A bit confused about V1 and V2 in my Mesa F-50

[Andree88]

Hi everyone.
I'm a bit confused about V1 and V2 in my Mesa F-50.

I just need more gain in Channel 2 (not contour, I don't like no-mids). I've tryied all (combinations, changes, pickups, external eq..) but channel 2 still has not so much gain as I need and expect from a Mesa (and I don't want to use my pedal Blackstar HT-Dual on it, with the first channel on pedal I get a little more gain as chan 2 in Mesa but the pedal one has more "chunk", more liquid/wet tone I think.)

I basically need 3 sounds:
Clean (channel 1) - perfect
Crunch (channel 2) - need a little more gain/chunk/liquid-wet
Lead (channel 2 + TS9) - almost perfect

I though that V1 was for clean and V2 for crunch, but I saw in the manual that V1 and V2 are "both channel input". And I've red that V2 comes first in signal chain.

Now I have
V1 Mesa 12AX7-A
V2 TAD ECC83WA (the one that was inside my HT-Dual)
V3 Fx loop TAD 7025
V4 PI Genalex ECC83 Gold Pin

So I have a question: I'm near to buy a Shuguang 12AX7B (very cheap, but the seller told me that it has great gain to improve my crunch channel). Should I put the Shuguang in V2 or in V1? I'm a bit confused. Or should I buy 2 12AX7B?

Last question: in V3 I have a TAD 7025. Does I need a very hi-gain tube in FX Loop? Or should I use a "normal" 12AX7? Yeah, I use the FX loop everytime (delay, reverb, booster, phaser etc.)

Thanks all

P.s. for chunk/liquid I mean the palm mute sound or when I hit a string with pick.. like the one I see on videos from Mesa Throttle Box or like my HT-Dual (even first channel).. I can get this with my Blackstsr but not on my Mesa..

[loudthud]

Do you have a link to a schematic?

This link doesn't work: http://music-electronics-forum.com/a...boogie-f50.pdf

[Jazz P Bass]

V2 is indeed the first tube after the input jack (confused yet?)

BUT, V2A is the Lead channel.

V2B is Rhythm & it mixes V2A for Lead.

So you will not achieve what you want with a 'different' 12AX7.
(Am I missing something here?
Since when is a 12AX7 something else, gain wise?)

For more Lead gain, you will have to go in and change, at least, the plate resistor of V2A.

Mesa Boogie F-50.pdf

[Andree88]

Do you have a link to a schematic?

This link doesn't work: http://music-electronics-forum.com/a...boogie-f50.pdf

https://drive.google.com/file/d/0B01...BJakJaNlk/view

[Andree88]

V2 is indeed the first tube after the input jack (confused yet?)

BUT, V2A is the Lead channel.

V2B is Rhythm & it mixes V2A for Lead.

So you will not achieve what you want with a 'different' 12AX7.
(Am I missing something here?
Since when is a 12AX7 something else, gain wise?)

For more Lead gain, you will have to go in and change, at least, the plate resistor of V2A.

[ATTACH]41101[/ATTACH]

Oh.. I ask this because I see that when I use a different tube (like JJ or Genalex in V1 and V2) I really improve the gain a little but I don't like the dark tone I get..if I cannot get more gain even with "aggressive" 12ax7 then I have nothing to do
Damn, I don't wanna use Blackstar xD

[Justin Thomas]

Jazz,

I don't know what any of the numbers actually mean, but every time I order a few tubes from my vendor, if I get one each of Russian, JJ, and Shuguang, the "gains" listed on the little stickers on the boxes are:
Russian: 90-95
JJ: 95-100
Shuguang: 102-110
I've noticed this trend each time I order some 12AX7s.

So I think, at least according to SOMEONE's test rig, one tube does seemto be gainier than another... do i make broad assumptions about "this one gives more distortion than that one?" No, but in the identical circuit with no mods, I find the Chinese tubes brighter and brasher, and generally "microphonicer" than JJ or Sovtek... I usually end up relegating the Shuggies to "function" slots cuz they're too damn ringy for a gain stage.

That said, those Chinese tubes certainly add some "life" - slice&dice, highs, and general metal mayhem - to the distortion channel in my Prosonic... a bit TOO much.

Justin

[Justin Thomas]

Damn, I don't wanna use Blackstar xD

Why? If it <SOUNDS> good, then it <IS> good. Labels mean NOTHING. Not anymore. Not for sound. Does the Blackstar inspire you to play, and play BETTER? Use it!

Justin

[Andree88]

Why? If it <SOUNDS> good, then it <IS> good. Labels mean NOTHING. Not anymore. Not for sound. Does the Blackstar inspire you to play, and play BETTER? Use it!

Justin

Yeah Justin, you're right, but I've bought a Mesa amp to get rid of pedals (except for TS9, chorus, delay and phaser)..
I don't know why I cannot get what I just hear from a Mesa pedal (Throttle Box for example) with a Mesa amp and I though that a "more gainy" tube could help me..

[Chuck H]

I don't wanna ruffle any skirts with "my" opinion that some modern 12ax7's are significantly different, but...

The TAD 12ax7wa looks a lot like the Sovtek 12ax7WA (except the TAD is more expensive and says "selected" on the bottle ) I have a lot of experience with this tube. IMO they are lower gain, dark sounding and usually not microphonic (sometimes noisy), but can be good as the first tube in some amp designs that are too brash anyway and can benefit from the low microphonics. If you can get a selected Shuguang 12ax7A it will certainly be higher gain with a more balanced audio. Finding one that is stable as the first preamp tube is the tricky part, but I know from experience that they can be had. Now, as Jazz noted your rhythm and lead channels share the tube. So changing that tube will change your lead tone. Perhaps your lead setting can be readjusted and still acceptable. I think a non microphonic shuguang 12ax7a will get your rhythm sound closer to what you want. It's easy enough to try. If you can't readjust lead settings to your satisfaction I guess you need to put the TAD back in there and you're at square one again.

EDIT: It looks like Shuguang released their 12ax7B since I last shopped them. It's supposed to be an improvement in noise and gain. Probably worth a try. I'm going to.

[Andree88]

I don't wanna ruffle any skirts with "my" opinion that some modern 12ax7's are significantly different, but...

The TAD 12ax7wa looks a lot like the Sovtek 12ax7WA (except the TAD is more expensive and says "selected" on the bottle ) I have a lot of experience with this tube. IMO they are lower gain, dark sounding and usually not microphonic (sometimes noisy), but can be good as the first tube in some amp designs that are too brash anyway and can benefit from the low microphonics. If you can get a selected Shuguang 12ax7A it will certainly be higher gain with a more balanced audio. Finding one that is stable as the first preamp tube is the tricky part, but I know from experience that they can be had. Now, as Jazz noted your rhythm and lead channels share the tube. So changing that tube will change your lead tone. Perhaps your lead setting can be readjusted and still acceptable. I think a non microphonic shuguang 12ax7a will get your rhythm sound closer to what you want. It's easy enough to try. If you can't readjust lead settings to your satisfaction I guess you need to put the TAD back in there and you're at square one again.

EDIT: It looks like Shuguang released their 12ax7B since I last shopped them. It's supposed to be an improvement in noise and gain. Probably worth a try. I'm going to.

Yeah I've red that 12AX7B are improvement of 12AX7A.. So should I put it on V2 and see what happens? I though that V1 and V2 shared the "tone", for this I though that both V1 and V2 will need to have hi-gain tubes in order to obtain the gain I need..

Ah last question.. the V2 is the second from right (looking behind amp)? 'Cause the previous owner (my amp is used) added a label and he wrote "V2, V1, V3, V4" instead the manual of F-50 says "V1, V2, V3, V4) and I'm confused again where to put the Shuguang Look the image to understand what the previous owner wrote (He doesn't mod the circuit anyway)..

[Enzo]

Why be confused at all? The tubes are in sockets. In the time it takes to write a post the new tube could be in one of the sockets for a listen. Then try it in the other socket. There is no right and wrong in spinning tubes.

[Andree88]

Why be confused at all? The tubes are in sockets. In the time it takes to write a post the new tube could be in one of the sockets for a listen. Then try it in the other socket. There is no right and wrong in spinning tubes.

I am waiting for Shuguang tube and waiting I try to understant how this amp works

[Enzo]

That is fine, I just urge you and anyone else to try the various tubes in ALL the sockets. Don;t feel obligated to one type tube in one socket because someone on the internet said so. Who knows if you would like the tone they like anyway. Tubes have a great range of performance, that is after all why we sometimes order them matched, because random tubes of the same type can be quite different. SO one tube may be quieter on paper than another, but individual tubes can turn that upside down.

[Chuck H]

V# is designated by the schematic, not the tubes location on the chassis. Looking at the schem and circuit layout I can see where it's likely the labels on your chassis are correct, but I can't be sure since I've never opened one of those amps. So, to be clear, I'm talking about using the Shuguang 12ax(A or B) as the first tube in the signal chain. That would appear to be the first tube in the row on your chassis and V2 on the schematic. And as Enzo said (going to paraphrase) no one get's hurt if you want to try it in either the first, second, both or neither.