Ampeg's New Tube Portaflexes... anybody give 'em a good scoping yet?

[jtougas]

http://www.ampeg.com/products/portaflex/pf-50t/

Got very interested in getting my hands on one of these after seeing their feature set last week.

Not being a gigging bassist, I don't think their lower wattages would be an issue for me, and they look like they've got an ideal feature set for recording - DI pre/post EQ, lower wattage.

One odd thing I've noticed - the 50w's tube complement specifies 2x 12ax7 for the preamp, and 1 12au7 & 2 6L6 in the power amp... why a 12au7 there? And could I swap it out?

 

[YeRedHouseOverYonder]

Ampeg's New Tube Portaflexes... anybody give 'em a good scoping yet?

I would suspect that Ampeg designed it to utilize the 12au7's low(er) gain structure along with the 6L6's. They use 12au7 (power amp as well) in the svt 3 pro which I own. In theory, you could swap it out with something that's pin compatible, but results may vary. Not so bad if the amp isn't being pushed. At live setting levels, you might fry something. You could introduce something that wasn't factored in the equation. Just my .02 cents.


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[dystrust]

Re: Ampeg's New Tube Portaflexes... anybody give 'em a good scoping yet?

I would suspect that Ampeg designed it to utilize the 12au7's low(er) gain structure along with the 6L6's. They use 12au7 (power amp as well) in the svt 3 pro which I own. In theory, you could swap it out with something that's pin compatible, but results may vary. Not so bad if the amp isn't being pushed. At live setting levels, you might fry something. You could introduce something that wasn't factored in the equation. Just my .02 cents.


Sent from my iPhone using Tapatalk

My guess is that they use a combination of 12AX7s and 12AU7s because the original SVTs use 12DW7s in the preamp which are essentially one side of a 12AX7 combined with one side of a 12AU7. When the SVT 3 Pro was designed in the early 90s there weren't any current production 12DW7s and I can't imagine Ampeg releasing an amp that required NOS tubes.

 

[YeRedHouseOverYonder]

Re: Ampeg's New Tube Portaflexes... anybody give 'em a good scoping yet?

Great info, didn't know about the 12WD7. You learn something everyday. I totally agree with your last sentence. Back to the OP, I would definitely hit up Ampeg to be sure you can swap out that 12AU7.

I can't imagine Ampeg releasing an amp that required NOS tubes.

 

[dystrust]

Re: Ampeg's New Tube Portaflexes... anybody give 'em a good scoping yet?

Great info, didn't know about the 12WD7. You learn something everyday. I totally agree with your last sentence. Back to the OP, I would definitely hit up Ampeg to be sure you can swap out that 12AU7.

I'd expect that you can swap them out, but the amp won't sound quite right. longcat has a SVT 3 Pro and honestly I think it sounds great with the 12AU7s in there.