Oasys mic preamps quality?

kenackr · Post by **kenackr** » Mon Feb 09, 2009 5:09 pm

Can anyone shed any light on the quality level of the mic preamps in the Oasys?

I've been wondering about that lately and and was getting ready to set up a test, but if someone knows that's even better.

Ken

Charlie · Post by **Charlie** » Tue Feb 10, 2009 5:20 pm

I cannot offer any "measured" data - only some practical experience and that was a positive one. Voices were recorded with a clear sound and a good quality IMHO.

What I did not like so much was adjusting the input level with the tiny knob on the back of the Oasys. But usually I did this only once or twice within a recording session.

kenackr · Post by **kenackr** » Tue Feb 10, 2009 6:05 pm

Charlie,

Thanks for the reply. I'm glad to hear your vocals came out well. It's good to know that if I decide to go with the internal preamps that all will be well.

I agree adjusting from the back of the unit is not the best, but is do-able. Obviously, its one of those many details that must be wrestled with during the design phase.

Ken

Charlie · Post by **Charlie** » Wed Feb 11, 2009 1:51 pm

Well, if you have a microphone give it a try and judge yourself. It's easy to set up and I recommend a test before a real recording session.

Daz · Post by **Daz** » Wed Feb 11, 2009 2:42 pm

I would file them under clean/transparent. If you want to add to add some colour/warmth/sparkle that one might normally hope to get from a dedicated pre, there are some really nice tube pre IFX flavours

przemm · Post by **przemm** » Wed Feb 11, 2009 8:24 pm

Yes, they are quite transparent, but I find them quite noisy with higher gains. You can't compare them with high-quality dedicated preamps, but that doesn't mean you can't get decent vocals. I plug in to my Oasys a Shure Beta 57 that I use while composing and that is a great feature because I don't have to switch on main preamp or FX boxes - it simple, fast and sounds good:-).

kenackr · Post by **kenackr** » Wed Feb 11, 2009 9:27 pm

przemm,

Would that be higher than 1/2 way on the gain adjust or lower than that?

Ken

przemm · Post by **przemm** » Wed Feb 11, 2009 9:50 pm

Definitely higher than 1/2:-). I meant rather the last 1/3.

steve m · Post by **steve m** » Thu Feb 12, 2009 3:45 am

I thought the Oasys may have used something like a SSM2017 mic pre-amp chip, as most of the semi-pro mixing consoles use these for Mic inputs and they have quite good noise figures, typically better than -110dB. However, it seems that the Oasys Mic/Line input just uses NE5532 Op-amps. It's quite a good low noise device and Korg seem to have put in plenty of filtering, so it should be OK for most microphones, though usually it's not used for that application.

The Oasys manual specifies the Mic input as being typically -95dB which isn't great compared to a good quailty Mic pre-amp where better than -124dB is common . For Mic's like SM58's or M88's the Oasys Mic input would be OK as they don't need much pre-amp gain compared to some others available.

kenackr · Post by **kenackr** » Thu Feb 12, 2009 3:50 pm

Steve,

What's the possibility of dropping a "THAT 1510" in it's place? The "That 1510" is pin compatible with the SSm's you mentioned. Would I assume correctly that the circuit configuration for the NE5532 op amps is not compatible with them?

Ken

kenackr · Post by **kenackr** » Thu Feb 12, 2009 5:29 pm

Steve,

After a little research, I answered my own question. No, they aren't a compatible swap out. There is, however, some controversy on the net about the quality of the 5532's for preamp use. Some love 'em and some don't.

After reading a number of posts on changing out the 5532's with another OP amp, I gained the perspective that they're probably best left alone. It depends on the overall circuit design as to how well they perform. Without a schematic you're shooting in the dark with any replacement.

Oh well.

Ken