Wouldn´t be wise to call a balanced single end circuit (as SOZ) PP, the same way as the first differential/PP tube amp was called. I think this also is the most common "name" in litterature.
A complementary amp would be a SS with N and P devices.
And quasi complementary as Linn and similar with two P OR N devices (not one of each) but NOT bridged across the load as in SOZ.
The way I see it it´s simply not logical to call two circuits that are so different push-pull. There is a big difference between a bipolar NPN/PNP amp (and FET N/P) and a PP tube amp/SOZ.
Ideas??? Any accepted "rules" for naming topologys?
Head still hurts
/Peter
A complementary amp would be a SS with N and P devices.
And quasi complementary as Linn and similar with two P OR N devices (not one of each) but NOT bridged across the load as in SOZ.
The way I see it it´s simply not logical to call two circuits that are so different push-pull. There is a big difference between a bipolar NPN/PNP amp (and FET N/P) and a PP tube amp/SOZ.
Ideas??? Any accepted "rules" for naming topologys?
Head still hurts
/Peter
Hi,
Hmm, about the “Dynamic class-A of Krell”, you are probably right. I did read it once in a review and it was not from literature of Krell itself.
Peter,
A balanced tube amp and SS amp with a plus and a minus PSU and where both transistors are driven are not the same. But both are Push-Pull (PP) amps.
In a tube amplifier both tubes are coupled though the transformer. This was also done in the early transistor amps, and I have a car amp here that also uses an output transformer that way to get more output power.
In a SS-PP amp the output transistors are coupled directly without a transformer. This was also employed once with tubes by Philips in their radios. They made a special tube for it, the EL86 if I remembered it right, and special 800 ohm speakers.
A SE tube amplifier with an output transformer and a SE transistor amp with a constant current source are also not the same. Both are however SE (Single Enderd) amps.
Maybe you can it see this way:
A SE is biased at the idling current that has to be delivered as maximum to the load. The load is driven by one active controlled output device.
A PP is biased at an idling current from zero up to halfway the current that has to be maximum delivered to the load. Two active controlled output devices drive the load.
Regards
Hmm, about the “Dynamic class-A of Krell”, you are probably right. I did read it once in a review and it was not from literature of Krell itself.
Peter,
A balanced tube amp and SS amp with a plus and a minus PSU and where both transistors are driven are not the same. But both are Push-Pull (PP) amps.
In a tube amplifier both tubes are coupled though the transformer. This was also done in the early transistor amps, and I have a car amp here that also uses an output transformer that way to get more output power.
In a SS-PP amp the output transistors are coupled directly without a transformer. This was also employed once with tubes by Philips in their radios. They made a special tube for it, the EL86 if I remembered it right, and special 800 ohm speakers.
A SE tube amplifier with an output transformer and a SE transistor amp with a constant current source are also not the same. Both are however SE (Single Enderd) amps.
Maybe you can it see this way:
A SE is biased at the idling current that has to be delivered as maximum to the load. The load is driven by one active controlled output device.
A PP is biased at an idling current from zero up to halfway the current that has to be maximum delivered to the load. Two active controlled output devices drive the load.
Regards
Pan said:
Well let's see, we typically refer to the output of say, an opamp as being "single-ended." So if you use two opamps, one inverting, one non-inverting to produce a balanced output, that too would be "balanced single-ended" no?
I don't have any problem with saying the SoZ is push-pull with regard to its output. That's how it drives the load. Push-pull.
Where the load is bridged by the output as with the SoZ or say a stereo amplifier bridged for mono, the push-pull is simultaneous. Driving the load single-ended with a complimentary output stage, the push-pull is alternating.
And I don't see why the SoZ shouldn't be called differential/push-pull. It's input is differential and it drives the load push-pull.
Both the input and output are "balanced" but balanced only refers to the input/output impedances with respect to ground.
I think Nelson called it "balanced single-ended" because he wanted to avoid using the term "push-pull" because he'd posited in the original Zen article that push-pull was less "natural" than single-ended.
I think it's quite logical. Both drive the output push-pull. The only distinction is how they go about doing it.
And with a quasi complimentary output, even though the final outputs are of the same polarity device, a complimentary device is used to drive one of the outputs so that for all intents and purposes, it behaves as a complimentary device.
How 'bout complimentary push-pull, quasi-complimentary push-pull and bridged single-ended push-pull?
se
"And I don't see why the SoZ shouldn't be called differential/push-pull. It's input is differential and it drives the load push-pull."
My sloppy language again, I certainly agree that SOZ is "PP" as it is very similar (in my eyes) to the "original" PP tube amps.
"I think it's quite logical. Both drive the output push-pull. The only distinction is how they go about doing it"
I guess you´r right.
"How 'bout complimentary push-pull, quasi-complimentary push-pull and bridged single-ended push-pull?"
I buy that And just SE or PP for tube circuits then?
Have we not better things to do with our time
Regards,
/Peter
My sloppy language again, I certainly agree that SOZ is "PP" as it is very similar (in my eyes
) to the "original" PP tube amps."I think it's quite logical. Both drive the output push-pull. The only distinction is how they go about doing it"
I guess you´r right.
"How 'bout complimentary push-pull, quasi-complimentary push-pull and bridged single-ended push-pull?"
I buy that
And just SE or PP for tube circuits then?Have we not better things to do with our time
Regards,
/Peter
Pan said:"How 'bout complimentary push-pull, quasi-complimentary push-pull and bridged single-ended push-pull?"
I buy that
Sure, until someone comes up with complimentary tubes.
Have we not better things to do with our time
Yeah. And I've been trying to do 'em all morning. Best laid plans and all that ya know.
se
This doubles efficiency over a single ended SS with a constant current source.
Don't forget tube SEPP, (Single Ended Push Pull) where 2 tubes are connected in series and output is taken from the connecting point, similar to a quasi complimentary SS stage with 2 NPN output transistors, this stage is common for OTL tube amps as is the Cyclotron push pull which is a bridge amplifier circuit.
Regards Hans
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.