18Watt.com

Yes, that's a very good point Geoff! And we also shouldn't forget that the PI might not be perfectly balanced either. Needless to say,I prefer some imbalance in a PI, like the Marshall 18W has

On the flip side of that, the definition of matched tubes is loose. Some people consider 5% variance matched, while others consider as much as 20% (sometimes more??) as matched.

Then there's the fact that most matched tubes aren't actually matched. Matching transconductance (a common method of matching) isn't nearly as accurate as matching with a curve tracer, and probably nobody selling tubes uses a curve tracer.

I do usually get matched tubes, but the matching I bother with is free (and as I mentioned above, usually meaningless). So whether matched or not, they're probably not. Or maybe they are. Who knows (just kidding, I know, I have a curve tracer).

If you take two random tubes that weren't matched to begin with, and install them in an amp, they might be matched. You'd have to test them to know.

Now what I think is a waste of money is overpriced NOS tubes. If you don't have a really good tube tester, or a curve tracer, then chances are you're getting ripped off (and even if the tubes are good, do they reeeeeeeally sound better?). This isn't an issue of simply matching as much as it is in tube performance, and life expectancy. People love paying for mojo though.

The only way we could really test this theory of matched vs. not matched is to curve trace tubes, and make sure at least 2 are well matched, and a 3rd is not matched within at least 20 or 30%. Then we could swap one of the tubes and do a real A/B comparison.

JMPGuitars wrote: ↑

Wed 03/18/20 5:52 pm

I do usually get matched tubes, but the matching I bother with is free (and as I mentioned above, usually meaningless).

But if it's not the meaningless kind, it will probably degrade the tone of your amp, as I found out for myself. That was a real waste of the extra $$ I paid.

JMPGuitars wrote: ↑

Wed 03/18/20 5:52 pm

If you take two random tubes that weren't matched to begin with, and install them in an amp, they might be matched. You'd have to test them to know.

If they're matched, they will usually give a bit less hum than a non-matched pair. I've actually done that - ie found a pair of approximately matched tubes in a bulk lot by choosing pairs that gave least hum in an amp

JMPGuitars wrote: ↑

Wed 03/18/20 5:52 pm

Now what I think is a waste of money is overpriced NOS tubes. If you don't have a really good tube tester, or a curve tracer, then chances are you're getting ripped off (and even if the tubes are good, do they reeeeeeeally sound better?).

If they're genuine Mullards, they probably will sound better, but not just because they're old. Mullard's quality control was simply phenomenal.

zaphod_phil wrote: ↑

Wed 03/18/20 6:44 pm

But if it's not the meaningless kind, it will probably degrade the tone of your amp, as I found out for myself. That was a real waste of the extra $$ I paid.

I'd like to test this scientifically(ish). Maybe I'll put some effort into it at some point.

zaphod_phil wrote: ↑

Wed 03/18/20 6:44 pm

If they're genuine Mullards, they probably will sound better, but not just because they're old. Mullard's quality control was simply phenomenal.

Sure, Mullard was a great brand, and I like the new production stuff too. But the question is, does the NOS Mullard sound like it's worth $200 instead of under $20 per tube? Is it really 10 times better?? I doubt it. I know it certainly isn't worth it to me. Now if somebody gave me a NOS set as a gift, I guess I wouldn't be upset.