El34 PP Vs. El34 PSE

[alexmoose]

Hello, I am so hungry to build another power amp. I am trying to decied between an El34 PP triode design, or just a PSET design.

I am having trouble finding PSET designs for just 2 El34s Per Channel.

Will El34s running in PP in triode mode even go beyond Class A?

Would someone please direct me toward a good PSE design that uses 2 tubes per channel? I am dying to try this out.

Or as I am still a newbie, should I build a PP amp first before I try PSE?

I am lost! please help me!

-Moose

[Eli Duttman]

Triode, UL, or pentode, how you bias the tube determines the class of operation. Only Class "A" is suitable for HIFI when SE topology is employed. You have options when PP "finals" are used. IMO, "shallow" Class "A" operation has a lot going for it. You squeeze out a little more when peak power O/P is needed, while avoiding cross over problems most of the time.

[tubelab.com]

2 tube PSE, I will tell you what I do. If the power supply in your existing amp is capable of supplying twice the current, you can do this. Wire a second (same brand) EL34 directly in parallel with the existing tube. The best way to do this is to use seperate stopper resistors for each tube. The cathode resistor now needs to be half its original value. The output transformer must now be half its impedance also. This will double the output power, so to take advantage of this power, you need a larger transformrer

Running two tubes in P-P allows the tubes to operate in class A, B, AB1, or AB2. A SE amp must always run in class A

[ray_moth]

Exactly as Eli says. From class A in triode PP, you only get 12w output. In class AB1, you can get 16w. I doubt if anyone would be able to tell the difference, in terms of distortion.

[Tubes4e4]

Hi Alex,

Would someone please direct me toward a good PSE design that uses 2 tubes per channel? I am dying to try this out.

Have a look at the Randall amp pages

Also, this extreme 4*PSET one comes to mind.

Tom

[TJ]

Originally posted by alexmoose
Hello, I am so hungry to build another power amp. I am trying to decied between an El34 PP triode design, or just a PSET design.

I am having trouble finding PSET designs for just 2 El34s Per Channel.

Will El34s running in PP in triode mode even go beyond Class A?

Would someone please direct me toward a good PSE design that uses 2 tubes per channel? I am dying to try this out.

Or as I am still a newbie, should I build a PP amp first before I try PSE?

I am lost! please help me!

-Moose

What speaker did u use ? if not more than 90db ... please dont built it !! complete waste of $$$$ !! unless u built for ... hobby

[alexmoose]

my speakers are 90 db, they get loud enough with one Triode-connected EL34 per channel, so I am just looking to add a little more *umph* in a new amplifier

[Klimon]

I seriously doubt that, beyond a certain minimum threshold, more watts equal more oomph. My 94db/w backloaded horns sound more powerful when driven by a 1.5watt el84 set when compared to an el34pp, 30watts/channel. You could also try to connect the el34's screen with the Bill Perkins gizmo, this will give a lot more attack to the overall sound + tighter basses. A somewhat weak, smudged sound is inherent not in low-powered amps but a result of the conventional resistor triode-strapping method.

Simon

[Tweeker]

More watts means more oomph right out to the limits of the speaker. Its just that the numbers get big in a hurry due to the exponential relationships.

It takes about 10x the power for something to be percieved as twice as loud, depending.

[Klimon]

More watts means more oomph right out to the limits of the speaker. Its just that the numbers get big in a hurry due to the exponential relationships.

I don't agree. I don't think the threadstarter want to play music at louder volumes, I think he wants the music to sound more powerfull (correct me if I'm misunderstanding). At the same spl, one amp can sound more powerful than another. A 30watt amp putting out 1watt will not necessarilly sound more powerfull than a 2watt amp putting out 1watt. This being said, I do think that 3.5 watts (or how much does el34 set yield?) is on the low side to drive a 90db/w speaker, depending on the impedance load.

There's that famous phrase: If the first watt doesn't sound good, etc... Quantity won't solve a quality problem

Simon