do tubes still glow if they are shot?

cstockdale

cstockdale

supafly killa homey
I have a Fender Hot Rod Deluxe. The last week it was pretty crackly, now today it is gutless, no ooomph, all high end, no low, sounds like it is on the drive channel at low volume all the time. I was thinking I have blown a tube, but this is the first time I have done that.

Do the tubes still glow if they are shot?

How can you figure out which one is shot?

Do you need to change them all (power amp and preamp tubes)?
 
Hey man.. take your amp to the shop and tell em to re-tube and bias it. (Full service or whatever they call it)


Under normal playing conditions ya gotta have that done every 6 months otherwise your sound will suffer.. and ultimately end up at the point you are. Sure tubes will glow if they are screwed but you gotta get that service done before you accidentally do some real damage to that amp.



Good luck
 
Thanks man. I have been a guitar player for 12 years: acoustic only for 9, electric now for 3, but tube amps are something I ahve only owned for 6 months or so, so I am new to this stuff.
 
I concur on the rebias. Not because it will need it, but because I prefer mine biased a little bit "dirtier". Also, changing brand or era of tubes generally requires a rebias. If you are doing a straight replacement of power tubes, a rebias isn't always needed.
More than likely it is just power tubes. You can burn through a set of power tubes in six months or so playing 15-20 hours a week at high volumes, especially the (generally) junky stock Fender tubes. Preamp tubes can last for years. Try a few different ones, you should be able to find something you really like.
I have a few different sets of tubes sitting around just to check my amps against known good tubes. Don't just replace tubes every six months. It's a waste of money and tubes if the amp doesn't need it.
 
It could also be a warranty issue. Cobradenim of this forum has an HR Deville which has needed to go in several times and have stuff re-soldered to the board, which has fixed a similar-sounding problem.

Yes, tube filaments often work even when the tube is shot. I had an EH 6CA7 die on me recently and it would light up, but it would also hum even on standby.
 
The first time I had tube trouble in my DeVille, it blew one power tube and I had 1/4 the amount of power. I replaced them with "Fender" tubes. For those of you who don't know, Fender does not make tubes. Fender takes Sovtek tubes and puts their logo on them. Don't waste your money! Buy JJ tubes. WWW.eurotubes.com. After I purchased the Sovtek tubes, it still didn't sound all that great so that's when I went to Eurotubes and replaced ALL of the tubes with JJs. BIG difference! Because that first sovtek tube blew, I had some grid resister trouble which kept burning tubes. It was fixed under warranty and my tube troubles were over. I've had some "crackling" issues but it was also repaired under warranty a while back and was not tube related. Regarding the bad Sovtek tube, I think that is when my grid resister problems started. I think it burned out that first tube. At the time I thought it was just a bad tube, but after I went to the JJs, the problem continued. The JJs are virtually bullet proof and even though the tube was burned pretty bad, held up reasonably well with just some lost tone. The problem has since been fixed and my JJ tubes last a year with out loosing any power or tone.
The problem Chill is referring to is that at high volumes, the volume will fluctuate and switch in between the overdrive 1 and 2 stages. It has been repaired under warranty 3 times now and the problem was, each time, bad soldering joints. I've discovered that using an external speaker cabinet at high volumes eliminates that problem, which is bullshit! When you pay $700 for an amp with speakers, you should be able to use them!
All in all, The Fender Devilles are problematic at high volumes, which is a shame because they sound pretty good...I'm gonna have to buy a Chilltone!!
 
I did some troubeshooting last night:

guitar-HRD-preamp out-second amplifier power amp in: sounds great
guitar-other amplifier-preamp out-HRD Power amp in: toast

99.9% sure that the problem is in my poweramp of the HRD, just hope that a tube change will do the trick.

It has the GrooveTubes G6L6B tubes, which are relabelled Sovtek 5881 WXT tubes. Trouble is here in Victoria, BC where I live, there isnt much choice for replacement tubes.
 
It could be your PI tube, but my first guess would be the power tubes.

IMO JJ's 6L6's and 12ax7's are the best out there, but I also have not tried all of them. I'd stay away from the Sovtek 5881 and 12ax7wa and 12ax7wb in particular, their other tubes may be better. Somebody's got to ship to BC, whether it's eurotubes, newsensor, tubesandmore, lord valve, or triode electronics...if they don't they may know someone who does, and may also have other suggestions for retubing the HR's.
 
Ughh, Sovtek 5881's!
Still living with, and regretting that purchase.

Is there a tube that is particularly good for getting extreme amounts of distortion, but not sounding thin or harsh?

Sovteks are partucularly great, if you like thin and harsh, and also want to use a pedal to get any decent amount of distortion.....
 
well, I was 99.9% sure, but I nailed the 0.1%. Not the tubes. Changed them, no change. Somewhere between my preamp and poweramp is a problem. Time to go to a tech!
 
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