Ca semble être confirmé sur le forum Fender :
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And according to Bill M., this is not just a tube power amp stage at play, but
the 12AX7 is also a significant part of the preamp gain stage. So its not just the classic hybrid all SS front end with a tube output stage.
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Bill M says the 12AX7 is doing double duty as both a phase inverter and a preamp stage gain element. And that ALL the overt
distortion comes from the DSP, while the tubes add warmth and natural compression, but not classic tube clipping. Hence the larger clean headroom in the SCXD over the BJ. The tubes aren't getting driven to distortion/clipping levels.
Un truc intéressant niveau upgrade sinon :
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Swapped out the Weber ceramic for a Jensen P8R. The Jensen is much smoother and warmer than the Weber, it has less volume though. That speaker with the gold pin Tung Sol 12AX7 and a Tung Sol 6V6 have made this an incredible amp. This is exactly the amp I was looking for.
Pour une review complète de chez complète :
http://www.fender.com/communit(...)rt=45
... et sur cette page vous trouverez l'analyse d'un gars qui semble s'y connaître, le Bill M en question, qui a disséqué la bête :
BillM a écrit :
[...] The DSP adds the gain, tone, amp simulation and efx settings and then sends them to a tube stage for "warming," then to another tube stage for phase inversion, then to the 6V6s for amplification.
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The phase inverter uses half of the 12AX7, the old concertina style, which doesn't have gain. It has a slight bit of loss, in fact. The other half of the 12AX7 comes before it, and it's a standard Fender preamp gain stage. It takes the signal from the digital stage and boosts it to drive the PI. The fact that they did this with a tube instead of a transistor tells me that they wanted to add some tube warmth. I haven't gone in with a signal generator and a spectrum analyzer yet to see how much harmonic content gets added, but there must be some--it's a fairly high-gain stage.
But all of the tone that matters--breakup, distortion, etc--comes from the DSP. The SCXD does not depend, as far as I can see, on the tubes for distortion, just overall warmth and graceful compression as you approach maximum power. Since the 6V6s operate below their maximum rating, I doubt that you'd ever hear power tube distortion from this amp.
Then again, power tube distortion is actually somewhat uncommon in most amps, despite what people think. Most of the time, they're hearing preamp distortion or even distortion in the phase inverter.
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No, it's not a true all-tube amp. The DSP is always active and provides the basic voicing and controls the volume and tone, even if you're on channel 1 and the the efx are off.
The DSP is always doing some preamplification and tone shaping/voicing. It's kind of the reverse of many hybrid amps, which have a tube preamp for warmth and overdrive and then use a solid-state power amplifier to make the tube tone louder.
En résumé, la distortion vient entièrement du DSP mais repasse par la 12ax7 pour réchauffer et ajouter la compression naturelle de la lampe, et ensuite c'est amplifié par les 6v6. J'oublie l'inversion là-dedans, c'est volontaire
