulent marketing purposes. But now with the dating on the choke it became somewhat confusing for me as I know some rev C units with later production date. You could ask Mesa if they had any data on that particular serial number - or other possible Rectos checked on that particular day.

 

[LesPaul70]

It could be a case where a malfunctioning or broken circuit board had to be replaced and they were shipping Rev F's when they did that.
That has happened with some early Rec's, I remember reading about a 'pre 500' that was the real deal except that it had a Rev G board inside. Reportedly, Mesa had switched the board during amp maintenance.

But as long as the rest of the package (transformers etc.) is Rev C/D, you should be able to revert a Rev F to the Rev C specs pretty easily (well, except for the circuit board marking, that is).

 

[Silverwulf]

Best guess is Mesa had it in for repair back in '93 or '94, so it ended up getting an F board dropped in. Send "Authorized Boogie" a PM and see if he can find any repair records for it around '93 or so.

 

[Nico]

Here is the final explanation from product specialist Trent Blake:

In May of 1993 your amp was sent to us by our UK Distributor at the time (Rock Road Co.) for a clean mod update. This required the use of a new circuit board and associated parts.

Best regards
Nico