#1
Hi All

Ok please bare in mind I am a total newbie to amps so I really need some help on sorting out a valve problem.

I noticed the drive channel wasn't as loud as usual and then there was a hum, a burning smell and now it plays quietly but crackly so I am guessing this is a blown valve, would I be right in thinking this?

If so then which valve will it be that I need to buy a replacement for and if its one of the bigger ones should I be able to replace it myself?

Also when buying replacements are there cheap and expensive makes of valves? I am skint so can't afford to pay loads so if anyone can recommend a shop that sells them reasonably priced that would also be awesome.


Many Thanks in advance if you can help guys!
#2
Looking at the amp from the back, the drive channel position should be the tube 2nd from the right. However if you have had the amp a while/it has the stock tubes, I would go ahead and replace the tube set. You need 3 12AX7's (also called ECC83), and 2 6L6 tubes. The 12AX7's are the small ones, the 6L6 are the big ones.

There are more expensive brands/models of new production tubes but their influence on the sound is often minimal and their construction does not last much longer- many of the more expensive tubes are not really worth the price. I would just buy JJ's throughout the amp. I buy from TubeDepot.com. Maybe buy a Tungsol for V1 (the tube closest to the right) if you would like a touch more brightness from the amp. If you want to buy NOS (never used tubes, but made a long time ago, "new old stock") then you will likely notice changes that are more noticeable and they will also last quite a while- but they can be fairly pricey.

One last thing, if you do end up changing the entire tube set- you need to buy your power tubes matched. Further, if you have a Reissue BD (made after 2004) then you will also need to adjust the bias of the output tubes. That is not a really difficult process, but you do have to work around lethal voltages. And if you are as inexperienced as you say you are, I would suggest you have a tech do it for you and teach you how to do it safely in the future.
Last edited by Will Lane at Feb 27, 2017,
#4
Brilliant thanks for the replies but I have just tried the amp again today and the drive channel seems to be working again now, how bizarre? Can anyone hazard a guess at what might be wrong? What could the burning smell have been? I have called a local technician who said he will have a look at it but he was very concerned when I mentioned the burning smell, he said he didn't like the sound of it but he would check it out, I just want to make sure I don't get ripped off.

Thanks again
#5
your power tubes are likely fried. let's hope that they didn't take anything out with them. you could have fried a transformer.

For future reference, if you get smoke, turn the fucker off and don't power it up again.
WTLT 2014 GG&A

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#6
Thanks trashed, I can confirm there was no smoke and like I said it is working fine today, weird huh!
#7
Quote by bootcutboy
Thanks trashed, I can confirm there was no smoke and like I said it is working fine today, weird huh!


not that weird. you are on borrowed time. throw new tubes in.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/