PCM stuttery playback PC-E

[22:56]  <bazz_> Ryphecha, tehcloud [PCE ppl] -- do you know anything about PCM playback via the 6.99 Khz timer interrupt becoming uneven, and therefore buzzy/stuttery?? -- I get stuttery playback even in the most basic game loops, where I'm updating other data or writing to VDC regularly (moving sprites). I've been successful using DDA in the most basic situations smoothly, but I'm not sure how to take the stuttering away -- believe me I've minimized any use of TII/TIA etc., I
[22:56]  <bazz_> cli pretty early in practically all IRQ .. So that's where I'm at. Any ideas? thx in advance
[23:00]  <bazz_> rephrasing -- "I'm not sure how to take the stuttering away when I introduce more code into the game loop -- and I haven't yet identified why, I expected the timer IRQ to fire evenly, I'm not sure what's the issue." -- I'm using mednafen of course to emulate -- I noticed pce_fast module has less uneven playback in my bad situations but it's still there -- besides, other games seem to be performing DDA mid-game, though I don't have good references..
[23:02]  <bazz_> I doubt this is going to make or break the key response to my situation- but I'm using 8-bit unsigned PCM which I use the top 5 bits of.. I originally was using 2 channels for a combined 8bit, but now I'm just doing 1 channel with the top5 bits.. like I said it sounds smooth when I dont have much other logic running simultaneously
[23:08]  <Ryphecha> bazz_: Does it still buzz if you disable SATB DMA?
[23:08]  * CyberWarriorX has quit ()
[23:10]  <bazz_> better but not perfect
[23:11]  <bazz_> I'm still getting some pops even on samples that have played perfectly in another situation (strangely enough i think the satb dma was enabled then as well)
[23:15]  <bazz_> In the "shop" setting -- a part of my game that is pretty inactive -- the sample plays perfectly even with auto-satb dma on (I assume that's what u meant) -- but on the title screen, the same sample plays choppy, albeit less choppy with the dma satb disabled..
[23:16]  <bazz_> but even on the titlescreen -- all I'm really doing is scrolling about 11 sprites, I wouldn't consider that heavy lifting...
[23:19]  <bazz_> and when I don't call their updating logic routine -- the pcm playback is improved slightly, but still with defects .-.  -- besides that I'm just polling 1 joypad this makes no sense to me…. I'd rather not share my code -- I was hoping the problem could be identified otherwise
[23:21]  <bazz_> btw, in the shop setting -- I am also polling input -- but any visual updating is performed before the sample is triggered… However in this title-screen, I am updating the VCE in accordance with the audio and it'd be a nice effect..