PushPull vs ParalelSE

tinitus · 2nd July 2010, 01:38 PM

Any reason why we never see any Paralel SE with say 4x EL84 in paralel ?

DF96 · 2nd July 2010, 02:01 PM

High power SE needs big expensive transformers. If you are doing something big and expensive, you might as well use a big expensive valve too.

If you want to use a pair or quad of EL84, better to use P-P and have a cheaper transformer and largely cancel even-order distortion. Also have less audio going through the PSU.

Andrewbee · 2nd July 2010, 02:43 PM

EL84 Quad SE

tinitus · 2nd July 2010, 03:37 PM

Ok

seems Lundahl LL1627 cost the same whether its PP or PSE version, 190EUR ea

http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf

DF96 · 2nd July 2010, 03:55 PM

But the PP version has much higher primary inductance so handles low frequencies better, and can handle much higher power. So for a given performance, a PP transformer is much smaller and cheaper than an SE transformer.

kevinkr · 2nd July 2010, 04:13 PM

Push pull operation of a pair of tubes may give you as much as 4X the power of a single tube in SE, whereas PSE will give you 2X the power.

The objection some people have to PSE is that it is alleged to loose something sonically (imaging, timbre, detail) as compared to a single tube implementation. IMLE with some high end 300B amps (very expensive, but to remain nameless) this did in fact seem to be the case.

Bigun · 2nd July 2010, 04:20 PM

I'm not surprised PSE sounds different from SE given that you effectively have a different tube in there - with two tubes in parallel the average transfer curve isn't the same as either tube, total inter-electrode capacitance will be higher etc.

Yvesm · 2nd July 2010, 04:25 PM

Quote:

Originally Posted by Andrewbee

EL84 Quad SE

OMG

1st of April issue ?

Yvesm · 2nd July 2010, 04:29 PM

Quote:

Originally Posted by tinitus

Ok

seems Lundahl LL1627 cost the same whether its PP or PSE version, 190EUR ea

http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf

Sure . . . but look at "Max Power" . . .

Bandersnatch · 05:02 PM

Quote:

Originally Posted by kevinkr

Push pull operation of a pair of tubes may give you as much as 4X the power of a single tube in SE, whereas PSE will give you 2X the power.

hey-Hey!!!,
For Class A operation, two tubes PP deliver the same power as two PSE. Now with PP one can go AB or even B and step power up considerably( though I am not at all convinced it is a good idea). PPP or 4PSE ( each with 4 finals ) does the same thing with a change to the power multiplier over single-final SE.
cheers,
Douglas

2nd July 2010, 01:38 PM	#1
tinitus diyAudio Moderator Join Date: Nov 2005	PushPull vs ParalelSE Any reason why we never see any Paralel SE with say 4x EL84 in paralel ?

2nd July 2010, 02:43 PM	#3
Andrewbee diyAudio Member Join Date: Apr 2002 Location: Cayman Islands	EL84 Quad SE __________________ None of us are leaving this world alive. Enjoy it responsibly as you may.

2nd July 2010, 04:13 PM	#6
kevinkr diyAudio Moderator Join Date: Sep 2004 Location: Boston, Massachusetts Blog Entries: 6	Push pull operation of a pair of tubes may give you as much as 4X the power of a single tube in SE, whereas PSE will give you 2X the power. The objection some people have to PSE is that it is alleged to loose something sonically (imaging, timbre, detail) as compared to a single tube implementation. IMLE with some high end 300B amps (very expensive, but to remain nameless) this did in fact seem to be the case. __________________ www.kta-hifi.net

2nd July 2010, 04:20 PM	#7
Bigun diyAudio Member Join Date: Jan 2009 Location: K-W Ontario Blog Entries: 2	I'm not surprised PSE sounds different from SE given that you effectively have a different tube in there - with two tubes in parallel the average transfer curve isn't the same as either tube, total inter-electrode capacitance will be higher etc. __________________ "The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.

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2nd July 2010, 02:01 PM	#2
DF96 diyAudio Member Join Date: May 2007	High power SE needs big expensive transformers. If you are doing something big and expensive, you might as well use a big expensive valve too. If you want to use a pair or quad of EL84, better to use P-P and have a cheaper transformer and largely cancel even-order distortion. Also have less audio going through the PSU.

2nd July 2010, 03:37 PM	#4
tinitus diyAudio Moderator Join Date: Nov 2005	Ok seems Lundahl LL1627 cost the same whether its PP or PSE version, 190EUR ea http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf

2nd July 2010, 03:55 PM	#5
DF96 diyAudio Member Join Date: May 2007	But the PP version has much higher primary inductance so handles low frequencies better, and can handle much higher power. So for a given performance, a PP transformer is much smaller and cheaper than an SE transformer.

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