Were there different Monitor 7C's

[GhostriderTx]

I was scanning ebay and saw what was advertised as Monitor 7C's that were different from mine. These had a fuse on the back and near the terminal inputs had a seriial number. Mine do not have a fuse and while there is a place for a serial number near the terminals the only serial number I have is on the corners. I bought these new is 1991 according to my receipt so I was wondering if they made changes to the model 7's and I have a different version...
Sorry for the double post. I tried to edit and add "C" but it posted twice...

[BobMcG]

There were different Monitors made including what some might call the original series (had fuses on their backs) and the later Series-2s.

Yours were new in '91? Sound like they are from the Series-2 family of Monitors then.

[GhostriderTx]

the label on the back says Monitor 7 and a serial number around 62000. It doesn't say Series 2. I looked at the receipt and it says Monitor 7 although it is handwritten so probably not accurate. The installation guide shows all the monitor series and no Series 2 jsut 7C and the other models. The only other thing is to climb in the attic and see what the boxes say but I think I may try that in daytime..

[BobMcG]

Here's a bit more info... The original 7s, 7Bs and 7Cs are 24"H x 14"W x 9.25"D. The 7 Series-2 are 24"H x 13"W x 10"D.

[GhostriderTx]

if the 9.75 includes the grill cloth. Otherwise it's 24x14x9.25. I guess they removed the fuses from later models or the ebay guy is wrong...

[BobMcG]

Measurements are without the grill cloth.

I don't know when Polk dropped the fuses on the backs design but it could have been during the 7Cs run. I thought maybe it was with the start of the Series-2 run.

[GhostriderTx]

I climbed in the attic and the boxes also say Monitor 7. I am fairly convinced I have 7C's.