phono preamp battery powered design

[ilaboo]

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

 

[Don Bowey]

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

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:

http://www.epanorama.net/circuits/phono.html

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

http://www.geocities.com/rjm003.geo/rjmaudio/diy_pho5.html

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

 

[gearhead]

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

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

 

[mng]

http://sound.westhost.com/project06.htm

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.

 

[Michael A. Terrell]

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

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



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Tam]

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

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

 

[Ecnerwal]

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.

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.

 

[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.

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

 

[Jim Thompson]

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

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

 

[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.

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:

http://www.reprise.com/host/circuits/riaa_preamp.asp

http://www.paia.com/prodimages/riaasch.gif
or buy that:
http://www.paia.com/riaa.asp

A tube version:

http://www.ominous-valve.com/images/riaa_preamp.gif

And transistor:

http://www.lh-electric.4t.com/bin/riaa1.gif

 

[Ecnerwal]

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

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

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

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.

 

[Mark Zenier]

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)

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 [email protected]
Googleproofaddress(account:mzenier provider:eskimo domain:com)

 

[Paul Hovnanian P.E.]

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?

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.

 

[whit3rd]

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

There are lots of example circuits in the archives, like

<http://www.national.com/an/AN/AN-346.pdf>
<http://ee.wustl.edu/class/fl04/ese498/AN-32 FET circuits.pdf>

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?

 

[donald]

There are lots of example circuits in the archives, like

<http://www.national.com/an/AN/AN-346.pdf>
<http://ee.wustl.edu/class/fl04/ese498/AN-32 FET circuits.pdf>

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