Shielding a speaker?

[3choplex]

I've been working on an old Gibson Scout lately. The other day I put in a speaker, a 12" Pyle Driver. Everything says the Scout had a 10", but the baffle is cut for a 12", shrug.

With the speaker in, the reverb is humming like crazy. I've moved the tank around, the only place I lose the noise is a couple of feet from the speaker. Is it possible to create a shielded bag or something, or am I going to need to get a different speaker with a smaller magnet? Ideas?

[stratele52]

Gibson Scout is a vintage amp . Why don't you keep it as most original you can ? Don't loose your time with 12 inches Pyle speaker ( are they good those speaker ? ) and trying to shield reverb tank.

Put a good 10 inches .

[3choplex]

I got the amp free, not working and with no speaker. The baffle was already cut for a 12", so I put in one. :)

[jjasilli]

I got the amp free, not working and with no speaker + With the speaker in, the reverb is humming like crazy.

As stated, this is not sufficient information to conclude that the speaker is the problem. 

[stratele52]

3choplex , are you sure you reverb tank 's wire have good shield ?

Even with a 10 inches speaker , your reverb tank wiil be too close from the magnet if you need few feet. So it is probably not the speaker's magnet  your problem but a defective ground on the reverb tank or their cables .

Have you check that ?,

With no reverb tank is the amp work well ? If not fix it before go farther.

[tubenit]

I don't think the speaker is "the" problem. Something else is amiss like the wire shield isn't grounded or the tank isn't grounded properly. I think it's some other issue even maybe the reverb tube has gone bad?

With respect, Tubenit

[3choplex]

I did a little test this morning, removing the speaker. You guys are right. It's not the speaker. I'll start checking other stuff. Thanks.

[stratele52]

I did a little test this morning, removing the speaker. You guys are right. It's not the speaker. I'll start checking other stuff. Thanks.

+1
I was shure of that .

[3choplex]

I just realized I didn't give all the information in my original message. The reverb was quiet when plugged into an external cab, then when I installed the speaker in to combo cabinet I got the noise. Apparently unrelated, but that was why i was attributing it to the speaker. It was the only thing that (I was aware) had changed. Just mentioning so I don't appear crazy. 

[stratele52]

The reverb was quiet when plugged into an external cab, then when I installed the speaker in to combo cabinet I got the noise

Reverb cable and reverb tank look to be good so  !!!

IMO , the noise have nothing to do with the reverb .

Can we just say ; the amp is noisy ( with speaker in ) ?

Ok noisy amp ;
1- more volume = more noise ?
Yes;
a) check with guitar plug in , guitare volumes to "0"
   No Noise ; defective or no input shorting jack

   Noise ; check tubes , ground . Some of Gibson amp don't have heater center tap ; this make noise . Make an artificial center tap with 2 X 100 ohms resistors

Do you have the schematic ?

[stratele52]

Gibson scout is a GA17RVT

www.gibson.com/Files/schematics/GA-17RVT%20Amp%20Scout.pdf

Schematic show there are ;

1- No heater center tap ; = noise,  install 2 X 100 ohms

2- There is 2 input shorting jacks ; Check if they work , if go to ground with no guitar , contact often dirty = noise.

3- No three prong AC cord ;= caution electrical hazard and noise;  Install one ,

4- Check for unmatched output tubes = noise