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Topic: Fender Princeton Rectifier |
Brian LeBlanc
From: Falls Church, Virginia, USA
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Posted 24 Jan 2022 7:32 am
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Suggestions for Rectifier on early Silver Princeton (non-Rev)
- stock
- spent hr yesterday reading
- now my head hurts
...and Princeton Reverb (Black face) as well! _________________ 'Frenchy' LeBlanc...
ShoBud & Twins |
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J Fletcher
From: London,Ont,Canada
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Posted 24 Jan 2022 7:40 am
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Why not use a GZ34 / 5AR4 ? That's what they shipped with .
Later versions had a 5U4 , but that draws 3 amps from the 5 volt winding , the 5AR4 draws 2 amps . Or you could try a Weber solid state 5AR4 , I have used one for years .
What does the tube chart inside the amp cab say ? |
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Brian LeBlanc
From: Falls Church, Virginia, USA
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Posted 24 Jan 2022 7:47 am Tube Chart !
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..we dont need no stinkn tube chart....
- heard they need to be taken with grain-of-salt
- GZ34 looked good
- but by time i was done reading...i didnt know which way was up _________________ 'Frenchy' LeBlanc...
ShoBud & Twins |
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J Fletcher
From: London,Ont,Canada
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Posted 24 Jan 2022 10:43 am
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What other rectifier options were you considering ? |
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Dave Mudgett
From: Central Pennsylvania and Gallatin, Tennessee
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Posted 24 Jan 2022 2:46 pm
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I would try to find a semi-reasonable NOS 5U4 or GZ34/5AR4 rectifier tube or perhaps a solid-state plug-in rectifier. Nothing is cheap right now, but there's 'not cheap' and there's 'WOW'. But I have not had good luck with recent manufacture rectifier tubes for a while now. So I don't know what to suggest in current production. Perhaps others have a better handle on this, but I gave up on them a while ago.
As far as what capacity rectifier to use goes: since this is a roughly 50-year old vintage amp, I think that depends on the condition of the components in the amp. Are your electrolytic filter capacitors strong and are they fully rated for B+ voltages you'll be seeing if you use a higher-current/lower-voltage-drop rectifier like a GZ34/5AR4 or a solid-state rectifier, which can stress those components if they aren't totally up to spec?
I suggest you look at this page - https://music-electronics-forum.com/forum/amplification/guitar-amps/theory-design/48269-tube-rectifier-b-differences/page3 - and especially the little tube data cheat sheet PDF linked there - https://music-electronics-forum.com/filedata/fetch?id=857583&d=1547000739. These charts should give you a rough idea how much voltage drop to expect from various rectifier tubes, how much current the tube can deliver, and various other characteristics of the tube.
As you can see from the charts, from a 425 volt DC starting point, the solid-state diode rectifier drops essentially no voltage, the GZ34/5AR4 drops only about 10 volts DC, and the 5U4 drops about 45-50 volts DC. So the tradeoff is that you put a higher voltage on the tube plates with the solid-state or GZ34 rectifiers and deliver more current. So, in principle, if everything else is strong, you should be able to extract a bit more clean headroom. But on the other hand, if you have components are not fully up to spec for that voltage, you could have a problem.
There are always tradeoffs. |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 5 Feb 2022 7:23 pm
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It's only a 10-12 watt amp, so I wouldn't expect too much if it's used on pedal steel. Might be okay for straight guitar, where the emphasis is on bite and breakup, and not clean/full tones. But if you want some real tone improvement, a good graphic EQ will do wonders with low powered amps. Just don't expect a lot of volume if you do serious tone-shaping.
These amps are bringing stupid-high prices now, and if I was smart, I'd have bought a few of them 20 years ago, when you could buy minty ones all day long for two hundred bucks (or less). ![Confused](images/smiles/icon_confused.gif) |
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