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Vintage threads from the first ten years

previous: james I have a 5U4G on hand. Is this sui... -- 6/11/2000 5:14 PM

Re: rectifiers?

6/11/2000 6:04 PM
Graywater	Re: rectifiers? James, Actually, you will get more "sag" (voltage drop with increasing current) from the 5U4 - this is why many folks prefer the GZ34/5AR4. The 5U4/GZ31 is rated for 225mA, the 5U4A is rated for 250MA, and the 5U4B is rated for 275mA. Hopefully you've calculated your average maximum current requirements (as opposed to peaks) and know what you need. A quick review of the Tube Amp Book seemed to reveal that Fender didn't use the 5U4 in any of its 4 - 6L6 designs perhaps due to too much "sag" - the 5U4B has almost twice the current capacity of the GZ34. If you've got the filament current for the 5U4 available, 3.0 A, you can try it out andif you don't like it you can insert a GZ34 into the same socket (1.9A filament, 130mA plates). GW

6/11/2000 6:04 PM

Graywater

Re: rectifiers?

James,

Actually, you will get more "sag" (voltage drop with increasing current) from the 5U4 - this is why many folks prefer the GZ34/5AR4. The 5U4/GZ31 is rated for 225mA, the 5U4A is rated for 250MA, and the 5U4B is rated for 275mA. Hopefully you've calculated your average maximum current requirements (as opposed to peaks) and know what you need. A quick review of the Tube Amp Book seemed to reveal that Fender didn't use the 5U4 in any of its 4 - 6L6 designs perhaps due to too much "sag" - the 5U4B has almost twice the current capacity of the GZ34. If you've got the filament current for the 5U4 available, 3.0 A, you can try it out andif you don't like it you can insert a GZ34 into the same socket (1.9A filament, 130mA plates).

GW

Replies:

james Thankyou GW for the very informativ... -- 6/12/2000 3:48 AM