Hypnotoad
14-06-2011, 01:48
As I found out and most of you know the phono stage is a critical part of analog playback, not only does it allow compensation of the RIAA curve. It is imperative to have one that gives faithfull reproduction, wide 3Dsoundstage, pinpoint accuracy, plenty of detail and smooth sound.
I got a nice Pro-Ject Tube Box II used and put some Mullards then some Philips/Amperex valves in it. It got most of the things right but there was something missing.
That's until I did a lot of experimentation with a Cambridge Audio 640P, with the right modifications it could surpass the Tube Box II. But still something was missing. With all this experimentation and a hell of a lot of reading I built this, the PCB was made at home also:
http://i729.photobucket.com/albums/ww297/Hypnotoady_photos/P06Components.jpg
A joke you say? No not at all, it has no electrolytic's in the signal path, accurate RIAA, I use twin AD823 op amps and run it on batteries, none of that AC line noise, hum or other nasties. I can buy 4 x 6v lantern batteries for less than $4.00 each and have a +12v -12v supply that will last well over a year. The op amps are rail to rail and don't suffer headroom problems with lower voltages like earlier ones do.
The sound is superb, it has a wide 3d soundstage, super detail, low noise, ample gain, pinpoint accuracy and smoothness to die for. It cost very little to make, of course I have added some nice gold plated RCA connectors and will be putting it in a case with power switch and LED.
It's only MM, but when I get a MC cart I have made this:
http://i729.photobucket.com/albums/ww297/Hypnotoady_photos/MCHeadAmp.jpg
A DIY MC common emitter head amp with low noise paralleled transistors with adjustable gain.
Not to leave well enough alone I have a couple more projects in construction, to surpass the performance of those above.
One of which is a high end MC stage using AD797 op amps and a Mosfet in the output stage which is a Nelson Pass idea.
The good thing about these is I can try an idea, make a PCB which only costs a few dollars. I can reuse the components as well on another project if I work out something better. There is also something fulfilling about making something yourself.
I got a nice Pro-Ject Tube Box II used and put some Mullards then some Philips/Amperex valves in it. It got most of the things right but there was something missing.
That's until I did a lot of experimentation with a Cambridge Audio 640P, with the right modifications it could surpass the Tube Box II. But still something was missing. With all this experimentation and a hell of a lot of reading I built this, the PCB was made at home also:
http://i729.photobucket.com/albums/ww297/Hypnotoady_photos/P06Components.jpg
A joke you say? No not at all, it has no electrolytic's in the signal path, accurate RIAA, I use twin AD823 op amps and run it on batteries, none of that AC line noise, hum or other nasties. I can buy 4 x 6v lantern batteries for less than $4.00 each and have a +12v -12v supply that will last well over a year. The op amps are rail to rail and don't suffer headroom problems with lower voltages like earlier ones do.
The sound is superb, it has a wide 3d soundstage, super detail, low noise, ample gain, pinpoint accuracy and smoothness to die for. It cost very little to make, of course I have added some nice gold plated RCA connectors and will be putting it in a case with power switch and LED.
It's only MM, but when I get a MC cart I have made this:
http://i729.photobucket.com/albums/ww297/Hypnotoady_photos/MCHeadAmp.jpg
A DIY MC common emitter head amp with low noise paralleled transistors with adjustable gain.
Not to leave well enough alone I have a couple more projects in construction, to surpass the performance of those above.
One of which is a high end MC stage using AD797 op amps and a Mosfet in the output stage which is a Nelson Pass idea.
The good thing about these is I can try an idea, make a PCB which only costs a few dollars. I can reuse the components as well on another project if I work out something better. There is also something fulfilling about making something yourself.