Quad 2 - non-standard capacitor values

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marantz123

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Need some advice regarding capacitors used in the Quad 2.  C1, C2 and C3 are specified as 100nF.  I have come across a configuration where C1 has been chosen as 220nF and both C2 and C3 as 680nF. I gather that a characteristic of the Quad 2 input stage is that it requires a preamp output/input signal capable of up to 1.4 V of swing for satisfactory performance, which I understand is a characteristic of the QC2 preamp designed to be used with the Quad 2.

Understandably a larger capacitor (C2, C3) would allow a higher amplitude of signal to pass across it. Is it possible that the mentioned higher capacitor values were "chosen" such that the Quad2 would perform well enough with a modern preamp output, assuming 1V of output swing as an example ?

Would the larger C1, C2 and C3 affect the lifespan of the tubes or other aspects of the amplifier ?
What would be a suitable alternative preamp for the Quad 2, would the preout from a Marantz 1060 perform well enough with the original configuration ?

Is there any merit in the non-standard capacitor configuration mentioned ?

Thanks
Marantz123.
 

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