Which preamp for Acoustic?

  • Thread starter Thread starter BulldogsMusic
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So what's the best affordable sound for entry level? I promise to upgrade later, but until then?

Entry level you would be correct at DMP3 (which has a similar noise spec to the JM-130, and also note that preamp noise is not terribly important when using condensers). You might want to upgrade later--the RNP is slightly nicer, but it's slight. Somebody did a blind comparo here but I think it was a couple of years ago. The DMP3 won, but I did think the RNP was a bit better myself. Either works just fine. So you might never really need to upgrade, quite honestly. The ART thingy should work fine too, used to have a DMPA and it never caused me pain.

The most important consideration for recording acoustic is a reasonable acoustic space. Shouldn't be too hard on a college campus, especially if you can score an auditorium or classroom during off-hours. Or a meeting room in the campus center. Anywhere big and quiet will work well, especially with high ceilings and nonparallel walls.

Here is where something portable like the DMP3 or RNP will absolutely kill a giant rack full of gear. I used to tote around a 12u slant case on really nice casters, but why bother anymore? I want a preamp the size of a cell phone :)
 
Well you can ask Fletcher if he considers himself a Top engineer:

http://www.gearslutz.com/board/5778299-post30.html

Of course you were already on that thread stating that the RNP wasn't high end. I think your argument was that it didn't cost enough.

The bottom line is that you came on this thread to recommend to a college student that he spend over 3x his budget to buy a preamp that you sell, and if he didn't, then he could never be a Top engineer. That is crass as hell, and it's also spam, so I suggest you limit your posts to responding to questions where people have actually mentioned your gear before you do.

PS: sure the RNP + input transformer can match noise spec, it would require changing a couple of resistors in the RNP, but that's all. Low noise isn't that hard when you have 1:4 on the front end . . .

PPS: who really cares about gonzo headroom? +/-24V rails, hooray. Does nothing when your converter runs on 5V. I suppose you can saturate the output transformer more, but that's not headroom then, is it?

You don't read very well do you, never said ANYTHING about does NOT cost enough...WOW...
I would bet I could mod a Mackie, put an iron core trans on the output and it would smoke the FMR and still be less than HALF per channel...PLUS you get a real power supply and chassis and decent Eq's...

By the way the analog section of a DA/AD does NOT run on 5V..More like +-18V...
And the digital is more like 3.2V...
 
You don't read very well do you, never said ANYTHING about does NOT cost enough...WOW...
I would bet I could mod a Mackie, put an iron core trans on the output and it would smoke the FMR and still be less than HALF per channel...PLUS you get a real power supply and chassis and decent Eq's...

How many times are you going to respond to the same post? Sure, you can "mod" anything to be anything else. So?

By the way the analog section of a DA/AD does NOT run on 5V..More like +-18V...
And the digital is more like 3.2V...

Ahh, but somewhere the analog and digital must meet. Link me a datasheet to an ADC IC that accepts a +/-18V input. 6-7V is far more typical, and the maximum swing for 0dBFS is usually much less than that range.

Such that any box that accepts a +/-18V input signal will merely attenuate its input to fit the range the chip can actually accept.

Here are four examples:

AK5394A : max swing 5.6Vpp
PCM1794A: max swing 6.8Vpp
PCM4202 : max swing 6.6Vpp
CS5381: max swing 7.4Vpp

If you are designing a converter that uses such ICs, you *have* to limit the ADC input to those levels or you risk destroying the IC. So you have a choice, you either assume the incoming levels are always higher and you pad them, or you assume they are usually lower and you clamp them, or you do a combination of padding and clamping (you're going to clamp anyway to make sure nothing explodes). Or you put in a switch so you can let the user decide.

So what does increasing level to 48Vpp accomplish? As you know, increasing gain in a given stage will reduce bandwidth and increase distortion. You have to compensate for that by using faster amplifiers, which tend to be either noisier or less efficient. Thus it's practically impossible to do large amounts of gain, say >66dB, in a single stage, so you force a requirement for two gain stages. Why? Just so you have to attenuate the output?

Another possibility is the desire for transformer saturation. Fair enough, but then why spend the money on Jensens? Those are designed not to saturate. It's much more effective to use a transformer that saturates at lower levels if that is the desired effect. It's also quite a lot cheaper.

Thus, headroom as a goal in and of itself is pointless. Define the actual requirement, exceed it by a few dB, and have a few beers :drunk:

Anyway, as sexy as +/-24V sounds, it's a whopping 2.5dB more than +/-18V. Hardly seems worth the price of a discrete opamp, more expensive power supply, etc. Also, with an output transformer you could simply invert the output of a 36V IC opamp and feed both to the transformer. That would exceed the headroom of the single-ended 48V supply (although the transformer would probably be crying at that point).

Also, why not build your own opamp out of discrete transistors? I don't get why a part that is about 20 $0.10 transistors and the same number of resistors, and a capacitor or two costs $50+. It's only about $5 in parts.

Like this thing, for example:

http://www.diyfactory.com/data/Great_River_Opamp2.pdf
 
A buddy of mine has the JM-130. I was recently looking to buy a new mic pre in that range and I tested his out. The thing sounded HORRIBLE. Thin, muddy on the lows but ultra sensitive on the highs. I felt like I was using an Mxl 603s in the form of a mic pre. Avoid that and go with the dmp3. It was my first mic pre and I still use it occasionally to this day!
 
Note: the complaints about the commercial use policy unrelated to OP's question have been moved to BBS Feedback:

https://homerecording.com/bbs/showthread.php?t=311738

This thread is for discussion of the OP's request for recommendations for a preamp at his stated $600 budget. Posts in this thread that are not on that topic will be removed.
 
Note: the complaints about the commercial use policy unrelated to OP's question have been moved to BBS Feedback:

https://homerecording.com/bbs/showthread.php?t=311738

This thread is for discussion of the OP's request for recommendations for a preamp at his stated $600 budget. Posts in this thread that are not on that topic will be removed.

But .... But .... Damn. :D

Go with the FMR "RNP" It's with in your budget and for the price it can't be beat even with preamps costing 3x as much.







:cool:
 
Thats "good beer and cheap women"

The only pertinent off topic thing I have to add is that MSHlarious got it wrong with using those savings on "cheap beer and women."

I strongly advise "good beer and cheap women." Cheap women will drink Bud Light instead of the $50 bottle of 1969 Foussez Poussez. Then you can have all the imports and microbrews you can swallow.

Cheers!

Prado
 
You gotta go out back behind the lanes to where the guys are that set the pins back up! :drunk:







:cool:
 
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