Pre-amplifiers

Clack · Posted: Tue Dec 18, 2007 4:07 pm Post subject: Pre-amplifiers

Maybe a little off topic, but usefull if you want a microphione pre-amp in your system.

I need a microphine pre-amplifier for recording and I am on a low budget. I have been looking at various behrigner ones and thought " Hey I could just build my own for cheaper and in a custom rack case/panel?" ( which always seems to be the case at the moment )

My question is - if I built this

http://sound.westhost.com/project66.htm

would it be able to mach or maybe out perform the quality of a low cost commerical pre-amp? - I guess by taking out all the bells and whistles of a product you end up with a cleaner signal?

I am also wondering if there are any pre-amplifier circuits/projects out there that people have experimented with and can reccomend?

I guess there is a level at which building a pre-amp can out cost its quality? much like the uselessnes of building your own mixing desk?

elektro80 · Posted: Tue Dec 18, 2007 4:13 pm Post subject:

I think this one based on the THAT 1510 is far better than the superduper lownoise stuff found in the low end Behringer mixers.

Five Fish Studios Pre-amp kit

elektro80 · Posted: Tue Dec 18, 2007 4:26 pm Post subject:

Ah.. now the ESP page finally loaded. That one looks interesting as well.

TheAncientOne · Joined: Dec 26, 2006 Posts: 144 Location: United Kingdom

The ESP one works nicely. He makes some good points about the 78/79 series regulators too - no instrumentation engineer would give them house room.

Take a look at:

http://www.seventhcircleaudio.com/

These are better laid out than the FiveFish studios board, and their T15 is roughly the same device for $20 less. If you're not in the USA - bad news, they use UPS and their carriage costs to Europe are high, (like $105 for $160 worth of kits. This would average out on a large order though).

Another firm who's kits impress me are

http://www.jlmaudio.com/kits.htm

and with the Australian Dollar exchange rate you're winning too.

bearblock · Joined: Sep 27, 2006 Posts: 90 Location: uk Audio files: 1

Clack · Posted: Wed Dec 19, 2007 1:52 pm Post subject:

awsome, posh stuff .. thanks. Shocked

julianw · Joined: Jul 30, 2007 Posts: 78 Location: UK

I found this article fascinating:

Prof builds a simple $5 pre-amp circuit which blind tests would indicate 'blows away' $1500 preamps.

Judge for yourself (with audio samples)
http://www.record-producer.com/learn.cfm?a=3062

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

I'm sure you know that the link below is the mother lode of pre-amp info, but I'll put it here for anyone who hass not seen it already.

http://www.prodigy-pro.com/forum/topic-16909.html

Coriolis · Joined: Apr 11, 2005 Posts: 616 Location: Stilling, Denmark

I built that ESP P66 preamp. Rod seems to be a good trader, board got here fairly fast (Australia to Denmark).
I power mine with 2 9V batteries and use it for fieldrecording with my minidisc. Put a TL072 in mine - no noise that I can hear. If you can lay out the board yourself, it is very cheap to build. THAT 1510 isn't exactly cheap...

Maybe try the Green Pre? Supposedly a clone of the Amek Mozart preamp, and reported to sound very good and have very low noise.
http://1176neve.tripod.com/id10.html
This guy is on prodigy-pro as well and sells boards at 10$ a piece for the Green.

C

Funky40 · Posted: Thu Dec 20, 2007 4:50 pm Post subject:

bearblock · Joined: Sep 27, 2006 Posts: 90 Location: uk Audio files: 1

hi,

you are looking for pins 1 and 8. the resistance between these pins controls the gain of the amp. beware though - if you want it to behave like a standard 'volume knob' you will have to put a reverse-log potentiometer here.

you should be able to drop in a SSM2019 or THAT1510 here without having to make any other changes.

Funky40 · Posted: Fri Dec 21, 2007 2:05 pm Post subject:

Funky40 · Posted: Sat Dec 22, 2007 6:29 am Post subject:

bearblock · Joined: Sep 27, 2006 Posts: 90 Location: uk Audio files: 1

no problem Very Happy

10k would probably be a good value to start with. as you say, you might need to experiment to get it spot on. http://www.musikding.de/ have a good range of reverse log pots for sale, amongst other things.

Funky40 · Posted: Wed Mar 26, 2008 5:20 am Post subject:

regarding to the 5$ Mic Pre
http://www.record-producer.com/i/ina217-large.gif

sneakthief · Joined: Jul 24, 2006 Posts: 569 Location: Berlin

this FET pre, called the FETboy, sounds great and has tons of gain:

http://www.diyfactory.com/projects/fetboy/fetboy.htm

Posted Image, might have been reduced in size. Click Image to view fullscreen.

i built two and put them in a diy passive-mixer:

Posted Image, might have been reduced in size. Click Image to view fullscreen.

more info here - http://www.prodigy-pro.com/forum/post-261856.html&highlight=#261856

sneakthief · Joined: Jul 24, 2006 Posts: 569 Location: Berlin

oh and "Peter C" makes another great one called the Green Pre:

http://www.diyfactory.com/projects/green/green.htm

check out Peter C's other great pre's and projects here:

http://1176neve.tripod.com/