markslespaul
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I have a stiletto ace 2x12 combo and would like some advice for the power and preamp tubes.Any and all suggestions would be great. :?: :?:
stiletto ace 2x12 tube question
- Thread starter markslespaul
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Tons of info on this forum.
I have my stiletto modified for setting the bias.
Have used SED =c= power tubes. (=great and very reliable) Has done many many hours and gigs
Also have used in the past EL34LS - not my cup of tea. Offcourse depending on the style you like
have a duet of TUNGSOL el34b. (not tested yet)
Currently using the new JJ 6ca7 tubes. Great!.
Preamp tubes. Have tried loads of preamp tubes. Many times swapped other brands, types (12ax7, 12at7, 12au7, balanced tubes ...) currently running mixed set of jj and tung sol 12ax7. balanced sovtec LPS in the PI
good luck. find out for yourself what works best for you.. !
I have my stiletto modified for setting the bias.
Have used SED =c= power tubes. (=great and very reliable) Has done many many hours and gigs
Also have used in the past EL34LS - not my cup of tea. Offcourse depending on the style you like
have a duet of TUNGSOL el34b. (not tested yet)
Currently using the new JJ 6ca7 tubes. Great!.
Preamp tubes. Have tried loads of preamp tubes. Many times swapped other brands, types (12ax7, 12at7, 12au7, balanced tubes ...) currently running mixed set of jj and tung sol 12ax7. balanced sovtec LPS in the PI
good luck. find out for yourself what works best for you.. !
Riff Blister
Well-known member
I was running the Mullard EL34 reissues for years in my Deuce and was really happy with them.
Not too long ago I dropped a set of JJ 6ca7 tube in my amp and wow! Think I might stick with them for a while.
For preamp tubes I've got the Doug's Tubes Rock/Hard Rock tube kit plugged in. I always keep going back to that set up.
Not too long ago I dropped a set of JJ 6ca7 tube in my amp and wow! Think I might stick with them for a while.
For preamp tubes I've got the Doug's Tubes Rock/Hard Rock tube kit plugged in. I always keep going back to that set up.
Don't use a Russian tube in V3 or V4.
(It's a long read)
SOUND “DROP-OUTS” / INTERMITTENT SIGNAL
One Possible Cause
Many (but not all) Mesa/Boogie amplifiers have one or two “cathode follower” tube
stages in their preamps. Tube selection is CRITICAL in these stages.
Specifically, in a 12AX7 tube used as a “cathode follower”, the voltage difference
between that present at the cathode, as compared with the heater voltage, can be
withstood or tolerated by certain types of tubes, whereas other tubes will fail. The
failure of a “cathode follower“ tube will cause sound dropouts or signal loss.
For the past few years, Mesa has been using two types of 12AX7 tubes: ones
originating in Russia (Sovtek EH), and ones originating in China. The Russian (Sovtek)
tube is NOT reliable as a cathode follower. Of the tubes we are using today (March
2008), ONLY THE CHINESE 12AX7 IS RELIABLE AS A CATHODE FOLLOWER.
In conclusion, if you are troubleshooting for signal dropout in a Mesa/Boogie amp,
suspect a cathode follower tube, and try replacing it with a Mesa 12AX7 that is marked
as “CHINESE” (silk-screened on the tube itself).
Below is a partial list of Mesa amps and cathode follower tube locations:
Lone Star & LS Special: V3
M-Pulse: V2
Stiletto: V3 & V4
Venture: V2
Road King I: V3 & V4
Big Block 750: V4
Road King II: V3 & V5
Titan: V4
Roadster: V3 & V5
M2000: V2
Dual & Triple (2ch or 3ch): V3 & V4
Bass 400+: V2
Tremoverb: V3 & V4
ANOTHER POSSIBLE SCENARIO may occur in the “SPONGY” (or on some models,
“TWEED”) power setting: the reduced filament voltage may cause very low output from
a RUSSIAN preamp tube. Again, the recommended fix is to replace the “sagging” tube
with the CHINESE type of Mesa 12AX7 - which are more immune to this type of failure.
(It's a long read)
SOUND “DROP-OUTS” / INTERMITTENT SIGNAL
One Possible Cause
Many (but not all) Mesa/Boogie amplifiers have one or two “cathode follower” tube
stages in their preamps. Tube selection is CRITICAL in these stages.
Specifically, in a 12AX7 tube used as a “cathode follower”, the voltage difference
between that present at the cathode, as compared with the heater voltage, can be
withstood or tolerated by certain types of tubes, whereas other tubes will fail. The
failure of a “cathode follower“ tube will cause sound dropouts or signal loss.
For the past few years, Mesa has been using two types of 12AX7 tubes: ones
originating in Russia (Sovtek EH), and ones originating in China. The Russian (Sovtek)
tube is NOT reliable as a cathode follower. Of the tubes we are using today (March
2008), ONLY THE CHINESE 12AX7 IS RELIABLE AS A CATHODE FOLLOWER.
In conclusion, if you are troubleshooting for signal dropout in a Mesa/Boogie amp,
suspect a cathode follower tube, and try replacing it with a Mesa 12AX7 that is marked
as “CHINESE” (silk-screened on the tube itself).
Below is a partial list of Mesa amps and cathode follower tube locations:
Lone Star & LS Special: V3
M-Pulse: V2
Stiletto: V3 & V4
Venture: V2
Road King I: V3 & V4
Big Block 750: V4
Road King II: V3 & V5
Titan: V4
Roadster: V3 & V5
M2000: V2
Dual & Triple (2ch or 3ch): V3 & V4
Bass 400+: V2
Tremoverb: V3 & V4
ANOTHER POSSIBLE SCENARIO may occur in the “SPONGY” (or on some models,
“TWEED”) power setting: the reduced filament voltage may cause very low output from
a RUSSIAN preamp tube. Again, the recommended fix is to replace the “sagging” tube
with the CHINESE type of Mesa 12AX7 - which are more immune to this type of failure.
Riff Blister
Well-known member
booger73 said:
The 6ca7 tube is from the EL34 family so they work fine straight up. If you have a stock Stiletto it has a fixed bias anyway. Just let your tube supplier know that you have a Stiletto so that you can get tubes rated to work with that amp.
I had my amp modded so that I can adjust the bias and I got to tweak it a little when I went from the Mullards to the JJs. I don't run the JJs as hot as I did the Mullards.
You can run any 12AX7 in any position (V1-V5) without doing anything other than unplugging and plugging a new one in it's socket.
Powertubes are a different story.
If you ask any non-mesa owner with a fixed bias amp we will tell you that you absolutely MUST bias your amp when swapping powertubes.
A bit different with Mesas though. I'll try to explain this in 1million words or less.
You can't just replace a worn timing chain or belt in your (old) car without adjusting the ignition timing. It'll probably run but not at it's best. Performance wont be great....probably wont at least.
Now will your wife notice that the plugs are firing a little early or late? Probably not. Unless it's backfiring like crazy or running-on when she kills the ignition.
Well, Mesa decided, to continue to use the timing belt analogy...hey we will set-up all our cars to run in the safest/most reliable range. Then we will sell MESA branded replacement timing belts that when you install one, it will be the same dimensions and specs as the original stock belt. SO, when our customers install a new timing belt they wont have to re-adjust the timing. It will just fall back into acceptable timing range if everything else in the engine is left alone.
Their ads would say..."With Mesa cars you will never again have to adjust timing. Having issues? Simply head to your authorized Mesa dealership and pick-up a new timing belt and poop her in! No need for adjustments ever again. You can throw your bias probe...I mean timing gun into the TRASH!".
Well that's all fine and good...until you want to race that Mesa car or just change it's performance or if you want the timing advanced a bit or want to add a CAI or headers or a new chip or burn lower octane fuel..or higher octane...or if you want to change compression...you will NEED to adjust the timing to squeeze every last drop of performance out of it.
OK so Mesa does a similar thing with their power sections.
They sell their amps with non-adjustable fixed bias so you CAN'T adjust the timing...I mean bias. They say that as long as you continue to buy MESA branded tubes (can you say held hostage?), your amp will operate within ACCEPTABLE parameters and will last a long time..the tubes will I mean.
Some of us though, especially fixed bias EL34 amp players who like some power section crunch and overdrive, want to be able to run ANY powertubes. Mesas, non-Mesas, old, new, Used, NOS....
Now, you CAN go to an online tube dealer and tell them you want JJs or Winged-C- 34s etc...for your mesa, they will sell you a set that will work "acceptably" in your Mesa without the need to adjust the amp's bias.
IF you want to run vintage or un-matched or even new production tubes that just aren't "Mesa rated"...while you might get lucky and stumble upon a set that coincidently falls within Mesa range, odds are that you wont.
The only answer, if you want to be able to run ANY powertubes properly and to enjoy their best performance, you will need to adjust the bias. No worries...all that requires is to clip one stock bias resistor and replace it with one of a different value in series with an adjustable trimpot. Cheap and easy and WAY worth it if you want to be able to adjust your timing!
Powertubes are a different story.
If you ask any non-mesa owner with a fixed bias amp we will tell you that you absolutely MUST bias your amp when swapping powertubes.
A bit different with Mesas though. I'll try to explain this in 1million words or less.
You can't just replace a worn timing chain or belt in your (old) car without adjusting the ignition timing. It'll probably run but not at it's best. Performance wont be great....probably wont at least.
Now will your wife notice that the plugs are firing a little early or late? Probably not. Unless it's backfiring like crazy or running-on when she kills the ignition.
Well, Mesa decided, to continue to use the timing belt analogy...hey we will set-up all our cars to run in the safest/most reliable range. Then we will sell MESA branded replacement timing belts that when you install one, it will be the same dimensions and specs as the original stock belt. SO, when our customers install a new timing belt they wont have to re-adjust the timing. It will just fall back into acceptable timing range if everything else in the engine is left alone.
Their ads would say..."With Mesa cars you will never again have to adjust timing. Having issues? Simply head to your authorized Mesa dealership and pick-up a new timing belt and poop her in! No need for adjustments ever again. You can throw your bias probe...I mean timing gun into the TRASH!".
Well that's all fine and good...until you want to race that Mesa car or just change it's performance or if you want the timing advanced a bit or want to add a CAI or headers or a new chip or burn lower octane fuel..or higher octane...or if you want to change compression...you will NEED to adjust the timing to squeeze every last drop of performance out of it.
OK so Mesa does a similar thing with their power sections.
They sell their amps with non-adjustable fixed bias so you CAN'T adjust the timing...I mean bias. They say that as long as you continue to buy MESA branded tubes (can you say held hostage?), your amp will operate within ACCEPTABLE parameters and will last a long time..the tubes will I mean.
Some of us though, especially fixed bias EL34 amp players who like some power section crunch and overdrive, want to be able to run ANY powertubes. Mesas, non-Mesas, old, new, Used, NOS....
Now, you CAN go to an online tube dealer and tell them you want JJs or Winged-C- 34s etc...for your mesa, they will sell you a set that will work "acceptably" in your Mesa without the need to adjust the amp's bias.
IF you want to run vintage or un-matched or even new production tubes that just aren't "Mesa rated"...while you might get lucky and stumble upon a set that coincidently falls within Mesa range, odds are that you wont.
The only answer, if you want to be able to run ANY powertubes properly and to enjoy their best performance, you will need to adjust the bias. No worries...all that requires is to clip one stock bias resistor and replace it with one of a different value in series with an adjustable trimpot. Cheap and easy and WAY worth it if you want to be able to adjust your timing!
