Class D Technology

Congratulations geekboy!

Be patient with your new BC Ref600S before evaluating them seriously.... Unless they were completely broken in before you got them, it will take anywhere from a few hundred hours to about 1000 hours for them to reach their full potential.... Try leaving them powered up 24/7 and let them crunch a signal at medium lowish volume... E.g. the interstation hash from an FM radio tuner.... That should clear their musical throat quite nicely. Full break-in on class D amps is essential... The difference is quite staggering.

Once they have stabilized, the careful selection of PCs will bring them to even newer hights. For PCs that are not super-expensive, I would suggest Shunyata Alpha

Regards, Guido

ee

Guido have you heard ref1000m amps respond similarly to power cords?  In what way specifically?  Thanks.

noble100
Georgelofi acknowledges the benefits of class D but mentions its low cost in a manner that suggests it’s not a further benefit,

Now that’s twisting words.
I suggested that future technology in higher switching frequency will be of great benefit to class-d, so then the output filter can do it’s job properly without effecting the audio band.

We’re trying to band fix the switching noise problems with some innovative (ML below) (Belcanto my last post) but not completely successful filter ideas.

Just look for one at the $50k Mark Levinson No53 Class-d monos. 4 x massive inductors for the output filter probably cascaded to get rid of the switching noise. Speaker designers know that doing this with filters has it’s own set of interaction problems. Didn’t get a great Stereophile review/measured performace.

http://www.stereophile.com/content/mark-levinson-no53-reference-monoblock-power-amplifier#kXGk3Vi1RAApjFoi.97

Like I said before, I’ll be the first to get a Class-D once the switching frequency is around 3-5mHz so the filter can do it’s job properly, but at the moment nothing save for the very exclusive $30k Technics SE-R1 with a higher (double) but not high enough switching frequency, then my linear amps will become boat anchors.

Cheers George

Hi George,

     I didn't intend to twist your words, sorry.

     I reread your posts and I get that you are waiting for the switching frequency to be significantly raised before you'd be willing to 'switch' to one.

   I understand the theory that the current class D switching frequency is too low and affects the sound in the audible range but I can honestly say I don't hear any irregularities when listening intently to my system.  You may be completely correct but I'm just having a hard time faulting what I hear.  When I listen explicitly for switching frequency issues I mainly concentrate on the highest frequencies to make sure they are well extended and to make sure that spatial cues are present and the sound stage is well defined and stable both laterally and front to back.  

     Am I listening for the wrong things?

     Is there a simpler method to determine if the  switching frequency is too low and is  affecting anything in the audible band?

   I'm not really disputing the theory that a higher switching frequency  would upgrade class D amp performance.  I was just hoping to gain a better understanding of exactly how.

 Any assistance is greatly appreciated,
     Tim

























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