The Steel Guitar Forum Store 

Post new topic Tube amp blowing fuses
Reply to topic
Author Topic:  Tube amp blowing fuses
David Cook

 

From:
Florida, USA
Post  Posted 25 May 2017 10:28 am    
Reply with quote

Help, My 20 watt Jet 20 Ampeg tube amp keeps blowing fuses.. Any suggestions?

Thanks
View user's profile Send private message Send e-mail

Jack Stoner


From:
Kansas City, MO
Post  Posted 25 May 2017 11:08 am    
Reply with quote

Hard to tell from your description. Could be a tube (if it is most likely the power tube(s). Could be power supply, filter caps, rectifier. Just too many possibilities. Best option is take it to an amp repair tech.
_________________
GFI Ultra Keyless S-10 with pad (Black of course) TB202 amp, Hilton VP, Steelers Choice sidekick seat, SIT Strings
Cakewalk by Bandlab and Studio One V4.6 pro DAWs, MOTU Ultralite MK5 recording interface unit
View user's profile Send private message Send e-mail

David Cook

 

From:
Florida, USA
Post  Posted 25 May 2017 11:38 am    
Reply with quote

Thanks Jack,

The light stays on until I turn on the standby
View user's profile Send private message Send e-mail

Ken Fox


From:
Nashville GA USA
Post  Posted 25 May 2017 12:38 pm    
Reply with quote

Pull the power tubes and try it again. Looks like it has 2 each 6V6 power tubes.
View user's profile Send private message

Dave Meis


From:
Olympic Peninsula, Washington, USA
Post  Posted 25 May 2017 11:00 pm    
Reply with quote

Had that happen just a few weeks ago on my Fender Bandmaster. Shorted out power tube. Swapped 'em out, good to go. Good luck.
View user's profile Send private message Send e-mail

Ken Fox


From:
Nashville GA USA
Post  Posted 26 May 2017 4:34 am    
Reply with quote

A lot of times a shorted power tube can take out the screen grid resistor at the power tube socket, 470 ohms in the case of Fender amps. When that happens that tube will not pass audio until the resistor is replaced. Just a passing thought!
View user's profile Send private message

Jay Ganz


From:
Out Behind The Barn
Post  Posted 26 May 2017 5:22 am    
Reply with quote

Also...if the capacitor on the input grid of a 6V6 tube starts leaking, it throws off the bias voltage
and the tube will start to glow red inside from excess current draw...then the fuse pops.
Got that? Rolling Eyes
View user's profile Send private message Send e-mail Visit poster's website

Ken Fox


From:
Nashville GA USA
Post  Posted 26 May 2017 5:26 am    
Reply with quote

So true, Jay. Seen that and forgot to mention it.
View user's profile Send private message

Jay Ganz


From:
Out Behind The Barn
Post  Posted 26 May 2017 5:34 am    
Reply with quote

Guess it depends on whether it blows the fuse instantly or it takes a minute or so.
That will point out if it's just a short in the power supply itself.
View user's profile Send private message Send e-mail Visit poster's website

Jack Stoner


From:
Kansas City, MO
Post  Posted 26 May 2017 7:14 am    
Reply with quote

I don't remember on a 6V6 but on the Fender's with 6L6's the 470 ohm Screen Grid resistors will go and can also cause fuses to pop.
_________________
GFI Ultra Keyless S-10 with pad (Black of course) TB202 amp, Hilton VP, Steelers Choice sidekick seat, SIT Strings
Cakewalk by Bandlab and Studio One V4.6 pro DAWs, MOTU Ultralite MK5 recording interface unit
View user's profile Send private message Send e-mail

Bill Hatcher

 

From:
Atlanta Ga. USA
Post  Posted 26 May 2017 12:25 pm    
Reply with quote

blows fuse and then blows more fuses.....you have a problem.

old amp?....filter caps. power tubes and the rectifier tube. swap the tubes and see if it blows. if not...problem solved. if so...filter caps. they need changing anyway....
View user's profile Send private message Send e-mail

David Cook

 

From:
Florida, USA
Post  Posted 2 Jun 2017 6:33 pm    
Reply with quote

Thanks everyone for the replies. I took it to a tech and he said it was the rectifier tube. This is a 2 year old amp
View user's profile Send private message Send e-mail

James Phillips

 

From:
Michigan, USA
Post  Posted 3 Jun 2017 5:31 am    
Reply with quote

David Cook wrote:
Thanks everyone for the replies. I took it to a tech and he said it was the rectifier tube. This is a 2 year old amp

You could buy one of these from Weber ,, https://www.tedweber.com/wz34
They are nice to have around for trouble shooting ,or to replace that tube all together.
Good thing to have in your gig bag,too.
_________________
Visit my Studio: LimeStoneLabs at.. http://Facebook.com/LSlabs

"Let the Bridges We Burn Light the Way"
View user's profile Send private message Send e-mail Visit poster's website

Jim Sliff


From:
Lawndale California, USA
Post  Posted 4 Jun 2017 7:50 pm    
Reply with quote

Got to the thread late - the tech was undoubtedly right. That's the most common reason.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional
View user's profile Send private message Send e-mail

David Cook

 

From:
Florida, USA
Post  Posted 11 Jun 2017 5:57 pm    
Reply with quote

Will I have to readjust the bias if I install the Copper cap to replace the rectifier tube?
View user's profile Send private message Send e-mail


All times are GMT - 8 Hours
Jump to:  

Our Online Catalog
Strings, CDs, instruction,
steel guitars & accessories

www.SteelGuitarShopper.com

Please review our Forum Rules and Policies

Steel Guitar Forum LLC
PO Box 237
Mount Horeb, WI 53572 USA


Click Here to Send a Donation

Email admin@steelguitarforum.com for technical support.


BIAB Styles
Ray Price Shuffles for
Band-in-a-Box

by Jim Baron
HTTP