I own a Counterpoint NPS 200E power amplifier. Unfortunately the power transfer fried recently due to an unknown reason. The amp was at standby and I was out from home..
Now I need to have it repaired and for this I need a copy of the service manual. Michael Elliot is long disappeared and altavistaaudio is not operational anymore. My only hope is you..
I desperately need any of the followings:
1. A copy of the service manual for Counterpoint NPS200E.. I am ready to pay a reasonable price for this
2. The values for the fried mains transformer..
3. An information regarding where I can supply a replacement transformer
As said before you guys are my only hope.. I need your help..
Best regards..
Now I need to have it repaired and for this I need a copy of the service manual. Michael Elliot is long disappeared and altavistaaudio is not operational anymore. My only hope is you..
I desperately need any of the followings:
1. A copy of the service manual for Counterpoint NPS200E.. I am ready to pay a reasonable price for this
2. The values for the fried mains transformer..
3. An information regarding where I can supply a replacement transformer
As said before you guys are my only hope.. I need your help..
Best regards..
Hi Darkwingduck,
have some info for you - no direct transformer data, but a copy of the voltage regulation.
the TP 21 voltage should be around 188V ac, the TP22 is the heating of 2 times the valve V6CA4 and TP23 is 9V ac. The power stage needs +/- 59V which means 42V ac. As the specified output power is 2 * 200Watts/4 Ohms I would recommend about 800VA transformer to provide stable output for the amp.
best regards
Dieter
have some info for you - no direct transformer data, but a copy of the voltage regulation.
the TP 21 voltage should be around 188V ac, the TP22 is the heating of 2 times the valve V6CA4 and TP23 is 9V ac. The power stage needs +/- 59V which means 42V ac. As the specified output power is 2 * 200Watts/4 Ohms I would recommend about 800VA transformer to provide stable output for the amp.
best regards
Dieter
I do have the same request...I loved my nps200, but I lost significant gain in one channel and do not know why...but I never got the full service manual...so would be as well very interested...
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Hi Blitz,
Check the voltages around V1, if they are completely different I would exchange the v1 with the other channel, if this does not help there maybe a problem with the current generators around v1.
Kind regards
Dieter
Check the voltages around V1, if they are completely different I would exchange the v1 with the other channel, if this does not help there maybe a problem with the current generators around v1.
Kind regards
Dieter
Likely a problem with the B- -50 v negative bias for the cathode for the 6922
I have serviced many NPS200/NPS400 in the past 3 years.
It's one of the easier counterpoints to service.
MOst of them have issues related to the tube gain stage.
B+ should be abount 250V and plate should be about 140V with a constant -50V cathode negative bias.
Hope this is the case and if so it would be an easy fix with the emitter follower based B+ B- regulators.
If its not the tube stage then the pre-drivers likely messed up.
Takes a bit of steady hands to desolder and remount the small PNP next to the trim pot and the MJE340s next to the rails.
I have serviced many NPS200/NPS400 in the past 3 years.
It's one of the easier counterpoints to service.
MOst of them have issues related to the tube gain stage.
B+ should be abount 250V and plate should be about 140V with a constant -50V cathode negative bias.
Hope this is the case and if so it would be an easy fix with the emitter follower based B+ B- regulators.
If its not the tube stage then the pre-drivers likely messed up.
Takes a bit of steady hands to desolder and remount the small PNP next to the trim pot and the MJE340s next to the rails.
Thanks for the hints...does anyone have a schematic of the input stages ? If I remember right there have been funny input chips etc...
Input to tube has no funny input chips.
Mki of the amp has Constant current source and Sink on cathode and plate.
Mkii has them removed.
PLate of tube drives a .1uF cap and if that cap leaks DC it can damage the whole driver and output stage. Resistors and chips can literally go up in smoke.
The driver stage is the one with all sorts of complicated transisors and chips working with each other.
You can get the full manual from
: Cathy Weber [mailto:catherineweber87@gmail.com]
Mki of the amp has Constant current source and Sink on cathode and plate.
Mkii has them removed.
PLate of tube drives a .1uF cap and if that cap leaks DC it can damage the whole driver and output stage. Resistors and chips can literally go up in smoke.
The driver stage is the one with all sorts of complicated transisors and chips working with each other.
You can get the full manual from
: Cathy Weber [mailto:catherineweber87@gmail.com]
Hello. Im from Poland.
I fix tv, amplifier, computers. Now I need service manual for Counterpoint NPS 200A. If its possible please send me. darekrzedzicki@poczta.onet.pl
I will be grateful.
I fix tv, amplifier, computers. Now I need service manual for Counterpoint NPS 200A. If its possible please send me. darekrzedzicki@poczta.onet.pl
I will be grateful.
Fuse placement clarification ..
I am trying to upgrade fuse products (HiFi Tuning) on my NPS 400.
Can anyone clarify fuse description/placement for me. The manual states that "mains" fuse are on the "rear" deck, as well as the speaker fuses (no labeled pics). But 2 speaker fuses are located there only.
Then it makes reference to "internal" fuses .. on external corners each board has etching F2/F4 are to the front of the unit by the large transformer, mine had 15A initially. To the rear/speaker output area are labeled M2/M4 and had 20A fuses installed. (in pic the dark oblong plastic cover obscures the fuse visually)
My issue is the manual states that the only 20A fuse was a slow blow for the "mains".
Any help?
I am trying to upgrade fuse products (HiFi Tuning) on my NPS 400.
Can anyone clarify fuse description/placement for me. The manual states that "mains" fuse are on the "rear" deck, as well as the speaker fuses (no labeled pics). But 2 speaker fuses are located there only.
Then it makes reference to "internal" fuses .. on external corners each board has etching F2/F4 are to the front of the unit by the large transformer, mine had 15A initially. To the rear/speaker output area are labeled M2/M4 and had 20A fuses installed. (in pic the dark oblong plastic cover obscures the fuse visually)
My issue is the manual states that the only 20A fuse was a slow blow for the "mains".
Any help?
Dear GuudTunes, may I help you about fuses ? Or you have it done ? I am not a owner of NPS 400 but here I have a unit that makes a noise just after the unit turn on (relay audio ON). Could you tell me if it happens in your unit ? Is it regular for this unit? Thanks
Hello,
I need to Driver and output stages schematic of NPS 400. I have to repair my amp and set up bias and offset...
Can anyone help me?
Thanks and Healty days🙂
I need to Driver and output stages schematic of NPS 400. I have to repair my amp and set up bias and offset...
Can anyone help me?
Thanks and Healty days🙂
Not anymore, apparently. My recent emails to that address have gone unanswered.
My amps (NPS-400 and NPS-200 MkII) work fine, but I'm finally replacing the tubes (and power-supply caps) after 100,000+ hours. While the amps are open, is there anything I should check or adjust?
Happy to pay for a copy, scan, or even photos of an NPS-200/NPS-400 service manual.
... but the answer eventually did arrive, and it turns out that service manuals are still available from Mrs. Weber.