Recommend me a DIY studio preamp

[Xavier]

I will soon start recording a new CD and all I have a cheap Phonic mixer, which isn't exactly "low noise", "quality" preamp..... my computer setup has a nice good sounding soundcard with XLR inputs but I need a good front end also............

I need a mono preamp for both mic and instrument. There are some very nice Neve DIY copies out there but I'm afraid they are too expensive. I'm looking forward to a simple discrete design (which sometimes is better). Simple circuits like the AMZ Mosfet booster sound awesome with a very low parts count, I'm wondering if there's some kind of an equivalent out there for studio use.

Since I purchased a few Burr Brown opamps I guess there are better uses for them than OD pedals  .

Any suggestion?

[newfish]

Hi,

I'm reliably informed that some of the Behringer mixers are almost direct copies of Mackie kit.  There was some sort of legal wrangling over it, so they must be pretty close.

Might be worth upgrading your mixer to one with a preamp (if such a thing exists?)

[maxime]

you should have a look at "the lab" in this forum:

http://www.prodigy-pro.com/forum/

the "green pre"  should be perfect for you


building a complete kit will save you a lot of troubleshooting time:

http://www.hamptone.com/HJFP2.htm
or
http://www.jlmaudio.com/


have fun !

maxime

[swal]

I agree with maxime, the green pre is a great pre, I am in the middle of building two right now.

[Dai H.]

it isn't DIY but I'd suggest finding and trying out a used joemeek channel strip thing (VC3, VC3Q, MQ3, etc.). As a sort of reference *to my ears* it usually sounds bad when plugging in an electric gtr. or bass directly into a cheap mixer, cassette recorder, etc. My VC3Q actually sounds good and seems closer to a clean tube sound. The compressor is part of what my ears like too.

[Ardric]

I have a Phonic firewire mixer.  The pre's are ok... they're clean and low noise, though not absolute top shelf.

Much of the stuff discussed here (Neve pre, Green pre, Mosfet booster?) is not clean at all.  It's basically a distortion box for microphones.  And most of  that 'character' comes from the input and (especially) output transformers used.  Getting the correct transformers is very expensive.

That's ok if that's what you're looking for... lots of vocal tracks sound better with eq/compression/distortion/etc.  But don't assume that a distorting pre makes everything run through it sound better... it doesn't.  IMHO.

[rnfr]

it looks to me like the green is a transformerless design.  they sell boards, pretty cheap too.  i think i might have to build me a couple of these!
i think they would probably be great for my live sound rack, and they don't look too expensive parts-wise.

[.Mike]

First post here...

I did tons of research on building some preamps for my online radio show (talk show). I wanted something more accurate than the Behringer T1953 I had (naively) picked up, and I needed more gain for my mics (Heil PR-40s) than my Yamaha mixer could provide. I ended up getting a Symetrix 302 for about $75 on ebay. Excellent, flat, colorless preamp. Underrated and under-priced in my opinion.

But anyway, here are my bookmarks on diy preamps. I don't know if any of these fit the bill for you, but they're worth mentioning:

http://fivefishstudios.com/index.php?option=com_content&task=view&id=40&Itemid=59

http://sound.westhost.com/projects-2.htm (#37 & 37A)

http://www.record-producer.com/learn.cfm?a=3080



Mike

[richon]

look at my blog :  www.richon-caster.blogspot.com I just build a Green Pre with 2 channels and it sound awesome...


Right now i'm in the middle of desiding to build or not a Class A tube preamp : ALTEC 1566 A

[ashcat_lt]

$5 mic preamp

Apparently beat out several very expensive pres in blind taste test.  I don't think the $5 includes packaging or connectors...

[flo]

I wonder if all the recommended mic preamps have sufficient high impedance to use as an instrument input ( Zin >= 1M ohm). Like, for instance, the (very interesing) $5 mic preamp.

[earthtonesaudio]

I would definitely use separate inputs for high Z and low Z sources.  You could go crazy and build in a rotary impedance switch, like some really high-end mic pres have.  Just make sure you get the R-C calculations right. 

Another consideration is to use a JFET input for the high Z preamp, and bipolar for low Z.  I've heard that bipolars tend to have lower noise than JFETs when used at very low impedances (less than 1k).