as-audio,
If interested I have the A75 schematic.[/QUOTE]
Thank you for the offer.
How do these compare?
Talking about schematics I would be interested in getting those for the earlier A100 pwr amp and C100 pre amp.
Back on topic I have an A3i and it works fine but those transistors do get hot! On my amp they are raised fully from the pcb and I have a small fan on them as well. Amp sounds quite good, better than the A100/C100 I think. It has the ability to grab your attention if you are doing something else whereas the pre/pwr justs plays away in the background.
sp
Back on topic I have an A3i and it works fine but those transistors do get hot! On my amp they are raised fully from the pcb and I have a small fan on them as well. Amp sounds quite good, better than the A100/C100 I think. It has the ability to grab your attention if you are doing something else whereas the pre/pwr justs plays away in the background.
sp
No it doesn't
The A75 is a Class A amplifier from Nelson Pass and the A70 is from Cambridge Audio.
To Alex (X-PRO)
Could you please tell me what was the original power supply voltage on your A3i amplifier design.
Thanks
Ric
Thanks
And can you tell me (and the others) what changed in the production units ?
You say on the first posts that AP jacked the the power supply so they could make it a 60W/channel amplifier leading to the heat spots in some areas of the board.
Ric
Hi x-pro,
just noticed your original schematic on page 1 showing ps voltage of +/- 38V and your response to RS232 that the original supply was +/- 35V.
You said the original design was 40W but Cambridge boosted it to 60W by changing the ps voltage. Will 35 to 38 V do this?
I can easily change my line voltage so can you tell me the best operating voltage for the A3i.
Thanks, sp
just noticed your original schematic on page 1 showing ps voltage of +/- 38V and your response to RS232 that the original supply was +/- 35V.
You said the original design was 40W but Cambridge boosted it to 60W by changing the ps voltage. Will 35 to 38 V do this?
I can easily change my line voltage so can you tell me the best operating voltage for the A3i.
Thanks, sp
Ok
Just fired up the first of the 3 A3i I have and it works...
I haven't make any changes/mods to it yet because its working fine...
No over heating to speak of apart from the normal(?) spots and heatsink but...
It works fine with the cover off (over 2 hours with my turntable) but as soon I put the cover it works for 20/30 minutes and goes in to protection.
Any idea were/what to look for ?
Is the +/-35 AC or DC ?
Ric
Just fired up the first of the 3 A3i I have and it works...
I haven't make any changes/mods to it yet because its working fine...
No over heating to speak of apart from the normal(?) spots and heatsink but...
It works fine with the cover off (over 2 hours with my turntable) but as soon I put the cover it works for 20/30 minutes and goes in to protection.
Any idea were/what to look for ?
Is the +/-35 AC or DC ?
Ric
Hi Michel
No, not yet
I had a look in my email account and my private massages and nothing.
I send you a PM with my email account
Thanks
Ric
Just got the service manual for this amp ( thanks Michel) and already found the first snag(?) the manual shows a power supply of 35/0/35 DC and I have 39.6/0/39.6 DC is this normal ? The amp board is the V1.0 can this be caused by mine supply line (?) just asking because it never drops below 245V and is normally around 247/248V.
Will check the rest tomorrow.
Time to go to bed.
Ric
Will check the rest tomorrow.
Time to go to bed.
Ric