Have this pre-amplifier nearly three years already, and finally have modified it to improve few major flows, well at least those I've found as such.
First of all it was nothing so wrong generally speaking and it's nice sounding device, from the first day just as it was built. Even though that Chinese 'officially' sold as 2x12AX7 and 1x12AU7 combo and PCB board have those misleading marks on it (with Music Prince title too lol), mine is actually wired for Soviet tubes: 2x6N2 and 1x6N1, and there is nothing wrong with that, it's even better cause these tubes cost a lot less and sound if not better but equally good as many 12's. I found more 'issues' in polyester caps they've used.
The other issues I couldn't stand from the first day was the fourth empty step (titled 'Video' but was MUTE in fact), and finally volume knob fixed on that long aluminium rod and so not firm.
Instead of 2+2 polyesters WIMA (interstage) coupling capacitors I've placed two Russian made K40Y-9 200V 0.47uF PIO and two Mundorf MCap EVO 3,3uF 450V
To make one more input I had to drill new holes for RCA at the back, and solder a couple of good quality wires into the empty holes in selector's PCB board (why they have left this empty while the selector has four steps is beyond my comprehension).
I replaced the small volume pot with the larger original NOS Alps made in Japan and fixed it on the front, and here I used quality 26 AWG Shielded Silver Teflon mil. spec. wire made by Thermax to connect all points.
I had to drill a wider hole on the metal case and one also on the frontal wooden plate for that purpose.
Bought three new full aluminium knobs to replace plastic ones, one for power switch and another for selector have that old school 'Luxman' style I really like, and are obviously much easier to turn on/off.
I think that's all, here are some pictures of course.
If somebody made mods on this pre-amplifier it would be interesting to share some story here, I haven't found similar mods so far.
Sound of course is better as expected. Bass is tighter and punchier, details are clearer and that is something I've noticed immediately with the few CD's I play on Pioneer DV-610AV (SACD) player via that new input ('Video') .
However caps are still young and it will take some time for them to settle. But so far everything was worth time, effort and (not so much) money invested in this device!
cheers
![Click the image to open in full size.]()
![Click the image to open in full size.]()
![Click the image to open in full size.]()
First of all it was nothing so wrong generally speaking and it's nice sounding device, from the first day just as it was built. Even though that Chinese 'officially' sold as 2x12AX7 and 1x12AU7 combo and PCB board have those misleading marks on it (with Music Prince title too lol), mine is actually wired for Soviet tubes: 2x6N2 and 1x6N1, and there is nothing wrong with that, it's even better cause these tubes cost a lot less and sound if not better but equally good as many 12's. I found more 'issues' in polyester caps they've used.
The other issues I couldn't stand from the first day was the fourth empty step (titled 'Video' but was MUTE in fact), and finally volume knob fixed on that long aluminium rod and so not firm.
Instead of 2+2 polyesters WIMA (interstage) coupling capacitors I've placed two Russian made K40Y-9 200V 0.47uF PIO and two Mundorf MCap EVO 3,3uF 450V
To make one more input I had to drill new holes for RCA at the back, and solder a couple of good quality wires into the empty holes in selector's PCB board (why they have left this empty while the selector has four steps is beyond my comprehension).
I replaced the small volume pot with the larger original NOS Alps made in Japan and fixed it on the front, and here I used quality 26 AWG Shielded Silver Teflon mil. spec. wire made by Thermax to connect all points.
I had to drill a wider hole on the metal case and one also on the frontal wooden plate for that purpose.
Bought three new full aluminium knobs to replace plastic ones, one for power switch and another for selector have that old school 'Luxman' style I really like, and are obviously much easier to turn on/off.
I think that's all, here are some pictures of course.
If somebody made mods on this pre-amplifier it would be interesting to share some story here, I haven't found similar mods so far.
Sound of course is better as expected. Bass is tighter and punchier, details are clearer and that is something I've noticed immediately with the few CD's I play on Pioneer DV-610AV (SACD) player via that new input ('Video') .
However caps are still young and it will take some time for them to settle. But so far everything was worth time, effort and (not so much) money invested in this device!
cheers
