Big John
pfm Member
Examining the two Isolater's they are now approaching 20 years old so probably better not to use them. When I bought my amplifier from another forum it came with a cage to stop the valves being touched I fitted it, it stopped a lot of extraneous noise except a pop pop popping sound in particular that I traced to my Virgin modem a bit of screening with copper foil covered card between it and the system eliminated the PPP sound.
I then made a "faradic" cage actually a foil covered box to enclose my MC7R pre-amp nothing changed.
Thinking about it rationally rather than surmising/guessing the MC7R would also be affected, I realised on full volume nothing playing there was no noise on the digital inputs, CD analogue or FM radio inputs. ergo it must be the Croft still causing some noise, yesterday I completely encircled above & below the Croft transformer with copper foil faced cardboard, to screen the internal PSU wiring & wiring on 3 big capacitors .
The noise now with phono on full gain has reduced, there is a little noise not a 50Hz hum but "gain" I lack the vocabulary to be quantify exactly however that disappears on moving MC7R volume control from max at about 5 o'clock to 3 o'clock, at my preferred 12 o'clock the sound was more expansive in all areas.
Using a thin pipe cleaner with a little DeoxIT Gold, I applied it to the fuse ends & holding clips, the 3 valve's WD40 switch cleaner cleaned pins & the 2 socket saver adapters I made for the 2 6N2P EV OS valves to fit the ECC83/12AX7 sockets, plus the input/output phono sockets. There is no less "gain" noise on full volume/gain, I really hesitate to use the hackneyed phrase "as if a veil lifted" but it was just as if a very very thin veil or mist did lift, the DeoxIT Gold effect was sufficient effect that at some stage I will apply it to all of the cable connectors after getting used to the current improvement.
I then made a "faradic" cage actually a foil covered box to enclose my MC7R pre-amp nothing changed.
Thinking about it rationally rather than surmising/guessing the MC7R would also be affected, I realised on full volume nothing playing there was no noise on the digital inputs, CD analogue or FM radio inputs. ergo it must be the Croft still causing some noise, yesterday I completely encircled above & below the Croft transformer with copper foil faced cardboard, to screen the internal PSU wiring & wiring on 3 big capacitors .
The noise now with phono on full gain has reduced, there is a little noise not a 50Hz hum but "gain" I lack the vocabulary to be quantify exactly however that disappears on moving MC7R volume control from max at about 5 o'clock to 3 o'clock, at my preferred 12 o'clock the sound was more expansive in all areas.
Using a thin pipe cleaner with a little DeoxIT Gold, I applied it to the fuse ends & holding clips, the 3 valve's WD40 switch cleaner cleaned pins & the 2 socket saver adapters I made for the 2 6N2P EV OS valves to fit the ECC83/12AX7 sockets, plus the input/output phono sockets. There is no less "gain" noise on full volume/gain, I really hesitate to use the hackneyed phrase "as if a veil lifted" but it was just as if a very very thin veil or mist did lift, the DeoxIT Gold effect was sufficient effect that at some stage I will apply it to all of the cable connectors after getting used to the current improvement.