Design question

[catalin gramada]

Hey. Did You ever designed an head amp with the chassis upside down (Fender style) ? Why ? There is any (as little) reasonable engineering reason to mount a chassis upside down into the case ? There are any problems mounting the reverb tank on the top of the headshell, for instance ?

[Chuck H]

I did it once. But the only reason was that Dean (Markley) wanted a modular design for both combo and head style amps. Same mountings, face and rear plates, etc. Otherwise I can't see any reason to do it, but...

You brought up the reverb tank issue. I can see this being a factor. Though to be honest I've had enough trouble getting reduced proximity noise from modern reverb tanks using them in combo cabinets in the last fifteen years. I did once add a reverb to a top mounted Traynor amp head and was able to scootch it around until I found quiet spot (no room for error) but that was probably twenty two years ago. Modern reverb tanks seem more sensitive and finicky than older ones IME and I might not tackle adding a reverb tank to a head cabinet now.

Fender made a lot of top mount head designs for the same reason I stated above. Modular product offerings. Tubes standing up is the superior design overall I think.

[The Dude]

It will work just fine, as long as you string the guitar in reverse to compensate.

[Mike K]

I've mounted the reverb on the top of the headshell - it's no issue. Just make sure you use the proper reverb tank (they are sensitive to orientation - you want horizontal, open side UP) and lay everything out to minimize any magnetic coupling and it works fine. You can use a bag or isolation grommets. I've done both, I recommend the bag.

I generally don't like the tubes hanging down if I can avoid it just due to natural convection heating.

[g1]

Another issue with 'upside down' mounting is weight. It's ok to a certain point (Fender seems to get away with it up to Twin size), but I've seen plenty of big Traynor and Garnet that have broken transformer mounts, or dented chassis at the mounting bolts.
Part of that is being heads rather than combos. It's harder to toss a big combo amp around.

[Mike K]

I was going to mention the one advantage I know mounting your heads this way has to do with manufacture. Generally it's so you can use the same chassis and panel layout and not have to reverse the wiring layout. I can't think of any real advantage other than that and most "good" designs will swap the layout and chassis orientation between head and combo.

[Delta362]

I would think it's much easier to flip the nameplate (having a 2nd nameplate, that is, not upside down text for reading) on the amp instead of flipping layout and orientations of components.

[Mike K]

I would think it's much easier to flip the nameplate (having a 2nd nameplate, that is, not upside down text for reading) on the amp instead of flipping layout and orientations of components.

You can do that, but then your controls are opposite. For some people (I'm serious here), that's like the *end of the world*