RIAA sound 'colouring'

Hello all, a question from someone who knows nothing about DIY audio - so please forgive me if you feel this is a ridiculous question.

As someone who creates his own music using hardware and software synths, and listens to the sounds created using a pair of studio reference monitors (KRK RP8s), I'd like to find out what your opinion is on the differences in 'tonal qualities' of different components used in a battery powered RIAA preamp.

From my searches on these pages for a suitable unit/schematic, I'm faced with a dilemma in that I'd like to source a basic preamp which doesn't colour the sound if at all possible. Do different components of the same value have a dramatic effect on the sounds/signals passing through them, or am I worrying unneccesarily?

How difficult or costly would it be to achieve a close representation of the output of the cartridge? I'd like to import the track as it was intended to be played, ie, no major colouration. The reason for this is, I want to move away from using a hi fi amp so that my turntable can go direct into my digital mixer. I considered a software RIAA curve, but as I won't be recording at 96Khz or above, I've chosen not to go that route. Would a battery powered preamp be suitable for what I want? I'm also trying to acheive a good balance between a 'clean' signal and a low cost unit.

When you've stopped laughing, what advice can you give?!:D

Here's a link...


That explains the basics, if you haven't gotten to Googling it...

Some of the other 'standard' equalization curves would be interesting to try I'm sure.

As far as I understand, an RIAA equalized preamp just has a small (usually passive?) filter in it consisting of a few resistors and capacitors.

Going directly to track... Preamps are good. They lower the ratio of noise (usually) to recorded sound. Use a preamp.

If you don't want to use a preamp, just find a RIAA passive filter design and put it inline with your turntable before your recording interface. Try it out. Why not if you have the time. Let me know how it goes.

If you don't want an RIAA curve, use a regular line amplifier.


diyAudio Moderator Emeritus
2003-01-18 7:57 am
Near London. UK
You definitely don't want to attempt RIAA equalisation in software; it will eat up 40dB of your dynamic range. Given that even good soundcards have trouble bettering 100dB, that would leave only 60dB for the audio. But you need some headroom to allow for clicks, say 6dB. You now only have 54dB. That's a good deal worse than LP.

Making a good phono stage is about as difficult as making a good microphone amplifier. And the prices are similar, or higher. Try searching for "phono stage" or "RIAA stage". The "tubes" forum has plenty of RIAA stage designs, or, if you don't like high voltages, the semiconductor manufacturers have plenty of application notes with IC designs.