PF-50T: world's craziest DISTORTION PEDAL!

[Swiss Frank]

I just got rid of my SVT-2PRO and here's why. The PF-50T is not only more versatile... but... LOUDER???

The PF-50T as we all now know, is about the only tube amp that can run without a speaker load. Just use the AUX out to record in silence! Use the output transformer output so you get all the smoothness not just from slightly overdriven pre-amp tubes, but also the tube-amp secret: slightly overdriven POWER amp tubes, along with transformer and rectifier sag.

But what if you're not recording?

You can also take that aux out and just feed into a WT800 or whatever your choice of high-amperage MOSFET or class-D power is, and output as little as 1W or up to 1000W.

You can crank every knob on the 50T to ten and still talk over it if you want, or you can turn the 50T gain to near zero, turn up the MOSFET amp a bit and hear it as clean as a whistle with all the modern headroom you could want.

Then take the same setup to a small or large club and do the same.

Basically, you're disconnecting the decision of "how hard to drive the power tubes" from the decision of "how loud do you want to be today?" Get any tone at any volume.

On guitar amps you can use a Marshall Power Brake or similar, to decouple tone from volume. I've done it for 15 years with my Mesa Road King. The problem though is that guitar amps are typically 100W and that's what the Power Brake is rated for. an SVT 300W would instead literally set the Power Brake on fire. In contrast, the 50T basically has its own internal power brake, so you don't even need its speaker output. Just run its output into a second amp. And whether you want clean modern headroom, or old-skool warmth and compression, and whether you want it at late-nite practice volume or bringing the roof down in a big club, you're set.

 

[beans-on-toast]

It screams, doesn’t it. I do the same thing with a different amp, a ’69 Ampeg SBT preamp into the input of a tube amp to saturate the first stage.

You never know what will result when you start experimenting. Sometimes a happy outcome.

 

[two fingers]

Having fallen in love with the Ashdown LB30 a few years back, the PF50T has definitely been on my radar. (Honestly, I've been holding off to see if that huge thread regarding tube amps started by @agedhorse .... where he kicked off a discussion by asking US what WE want.... imagine that... produces some interesting results.... not that I'm secretly hoping for a third generation Walkabout powered by some 6L6 or EL34 tubes or anything..... wink wink nudge nudge.)

The compact 20-100W all-tube bass amp, with a tap off the output transformer going to the XLR out, seems to be the future catching up to the past in bass amps.

What cab(s) are you running @Swiss Frank ?

 

[Swiss Frank]

What cab(s) are you running @Swiss Frank ?

Hi Two Fingers,

Thanks for asking! I'm not even a real bass player. I've played since the 80s but just for fun or while recording demos. I have actually gotten a cab--Eden D210XST--but only recently. Until then I've been playing out of a (huge) home stereo if I'm not using headphones.

I do this exact setup I describe wtih guitar though. I have a Mesa "Road King" amp that is very flexible but I use it at 50W, main output into a Marshall Power Brake that simulates a speaker load. Then take the aux out (like the PF-50T, it's off the output transformer so sounds exact), and run that into stereo FX. Again, the amp, both pre-amp AND POWER-AMP, is acting like a complicated distortion pedal, in this case then going into stereo digital reverb, etc. The stereo FX goes into a non-descript 300+300W MOSFET PA amp, which then goes to the Road King's 2x12 speakers, which are now separate L/R channels.

The result is that you get the real sound of the amp as cranked as you want... all the way to 11... but with digital FX applied after that, coming out the amp speakers for proper coloration (critical for guitar, but may be the enemy for bass??). And you can have that at whisper volume or basically stadium rocker volume. It sounds identical to a fully-produced album guitar track, including being stereo, whether you're goofing around, practicing, band practice, jamming, gigging, etc.

So eliminate the FX, and use a real bass amp instead of a PA amp for the re-amping stage, and that's where I got my "PF-50T as purely a tone shaper" idea. And sure, use FX if you want, and stereo if you want. The idea of using an Eden or other high-headroom modern amp is that if you do NOT want dirt, if you want a clean modern sound for the entire gig, then leave the PF-50T at home.