What are the specs for the RH10 mic pre?

[dgelting]

I'd like to get lower-noise recordings w/ my rh-10. Does anyone know what the s/n ratio or self noise is on the built in mic preamp?

I'm shopping around for a pre amp so I can record in the line-in, but I'd like to compare the preamp candidate specs with the minidisc's preamp specs.

[dex Otaku]

I'd like to get lower-noise recordings w/ my rh-10. Does anyone know what the s/n ratio or self noise is on the built in mic preamp?

I'm shopping around for a pre amp so I can record in the line-in, but I'd like to compare the preamp candidate specs with the minidisc's preamp specs.

There's more to it than just the mic preamp.

In tems of makin low-noise recordings: possibly more important than the specs of the recorder's preamp [s:nr, dnr, noisefloor, gain ratios, input impedance, linearity, headroom, &c.] is having a mic with low self-noise and relatively high sensitivity.

I have rarely made recordings with either a MD or HiMD recorder whose measurable noisefloor didn't actually turn out to be either the self-noise of the microphone itself, or the ambient noise level of the location where the recording is taking place.

Questions:

What are you recording that you get audible noise with?

What kind of microphone are you using?

Are you depending on the preamp for reasonable levels, rather than microphone technique [i.e. move closer to the subject]? [And yes, I realise it's no always possible to move closer.]

[dgelting]

Thank you for the fast response.

You're right - I do still have to do more testing before I can put any of the blame on the RH10 mic pre - I just made an assumption that the preamp would not be of highest quality and would introduce noise when recording low volume ambient sound.

I'm happy to hear of such good experiences that you have had. To clairify, is it right that you do not use an external preamp and the line in imput to make recordings (of quieter sound) and you haven't been unhappy with the built-in mic pre?

I just got the recorder and have only made a couple of recordings (with more to come this weekend when I have more time).

One of them was in a large, empty concert hall, recording solo piano. I had the mics on stage within about a meter or two of the piano. There was some ambient noise in the hall as the heating system was circulating air, so this is not a difinitive experiment.

As for mics: I picked up a pair of Crown Soundgrabber II PZM mics, and these have been my first recordings with them.

specs from the Crown website:

Equivalent noise level (self noise): 21 dB SPL typical,

A-weighted (0 dB = .0002 dyne/cm2).

S/N ratio: 73 dB at 94 dB SPL.

These specs are not as good as other more expensive models, but it is within 1 or 2 dB of them.

My next project will be to a/b some minidisc recordings with my home based recording setup. I should be able to do some of that this weekend, and get to the bottom of just what component is doing what (not that my mixing desk is that quiet itself! ). If you're curious, I'd be happy to update you regarding my results.

Regardless, I still would be curious about what the specs are, just for fun. I'll keep looking around.

Thanks

[RockyJ]

I thought the same as you and decided to go line-in and use a preamp.

I did a simple test. I plugged a simple 1/8 stereo plug into line-in and mic-in and recorded at mic high sensitivity and level max 30/30. I recorded in a room about 30 feet away from my computer and the tv was off and the lights were off just in case.

I'm using the RH910 which is probably identical in these respects.

viewing the wav file in my editor I see the line-in at about about -75db and mic-in at -43db.

Here is a spectrum of the files. I notice the left and right aren't matched in mic in as well.

RH910 my mic-in open circuit test file:

[attachmentid=1490]

RH910 my line-in open circuit test file:

[attachmentid=1491]

[dgelting]

I finally got around to doing some a/bing with my PC recording setup, and my results confirmeed RockyDisc's.

While I didn't do any specific objective analysis with graphs, I did just record a silent room with a variey of setups and listed to the playback really loud to hear what kinds of noises were hanging out. I just set the gain to read out about the same reading for a test tone before recording the silence.

The mic in on my RH10 was produced about the same volume and "tone" of hiss as my old tascam 8 channel mixing desk's preamps. I use the mixing desk as an 8 channel front end using the channels' direct outs to feed into an Aark PC input box. I never really had any problems with the amount of noise it made, but I also rarely recorded anything quiet with it. For quiet things I always used the ART tube MP mic preamp that I have. In my test it proved to be much quieter than the other mic preamps.

I didn't have the proper cables to feed the ART into the line in of my RH10, but I did just record the line in without anything plugged in, and it was the quietest of all (go figure).

Anyway, not much exact science in there, but interesting to me.

Maybe I'll end up getting a battery operated preamp, I'm not sure. It depends on what kinds of situations I end up recording. It is tax return time......