Scott 210-E tube locations?

[sloober]

Have an old Scott 210-e I am going to test. Some tubes are missing, and none are marked on the chassis. Anyone have any idea how to find the location for the tubes?

Thanks, John

[EWBrown]

There is some info on the 210-E here:

http://hhscott.com/integrated_amps_mono.htm

It has 4 12AX7, 2 12AU7, 1 6AL5, 2 EL34 / 6CA7, and 1 5U4GB, for a total of ten tubes. 27 watts out (mono)

The site doesn't have a schematic for a 210-E but they do have one for its predecessor, the 210-D:

http://hhscott.com/pdf/fs/210D.jpg

The 1614 is a 6L6GC relative, with a military or industrial number.

/ed B in NH

[sloober]

but each model was pretty different and they don't show tube locations. I will have to locate someone who has one.

Thanks, John

[TomMcNally]

Hi John ...

It should be pretty easy to figure out where the tubes go ...

The EL-34's are self explanatory - they will be next to each other
and octal sockets. The 5U4GB rectifier will be by itself, also octal.
The 6AL5 is the only 7 pin miniature. The 12AX7's will be
likely be connected to the input jacks, and move forward
from there. The only mystery is where is where the
12AX7's and 12AU7's go - if you look at the schematic for
the D model and compare under the chassis, you can figure
it out. The 12AX7's and 12AU7's have the same pinout, you
can't hurt anything by experimenting a little !

... tom

[sloober]

I pulled some of the smaller tubes to see what they were, and thought I was dealing with all 12ax7 s . Then I saw 2 were 12au7 and it was too late. Although I think I have a clue. On the underside of the chassis, there are 6 tube sockets. 3 are 9 pin and have mounts for tube covers. 2 are for 9 pin w/o covers. I think the AX7 ones have covers, the AU7s are next to each other and don't have mount's that retain covers. There is one other 9 pin by all the other tubes on the rear of the unit. I think that too is a 12AX7, but not a Telefunken like the rest.

I will give her a go all sorted out, after I look inside and trace a bit.
Thanks all.

John

[sloober]

So I opened the top cover. WOW! I have restored a few amps, but the added circuitry was crazy in here. It looks like 3 guys were doing it at the same time and fighting over who got into a spot first. I will try to post a picture.
I decided to crank it up. It needed a new fuse. Turned it on, began to glow, then after about 15 seconds, pow! The fuse blew.
I need to go back and check things further. Getting to the rectifier is going to be tough!

John

[TomMcNally]

John -

A couple of tips ...

always have speakers or load resistors connected when you power up.

power it up with all tubes except the rectifier removed and see
what kind of high voltage you have (carefully)

there is a good chance the power supply caps are bad

[sloober]

Thanks Tom for the tips.

I decided to test the 5u4GB on another amp. Boom, blew the fuse in 10 seconds. So I am confident that the tube was a big part of the problem. I will test it later with a variac and a speaker attached.
John