On Wednesday, 3 February 2021 at 01:48:00 UTC, palli...@gmail.com wrote:
gareth magennis is super annoying :
=========================
How can I force this motorboating to happen on my bench, so I can deal with it?** FFS !!!
I've not seen it yet.
How will you ever know if you have fixed it ?????
Rule one of troubleshooting: " Observe the Fault "
..... PhilOk, I think I may have got to the bottom of this.
I found this, which I believe is the issue and its solution. https://www.gearslutz.com/board/so-much-gear-so-little-time/1104044-warm-eqp-wa-modifications.html
There, it states the mod is a 25pf in series with 100 ohms, which makes much more sense.
I fitted it and, of course, it doesn't drop the level by 12dB.
I did measure things before finding this, and the output inpedence of the circuit is around 360 ohms, in the method described by Mike.
Thanks MIke.
I also tried to measure the low frequency rolloff, which was way below 10 Hz.
Thanks, Phil.
Maybe there never was any "motorboating", this notion came from the customer in his email to the company.
I never found any, despite adding caps on the output like Mike suggested.
On Wednesday, February 3, 2021 at 11:40:16=E2=80=AFAM UTC, gareth magennis = >wrote:
Ok, I think I may have got to the bottom of this.=20circuit is around 360 ohms, in the method described by Mike.=20
=20
I found this, which I believe is the issue and its solution.=20
https://www.gearslutz.com/board/so-much-gear-so-little-time/1104044-warm-= >eqp-wa-modifications.html=20
=20
=20
There, it states the mod is a 25pf in series with 100 ohms, which makes m= >uch more sense.=20
I fitted it and, of course, it doesn't drop the level by 12dB.=20
=20
I did measure things before finding this, and the output inpedence of the=
Thanks MIke.=20Hz.=20
I also tried to measure the low frequency rolloff, which was way below 10=
Thanks, Phil.=20
=20
Maybe there never was any "motorboating", this notion came from the custo= >mer in his email to the company.=20
I never found any, despite adding caps on the output like Mike suggested.
Hi,=20
I am having the same issue that is reported in this conversation. I have a = >Warm Audio EQP-WA with a pretty low serial number ( less than 400). The mot= >or boating happens for me when running the XLR ins/outs to a patchbay. It i= >s a constant ticking sound that I could understand why it might be referred=
to as 'motor boating'. This happens a couple of seconds after the unit is =
powered on. If I bypass my patchbay and run from the TRS ins/outs the motor=
boating doesn't occur from powering the unit however when extreme boost or= cut is applied a similar 'motor boating' sound does occurs but it does see=
m to match the relevant frequency boosted or cut and I can understand why i= >t might be described and an oscillation. I am happy to shoot a video showca= >sing the setup and issues to share, however I am more interested its little=
more information of on the fix above to be able to relably use this unit.
I am having the same issue that is reported in this conversation. I have a =
Warm Audio EQP-WA with a pretty low serial number ( less than 400). The mot=
or boating happens for me when running the XLR ins/outs to a patchbay. It i=
s a constant ticking sound that I could understand why it might be referred=
to as 'motor boating'. This happens a couple of seconds after the unit is =
powered on. If I bypass my patchbay and run from the TRS ins/outs the motor=
boating doesn't occur from powering the unit however when extreme boost or=
cut is applied a similar 'motor boating' sound does occurs but it does see=
m to match the relevant frequency boosted or cut and I can understand why i=
t might be described and an oscillation. I am happy to shoot a video showca=
sing the setup and issues to share, however I am more interested its little=
more information of on the fix above to be able to relably use this unit.
The thing is motorboating. It's motorboating because the poles are on the wrong side of the plane; when a capacitive load is put on the output, the feedback around the output amplifier is delayed sufficiently that it goes from amplifying to oscillating. This is a design problem.
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