It is currently Tue Mar 17, 2020 1:24 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 4 posts ] 
Author Message
Post subject: Blues JR Chocolate Tweed 2012 Distortion Issue
Posted: Thu Nov 08, 2012 4:22 pm
Offline
Hobbyist
Hobbyist

Joined: Sun Sep 02, 2012 2:21 am
Posts: 8
Hi All,

Well I finally got myself a Blues Jr III Chocolate Tweed over here in the UK and absolutely love the look.

All was fine with home jangling at low volumes, getting lovely clean tones, turning the gain (names volume on the JR for some reason) up for some break up.

However I recently took it to a practise room and cranked the master up past 6 for some band practice and for the first 10mins or so all is dandy then the amp just seems to break up into a distorted mess even when the gain is down to 2 or so. Even if I then turn the master down, it remains the same. Round the back, my right EL84 (power tube??) is glowing bright as a 60watt light bulb whilst the baby preamp tubes and the other EL84 remains illuminated only slightly. I thought there must be a heat issue and powered the amp down, waited a few minutes and stuck a fan at the back to try and keep things cool which somewhat works but its not exactly a total fix.

Im a total tube amp/electronics newbie/phobe and I have read some forum posts on here which somewhat describe my problem but they have odd hums and rattles even when no instrument is plugged in which I don't. I have read something about biasing which I have no clue about and dont want to confuse myself reading about if its not that issue (a bit like you should never google health problems).

Any ideas?

Cheers in advance


EDIT: when playing low home volume, i do not get this issue.


Last edited by Flea24 on Thu Nov 08, 2012 5:02 pm, edited 1 time in total.

Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Blues JR Chocolate Tweed 2012 Distortion Issue
Posted: Thu Nov 08, 2012 4:42 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
" Round the back, my right EL84 (power tube??) is glowing bright as a 60watt light bulb whilst the baby preamp tubes and the other EL84 remains illuminated only slightly. "

The right EL84 is in thermal runaway. Prolly a shorted tube. If you are under warranty ask for another matched pair of EL84. Maybe a good idea to have the idle bias checked on those new EL84, before operating.

Good luck!


Top
Profile
Post subject: Re: Blues JR Chocolate Tweed 2012 Distortion Issue
Posted: Thu Nov 08, 2012 4:44 pm
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
Flea24 wrote:
Any ideas?


Yes. Return the amp to the place of purchase immediately. It could be something as simple as a bad tube or something as serious as a fault in the power amp circuit. Given your lack of knowledge, it would be better to let the dealer take care of things. Tubes are covered under the warranty for 90 days, but they will probably just give you a new amp. Whatever they do, make sure you try the amp out before leaving the shop.

_________________
Bill

Image


Top
Profile
Post subject: Re: Blues JR Chocolate Tweed 2012 Distortion Issue
Posted: Thu Nov 08, 2012 5:13 pm
Offline
Hobbyist
Hobbyist

Joined: Sun Sep 02, 2012 2:21 am
Posts: 8
Cheers for such prompt replies guys.

Got in touch with my retailer (as its night time here in the UK i guess ill have to wait until tomorrow for a reply).

Just really wanted to check on here in case it was something really obvious and dead easy to just sort like a loose plug.


Many thanks


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: