Fender Hot Rod Deville

[bsco]

Look at the schematic, the B+ supply. The higher voltage of the DeVille has a pair of stacked 350v caps, the Deluxe with lower voltage has a single 500v cap. So to use the same board, for the single C31, there needxs to be a jumper wher C32 would have been to complete the ground connection. Same thing happens on the othe side of the choke. The 220k equalizing resistors serve no purpose in the Deluxe, so they are left out.

Now look closely at the bias supply and related circuits. The volatges are different as ar how they are derived, so jumpers are removed or installed as apporpriate. Also note value of the resistors are different between the two bias circuits.



I leave it to you to explore the audio circuits. The differences are noted in the drawing, also read carefully teh notes at the bottom,. it addresses the differences in a number of them.

Thanks for your reply Enzo....I am trying to get time to get to this one...My wife slipped on the ice a couple of weeks ago...and broke her wrist.....so she has a cast on and can't do very much at all for the time being.......so I have to pretty much do everything... .....I will check out the differences in the two schematics...I was thinking of maybe just changing the output tube board as that would appear to be easier and faster......

[bsco]

OK. Back at this Amp again.....I changed over the tube board and left the main board intact.......There is one thing...There are two short coax cables in the deluxe at the first pre-amp tube which are not in the deville.....So I removed the coax from the new output board and then installed it....The amp appears to be fine but there is a low level hum which will disappear when I remove the 1st pre-amp tube.....I swapped it for another one but same thing.....I am thinking that the first preamp tube board is picking up hum for some reason...probably due to the fact that the short coax cables are removed....there is no factory connections for these cables on the main board....Any suggestions??
Cheers

[bsco]

Ok. Just getting over Christmas.... I was looking at this again very briefly, and discovered that the coax wires actually connect to the vacuum tube socket pins.....didn't really size up where.......I am going to remove that 1st pre-amp tube board and install the original as it is belonged to the original main board....the new one is definately different and I will take a look at the differences after...
Cheers

EDIT.....the coax connects to the grids of the tube......that is why there is no sound with hum.........I knew it had to be something foolish.....anyway, I will let you guys know how I make out.......
EDIT #2.......that was it....problem solved.....Amp sounds great....will run it for awhile to flush out anything else but I don't think there will be any more issues.......and I learned something new......and gained just a wee bit more experience......