I have heard lower watt push pull tube amps with single pair output tubes etc. that get close to what single ended can do- enough to be very happy on more pop/rock type music, but never equal the sound of set. I believe it is not possable ever. I have also never heard sets that have two output tubes per channel ever equal a single pair of output tubes. Again, I don't believe it's possable ever. Also, the higher power sets do not equal the lower power sets and never will. I think as long as you don't fall for the "It's as good as low watt set but not" marketing from anybody-I don't care how expensive, then you could be happy with the compromise-knowing it's a trade-off either way you go. just don't kid yourself. |
Properly designed push-pull can be as good as SET amp. 100.000$ Kondo Gaku-OH is a push-pull. |
I think that it would greatly depend on the music that you listen to. The SET has the most AIRY HIGHS and the BEST MID. The PUSH PULL configuration will have more watts and will have better control of the Bass perhaps sound somewhat puncher, but I think that the mid and the highs suffer somewhat. |
In case of Zanden 9000 dont forget that this not just a push pull design but like kondos gakuh-on a very special superior design to most others. |
Basicaly, in a SE configuration you have one output device (tube, MOSFET, transistor, ...) which is usually working in A-class. That means that it is always open and transmits the whole "sinusoide" - actually the whole signal. It usually get very hot, and the losses to the heat are considerable. This design is probably the oldest one (with WE 300B).
Push-Pull design has two output devices at the output. Each device transmitts the half of the sinusoide. PP devices can work though in different classes. They are usually more efficient and provide more power at the output than SE. That is why they are preffered solution with more critical loudspeakers.
Typically SE is considered as superior design in respect of sound reproduction. It has though some limitations - the most important one is the power that it can provide and accordingly, the matching with appropriate speakers. PP can be also extremly successful in sound reproduction. It depends actually on implementation; output devices that are used; quality of transformers; etc. So there are seriously sounding PP designs as well as poor sounding SEs ...
I wouldn't worry though to much about all this. Listen to this amp (if possible with your speakers) and see whether you are happy with the sound. If yes ... then ... no problem which internal design has been implemented. |
The primary issue between SE and PP is the output transformer, although PP often has some additional circuit complexity. But its the transformer that makes the difference.
When running PP, the signal has to go from positive to negative and then the other way. Magnetics being what they are, they resist the change in polarity. This is called hysteresis loss. In a SE amp, all that is happening is that the current through the transformer is changing intensity, but never polarity: there is no hysteresis loss.
Due to hysteresis loss, a little bit of extra energy is required to change the polarity. This energy comes from the low level signal, essentially trading distortion for signal. That is why SETs have such great low level detail. Of course, PP has bandwidth that SETs cannot match.
Take away the output transformer and you take with it the issues of hysteresis loss- and any argument for SET. Then you can have the low level detail and the bandwidth at the same time. To my knowledge though, there was only one 300b true OTL ever built, and it was a prototype. OTLs need different tubes that are lower impedance, and they have their own requirements for speakers, although they can usually drive anything an SET or other low-powered PP amp can. |
Nice thread. Is it critical to have a low impedance or low capacitance speaker cable connection to reduce the loss of dynamics or drive coming from an SET?
I am struggling with keeping my SET amp which has 6 small power supply banks so it never runs out of juice on peaks but I could not believe the authority a 7 watt PP Integrated with mickey mouse caps had over my speakers. |
@La45
Theoretically it could be an issue and probably speaker cables with less capacitance should work better. But I had once on test at home SET 300B (Audiogon Silver Night) connected to my speakers with Kimber 8TC - which are known for relatively high capacitance - and it worked very well. No problems ...
I believe that the careful matching with the speakers is much more of an issue, when we are speaking about SET 300B, although (and that has to be said as well) they are capable of driving speakers that would never say that it is possible by just looking on speaker figures/numbers ... |
High capacitance is not that strange in a speaker cable, as the capacitance contributes to lowering a quality known as characteristic impedance. When the characteristic impedance of a cable matches that of the speaker, you get a little more efficient power transmission from the amp due to less reflections. |
How does copper or silver cables fit the equation when matching an SET amp to a speaker? My cables are non wire just foils so I hope they are low capacitance.
|
Interconnect and speaker cables are endless story. And there are many different opinions about it. And then silver vs. copper ... if we start that subject this post could last for years.
Therefore I will only tell you what I did and what I am doing ... All internal wiring within the pre-amp with Mundorf silver wire (0,5 mm). All inteconnects Crystal Cable silver wire (with 1% of gold). I am planning also to go for Crystal Cable speaker wire. All connectors WBT silver (on the pre-amp)etc.
So you can see that I am a fun of silver. But you should take care about several issues with silver. First, it is expencive. Second, if it is of low quality it can sound harsh, ... rough, ... unpleasently unrealistic. I was bought on Crystal Cable sound, though.
Therefore try by yourself, listen carefully and see for yourself whether it is something that you like. And whether you can hear the difference in your system, with your speakers, in your room. There are also some excellent sounding copper wires as well, so there is definitely no lack of choice in this area ... Take some time and compare them ... and you will see ... There is no clear and definitive answer, I think ... |
"Push-Pull design has two output devices at the output. Each device transmitts the half of the sinusoide."
Dejanm, you are describing Class B amplification. Class A push-pull has one terminal transmitting the full signal, and the other terminal transmitting the full signal but inverted. See Wikipedia's entry here:
http://en.wikipedia.org/wiki/Electronic_amplifier#Class_B_and_AB
Someone correct me if i'm wrong, but I cannot think of a single Class B amp which uses 300B tubes. |
