Joe, After much fiddling today, I believe I've finally come up with a reasonably= good solution to volume reduction. (Sorry if I missed any replies subsequ= ent to my earlier post today, but again I get the digest of this list.) In Ver.0.3 & Ver.0.4 of the ASM code I posted links to earlier today, I mad= e a stupid mistake forgetting the NCO can only be gated into GATE 1 of the = CLC1 module. The NCO cannot also be gated into CLC4 module (or CLC2 or CLC= 3 either). The second problem was that I wasn't getting the CLC to output = to the RC4 and RC5 pins. I finally realized I had not been shutting down th= e CWG module completely, and therefore it was retaining control over those = pins instead of handing it over to the CLC. Here is my Ver.0.5 code, which again is still in the testing stage, but now= gives me the proper volume reduced waveforms on RC4 and RC5: https://cl.ly/1v1a1P370L2n Putting a scope on 16F1508 pins RC4 and RC5, I verified the two waveforms a= re accurate, and after that I confirmed proper operation using my H-BRIDGE = and 8-ohm speaker. Using a Sound Meter, I verified a 9dB volume drop (115d= B), as compared with the normal volume output (124dB). No tonal distortion= is noticeable to my ears either. The tone is the same, just softer. Ver.0.5 of my ASM code implements this: ----- ----- NCO ----|CLC1\__LC1_out__o|CLC4\________ to RC4 (pin 6) PWM --*-|AND / -------|AND / | ----- |PWM ----- | | -------------- The "o" on the LC1_out line (CLC1 output) means it is inverted as it enters= the CLC4 AND gate. PWM is 32kHz. Before I wrote the revised code today, I tested the above dual-AND gating i= n the iCircuit simulator app on my Mac and found that propagation delay cau= sed glitching in the output complementary waveform at times when the wavefo= rm should be zero. However, in my tests on the actual PIC, I am not seeing= any glitching at all. =20 The only caveat is that there is no deadband. However, I zoomed in on my sc= ope, with both waveforms atop eachother, I cannot see any ON-time overlap o= n RC4 and RC5 (which would cause an H-BRIDGE short). Obviously, it would be "best" to have deadband on my complementary output w= aveform, but I don't see how it's possible to implement. For now, I will j= ust take this Ver.0.5 ASM code as a solution to volume reduction and begin = work on the most difficult part of all: audio SWEEPS via the NCO. Thank you for your kind assistance to date. Best, James W. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .