Building our own mic pre! Inquire within...

[tubedude]

I posted this last night after a few people expressed interest in building a mic pre:
"...I think we should look up a good schematic, say for a Neve 10xx series, or maybe a tube schematic like the Avalon (very nice) and find someone that knows what they are doing, and we all buy and build it a piece at a time, with the helpful instruction of one in the know. Kind of like Harveys big mic post, only building something. We could learn a ton, spend slowly, and eventually have a very nice preamp that we can be extra proud of.
I thik that one link has some schematics, or tons of them... http://nanaimo.ark.com/~pat/index.htm

Anyone be interested in this little group project? We could stretch it over about 4 or 5 months so as to go easy on the pocketbook, and expect to spend about $400-500 total.
My vote is on a Neve 10 series or maybe 1274.
If anyones interested, I'll round up some experienced moderators for the new thread we'll start for this. Let me know. "

Ok, heres the deal. I say we find out how many people want to do this, by voting yourself in, and everyone nominating/voting on a design that they would like to build. I myself, as said before, am interested in a Neve style pre, of course. I think many will follow suit. When have decided what we want to do and how many people we have to do it, we'll get some "in the know" hosts involved. This could possibly go quite well. I'm anxious.
Paul

[Henri Devill]

Great idea !

Don

[db51]

I'm definitely interested, just hope whatever parts I'll need can be found outside the US...This is gonna be fun

[ametth]

RE suggested an API 312..that gets my vote too. It's a very simple design, with relatively easy to find parts, very good project for a newbie...The Neve designs, will be much harder to build, costly and time consuming.

[MISTERQCUE]

Count me in! I can read a schematic drawing,some knowledge of capacitors,transistors etc,. Soldering iron and a willingness to give it a go.

I say we design a pre that's even better than the NEVE!! Why not! We ain't got nuttin' to lose!

Whenever you're ready tubedude,start it off!

[charger]

I vote for the API too, if you can get a schematic. I like that pre. I have a soldering iron, woohoo!!

[Dolemite]

Hey guys, I've actually been toying with the idea of making a pre based on the Davisound MP-2, which is a high-quality opamp-based pre circuit. I believe our very own RE has a couple of their "Tool Box" products, so I would be interested to hear what he thinks about the MP-2. The MP-2 comes with a mic pre schematic that is identical to the circuit used in their $650 4-channel unit (which uses MP-2's). It also contains the majority of the necessary electronics already in place so very few additional parts are needed. I have been in contact with Hayne Davis at Davisound and he claims that a pre could actually be built around the MP-2 without even soldering! Personally, I would never rely on non-soldered connections but that should at least let you know that this would be a pretty easy project. The MP-2 unit itself is $69.00, so I'd guess the whole project could be done for under $140 for one channel. Something to consider anyway:

http://www.davisound.com

Also, Paia makes a tube preamp kit for $60/channel that looks to be the standard single 12AX7 design. BTW, here's the schematic for it if you're interested:

http://www.paia.com/fantusch.gif

I have looked into building an API or John Hardy-like unit and to be honest, after finding and buying all the parts, I think you'd be better off just buying one. For one thing, the parts themselves, especially the transformers (if you can even find them), are quite expensive. You factor in the possibility of ending up with an expensive lesson in soldering and I'd avoid the Neve/API design as a first project. I'd try something like the Paia or Davisound, where I could afford to fuck it up, before I attempted a more expensive/advanced project.

So, if we can get some professional help in here (I know I'll need it ) and keep it under $200, I'm in!

EDIT:

I just found an API 312 schematic:

http://www.easystreet.com/~audio/Sch...PI/API_312.htm

Now where do we get a 2520?

[Roel]

Well, what I tried to post yesterday... (couldn't get thru.)

Building stuff is fun. It's alot of fun. But VERY time-consuming, and not cheaper than buying something. And you don't need alot of electronical skills... if it works from the first time on. If it doesn't work... Well, then you need expensive measuring tools (scope, regulated power supply, signal generator), and some experience to repair it.

I'm building a modular synth, since 2 years from now, still nothing that works. hehe... I've built some kits (paia) for other people and did some basic synth and amp-repairs. Without a basic electronics course, you really cannot start to debug that.

Also, what alot of people tend to forget, the electronic components are cheap but designing a -working- PCB takes alot of time, getting it manufactured nice and clean costs more than components, and getting the box and frontpanel and knobs is the real big cost. (Not counting in time and development cost, and transformers etc cost ALOT too...)

Tube circuits might be easier to build, but they are dangerous. With tubes you need high voltages, and everything I read about it says that you shouldn't start with it unless you worked with tubes before. (Well, how can you start with it then??? )

Don't want to discourage all of you. I like the idea too. But you shouldn't underestimate it.

Anyway, if I find the time, you can count me in on it. I will try building it after I get a good schematic and a working pcb design...

[tubedude]

Wow... I totally expected to see everyone shooting the idea down because it would be "too hard"! It might be too hard for all I know. I've been at work all night talking myself out of it "thats kinda stupid" kinda stuff... maybe its not...
Well then.. we have 2 votes for an API style, 1 for a Neve, and 1 for a design it ourselves type.
The API is probably a good idea, considering easy is gonna be a huge factor here. I don't want to burn my house down the 1st time I turn the power on!
I'll start the hunt for a few hosts. I have some decent people in mind. Invite those you may know also.

[Roel]

If the API is an easy one, you should start with that. You can always try a harder one if you got this one working and still have the courage to start on the next one.

You might want to consider getting pcb's manufactured for it. If you can have them manufactured all at once, it will save you alot of money.

By the way, with all respect to paia, I built some of their kits (theremin), and those are not designs that you want to put in a studio. Maybe if you put a decent power supply in... (The supply is one of the big costs you should count in. PowerOne is excellent.)

[tubedude]

I totally dig the davissounds idea. Totally.
We could actually turn it into a contest and see who can make the coolest/most professional/wackiest front panel. Your pre ahs to work in order to enter the contest
davissounds, anyone? premade pcb.... sounds feasible...

[tubedude]

uh oh...
http://www.musicplayer.com/ubb/Forum3/HTML/000311.html

[Roel]

My point exactly.

BTW, I'm a test engineer, I work with VERY expensive measuring equipement everyday (scope, (hardware) frequency analyzers (up to several MHz), logic analyzers...). I'd rather buy a good mic pre than spend that kinda money ona decent scope.

[Scooter B]

I have had this on my long range plans list for a while. I woud start now with you guys but i am in a financial crunch for a while so I will be folowing your developments.

The thing with tube pre's and safety (from what I have read) is that a lot of high voltage is stored in capacitors etc even AFTER the pre is shut down AND unplugged. You have to know how to bleed off or discharge any stored electricity before you start touching anything.

I coresponded with a guy I read about in Bassplayer that has done some of his own and I am attaching a list of resources he sent me. Hope it helps.

[Wallycleaver]

Here's an easy one
http://www.easystreet.com/~audio/Sch.../Urei/LA_2.htm

[CyanJaguar]

I am in.


we could also get a budding engineer to build them for us, and charge us something like $250, providing we order about 30.

NEve quality for dirt. I am totally in.

[Recording Engineer]

I see some people are on to DaviSound and I!

Yes, I have a DaviSound TB-1, TB-3, and TB-8, and a pair of DS-1950s and a custom console in the works.

You can read my comments on the TB-3 and TB-8 on the DaviSound website if you're interested.

Anyhow, the MP-2 module is what makes-up the "Mic All" preamps (along with "DaviSecrets" having to do with HOW the MP-2 module is used) in the TB-6 and TB-3. It's of the "natural" and "transparent" flavor type of pres and I am MOST happy with it's performance!

I'd most definitely say it'd hold its own next to a Grace Design, Great River, or even a Millennia Media. I've always said it'd be fun to be able to have all 3 in the same room with my TB-3... Even if you wouldn't tell me anything... Other than "This is what THIS manufacturer things of as "natural" and "transparent."

Well, to show you how confident I am of the "Mic All" pres, I'll tell you that those are the pres going into my console.

Now I'd say that the DaviSound MP-2 module would be an even better "First-Timer Kit" than the API 312. THEN, I'd suggest the 312 after that... THEN, MAYBE move-on to a tube design... THAT'S just MY suggestion.

[Dolemite]

Thanks for the recommendation, RE! BTW, emails from Hayne Davis suggested that getting the right power supply might be the most difficult part in building a pre based on the MP-2. Any idea on what type of power supply this circuit requires and where one might be obtained? Correct me if I'm wrong, but couldn't you just get a "wall-wart" style power supply with the appropriate voltage/amperage? I know that's probably not the ideal solution but I have plenty of prosumer gear that's crowding up my power strips with those damn things! That doesn't seem terribly difficult. Personally, I wish they sold a "Mic All" kit, but I suppose I'll have to scrape the parts together myself.

[hixmix]

If I say I'm "in", will it get me pussy quicker?

[ametth]

Originally posted by hixmix
If I say I'm "in", will it get me pussy quicker?

No, your a hopeless case.

[tubedude]

Ok, at this point I've done a few things...
1st, I've emailed around looking for someone to take the bait...
2nd.. I've looked up alot of stuff on electronics and class A preamps, and WHOA... we're in deep if we do this. I think I'm a bit scared of it at this point.
3rd... I've registered in the electronic circuits class at school along with my other classes for this fall. They cover all this stuff, class A, B and even C amps and circuits, including building filters and stuff, too. I think it'll be fun. Fun, or totally terrible. I'll see, I guess.
Time will tell, dont give up yet...

[sondriven]

I would like to build a nice pre, kinda getting sick of my Tube MP. Good pre but a little weak for my needs. Im in!

sondriven

[Roel]

Originally posted by tubedude
3rd... I've registered in the electronic circuits class at school along with my other classes for this fall. They cover all this stuff, class A, B and even C amps and circuits, including building filters and stuff, too. I think it'll be fun. Fun, or totally terrible. I'll see, I guess.

Woehoe... Congrats. It will give you alot more insight in what you're doing. Very interesting. But totally terrible.
I hope you have a good insight in what fourier is all about, frequency versus time domain,... All of that crazy maths-stuff. In fact, that is about the worst maths can get.

Did you have basic electronics courses already? Don't know how your system works... I guess so, it's not very usefull to study amps and filters if you don't know how a transistor works.

Anyway, we didn't see too much of that analog stuff. A course on opamp designs was about it (filters were covered, amplification too, not the class a b stuff, some oscillators,...). I hope you see more than that. But my bet is, you finish the course, you get the theory, you understand all the schematics, but you hardly know how to make a good design, have hardly seen the real advanced measurement tools, and still lack the knowhow to implement your schematic in a decent way (choosing components, pcb design taking shielding etc into count).

I'm being pessimistic. Maybe. Anyway, go for it. It will not take you all the way, but it will get you on the road. I really wish I had chosen the analog-type classes instead of the (for me, easier) programming stuff...

[Roel]

This is the book we used... All I know about opamps.

'Design with Operational Amplifiers and Analog Integrated Circuits'
by Sergio Franco

[NoFO]

Sounds like this could be very benificial financially if we do this right, b/c i have been thinking about buying 1 or 2 higher quality preamps, just make sure we get a mentor who has built something like this before.... I don't want to burn my place down, i just got finished rearranging everything!!

Chris