Preamp design

[Alex]

Hi all,

Im fairly new to the world of audio DIY, and am currently building a couple of 200W mosfet modules for my stereo. However I am having alot of difficulty finding a suitable pre-amp design to use.

I am not using vinyl sources or anything, and am just looking for something with volume/balance/tone. Almost all of the designs I have come across on the internet deal with tubes, mic inputs or vinyl inputs - i have had very little success trying to find something that I can simply connect to my CD player!

So if anyone knows of any designs which fit my application or can point me in the direction of some schematics I would be most grateful.

 

[Geoff]

Alex

This project at the ESP Audio Pages should meet your requirements:

http://sound.westhost.com/project02.htm

Geoff

 

[Alex]

Thanks, that looks pretty much ideal =)

Any other designs so that I can shop around before I commence building?

 

[paulb]

An alternative is to use an all-in-one chip:
http://www.national.com/ds/LM/LM1036.pdf

 

[Alex]

Paul,

Those chips look fairly impressive - but i want to make sure I am getting a high quality sound. Do you think that this arrangement is any better or worst with regards to sound quality than a basic discrete op-amp setup, similar to the project described at

http://sound.westhost.com/project02.htm

(Thanks for pointing out that one Geoff.)

Could anyone who has had expereience with these chips (LM1036) post their opinions?

Thanks

 

[paulb]

A member here named partyjups was going to try this circuit - do a search on LM1036.
I'd go with the op-amp circuit myself, just giving you some options. The LM1036 has an advantage in that only DC is going to the controls, not the audio itself.

 

[Geoff]

Alex

I haven't used the LM1036 so cannot comment on its sound quality but bear in mind that was designed for use in, quote, "car radio, TV and audio systems". Most devices intended for this type of application are definitely mid-fi at best.

The performance of a discrete op-amp design is likely to be considerably better than that of the LM1036, particularly if high grade devices are used. If you use sockets for the NE5532 op-amps in the design I linked to, you can upgrade initially, or at a later date as funds permit, to higher performance op-amps such as the OPA2134.

Geoff

 

[paulb]

I agree. Trying different stuff is the heart of DIY audio. The LM1036 doesn't give you a lot of latitude.

 

[Alex]

Thanks for the suggestions. I think I will build the pre-amp linked to by Geoff, from ESP electronics.


Simple high quality Hi-Fi preamp:
http://sound.westhost.com/project02.htm

Anyone build this particular circuit? Any contruction tips or modifications suggested?

Thanks again for the help =)

 

[vdi_nenna]

http://www.diyaudio.8m.com/jfet.html

 

[Alex]

Vdi_venna: In that design you linked to (http://www.diyaudio.8m.com/jfet.html) how hard would it be to incorporate a tone control?

 

[vdi_nenna]

I've seen passive tone coltrols. Thye don't look all that complicated topology wise. I think, on the same site, there is a small ciruits section. You might find a tone control there. Let me look....nope.

Try this one:

http://www.epanorama.net/audiocircuits.html#control
BTW- This site has tons of circuits, not just audio.

These are active circuits. I looked for passive and there was a wierd sign-on screen.

Good luck!

Vince

 

[paulb]

Also look on p. 3 of:
http://www.national.com/an/AN/AN-32.pdf
It uses an op-amp, probably same as the others.

 

[Alex]

Thanks for everyones ongoing help, I think these forums are the most useful Ive ever used.

I'll start building soon, let you all know how it goes.