How a SRPP stage sounds like?

[rvrazvan]

I have heard only SE and PP amps with SE driver stages.
How does a SRPP stage sounds like and what are the advantages/disadvantages of it(sonical).
It might sound silly but i don;t know what to expect.

[aardvarkash10]

you are right. It sounds silly.

The advantages and disadvantages of SRPP are well outlined and discussed in many articles, most germainely John Broskie's SRPP Deconstructed

[nigelwright7557]

I use an SRPP front end on my valve/MOSFET hybrid amps and have been very pleased with it. It has a clean sound.

[bigwill]

If it's well designed, it will have little to no sonic character.

[oshifis]

If you use cathode capacitor at the bottom tube cathode resistor, the sound character is greatly influenced by that capacitor. Sound is also very dependent on the PSU (I prefer C-R-C filter, but again the C matters). Finally, the tube itself. I prefer ECC88/6DJ8 for line stage, it has clean, a bit analytical sound. If you prefer "soft tube sound", go for ECC83, but this is unnatural for some. SRPP requests high load impedance, otherwise distortion goes up.

[aardvarkash10]

Originally Posted by oshifis

If you use cathode capacitor at the bottom tube cathode resistor, the sound character is greatly influenced by that capacitor. Sound is also very dependent on the PSU (I prefer C-R-C filter, but again the C matters). Finally, the tube itself. I prefer ECC88/6DJ8 for line stage, it has clean, a bit analytical sound. If you prefer "soft tube sound", go for ECC83, but this is unnatural for some. SRPP requests high load impedance, otherwise distortion goes up.

An interesting range of assertions. Whats the reasoning behind them?

SRPP was generally used for driving into constant, low Z loads. Bear that in mind before attempting to optimise the circuit as a voltage amp, especially into a varying G1 load

[nigelwright7557]

Originally Posted by oshifis

SRPP requests high load impedance, otherwise distortion goes up.

Old valve TV's used SRPP for driving loudspeakers.

[SY]

SRPP was actually used for video scan, not audio amps (See Amos and Birkenshaw). The circuit was indeed most useful for low impedances, especially with capacitive reactances and the high voltages needed for scan circuits. Merlin Blencoe published a very nice article showing that the distortion actually has a minimum at a relatively low load and it's a pretty sharp minimum. It's not as low distortion as a more conventional circuit, but definitely lower than running the circuit into a high impedance load. A variable load is not a good idea.

Topologies don't have a "sound." Specific implementations can, but presumably we want hifi, which means that the electronics do not contribute a "sound." if one wants an effects box, there are more efficient ways of achieving it.

[sheep]

I haven't tried this but what does a solid state CCS as the load and LED in the bottom cathode sound like?
The top tube of the SRPP acts like a CCS if the load impedance is high but as a push-push when the load is low according to John Broskie.

[SY]

I use that topology routinely (see His Master's Noise on this site and the ImPasse in AudioXpress for examples). You do have to buffer the output or account for the next stage load. It's very low distortion, and if you choose a good operating point and a low distortion tube, it's audibly transparent.