DIY pre amp board

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thoglette

Member
2008-12-20 5:59 am
I am looking for any supplier of a pre amp board.

Are you looking for a specific pre amp?

if not, that popular internet auction site is full of them (71 results for "preamp pcb" right now).

Do you need gain/low impedence output? A passive unit might do.

But most of the work is in mounting and wiring the input sockets; selector switch and volume knob.

And there's units like Lynn Olson's Raven which don't really need a PCB
 
I'm looking for a cheap solid state board that uses the 5532 style chips with some extra gain for when the CD player, phone ect doesn't have enough drive.

The ones of the auction site don't have schematics and I would rather add my own components as the actual assembly is what I enjoy the most.

I do like that Tube unit you linked to but for a tube pre.
I am slowly acquiring parts for some tube gear but at my income level it is a few years away/if ever :)
 

thoglette

Member
2008-12-20 5:59 am
A poor man's raven

I do like that Tube unit you linked to but for a tube pre.
I am slowly acquiring parts for some tube gear but at my income level it is a few years away/if ever :)

You might want to read Poor man's Raven. The thread shows clever ways to use significantly cheaper iron.

If you can afford a single 6SN7, 5687 or I believe 6900, 7044, 7119 and ECC99 (worst case, just a 12AU7), a few decent caps and some solder you can go play valves. You don't need to shop at Audio Note :D.

A valve rectifier will cut down power supply noise if you can find another meal's worth of cash.

I regularly use back-to-back mains-to-12V (or similar) transformers to get a
weird B+. And PA iron for PP opts. Mains transformers can work as power supply chokes if suitably derated. It's wrong but it works.



If all you want to do is build an op-amp PCB & roll your own components and you're on a budget find a small prototyping PCB. (Eg. this one) You can get them for a few bucks on ebay if you've no local shop.

I've built dozens of little circuits on them over the years of all types.

Particularly if you're going NE5532. It's better than a 741 or '072 but if your layout is half sane it'll be the limiting factor, not your soldering! There must be a billion op-amp circuits on the web by now. (And when you get a few dollars, swap that 5532 for something nicer from BB or AD)

You can get away with no PCB at all - I've seen people solder directly to an op-amp and hot-glue the op-amp to the chassis. Butt-ugly but functional.

Having said all that, "Try the search, Luke" (sorry :eek:). If I search the 'bay with "5532 PCB" I get quite a few bare boards. All of which can be reverse-engineered to create a schematic you can play with. The 5532 is so cheap (compared to your chassis, jacks, selector switch and volume pot*) that you just have a go.

* if you're really skint keep an eye out for trashed old "stereo" equipment. Strip the guts out and reuse the jacks, switches and (shiney) chassis. Avoid post eighties "home theatre" as it usually uses pushbuttons and microprocessors rather than real selectors. The pots and switches may be scratchy but there's ways around that if it really bothers you.
 

thoglette

Member
2008-12-20 5:59 am
Back to the original questoin.

I am looking for any supplier of a pre amp board.
Can't seem to find any, basically I want something that will let me use line level items (cd player, I pad, tape ect) to drive an amp.

Answering this directly you could do a lot worse than consider one of ESPs projects, perhaps the MkII. If you must have NE5532 use the Mk1.

All the PCBs are available directly from ESP's sale page

Here is a neat twist on the project using Radio Shack veroboard.

You can probably find something similar through some of the forum's sponsors
 
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