Hi Simon,
Nice cooling rig! Pin hestsinks that big probably were for a very large LED lamp? That looks fantastic. Big dia fans are also very quiet.
Nice cooling rig! Pin hestsinks that big probably were for a very large LED lamp? That looks fantastic. Big dia fans are also very quiet.
Simon,
Very good results. I like the heatsink; large fans are outstanding for moving air at low noise.
What are the CLC dimensions? What is your DCR on the inductor? Are you using the SLB?
As it happens, the PSRR of the AN is pretty good, since front end is filtered and output devices are connected to the rail with drains.
I have used CLC systems for this role - typically 22mF-15mH-22mF - and the ripple is down to about 10mV at 1.6A. What is your ripple?
Hugh
Very good results. I like the heatsink; large fans are outstanding for moving air at low noise.
What are the CLC dimensions? What is your DCR on the inductor? Are you using the SLB?
As it happens, the PSRR of the AN is pretty good, since front end is filtered and output devices are connected to the rail with drains.
I have used CLC systems for this role - typically 22mF-15mH-22mF - and the ripple is down to about 10mV at 1.6A. What is your ripple?
Hugh
Hi Hugh. The CLC is 24mF-10mH-22mF the DCR is about 0.15 Ohms. The ripple is right in my meters blind spot, somewhere between 6 and 10mV. I don't have a scope yet, this level of messing with amplifiers is new to me!
I'm going to try the Johnson/Gtose for a number of reasons, having parts already etc. It will be interesting to see what comes out of the comparison. Once I have a preference, I'll duplicate it for dual mono and crank up the bias. My toroid has four windings.
Thanks Simon, excellent results.....
The quality of a CLC power supply is outstanding but only the cost of inductors is tne main obstacle.
HD
The quality of a CLC power supply is outstanding but only the cost of inductors is tne main obstacle.
HD
Hi Hugh. I'm not sure that measurement is trustworthy. I'll borrow a scope when I can. I got the Johnson/Gtose capacitance multiplier up and running today. I set it for 1.8V across the pass transistors. This was an easy win for me. There was a slight sandiness in the lower treble that's gone and the music flows better. More organic. Maybe the CLC was resonating?
Is the current draw always symmetrical between rails?
Is the current draw always symmetrical between rails?
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Simon,
I learn something. Adding a cap mx seems to have sonic benefits. I did not realise this......
Thank you!
Hugh
I learn something. Adding a cap mx seems to have sonic benefits. I did not realise this......
Thank you!
Hugh
A CLC can sometimes resonate and a resistor in parallel with the L sometimes helps to dampen that. I often use a 30ohm to 50ohm resistor in parallel - should be tuned using an O-scope. I have seen a CLC increase output ripple for this reason.
“Sandiness” or “grit” as described in the sound does sound like some sort of oscillation.
Cap Mx will usually give you a deeper black background. SLB can usually provide 1mV rms ripple even under 3A load.
It’s a tradeoff though as lower ripple means higher dropout and less available peak power.
“Sandiness” or “grit” as described in the sound does sound like some sort of oscillation.
Cap Mx will usually give you a deeper black background. SLB can usually provide 1mV rms ripple even under 3A load.
It’s a tradeoff though as lower ripple means higher dropout and less available peak power.
Nice work, Jimk04! Good luck with first turn on. It’s a pretty easy amp to start up. No adjustments needed if built right.
Thanks X. Mouser order in place for the remainder. Have a 22v 400va doing nothing and also some Capmx boards and some LT4320 so I can maybe jerry rig an SLB type PSU for now!
Ksa992 matched up to within 1 point hfe , one pair identical. Well until you breath on them!
Ksa992 matched up to within 1 point hfe , one pair identical. Well until you breath on them!
Thanks X. I have populated R113 with 22r as per your 'build guide'. If I use the 3k2 should I maybe remove R113 and use a 100r trimmer at x111.
Or just but some 3k3!
Actually I can probably parallel something to get near to 3k3
Or just but some 3k3!
Actually I can probably parallel something to get near to 3k3
My second AN39 has been playing well for a week, all went well, temperatures on the outputs and heatsinks all in expected range.
Great amp, thanks Hugh and X.
Great amp, thanks Hugh and X.
AN has an amazing control over the speakers. It always sounds musical, clean and just pure fun.
