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Has anyone built Andrea Ciuffolis Phono End ?

artosalo

Member
2010-02-16 9:00 am
I briefly looked at the link you gave and some comments:

The author says: "No capacitors on the signal path..". Bothe tubes have 220 uF cathode bypass capacitors, which certainly are inside the signal path.
Similarly with resistors that was mentioned to not exist in the signal path.

There was also a FFT-plot that shows that 50 Hz hum is only 40 dB below signal level.
This is - if true - a very poor situation. I would not accept less than 60 dB.

The frequency response seems to vary from RIAA curve some -2 dB at the bass end and +3 dB at the high end.
I would not call anything as Hi-End with such frequency response.

The author calls his project as: "no compromise phono preamplifier without budget limit".
I would say that there are many compromises and thus only average class performance.
 
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I haven't tried the Ciuffolis design but I am familiar with a similar design described on Stephen Robinson's website (Izzy Wizzy Audio). He uses a D3a for the first stage and 5687 for the second.

Izzy Wizzy Audio

One benefit of Stephen's design is the flexibility of adapting it to cap coupling for either the interstage or output. Also for running the D3a in pentode or triode. My version started out like what's shown as Mk 15 on Stephen's site but has gone through many iterations since then.