Mesa/Boogie D-180

[mikeswals]

Thanks for the help guys. I believe someone has been into the chassis of this one....

I believe the fuse holder has been changed because it's blocking the rating below it. It has a 15 amp fuse in it! What is the rated value supposed to be?

It should have a 6.25 amp slo-blo fuse in it. Clearly someone has been monkeying with it. You can still be able to get the on/off/standby switches from Mesa.

My D180 was from '86. And it had a 12AT7, there was only one preamp tube slot that had a metal cage on it, and that was where it went. I did run all 12AX7's in it for a while and I liked it either way.

 

[chaosMK]

I think I ran 12AX7 in my D180. In my Bass 400 I'd have to check but I am pretty sure I use a 12AT7 in V3 (Driver slot). I wouldnt use 12AT7 in V1 or V2 (tone related), they are a bit dry sounding.

I am not sure if you can use a full set of 6550's in the power because (as Agedhorse once informed) the heater current may be pushed beyond spec.

When I had my D180 I had a sextet of Winged =C= 6L6 and it sounded fantastic.

IMO the D180 is one of the best sounding amps. My 400 with 6550's sounds deeper and heftier, more solid on the lower frequencies (I often play in B), bit more headroom and that was why I kept it but in terms of tone and pushy forwardness the D180 was just a hair sweeter.

I am pretty sure the 6550s in pic are in the wrong spots if you are going to use them. Others may know better but I thought the power tubes were matched in a mirror layout.

 

[kranahan]

Which tubes are the driver tubes when looking from the front of the amp?

 

[Wasnex]

I am pretty sure the 6550s in pic are in the wrong spots if you are going to use them. Others may know better but I thought the power tubes were matched in a mirror layout.

Not sure what pic you are talking about. The article I reference earlier shows the D180 with six 6550s in it. Here's the link again: My Mesa d180...

I am have seen multiple posts that claim Mesa tech support says the D180, Buster, and 400 are all safe with 6550s. This does not mean you can simply drop 6550s into these amps. If you drop 6550s in an amp setup for 6L6GC without adjusting the bias, the tubes will probably red plate. It's necessary to either install a variable bias pot, or change the bias scaling resistor, so the tube current can be set to the proper range.