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PT for 2-el84 12-15 watt amp?

8/2/2004 11:07 PM
PT for 2-el84 12-15 watt amp?
Looking for a PT to build a 12-15 watt 2-el84 amp, any suggestions? Is the PT from a blues JR a good choice?
8/3/2004 1:30 AM
Carl Gigun

Yeah that would work, you couldn't experiment with tube rectifiers though, I don't know if that's important to you or not. A four diode bridge rectifier should give 329 Vdc according to fender.  
You could ask the 18 watt guys if there are any good deals out there, they build plenty of 2 x el84 amps.  
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8/3/2004 8:05 AM

Heyboer winds a nice one with chose of primary and rectifier taps for an 18 watt.  
8/3/2004 2:26 PM

I was going to use a weber copper cap GZ34 module and a PV classic 20 OPT. A simple fender design for the pre and power section. I want a really low wattage push-pull amp for my bedroom and recording. I don't like the champ sound and a princeton is too loud. I can get the PT from Angela for $45.
8/3/2004 7:54 PM
Carl Gigun

Okay, but the 6V6 tubes used in the princeton and your EL84 tubes produce very similar amounts of power. A princeton IS a 12-15 watt amp, and yeah, that's loud for a bedroom.  
Things to try,  
Find a lower voltage power transformer than the blues jr, aim to produce 250vdc or less, and bias the tubes quite hot, that could get you down as low as 8w. Triode switch, even less power. It's questionable whether there's much of a difference between an 8w and 12w amp though.  
Find an inefficient speaker and use only one. Use an open back cab and don't put it against the wall or in a corner (to me these don't seem to get the whole room rumbling the way closed back cabs do).  
Find a smaller output tube.  
Find a bigger practice room ;)  
8/3/2004 10:02 PM
BEST IMO is:  
Magnequest MQ-565 17 watter available from Triode Electronics for $99. Perfect for 2-EL-84s PP. Smoothest sounding 17 watt OT available IMO. Costs a little more but worth it.  
Yeah, I know, your friends probably all told you that you have to use a designer tranny from the usual guitar tranny designer specialists to get the best tone. Myths abound these days.
8/4/2004 3:51 AM

Also consider the PT from a Peavey Classic 20. This neat little amp has a pair of EL84 and a couple 12AX7s. PV trannys are not expensive. This one has HV and 6V windings, neither center tapped though. If interested, write and ask for prices.
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