Apollo Twin MKII Distortion Issue - With example

[BrandonUnis]

Originally Posted by BScout

Did you run a 10Hz to 20+kHz sweep? That sweep looks seriously limited in bandwidth.
What sample rate are you at?
I can see the tell tale ripple in the freq response I see on the unison mic preamps. That's nothing to worry about when you realize the scale but that sweep needs to be done over a larger bandwidth. And what level were you sending/receiving? Since a sine sweep directly in to out should have no peaks, you should be able to run this at fairly high levels to make any problems really apparent (like -6dBFs) (just make sure you don't have speakers going at the same time)

Also, attach/post the mdat if possible (the saved file from REW). It's easier to look at than the graphs (since you can adjust scales/zoom/smoothing)

Ah my mistake. Ok I now have it set to go from 0-20khz - here is the m.dat file. I've never used that app before so apologies for my learning curve.

https://www.dropbox.com/s/v6kdggbhyh...0_10.mdat?dl=0

Does this tell you anything more?

[Southsidemusic]

The NT1-A mic is a crappy piece of gear and i am not surprised you get a bad sound from it. Just the facts of life. It is a cheap,mic aimed at ... no one really who want to achieve great recordings. It distorts really easy and the high is harsh and mids just bad. Try another mic and see what happens.

We use our Apollo Duo MK2 everyday as a monitor controller for our Apollo cards and will be used with our new Apollo X8P as soon as Mac Pro Trashcans are suported from UA.

The Apollo Duo MK2 is awesome and should not sound like your experience even with a NT1-A. I found a Röde mic same as yours in the closet here and did a good recording test and even though your isssue is intermittent the NT1-A thru a External real Neve 1073 and into a real Hardware LA2-A and that mic is a sad sad thing. Even though the recorded vocals sound OK, the next recording with the same chain except with a Manley Reference Gold was from outer space compared to the Röde Mic.

Dunno what to say more than if you want to get the Apollo Duo xperience full on you need to get better mics.

[Darryl Ramm]

Originally Posted by Southsidemusic

The NT1-A mic is a crappy piece of gear and i am not surprised you get a bad sound from it. Just the facts of life. It is a cheap,mic aimed at ... no one really who want to achieve great recordings. It distorts really easy and the high is harsh and mids just bad. Try another mic and see what happens.

We use our Apollo Duo MK2 everyday as a monitor controller for our Apollo cards and will be used with our new Apollo X8P as soon as Mac Pro Trashcans are suported from UA.

The Apollo Duo MK2 is awesome and should bot sound like your experience even with a NT1-A. I found a Röde mic same as tours in the closet here and did a good recording test and even though your isssue is intermittent the NT1-A thru a External real Neve 1073 and into a real Hardware LA2-A and that mic is a sad sad thing. Even though the recorded vocals sound OK, the next recording with the same chain except with a Manley Reference Gold was from outer space compared to the Röde Mic.

Dunno what to say more than if tou want to get the Apollo Duo xperience full on you need to get better mics.

Ding! Ding! Thanks Christopher for proving me right about a hater coming along

Brandon: I can't read the last dropbox post, but I doubt it will help, I doubt any transfer function would help, ... but I was more curious why you had the HPF engaged... its a digital processor on the Apollo interfaces and not a true analog HPF (which I'd prefer) and I was wondering if you had it engaged for a reason or fi it was not engaged then something else would be wrong.

[BrandonUnis]

Originally Posted by Darryl Ramm

Ding! Ding! Thanks Christopher for proving me right about a hater coming along

Brandon: I can't read the last dropbox post, but I doubt it will help, I doubt any transfer function would help, ... but I was more curious why you had the LPF engaged... its a digital processor on the Apollo interfaces and not a true analog LPF (which I'd prefer) and I was wondering if you had it engaged for a reason or fi it was not engaged then something else would be wrong.

Thanks again for the input guys. I did experience the exact same issue with a U87 and with a TLM 149 in the past - we had them to try and rule out mic issues.

Regarding the LPF, sorry Im doing a million things and mis-read / spoke. the HPF was engaged just for low end attenuation.

[BScout]

the REW shows THD less than 0.012% and the freq/phase graph show things fine too (other than the Apollo inputs are never perfectly linear). There's nothing showing wrong with the Apollo.

[BrandonUnis]

Originally Posted by BScout

the REW shows THD less than 0.012% and the freq/phase graph show things fine too (other than the Apollo inputs are never perfectly linear). There's nothing showing wrong with the Apollo.

thanks for checking it out!

[Darryl Ramm]

HPF/LPF sigh, you can tell I need caffeine (I edited my post). I'm not sure you'll get any more insight here. The Apollo converters are well regarded, and I think lots of folks will point to the NT1-A mic as a suspect. Even if you've tested with other mics maybe there has been multiple things going on from artist technique to maybe a damaged mic etc.

If you get this to happen again badly with a setup then it would be great to grab a recording of the dry input. And other clues of problems like hum pickup, decreasing apparent sensitivity etc. might be helpful to note.

[BrandonUnis]

Originally Posted by Darryl Ramm

HPF/LPF sigh, you can tell I need caffeine (I edited my post). I'm not sure you'll get any more insight here. The Apollo converters are well regarded, and I think lots of folks will point to the NT1-A mic as a suspect. Even if you've tested with other mics maybe there has been multiple things going on from artist technique to maybe a damaged mic etc.

If you get this to happen again badly with a setup then it would be great to grab a recording of the dry input. And other clues of problems like hum pickup, decreasing apparent sensitivity etc. might be helpful to note.

it seems to defy all logic for sure.. I appreciate the advice given and time taken. I'll work towards getting a higher end mic as a permanent part of my set up.

I've got a Lauten LA320 which i know is still not considered high end (but it should be better than the NT1..) but it felt more susceptible to that grit / dirt and I chalked it up to its tube-ness coupled with potential Apollo issues (which appear to not be there after today's investigating).