Is there current in-rush protection built into the NAKSA amps? If not is a soft start circuit recommended?
Hugh and I have a mutual friend who wanted to build my NAKSA 70 during my absence. The rectifiers blew when the amp was powered on. I had a similar problem at his home with a Greg Ball amp, GB150D, and solved it, after repairing the power supply, by adding a soft start circuit.
Jim
Hugh and I have a mutual friend who wanted to build my NAKSA 70 during my absence. The rectifiers blew when the amp was powered on. I had a similar problem at his home with a Greg Ball amp, GB150D, and solved it, after repairing the power supply, by adding a soft start circuit.
Jim
Hi Jim,
No requirement for a soft start circuit on the NAKSA, the problem on Paul's is something quite different, relating I believe to LED voltage references. I'm replacing it routinely.
The switch on pulse on the NAKSA 70 is just less than 3V, quite trivial, the switch makes more noise.
Hope this is helpful,
Hugh
No requirement for a soft start circuit on the NAKSA, the problem on Paul's is something quite different, relating I believe to LED voltage references. I'm replacing it routinely.
The switch on pulse on the NAKSA 70 is just less than 3V, quite trivial, the switch makes more noise.
Hope this is helpful,
Hugh
Ah, no Jim, Paul has been blameless, the fault is likely mine!!
My apologies for delay..... I'm presently in another city visiting my Mom in hospital and this has played havoc with my timetable.
Hugh
My apologies for delay..... I'm presently in another city visiting my Mom in hospital and this has played havoc with my timetable.
Hugh
Hugh,
No reason to apologize; you have your priorities correct. Hoping your mother improves quickly. Take care.
Jim
No reason to apologize; you have your priorities correct. Hoping your mother improves quickly. Take care.
Jim
Jim,
Your amp is up and running. it is a lovely amp. I reconfigured your on-off switch. I'd originally configured the switch as a AC phase reversal switch [the fuse is always on the 'hot'], that would allow tweaking to minimize leakage currents on the safety grounded chassis.
The switch, with center off, is now configured with one 'on' labeled as 'start' which put a 10 Ohm in series with' hot' to minimize turn on surge. The other 'on' position is labeled 'run' and bypasses the resistor.
Not a fancy soft start, but adequate, if needed.
-Paul
Your amp is up and running. it is a lovely amp. I reconfigured your on-off switch. I'd originally configured the switch as a AC phase reversal switch [the fuse is always on the 'hot'], that would allow tweaking to minimize leakage currents on the safety grounded chassis.
The switch, with center off, is now configured with one 'on' labeled as 'start' which put a 10 Ohm in series with' hot' to minimize turn on surge. The other 'on' position is labeled 'run' and bypasses the resistor.
Not a fancy soft start, but adequate, if needed.
-Paul
Thanks Paul, great news, both that the amp got through OK - that pond is mighty big - and that all is well and Jim can have his amp quam celerime.....
Have you noticed the intense quiet of this amp, Paul, and the wonderful imaging?
Cheers,
Hugh
Have you noticed the intense quiet of this amp, Paul, and the wonderful imaging?
Cheers,
Hugh
Hugh,
When I put the Naksa70 in my system, I pulled it out to check that hardwired power cord I put in, connected safety ground to chassis and circuit ground..... not the slightest hum or noise with my ear pressed against the speakers. Its the quietest (by that metric) amp I've ever had in my system.
As to imaging, the Naksa70 accurately portrays height information (when in the recording and with speakers capable). Width (including placement outside the speakers positions), and to a lesser extent, depth, are generally easy for a power amp to convey, but accurate height portrayal is far rarer. The Naksa70 gets all 3 coordinates right!
FWIW,
Paul
When I put the Naksa70 in my system, I pulled it out to check that hardwired power cord I put in, connected safety ground to chassis and circuit ground..... not the slightest hum or noise with my ear pressed against the speakers. Its the quietest (by that metric) amp I've ever had in my system.
As to imaging, the Naksa70 accurately portrays height information (when in the recording and with speakers capable). Width (including placement outside the speakers positions), and to a lesser extent, depth, are generally easy for a power amp to convey, but accurate height portrayal is far rarer. The Naksa70 gets all 3 coordinates right!
FWIW,
Paul
Wow, Paul!!
Now, how do we measure imaging? There's a tough call......
Many thanks for careful work,
Cheers,
Hugh
Now, how do we measure imaging? There's a tough call......
Many thanks for careful work,
Cheers,
Hugh
- Status
- Not open for further replies.