How much do different preamp tubes affect tone? (6505 into Mesa OS samples)

GuitarHack

Krank it UP!
Sep 3, 2006
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Firstly, this is not a "Rate my Tone", thanks. :). I don't care about the overall tone, just the differences (if any). After recently reading an article about "How much a PI (Phase Inverter) tube can change tone", I decided to give it a shot. Basically, it was the author's opinion that a JJ ECC83S wasn't the best choice for a PI and that (among a few other tube types) a Sovtek 12AX7LPS was possibly a better choice. I had one lying around so did a quick test. Overall there are 3 samples using different tubes:

Sample 1
V1 (Gain Stage): Shuguang 12AX7
V2 (Gain Stage): Shuguang 12AX7
V5 (Gain Stage): Shuguang 12AX7
V4 (Loop): JJ ECC83S
V3 (PI): JJ ECC83S

Sample 2 (Just changed the PI to Sovtek)
V1 (Gain Stage): Shuguang 12AX7
V2 (Gain Stage): Shuguang 12AX7
V5 (Gain Stage): Shuguang 12AX7
V4 (Loop): JJ ECC83S
V3 (PI): Sovtek 12AX7LPS

Sample 3 (Stock Peavey installed preamp tubes my 6505 came with)
V1 (Gain Stage): JJ ECC83S
V2 (Gain Stage): JJ ECC83S
V5 (Gain Stage): EH 12AX7
V4 (Loop): Sovtek 12AX7LPS
V3 (PI): Sovtek 12AX7LPS

So, the difference in tubes installed between Sample 1 and 2 is Minor. The differences in tubes installed between Sample 1 and 3 are Major.

Sample 1
http://dl.getdropbox.com/u/437070/6505 Shuguang V1 V2 V5, JJ V3 V4.mp3

Sample 2
http://dl.getdropbox.com/u/437070/6505 Shuguang V1 V2 V5, JJ V3 Sovtek V4.mp3

Sample 3
http://dl.getdropbox.com/u/437070/6505 JJ V1 V2, EH V5, Sovtek V3 V4 (original Peavey).mp3

For those that would like all 3 mp3's in a RAR:
http://dl.getdropbox.com/u/437070/6505 Preamp Tube Comparison.rar

So do different Preamp tubes REALLY matter? :err:

Cheers for any feedback. :kickass:

EDIT: The Samples are absolutely RAW to make any differences easier to hear. Load them in your DAW for an easy comparison. If you like, feel free to make a drumbeat for them (110BPM). Any differences will be even less apparent.
 
Different preamp tubes DO matter. When I had my Triple Rectal Fire, I went from regular Mesa preamp tubes to several different flavors of Chinese and Russian tubes. Difference was astounding. V1's always gonna make the biggest different in sound, but I don't care who you are: Changing your phase inverters won't do shit for tone.

In my JMP1, I've tried many, many different sets of tubes. I knew a guy who worked on amps and had shoeboxes and shoeboxes full of preamp tubes. He gave me a bunch of stuff.. GE, Groove Tubes, Electro Harmonix, Mesa, Peavey, Marshall, Tung Sol, even a Mullard (expeeeensive). After testing all that he gave me, I found that a Groove Tubes 12AX7R-2 and a Tung Sol gave me the tone closest to what I wanted. The GT was mine, so I bought the Tung Sol from him. Afterwards, I bought another GT 12AX7R-2 to replace the Tung Sol, and I don't know that I'll ever be able to find another set of tubes to replace them. I went from having two generic Marshall tubes in my preamp and having a very British sounding tone to two GT 12AX7R-2s and having almost a Boss HM2-like tone. The only way I play my amp now is everything cranked to 11. Couldn't have done that before. Hell yeah.

So, in all, try the hell out of some tubes. The Groove Tubes Mullard reissue, GT12AX7-M, are really good. Pretty much identical to the original, and extremely musical.

When it comes down to it, though, it's still a JMP1. It's still a 6505. I think that the audible difference is so tiny that to the listener it doesn't matter at all, but the difference in feel is astounding, and really puts you in tune with your amp.
 
Really strange, since Sample 1 and Sample 3 sound pretty identical to me while Sample 2 seems to have a more noticeable difference (sounds clearer although in a really subtle way)...:err:
Didn't you do a similar test some time ago? If I remember correctly, the difference was, again, really slight...

Thanks for taking the time to do this!
 
I don't know what I hear. :loco: Shuguangs have a more prominant Midrange? Sovtek PI sounds a bit bigger? Sample 3 is darker maybe? Agreed, not worth worrying about so much.

Hades, yes I did a comparison with Shuguang and JJ. I wanted to test the PI idea with this one and since I had the original tubes still I thought I'd throw them in the test.

Here is the article/pdf by the way.

http://www.guitaramplifierblueprinting.com/files/Phaseinverter.pdf
 
Different tubes absolutely sound different. Even those from within the same batch! But a tube is not going to change the circuit, and therefore can only colour the sound. I use a pentalabs in the pi replacing a sovtek lps and I find it hits the power amp a bit sweeter.