How do you know when to change tubes for 2nd hand amp?

spuds

New member
How would you guage when you'd need to change your tubes if you picked up an amp 2nd hand... since you don't really know how it sounded originally?

And what would be a good choice of tubes that would give a fender amp a sound as close to its original character as possible?
 
Re: How do you know when to change tubes for 2nd hand amp?

That's a good Question.:) Best answer is if it sounds fine leave em'. You can check you Pre-amp tubes by gently tapping them with a pencil eraser head to see if they have gone microphonic? Power tubes in general will sound a bit raggy on the low end when they have seen better day's. If money is not a issue? It's not a bad idea to re tube anyway. What Fender amp is this?
 
Re: How do you know when to change tubes for 2nd hand amp?

Since you can buy tubes cheaper nowadays than almost ever before, it's not a bad idea to completely retube it, and check the bias (if you know how or have a tech that works cheap).
At least you'll be starting fresh with an amp that likely sounds better than it did new. Then, keep the original tubes as spares.

If the prior owner tells you they're fairly new, leave it alone. If he has no clue, they're probably too old.
 
Re: How do you know when to change tubes for 2nd hand amp?

Its a super six reverb (SF)... thats been converted into a "head". The previous owner chopped off the top and chucked out the rest.

When I bought it, they said it had new tubes... but i have my doubts... coz they all look a bit old and they're all mis matched... like different brands, markings etc...

I can't complain though. It does sound fastastic... I just wonder if it could sound MORE fantastic?

Haha... never happy are we?
 
Re: How do you know when to change tubes for 2nd hand amp?

Bring it to a competent tech and have him do a proper overhaul. Don't go cheap do it right. It will be worth it.

By the way it's just a Twin reverb with 6-10" speakers. So now it's a twin reverb without any speakers. They sound great with a good 4-12 cab.
 
Re: How do you know when to change tubes for 2nd hand amp?

BigDaddy said:
Bring it to a competent tech and have him do a proper overhaul. Don't go cheap do it right. It will be worth it.

By the way it's just a Twin reverb with 6-10" speakers. So now it's a twin reverb without any speakers. They sound great with a good 4-12 cab.

Yeah I know... so now its a twin reverb head. Haha.
I first used a 4x12 with it... but I just got pissed off carrying it around. So now I use a 2x12... Works well for me.
 
Re: How do you know when to change tubes for 2nd hand amp?

BigDaddy said:
Bring it to a competent tech and have him do a proper overhaul. Don't go cheap do it right. It will be worth it.

Agreed. The first thing I do with a used amp is rip out the tubes and get everything re-biased. Plus it helps if the tech does a general checkup and cleans the pots, etc ....
 
Re: How do you know when to change tubes for 2nd hand amp?

When I got my tube amp 2nd hand, I took it to a tech right away to have him overhaul it completely. He told me all the pre-amp tubes were still fine so I left them alone and changed out the power tubes.
The amp always sounded great but after I read so much about tubes on this forum I decided to experiment a little with pre-tubes. Holy crap! That tech can say all he wants but the difference is big!

Fresh tubes always sound better IMHO.
 
Re: How do you know when to change tubes for 2nd hand amp?

Cool, thanks guys. I'll do just that then.
 
Re: How do you know when to change tubes for 2nd hand amp?

spuds said:
Cool, thanks guys. I'll do just that then.
Good :D One more thing I forgot to add. As a rule of thumb. Anytime you buy a used/2nd hand amp... CHECK THE FUSE!! and keep spares on hand. If you find the wrong value fuse in there? This could mean there is a problem or the previous owner was a moron.
 
Re: How do you know when to change tubes for 2nd hand amp?

I'd also suggest buying all the tubes from a tube distributor, then pay about $25 to have it biased. If you take the amp in, they'll charge you more for the tubes, then add the bias fee.

I always suggest www.revolutionguitar.com since the owner is a friend of mine, and also one of the biggest distributors on Ebay. He has a lot of brands, and is cheaper than almost everyone.
 
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