It is currently Mon Mar 16, 2020 10:37 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 7 posts ] 
Author Message
Post subject: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 12:35 pm
Offline
Hobbyist
Hobbyist

Joined: Sun Jan 26, 2014 12:12 pm
Posts: 9
Hi all.

I'm new to the forum. I came here looking for advice as I have fairly recently acquired a '93 Blues Deville 212, and as this is my first valve amp I am a little unsure as to how it should behave.

I love the amp and have been playing it since November, but I have recently read some articles about biasing valve amps and it has got me thinking.

The amp seems to get very hot when playing, I once touched the power valves after playing quite loud for an hour and well, lets just say I won't try that again. But it's not just the valves, the faceplate with all the volume and EQ knobs on etc. gets fairly warm too...is this normal?

I'm just a bit worried that if the heat is coming from the valves and is getting all the way through to the faceplate, will the PCB or any other components be likely to burn out?

I once left the amp on standby for about 8 hours, and when I get back the amp was very hot, and there was a smell, which wasn't exactly a burning smell but kind of like the smell of hot old dust, which I thought was normal as the amp is over 20 yerars old.

So after reading recently that valve amps need biasing and that a lack of proper biasing can cause overheating and possible damage to the amp, I am here to ask if anyone can give me any advice on the matter. Should the valves get so hot that touching for even a fraction of a second feels as hot as an electric cooking stove?

Should the faceplate be getting warm when I play for an hour or longer or play loud?

ANy advice would be appreaciated.

-lodgi


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 12:42 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
lodgi, welcome to the Forum! :D

You can't tell the state of bias of the output valves, from tactile temperature. You need to take the amp to a tech and have him measure the idle bias values.

Try not to leave the amp on (standby on or not)... unattended or more than a few minutes. Certainly, not for hours.


Top
Profile
Post subject: Re: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 12:48 pm
Offline
Hobbyist
Hobbyist

Joined: Sun Jan 26, 2014 12:12 pm
Posts: 9
Hi BMW, thanks for the quick reply. While I appreciate your advice, I'm not really asking about the bias, just whether it's normal for that amount of heat to be produced? Until I learnt about bias, I thought that amount of heat was normal, now I'm thinking it might not be?


Top
Profile
Post subject: Re: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 3:02 pm
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
lodgi wrote:
Hi BMW, thanks for the quick reply. While I appreciate your advice, I'm not really asking about the bias, just whether it's normal for that amount of heat to be produced? Until I learnt about bias, I thought that amount of heat was normal, now I'm thinking it might not be?


The amp could be overheating because the power tube bias is not set properly (the bias on 1993 Blues Devilles is not adjustable), so do as BMW suggested and take it to a tech.

_________________
Bill

Image


Top
Profile
Post subject: Re: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 3:27 pm
Offline
Hobbyist
Hobbyist

Joined: Sun Jan 26, 2014 12:12 pm
Posts: 9
Is the amp overheating though? I'm not sure how hot it should be.


Top
Profile
Post subject: Re: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 3:44 pm
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
Maybe, maybe not. Are the plates of the power tubes turning red? If you are worried about it, take it to a tech and have it checked out.

_________________
Bill

Image


Top
Profile
Post subject: Re: My first tube amp, I need some advice
Posted: Sun Jan 26, 2014 4:02 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hi lodgi,

Welcome to the forum!

Very good advice given here, heed it. I would add that tube amps do produce a fair amount of heat, it is normal, and if you touch output tubes once they have reached normal operating temperature you can burn your fingers. The faceplate can get very warm, the power transformer can get very hot, and the smell is likely from the cab and/or the cab covering getting warm, or as you've stated from dust on the components getting hot.

No way to know if things are normal without checking. The bias setting is very important, not only for good operating temperature, but for good sound and good tube life also. Since you recently acquired the amp, you can't be sure that the bias is set properly, or if the output tubes have been changed and the bias set for those tubes.

DIY if you prefer. You can probably find all of the info that you will need, including bias instructions, suggestions for bias probes, suggestions for tube types, instructions for adding a bias adjustment, and much more, right here on this forum, just use the search feature and be prepared for lots of reading (take notes :wink: ).

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 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: