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.
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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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.
AN has an amazing control over the speakers. It always sounds musical, clean and just pure fun.
