Dating my Coliseum

[Swamp Gas]

The little tag on the front is unreadable. Is there another way to determine when mine was built/tested?

[JoeArthur]

The little tag on the front is unreadable. Is there another way to determine when mine was built/tested?

Pot dates? Transformer dates?  They are usually year/week-of-the-year format.  It's not exact, but your amp couldn't have been built before the pots or transformer - assuming they are original.

[Swamp Gas]

I have not been into it yet. This one has 4 machine screws on top and 2 on the right side (looking at the face.) If I remove those, will the amp be easy to remove from the case? Anything to watch out for?

[JoeArthur]

There are different models of coliseums and I haven't been into any of them.  

Four machine screws sounds typical of sunn amps so I would remove those first and check for how secure the chassis is in the case, then I would remove the two from the side if necessary.  It would probably slide out of the case through the back.

Things to watch out for  Normally the chassis is self contained and is just setting inside the case.  If the amp has reverb the unit might be secured to the top and cables need to be unplugged as with the concert so just go slow if that be the case.  

Otherwise, just try not to have the chassis remove any of the tolex that may be interferring with it's removal.

Don't forget to unplug the amp first!!  

[gray]

As I recall, you need to unscrew all six of the screws. Mine is the same way. It could be difficult to take it out; mine was. Just go easy on it and be careful of the circuit boards. I haven't opened the thing up in a while but I do know I unscrewed all the screws.

I think there should be some kind of a date somewhere in the amp. I never looked in mine, but I do remember that Sunn used to put manufacturing dates inside the amp's chassis.

[Swamp Gas]

It was fairly easy to pull out. I wanted to lube the pots, but they are blocked by a circuit board. I removed the knobs and carefully sprayed the shafts, letting the lube (contact lube) work it's way down. It was suprisingly clean on the inside. I know it probably wasn't the previous owner, 'cause the outside needed a good cleaning when I got it.  I did not recognize anything inside indicative of a date. After cleaning the tag on the front I was able to determine "who" inspected it, but not when. Mine is one of the later models with the 7 band rotary EQ and compressor. It has a plastic covering (not tolex.)

[gray]

The date on the schematic that came with the manual I downloaded from this site was 82, and if I'm not mistaken, Fender bought Sunn in 85. Therefore, I suppose it's safe to assume your amp was built sometime in that time period. A more specific date would be more difficult to determine if there are no other clues in or on the amp. I haven't found any in or on mine.

[Swamp Gas]

Thanks everybody! I am really digging this amp.