Easy DIY RIAA-preamp wanted.

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Hi, I am in need of a preamp for my old turnable.

It seems that the guys at HK neglected to put a phonoamp in my reciever......

so instead of buying one i thought that i perhaps could start up a new hobby and build one myself. But since there are so many schematics out there i thought that you guys could recommend one thats quite easy to build and with complete schematics for powersupply and amp-stage....

anyone got any suggestions?

imput sencitivity and impedance of the existing amp is 200mV and 47kOhm
 
thanks, but there was only the partial schematic.....

im not looking to buy a kit, only the parts and solder them together and put it all in a chassi (to make short summation ):)

much cheaper that way, and a kit feels like cheating......
 
kmj said:
thank you, coffin.

The el cheapo seems to be what im looking for.

could a PCB transformer be used instead of a torrodial?

how would a powersupply look in that case?

I use a small PCB transformer -- be careful to keep the a.c. line inputs away from the phono inputs. for the power supply I use a pair of LM317's and a pair of LM337's -- for the + and - rails.
the first regulator is set to 19 volts, the second to 15 volts -- the two regulators in series seem to prevent "turn-on" thump.
 

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for a first diy project you might want to avoid line power (esp european 230 VAC)

a pair of 9V alkaline batteries should last several days cont powering just 2 op amps

in the US i know many "wall wart" linear supplies are isolated from line/gnd so 2 "12 VDC" @ < US$ 5 ea could be a simple +/- 12 V supply

too many multi output supplies are switchers nowadays but some linears with +/-12 can be found for less than you can buy the parts - additional local RC filtering internal to your box could clean them up some

RC modelers use NiCd packs that are relatively cheap and I belive that NiCd can be indefinitely "trickle charged" so if your average use duty cycle is low enough this is a very simple and high quality option (the "on" switch disconnects the charger and connects the op amps)
 
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