Topic: Questions about Microtrack, pre-amps, AT-831, and CA-14's

[Isaac]

Hi all,

I have been taping with an AT-825 stereo mic (with AA battery) into the 1/4" Mic/Line inputs (no phantom power) of a MicroTrack I and have been pretty happy with the results. The only problem is that it is a pretty bulky set-up and I am thinking of finding something a little more portable.  I was originally thinking of some AT-831 or 853 with the flexible boom arms from SP:

http://www.soundprofessionals.com/cgi-bin/gold/item/SP-SPSM-4

But this would plug into the 1/8" Mic Input of the MT.

My questions for you experts (thanks in advance):

1. Is the pre-amp for the 1/8" Mic Input and the 1/4" Mic/Line inputs of a MicroTrack I the same pre-amp, or do they use different pre-amps?

2. Can the MT 1/8" Mic inputs drive the AT-831 without a battery box or pre-amp?

3. Will plugging in the AT-831 directly into the MT 1/8" Mic input result in more noise over the 1/4" Mic/Line inputs with phantom power? 

3. What are people's opinions of AT-831 vs AT-853 vs AT-898c?

4. My other option is to go for CA-14's and maybe a ST 9100 pre-amp, which seem to be favorites here.  For those that use the CA-14's, how do you usually mount them if you record from your lap?  I want to keep the mics off my body to avoid extra noise (that's why I like the flexible boom arms from SP).

5. Should I go CA-14 > ST 9100 > 1/8" Mic Input or
CA-14 > ST 9100 > 1/4" Mic/Line inputs or
CA-14 > 1/4" Mic/Line inputs with phantom power?

I have already emailed Chris Church and he has provided me great info about the CA-14.

BTW, I mainly record acoustic shows fairly close to the speakers.

Thank you for your time,
Isaac

[Belexes]

4. My other option is to go for CA-14's and maybe a ST 9100 pre-amp, which seem to be favorites here.  For those that use the CA-14's, how do you usually mount them if you record from your lap?  I want to keep the mics off my body to avoid extra noise (that's why I like the flexible boom arms from SP).

5. Should I go CA-14 > ST 9100 > 1/8" Mic Input or
CA-14 > ST 9100 > 1/4" Mic/Line inputs or
CA-14 > 1/4" Mic/Line inputs with phantom power?

I use this SP stereo mount when running my CA-14's in the open. 
http://www.soundprofessionals.com/cgi-bin/gold/item/SP-GNA-3

This is for running them from a stand.  I have not used the mount you posted above.

Run the rig CA-14 > ST 9100 > 1/8" Line In

[darktrain]

I can tell you that the 831's lack detail, especially in the mids, we just ran a set(same setup) with the hlsc's and there is definately a noticable difference and there is no problem running them plug in power except they would need that 4.7k mod for rock/metal shows

[Fried Chicken Boy]

I can tell you that the 831's lack detail, especially in the mids, we just ran a set(same setup) with the hlsc's and there is definately a noticable difference and there is no problem running them plug in power except they would need that 4.7k mod for rock/metal shows

I've had/been running the 831's for a few years and have always been happy with the results and their detail but YMMV.  For loud rock/metal shows you don't necessarily need the 4.7k mod but you will need a battery box to keep them from brickwalling.  I've used mine on some VERY loud shows with a BB and had no problems.  I also have a set of Church CA-11's and I must admit that I usually reach for those first when I choosing between the two; can't really put my finger on it but they seem a little more "comfortable" to me.

[fmaderjr]

My questions for you experts (thanks in advance):

1. Is the pre-amp for the 1/8" Mic Input and the 1/4" Mic/Line inputs of a MicroTrack I the same pre-amp, or do they use different pre-amps?

2. Can the MT 1/8" Mic inputs drive the AT-831 without a battery box or pre-amp?

3. Will plugging in the AT-831 directly into the MT 1/8" Mic input result in more noise over the 1/4" Mic/Line inputs with phantom power? 

3. What are people's opinions of AT-831 vs AT-853 vs AT-898c?

4. My other option is to go for CA-14's and maybe a ST 9100 pre-amp, which seem to be favorites here.  For those that use the CA-14's, how do you usually mount them if you record from your lap?  I want to keep the mics off my body to avoid extra noise (that's why I like the flexible boom arms from SP).

5. Should I go CA-14 > ST 9100 > 1/8" Mic Input or
CA-14 > ST 9100 > 1/4" Mic/Line inputs or
CA-14 > 1/4" Mic/Line inputs with phantom power?

I have already emailed Chris Church and he has provided me great info about the CA-14.

BTW, I mainly record acoustic shows fairly close to the speakers.

Thank you for your time,
Isaac

1) TRS inputs are quieter.
2) Yes, the MT provides 5 volts plug in power, enough to power even CA-14's.
3) TRS inputs are better than the 1/8 input. You need to turn the phantom power off when not using a phantom powered mic.
4) I use a stand and open taping and mount them in a hat for stealth.
5) CA-14 > ST 9100 > 1/4" Mic/Line inputs (set to L). This should produce excellent results. You need to turn the phantom power off when not using a phantom powered mic and you should not be running a preamp into a mic input when you have a line input available to you.

[Isaac]

Thanks to everyone for your responses.  I am leaning towards:

CA-14 > ST 9100 > 1/4" Mic/Line inputs

but wondering if anybody has ever run CA or AT mics directly in a MT, either:

CA-14 > 1/8" Mic input (with 5 V plug in power)

CA-14 > 1/4" Mic/Line inputs (with phantom power)

and how were the results.

Thanks,
Isaac

Thanks again,
Isaac

[fmaderjr]

but wondering if anybody has ever run CA or AT mics directly in a MT, either:

CA-14 > 1/8" Mic input (with 5 V plug in power)

CA-14 > 1/4" Mic/Line inputs (with phantom power)

and how were the results.

I'll say again, you must turn OFF the phantom power when running mics like the CA-14 into the 1/4" inputs. Phantom power will fry them. You need to power these mics with a battery box or preamp like the ST-9100.

I have run DPA 4060's (mics that require at least 5 volts of plug in power like the CA-14's) into the 1/4" inputs using a Sound Pro's dongle that fed the MT's plug in power to the mics to power them (phantom power off) and fed the signal from the mics to the 1/4" inputs. The quality was phenomenal and you should expect the same quality or better if you went CA-14 > ST-9100 > 1/4" Mic/Line inputs (except for any differences caused by differences in the mics). Remember to turn phantom power off. If you don't use phantom powered mics with the MT, you should turn off phantom power and put a piece of tape over the switch to be sure it never gets turned on by accident.

[Isaac]

Thanks for your input.  I think I get it now   I thought that the CA-14's were phantom powerable (my mistake).  Was that SP dongle you mentioned a custom job or off the shelf?

Thanks,
Isaac

[fmaderjr]

The dongle was off the shelf, but they don't make it anymore. It would work only with the MT 2496. With the MT II you'd get the dreaded "sprinkler noise" much discussed here.

They were pretty expensive. I paid $65 according to my records in the fall of 07. I'm not really looking to sell it, but I don't need it anymore, so would let it go for $50 shipped if you wanted it.

I would actually recommend using the mic into a ST-9100 and getting the proper 1/8 stereo-dual 1/4 mono TRS cable to go into the MT's line inputs (which is what I would do if I used my MT again). The advantage to this is that, besides the extra 20 dB of clean gain,  you don't need to worry about overloading the MT in very high sound pressure situations because the ST-9100 attenuates as well as amplifies.  A well known issue with the MT is that sometimes a 10 dB pad is required to record very loud sources without distortion. I suspect, though, that when using a CA-14 mic this wouldn't be an issue (the CA-14 is a very insensitive mic) and you should be OK using the dongle.

Should you be interested in the dongle, e-mail me at fmaderjr@comcast.net and I could send you a picture of it to show how little space it takes up when fitted on the MT.

You do know, I assume, that to record a concert of any length with a MT, you'll need an external battery. The internal battery lasts only about 2 hours when brand new. I use a small pack that takes 4 AA NiMh rechargeables.

[kozakz]

Buy 2 AT 853RX mics and build a XLR-TRS cable and you can run the AT mics with the phantom of Microtrack. It is much cheaper option then going for a ST9100 + mics.

[fmaderjr]

Live & learn. I didn't realize AT 853's would run on phantom power without an adapter to reduce the voltage to 9 volts or so.

There is one potential problem for very loud shows that you wouldn't have with the ST-9100 set up though. The 853's are very sensitive mics and could overload the MT when recording very high sound pressure sources without some sort of attenator.

[Isaac]

Thanks again for your input.  I am still leaning towards the CA-14 > ST 9100 > 1/4" Mic/Line MT inputs.  I like the fact that the ST 9100 can also attenuate, because my fav local venue just got a new soundboard whose output is very hot.  For the acoustic set, I didn't have a problem, but when the electric guitars were brought out, I had clipping issues, even with the MT set to "L" and gain all the way down (and I did not have a 10 dB pad).

Thanks again,
Isaac

[fmaderjr]

I am still leaning towards the CA-14 > ST 9100 > 1/4" Mic/Line MT inputs.  I like the fact that the ST 9100 can also attenuate, because my fav local venue just got a new soundboard whose output is very hot. 

A great choice for recording from any external plug in power type mic. And this set up would also serve you well if you add another recorder to your arsenal.

You might want to ask Chris Church how it would fare taking a feed from a soundboard. It may well be fine if only used to attenuate, but I am not knowledgeable enough to know whether feeding a soundboard feed into the ST-9100 could cause a problem given that the plug in power on the ST-9100 can't be turned off. It may be fine, but using the 10 dB attenuator might be better. I'm sure Chris Church could answer this for you. The attenuator isn't too expensive-around $20 shipped, I think.