|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: SE vs PP; what are the differences? posted by jarthel on November 4, 2006 at 01:47:23:
Okay, I'll bite. The following is a simplified explanation that sets out some of the main facts. You would be well advised to search historical threads on this forum and others, since this is a well-discussed subject.1. PP enables you to use classes other than Class A, which can mean that you get considerably more that twice the power from a pair of OP tubes than you could get from one such tube in SE, which must use Class A. That doesn't mean you can't use Class A in PP but you get no power advantage if you do that.
2. PP is easier on the OP transformer, since the current drawn through the primary by the two OP tubes is in opposition and the net magnetic field in the core (with no signal and assuming perfect balance) is nil. An OP transformer for PP needs no air-gap in the core and can be a lot smaller (and less expensive) than an SE OP transformer for the same power and quality.
3. While PP amps appear more complex than SE amps, they are generally easier to get working successfully. They also work well with a wide variety of speakers.
4. It is particularly difficult to apply large amounts of negative feedback to an SE amp, so a high damping factor is not possible. Output power available from SE is also usually much less than from PP, as mentioned earlier. The speaker for an SE amp needs to be of the type that can perform satisfactorily under these conditions, which usually means it needs to have a high efficiency of the order of 95dB or more.
5. Ripple from the power supply cancels out in all balanced stages of a PP amp and hum can be inadible if you build it well. Hum can be difficult to eradicate from an SE amp, which does not cancel ripple.
6. What also cancels in the balanced stages of a PP amp is even-order distortion. Odd order harmonic distortion is produced, however. Some people prefer the more even distortion spectrum of SE amps, which produce both even-order and odd-order harmonics, claiming SE sounds 'airy', 'sweet' and 'musical'. Others dislike this 'sweetness' and prefer the 'punchy' and 'authoritative' quality they attribute to PP amps.
7. Both PP and SE have their fans and which one you prefer will probably depend on the sort of music you like and the conditions under which you listen.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: SE vs PP; what are the differences? - Ray Moth 05:33:30 11/04/06 (2)
- Additional comment - mikeyb 10:45:13 11/04/06 (1)
- To A First Approximation - Lynn Olson 22:22:16 11/04/06 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
