Fender princeton which rectifier tube

May 6, 4. Posts: Fender used both with the Blackface Princeton. Check your tube chart on what came in your Princeton. My '59 Bassman has worked well for many years with the Copper Cap. The 5U4GB may sag a little more but either will sound fine. Have fun, Wayne. May 6, 5. May 6, 6. Age: 41 Posts: 6, When it comes to the PR at least original ones , the power transformer does a lot of the sagging under loud signals. Were it mine, I'd probably use the 5AR4 unless it pushed the idle voltages really high -- no sense in frying the tubes any more than necessary for that 15 watts!

May 6, 7. Posts: 40, I am going to think that the 'B' indicates that one use the 5U4 rectifier in that Princeton Reverb amp. Riff Rundowns. Why I Built this. The Big 5. Runnin' With The Dweezil. Wong Notes. Rig Rundown Podcast. Bass Gear. Gear Awards. Gear Review Inquiry. First Looks. Review Demos. DIY Projects.

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Ask Amp Man. Twang What Bohlinger Plays. Joe Gore's Subversive Guitarist. Last Call. Tone Tips. Bass Bench. Joe Gore's Recording Guitarist. Princeton Reverb with reverb and tremolo deleted three preamp gain stages so very different than blackface Princeton. Princeton Reverb Micro with reverb and tremolo deleted 1 watt 12AU7 true push-pull power tube. Original Princeton non-reverb Layout only two preamp gain stages. Every component function is listed.

Click on the layout to see the high resolution layout. Download the main circuit board Hoffman file and the bias board Hoffman file and upload them to HoffmanAmps. The signal flow colors match between the schematic above and layout below to help you follow the flow.

The AA Princeton Reverb is a 2x6V6 push-pull amp that's very similar to the AB blackface amps except for these major differences:. The cathodyne phase inverter is the primary cause of the tone differences between the Princeton Reverb and other blackface amps.

The cathodyne is notorious for funky double frequency blocking distortion when pushed hard into overdrive. Adding a k phase inverter grid stop resistor goes a long way toward correcting the overdrive issues and doesn't affect the clean tone at all.

I highly recommend this simple mod for all Princeton and Princeton Reverb models. The Princeton Reverb uses no choke in the power supply so it's a little softer with more power supply sag and compression.

The Princeton Reverb uses power tube bias wiggle tremolo versus the AB's preamp signal tremolo. Since bias wiggle tremolo doesn't load down the preamp signal like the AB's signal tremolo, the guitar signal flowing into the Princeton Reverb's third preamp gain stage is stronger and helps make up for the no-gain phase inverter.

Many people prefer the Princeton Reverb's bias wiggle tremolo but it does have a downside in that if you bias the power tubes too hot you will lose some tremolo intensity. The Princeton Reverb was biased pretty cool from the factory and sounds great so don't fret about this limitation. The Princeton Reverb has no power tube grid stopper or screen resistors just like the 5E3 Deluxe. I f you use no pedals for dirt and you want the speaker to break up a little: 10FT, 8 ohm, 25w , light dope I f you use pedals for dirt or you want the speaker to stay cleaner: 10FT, 8 ohm, 50w , light dope.

Weber on Dope:. Put simply: the higher gain you use, the more dope you should have on your speaker. You'll also need a power, output and reverb transformer, chassis, reverb pan and cables, cab, speaker and power cord.

Major differences between the blackface Princeton Reverb and blackface AB amps are the cathodyne phase inverter, bias wiggle tremolo, lack of power supply choke, lack of power tube grid stop and screen resistors and the use of a cap can for the power supply filter caps. The cathodyne phase inverter is responsible for most of the tone difference.

These are standard Princeton Reverb upgrades shown in pink that are universally praised. Adjustable bias is added, phase inverter grid stop resistor added, power tube grid stop and screen resistors are added and the "death cap" is deleted.

The bias pot has the authority to bias 6V6 and 6L6 tubes. Be advised though, if you bias too hot you will lose some tremolo intensity. The phase inverter grid stop resistor mellows the phase inverter's overdrive behavior by preventing nasty sounding double frequency blocking distortion--I highly recommend this mod for all Princeton Reverbs.

The grid stop and screen resistors help the power tube circuit deal with heavy overdrive and sweeten the overdrive tone. A 12 inch speaker can sometimes have too much low end so reducing the phase inverter input coupling cap from.

I also recommend upgrading the four voltage dropping resistors' watt rating two at far left of circuit board, one on the cap can and one on the bias board to the values shown in the layout above. Upgrading all of the plate load resistors to 2 watt resistors will reduce amp hiss and increase longevity. For slower and deeper tremolo see the Tremolo Depth and Slow Mod below. Replacing the three resistors on the input jacks with 1 watt metal film resistors can significantly reduce amp hiss.

If you need more clean headroom I recommend an upgrade to an efficient 12" speaker.