phono preamp battery powered design

i want to make a phono pream so i can take my vinyl and turn tracks into mp3

i hve a basic knowledge of electronics and am a an ok solderer

i wan something incredible simple --like buy this op amp connect input, battery , output and thats all

chatuling net not really helpful--kits to complicated and lots of soldering--

any help is appreciated--i know there are solid state amps (components)

tia peter

Reply to
ilaboo
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If all you do is "pre-amplify" the signal in the manner you describe, you won't like the result.

Your pre-amp needs to include a filter, in each channel, that is the inverse of the one used in the recording process. It's fairly simple and you can find schematics with some googling, which should include RIAA, such as "riaa filter".

Here's one for a start, but you must separately add gain before or after it:

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Instead, I suggest you look for an "riaa active filter" such as this:

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None of this is incredibly simple, but the alternative is to buy one.

Reply to
Don Bowey

p3

LM386 you can buy it from an online vendor like digikey.com or even Radio Shack

Reply to
gearhead

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You're not going to be able to find something "incredibly simple". You can hook up a single op-amp with a lot of gain, but it's not going to produce the proper equalization.

My suggestion is to take this opportunity to build something a bit more complicated than what you're used to.

Reply to
mng

Sure, if you want lots of extra noise in your MP3 files. The LM386 is a piece of crap for that application.

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Reply to
Michael A. Terrell

As somebody mentioned, you can not use a flat gain amplifier. Suggest you Google "RIAA Equalization". The signal output by a magnetic pickup will be quite low, a few millivolts.

Tam

Reply to
Tam

...

Yes, well, the more boggling part of this is why the OP wants a battery powered circuit in the first place. Wants incredibly simple. Wants to make his records into MP3s. Has Records - therefore most likely has access to a record player and a wall outlet, and thus access (simple) to

90 million or so wall powered phono preamps that are now quite inexpensive as people move out of record players and send the associated electronics to second hand shops or the dump. Sheesh.
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Reply to
Ecnerwal

Don't know what he has, but many newer rceivers do not have a phono input. So, he may have an old turntable, and nothing to plug it in to.

Tam

Reply to
Tam

Same problem here... I have a turntable dating to the '60's, Rek-O-Cut (IIRC... it's up on a shelf, 12' up)

Has anyone tried the "turntables" recently offered that have USB outputs?

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
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Reply to
Jim Thompson

And the correct solution, if not willing to wire a few resistors and capacitors to an op amp (evidently beyond the OP's concept of incredibly simple), following any number of circuits that are available from the web, is to buy either a dedicated phono preamp, or a receiver that has one, from a second hand shop, *B*y, craigslist, or the like. Given the OPs preconditions, I strongly suggest non-battery power and doing exactly that.

The more capable members of the phono-preamp-less-world can probably find these on their own.

A few of the 3,620 images google image search returns:

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or buy that:
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A tube version:

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And transistor:

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Reply to
Ecnerwal

The second-hand market is full of functional phono preamps. The audiophool market has your overpriced new ones.

Personally, I'm hanging onto my early 1980's unit, as being at the peak of turntable design/construction quality. Once CDs moved in and took over, turntables were not worth building well anymore, and were not/are not being built as well to this day, IMHO.

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Reply to
Ecnerwal

30-40 years ago, you could buy a prebuilt module that had a magnetic pickup input, used to convert consoles that had an older "crystal" pickup to new turntables. A little metal box, two sets of phono jacks, and a built in 120 V power supply. (I used one to upgrade my folks Zenith console).

A couple of years ago, MCM Electronics (a repair parts distributor, sibling of Newark Electronics) still had them in their catalog.

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

Reply to
Mark Zenier

A little searching with Google will get you a phono preamp with line/USB/Toslink outputs for US$100 or less.

A friend bought one (brand name Art, IIRC) and I think it has line inputs as well, so it can be used as a general purpose A/D converter for any audio source you need to get into a computer.

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Reply to
Paul Hovnanian P.E.

p3

There are lots of example circuits in the archives, like

and one can easily get suitable (possibly newer) op amps and transistors for the project, but the resistor/capacitor networks are critical and require precision components. It'll take a bit of work to hunt and bag those.

Since every old stereo or preamp from the past decades has the circuit already built in (use the Phono or Phono 1 or Phono 2 inputs, and the 'Tape Monitor' outputs), it's probably best to use an existing box. If you don't have one, your parents do. Hey, you found the turntable, didn't you?

Reply to
whit3rd

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Reply to
donald

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