How To Build A Preamp?

KingRazor · #1 03-13-2011, 03:57 PM

I want to know how to build a preamp. What do I have to know in order to be able to build one?

I know there are people on this board that know how to do it, how did you gain that knowledge?

Before you say it, I'm already checking out what I can find on google.

KingRazor · #2 06-07-2011, 04:29 PM

3 months of nothing bump?

MPU · #3 06-07-2011, 11:59 PM

I'd say buy circuit board from unclefluffy, buy parts for the preamp (there's a kit on eBay for MM style preamp that has all the parts), learn how to solder and solder the preamp.
For a low pass filter-based preamp there's a schematic, circuit board and layout on musikding forum.
If you want to design your own preamp that's way out of my skills.
Marko

KingRazor · #4 06-08-2011, 12:08 AM

Well, that's a start. Thanks MPU.

**line6man** · #5 06-08-2011, 12:16 AM

How's your knowledge of electrical theory?

I don't mean to be rude, but if you have to ask, this is probably above your skill level.

MPU · #6 06-08-2011, 01:38 AM

If you can read and look pictures and learn how to solder it's quite easy. Just follow the plans.
Marko

PhiDeck · #7 06-08-2011, 02:11 AM

One of the various Pournelle's Laws seems particularly pertinent:

"If you don't know what you're doing, only deal with someone who does".

Paradoxically, if you don't know what you're doing, it can be very difficult to identify those who do.

KingRazor · #8 06-08-2011, 09:23 AM

Quote:

Originally Posted by PhiDeck

Paradoxically, if you don't know what you're doing, it can be very difficult to identify those who do.

Exactly. I don't know what I'm doing. That's why I want to learn how.

**line6man** · #9 06-08-2011, 10:08 AM

Quote:

Originally Posted by MPU

If you can read and look pictures and learn how to solder it's quite easy. Just follow the plans.
Marko

Wait, are we talking about designing a preamp, or simply assembling one?

KingRazor · #10 06-08-2011, 10:20 AM

Quote:

Originally Posted by line6man

Wait, are we talking about designing a preamp, or simply assembling one?

Knowing how to assemble one would be a good start. But I'd also, in the future, like to know how to design one.

I have basic soldering skills and I can follow instructions.

**line6man** · #11 06-08-2011, 10:33 AM

Quote:

Originally Posted by KingRazor

Knowing how to assemble one would be a good start. But I'd also, in the future, like to know how to design one.

I have basic soldering skills and I can follow instructions.

In that case, this is fairly simple. Since you can solder, you're halfway there.

Can you read schematics? Preamp designs will almost always be given in schematic form, rather than like a wiring diagram. This is MUCH easier to follow along with, once you're familiar with how to read it.

The main thing will be the PCB design. There are three ways to go about this. Protoboard, etching your own PCBs with copper clad board, and designing a PCB layout with software and paying a PCB company to make it.

KingRazor · #12 06-08-2011, 11:37 AM

What about just making a buffer circuit?

**VincentSalizeri** · #13 06-08-2011, 11:40 AM

I believe this page would be of interest to you.

bluesdogblues · #14 06-08-2011, 11:52 AM

I get them sometimes ago,..maybe it helps? sorry if not

Vintage MM Stingray preamp
http://i55.photobucket.com/albums/g1...Basspreamp.png

Yamaha TRB5 onboard preamp schem
http://i55.photobucket.com/albums/g1.../cdtrb456p.jpg

Yamaha TRB5 onboard preamp component list
http://i55.photobucket.com/albums/g1...trb456pcmp.jpg

Bartolini NTMB preamp
http://i55.photobucket.com/albums/g1.../NTMBschem.jpg

Status Graphite preamp
http://i55.photobucket.com/albums/g1.../status100.gif

Albert Kreuzer JFET preamp
Onboard JFET Preamp

Jazz bass special preamp
http://hem.passagen.se/robin2/im/fjbamp.gif

Alembic-like preamp
http://i55.photobucket.com/albums/g1...le-filter-.jpg

KingRazor · #15 06-08-2011, 11:54 AM

So basically, for a buffer, you need a transistor (jfet, opamp, bipolar, etc), some resistors, and a couple of capacitors of the right values soldered in the right places?

**VincentSalizeri** · #16 06-08-2011, 12:01 PM

Yeah, basically. I'm not the most knowledgeable on the subject, but I think I have an idea of how it works. The transistor is what buffers the signal. You need a resistor to ground before the transistor to set the input impedance, The capacitor on the input is a low-cut filter, I've heard from a few people that it's not necessary but handy to have. The output capacitor is to remove any DC from the signal. No clue what the last resistor to ground is though. I think it's to set drain voltage, and therefore the output signal volume.

SGD Lutherie · #17 06-08-2011, 01:50 PM

Quote:

Originally Posted by KingRazor

So basically, for a buffer, you need a transistor (jfet, opamp, bipolar, etc), some resistors, and a couple of capacitors of the right values soldered in the right places?

Just ignore the bypass switch, unless you want that, and the pot should be a trim pot.

You can get circuit boards at General Guitar Gadgets.

KingRazor · #18 06-08-2011, 01:53 PM

Excellent!

**Thor** · #19 06-08-2011, 01:59 PM

Also, check the FAQ thread stickied at the top of the forum. It has some links at the bottom of the first post for DIY preamp builds that you may find useful.

Passinwind · #20 06-08-2011, 03:35 PM

Quote:

Originally Posted by KingRazor

I know there are people on this board that know how to do it, how did you gain that knowledge?

Before you say it, I'm already checking out what I can find on google.

As Thor said, check the Amps forum FAQ. Here are two good learning resources for starters though:

Electronic Projects For Musicians

Elliott Sound Products - The Audio Pages (Main Index)

Derek (Uncle Fluffy) is about ready to start selling whole kits for his preamp board. It sounds very good and is a relatively easy build.