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Tone gone deeper

PostPosted: Mon Mar 23, 2009 5:10 pm
by maxx england
I have a question. I have a Japanese reissue Strat and an old 70s Phoenix head, 1/2 valve, 1/2 solid state. Over the past few months, the tone of the pair when played together has become very deep with an almost exaggerated bass response . Is it the amp starting to stretch it's legs after some years of inactivity, is it the pickups losing the top end, or is it Captain Trouble flexing his muscles?

Re: Tone gone deeper

PostPosted: Mon Mar 23, 2009 8:34 pm
by texas blues
If the tone is progessively getting muddier, I would check the tubes.

Cheers, TB.

Re: Tone gone deeper

PostPosted: Mon Mar 23, 2009 9:49 pm
by maxx england
OK, what do I look for? Fit in their mounting holes? Discolouration? I be curious to know.

Re: Tone gone deeper

PostPosted: Tue Mar 24, 2009 12:44 am
by texas blues
How old are the tubes 5 years? 10? If they are 12AX7 or known in the UK as ECC83 just change them out with new. They're cheap. Lots of good brands. Determine which tubes you have by the numbers and or labels on them.

Here's some links that you might find helpful.

http://trdpartsonline.com/index.php?mai ... cPath=5_73

http://www.tubedepot.com/

I have JJ's in my Marshall in the preamp, Ruby EL34's for the power.
In my Fender type clones I have JAN Philips, Sovtek, Tesla, and Electro Harmonix. All good tubes. I should add that while in the past I have been against the use of Groove Tubes, I am told buy one of the best amp techs in the business they have a pretty solid lineup and overall good quality. He sold me on them and I just might try them.

I won't tell you straight out that the problem is with the tubes completely but usually, and I stress..USUALLY, that is the case. Should you swap them out and that is not the case, take it to a good amp guy or do one better and tech it to him now before buying tubes if you are a little strapped for cash.

Got any pics of that amp?

Cheers, TB.

Re: Tone gone deeper

PostPosted: Tue Mar 24, 2009 3:28 pm
by maxx england
Good question. No, but I'll see what I can do with the phone camera (knock them all you like, but you've always got a camera with you). I'll have to see if I can get back into my Photobucket account and post it there.

Re: Tone gone deeper

PostPosted: Tue Mar 24, 2009 4:08 pm
by goldbrick
From my dad, a former TV repairman( back when TV's had tubes)

Tap lightly on each tube -if it sounds hollow its time to change it.

Re: Tone gone deeper

PostPosted: Tue Mar 24, 2009 4:14 pm
by maxx england
Ah! Technical! OK, tomorrow I get to dig it out again. Unt zen ve schall k-know zer truce :twisted:

Re: Tone gone deeper

PostPosted: Tue Mar 24, 2009 4:18 pm
by zhyla
Pickups don't change much over time provided you don't bang on them or heat them up (things that can demagnetize them). Since there is probably only a couple tubes in your preamp I would just replace those. The chassis should be marked as to what they are. Just order replacements from tubedepot.com etc. If they don't make a difference, we'll you've got some spare tubes for when they do go bad.

You could get a change in bass response from some of the amp components drifting in value I imagine... I dunno, let's hope it's just a bad tube.

Re: Tone gone deeper

PostPosted: Tue Mar 24, 2009 5:44 pm
by songdog
It's probably the tubes however the fact that you have detected a sonic difference in a relatively short period of time could indicate the problem is elsewhere.

The little triode tubes generally degrade so slowly over time that your ears don't pick up on the change. Then one day you think that maybe it's time for some new tubes, so you plop a set of new ones in the amp and are immediately blown away by how good it now sounds.

Re: Tone gone deeper

PostPosted: Wed Mar 25, 2009 4:34 am
by ricochet
There's a reason tubes are plugged into sockets instead of soldered in place.

Tapping on them will identify microphonic tubes, but not tubes that are losing cathode emission. Replacement with a good tube is the best way to check a tube. You should keep spares around anyway.

Re: Tone gone deeper

PostPosted: Wed Aug 05, 2009 6:06 pm
by maxx england
I was given some "same spec" valves to try, but on opening up the lid today, I thought that these looked too dissimilar to the ones in place, so I put it back together. And for the hell of it, I turned it on, pugged in, and the bite is back. Odd.

But SO MUCH FUN! Snarl, bite, slash, shriek, whine, sustain, ANIMAL!!! :twisted: :twisted: :twisted:

Re: Tone gone deeper

PostPosted: Wed Aug 05, 2009 6:09 pm
by ricochet
What the tube look like means little. The numbers on the side are what's important.

(Yeah, I laugh at all y'all who think there's something special about particular brands and varieties.)

Re: Tone gone deeper

PostPosted: Thu Aug 06, 2009 2:00 pm
by maxx england
I'm going to look at the equivalents in different brands for ECC883, once I'm certain these are OK, I'll try them out. But, oh sweet jeeziz! I love my antique! The clang, the snarl, the maladjusted personality of it! :twisted:

Re: Tone gone deeper

PostPosted: Fri Aug 07, 2009 8:51 am
by maxx england
A thought - the cab was in a room with high humidity, the problem is solved now. Would the speakers (Celestion G12-80) have altered in tone? The house Marshalls aren't quite as muddy sounding just lately, so I wondered?

Re: Tone gone deeper

PostPosted: Fri Aug 07, 2009 6:20 pm
by ricochet
Yes, the cones can absorb moisture, which makes them both heavier and more flexible. They'll dry out in a day or two in dry air.