MA2275 Issue need some advice

Thanks everyone for the replies, will change the tubes around and see if I can isolate the problem. For the fuses, I'd think they would work or not work (blown). Is there something to look for in particular? This is my first tube source, but in general how do you know that the tubes need to be replaced? Thanks!

OK changed the tubes from right to left and still having an issue on the left channel. Does anyone know if the MA2275 shares any of the tubes?

One more check. Trace your cables on the left side including speaker and IC.

Not sure about sharing for the MA2275.

Lapierre, checked the cables and the interconnects, even removed them and connected with bare wire still having the problem. You said to check the fuse before, wouldn't the fuse either work or not work? Their is only one fuse so wouldn't that effect both channels? It's a slo-blo type fuse.

Someone else may want to check this to make sure. When I read a schematic like this (lot of parts) from a pdf reader, I get eye fatigue.

Anyway the way I can see is the V4 and V5 are for the phono. They share the left and right half in each individual tube.

The V6 and V7 (gain tubes) also share a left and right in each individual tube.

So assuming the V4 and V5 was physically swapped left to right side (of amp), the V4 and V5 would have should have replaced the gain tubes V6 and V7. I'm thinking the phono (V4+V5) and gain (V6+V7) shouldn't have a bad section on the same side (half) of two tubes. At least it doesn't seem likely, but strange things can happen. A lot of other parts in there. Possibly a solid state part, or other. You could call MAC to make sure also.

The center tubes (V5 to V7) aren't mirrored on top of the chassis, meaning the two on the left isn't for the one channel, and the two on the right side are not for the right channel only.

All of the other tubes (not center four) are for the side they are on I believe.

Link for schematic for anyone else. [http://www.berners.ch/McIntosh/Downloads/MA2275_ser.pdf]