tonally, do matched tubes make any difference?

[bunuel]

I was recently jamming w/ one of the most seasoned & toneful players I know. When we got to talking amp-tone-shop afterwards, he acknowledged the importance of good power tubes in the mix, but TOTALLY dismissed the notion that whether power tubes matched or not could be important. I found it hard to argue against his empirical arguments (tho he'd a never termed them so): 1) most of the best, most coveted amps were produced & sold before anyone thought of tube matching & 2) they weren't coveted because of happenstance tube matches; 3) many of the most famous recordings of great tube amp tones were undoubtedly made with amps that were NOT using matched power tubes, because they were made before anyone ever thought about matching power tubes. I found it hard to argue with. But, afterwards, we went farther & did several double blind experiments with several musician friends with several amps, including those using 6L6, 6BQ5 & 6V6 pairs. None of the matched pairs rated particularly highly in our listening tests, unmatched pairs rated slightly higher, though not in particularly significant way. But all these leaves me to wonder: is the ol' guy right?

 

[rockon1]

Back "in the day" tolerances between tubes were much tighter than tubes manufactured today. The need for matching wasnt as great or important IMO. These days tubes can vary greatly. I have a bunch of GE6L6's unmatched for instance. They all draw very close to one another-close enough to call them matched. Ive got a bunch of Sovtek 6L6's that are all over the place!

Close matching doesnt equal better tone from all Ive read. In fact it may mean less of what us guitarists like-harmonics and distortion. It will ensure that no hum is introduced from unbalanced power section but even then from what Ive seen power tubes need to be pretty unmatched to introduce hum.

With todays wildly varying tubes Im more inclined to say these tubes need to be matched. They are just to unpredictable and I personally feel better knowing they are in the same ballpark current draw wise. From he relatively small sampling of used old stock tubes I have I feel theres less of a need with tubes made "back in the day" Bob

 

[ontariomaximus]

It depends on the circuit. In a fixed-bias AB amp, it's not good having one tube draw 20ma and the other 55ma. But differing gain characteristics is actually good sounding IMO.

However, I designed a PP amp that uses a 6V6 and an EL84. It's maintains DC balance across the primary of the OT, and it sounds superb.

Here is clip:
http://www.youtube.com/watch?v=BguBjk55xpc

 

[Tone_Terrific]

For maximum fidelity and minimum distortion close matching makes sense.
For guitar tone...what is guitar tone, anyway?

 

[GearHeadFred]

For maximum fidelity and minimum distortion close matching makes sense.
For guitar tone...what is guitar tone, anyway?

+1.. Audiophile rules don't always apply to guitar amps. There is a good argument to be made that asymmetrical waveforms can add "richness" to the way a note sounds, or to whatever we call "guitar tone" !!

 

[phsyconoodler]

I used to have an old Peavey Ultra 60 watt combo.It sounded great.One day I was looking in the back of the amp and one tube was way brighter than the other,so I tested them.The dull tube was alomost dead,so I put in new ones.A matched set of Svetlana's.The amp did not even come close in tone to the totally mis-matched set of cheapo Sovteks.
I think it can be a science to get a balance of 'mis-matched' tubes.

 

[pgissi]

I used to have an old Peavey Ultra 60 watt combo.It sounded great.One day I was looking in the back of the amp and one tube was way brighter than the other,so I tested them.The dull tube was alomost dead,so I put in new ones.A matched set of Svetlana's.The amp did not even come close in tone to the totally mis-matched set of cheapo Sovteks.
I think it can be a science to get a balance of 'mis-matched' tubes.

Had the same exact experience with an old 70's Peavey Classic, the ss preamp and tube power section variety with the built in phaser. The amp was given to me so I took it home and it sat for weeks until one day I fired it up and was blown away by the tone by this amp.

Some time later, I decided to look the amp over and found one power tube almost dead also, a fainter glow from one tube.

Decided not to "repair" the amp but am planning on opening it up to make note of the operating conditions and leaving it alone since fixing it means that tone will go away.

From an operational perspective matching is ideal but tonally, not so much

 

[Tone_Terrific]

Some time later, I decided to look the amp over and found one power tube almost dead also, a fainter glow from one tube.

Hard to say exacltly what you were seeing, but assessing a tube as dead from appearance is a bit of a stretch.

 

[andrekp]

So let's say you match the tubes exactly.

Are the plate loads exactly matched? The cathode circuit? The windings of the OT? No on all three - so where does that get you?

Close is good enough and a little mismatch will sound better. When the vintage amps and NOS tubes were new, nobody cared about matching (yes, tolerances were closer, but they weren't exactly matched).

 

[pgissi]

Hard to say exacltly what you were seeing, but assessing a tube as dead from appearance is a bit of a stretch.

true but I failed to mention, the amp is not as loud as it should be, (in fact you could turn it to 10 and your granny would laugh at you, maybe putting out 10 or 15 watts). I dont suspect its (the tube) dead and since I said "almost dead" I am suggesting something component wise is out of spec and that tube is technically off, or maybe not "pulling" its own weight to insert a pun and thus, asymetrical output, albeit reduced at that.

Its along the lines of this possibly, read the reader question at the bottom of page 203. I will pull the tube and see what happens-

http://books.google.com/books?id=fv...X&oi=book_result&resnum=1&ct=result#PPA203,M1

 

[PatrickE_FenderADV]

I did an update today... removed a set of power tubes with a dead GT and replaced with a matched set of Sovtek 5881/6L6WGC tubes. I noticed a BIG change it tone, power and even compression. These are the tubes the Soldano uses, so maybe that has some influence on my Fender tone. I'm not very technical, but it's very noticeable.