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resonantdsp / SwankyAmp

Tube amplifier simulation
GNU General Public License v3.0
147 stars 12 forks source link

Volume decreases and the sound degrades until it disappears. #21

Closed 38github closed 4 years ago

38github commented 4 years ago

I am using the latest version in Reaper 6.12c and after a while the power section lowers the volume as the time goes on and unwanted distortion appears. When lowering the drive on the output section the issue disappears and the volume increases but the issue reoccurs again after a while and won't go away.

gmcgoldr commented 4 years ago

Hey, thanks for reporting this. I just fixed a bug that could have caused this sort of behaviour, but only after changing presets. If you get a chance to try out version 0.7.3, it might fix it. However what you're describing sounds a bit different, so I suspect it will require a bit more investigation.

38github commented 4 years ago

Thank you for your reply. I have now tried 0.8 and it has this issue too. It goes away after changing preset and going back to the problematic one.

gmcgoldr commented 4 years ago

Alright, I will definitely look into that. Could you help me understand: does the issue only occur when the power amp drive is high? Is there a particular preset or parameter configuration for which it happens? How long does it take to go from the normal to the quieter distorted signal? Thanks.

38github commented 4 years ago

I had to make a loop that played almost thirty minutes because it started happening after about seven or eight and then after that continues to degrade and lower the volume. I can't say yet for sure if it is the power amp's fault so I would then need to do another test.

Here is the waveform, screenshot of settings and the sound sample.

swanky_amp_08

swanky_amp_08_waveform

Opus audio sample, length 26:39. https://easyupload.io/nupyql

It is clear that the sound gradually degrades and while the sound volume decreases the sound starts sounding like a dying fuzz that sounds like it is acting as a gate and cuts out tones not strong in velocity/attack.

38github commented 4 years ago

Here is using the preset Pre Drive but the power amp drive is set to zero.

swanky_amp_08_sound_sample_pre_drive_no_power_amp_drive_waveform

Opus audio sample, length 30:44. https://easyupload.io/mxygpt

38github commented 4 years ago

I changed the title of the issue since a preset with no power amp drive behaved the same as one with.

gmcgoldr commented 4 years ago

Thanks for digging around, I know that takes a lot of time. The information is really useful, I think I've got the issue tracked down. I'll get a fix out as top priority.

38github commented 4 years ago

No problem att all. I am glad that I can help and seeing you doing this for free, me helping out is the last I can do.

Jul 25, 2020, 23:17 by notifications@github.com:

Thanks for digging around, I know that takes a lot of time. The information is really useful, I think I've got the issue tracked down. I'll get a fix out as top priority.

— You are receiving this because you authored the thread. Reply to this email directly, > view it on GitHub https://github.com/resonantdsp/SwankyAmp/issues/21#issuecomment-663907132> , or > unsubscribe https://github.com/notifications/unsubscribe-auth/AELSLBNZSGDQ3JTQM64FBF3R5NDXFANCNFSM4O5CKPBA> .

gmcgoldr commented 4 years ago

Thanks again for helping me track this one down. It turns out the low pass filtering in the pre-amp was the root cause of the issue. Hopefully it will be fixed now.

25

38github commented 4 years ago

No problem at all!

Jul 27, 2020, 19:21 by notifications@github.com:

Thanks again for helping me track this one down. It turns out the low pass filtering in the pre-amp was the root cause of the issue. Hopefully it will be fixed now.

25 https://github.com/resonantdsp/SwankyAmp/pull/25

— You are receiving this because you authored the thread. Reply to this email directly, > view it on GitHub https://github.com/resonantdsp/SwankyAmp/issues/21#issuecomment-664528804> , or > unsubscribe https://github.com/notifications/unsubscribe-auth/AELSLBKIJLDKMBRYHUIICVDR5WZRRANCNFSM4O5CKPBA> .