Would this make a simple preamp?

[Jim Karr]

http://www.analog.com/UploadedFiles/...4SSM2019_0.pdf

Please take a look at this preamp IC. Would it be possible or advisable to try and make a complete preamp based on this chip?

[klitgt]

Originally posted by Jim Karr
http://www.analog.com/UploadedFiles/...4SSM2019_0.pdf

Please take a look at this preamp IC. Would it be possible or advisable to try and make a complete preamp based on this chip?

For audio? If yes, then NO!
Take a look at the applications recommended in the datasheet!
APPLICATIONS
Audio Mix Consoles
Intercom/Paging Systems
2-Way Radio
Sonar
Digital Audio Systems

No AUDIO (HIFI) mentioned.
Maybe I am wrong, but I have never seen this chip discusssed for audio here

[AudioWizard]

Originally posted by klitgt


For audio? If yes, then NO!

Wow, that's a blunt statement.

The distortion figure is not overly impressive (although it should be adequate for most middle-end uses), but the noise one IS!

It's certainly not what we could call an "audiophile" preamp, but you can certainly do lots of adequate audio circuits with it.

[Leolabs]

Like the popular CS3310 or PGA2311

[builderandy]

Hi Jim,

a couple of weeks ago I had the same idea acctually, using ssm2019 as a preamp. But the total gain is never less than 1 and therefore it isn't suitable to use as preamp for Audio use. (My idea was to set the gain with a log pot and only use two ssm2019 and a pot as a preamp)

Using it as a preamp for a microphone seems to be good application.

/Andy

[AudioWizard]

Originally posted by builderandy

But the total gain is never less than 1 and therefore it isn't suitable to use as preamp for Audio use.

Using the gain as an attenuator isn't always, IMO, a good idea. Most audio preamps/AOPs ICs have degraded performance for gains below 1 anyway, so that's not really interesting. (But it all depends on what exactly you call 'gain').

A very nice solution for this is a PGA2320. Hard to beat for an integrated solution.

[builderandy]

AudioWizard

I totally agree of your choice, pga2320, do you have some interesting links with more information about this circuit for diy.

My idea in the first post was to build a very easy and small pre amplifier. Placing a variable Rg will give me a preamp with the gain 1 to 1000. But since the signal from the CD player is approximately 1 V the input signal to the power amp will be 1 V minimum.

Gain(ssm2019) = (10000/Rg) + 1, Rg is the external component.

You could place the pot infront of the ssm2019 and set the gain to 6 dB, Rg = 10k. But then you will have no isolation between the output of the cd-player to the pot.

/Andy

[AudioWizard]

An interesting project using a PGA2310 (which is practically identical, the 2320 is slightly better though): http://www.mhennessy.f9.co.uk/preamp/analogue.htm

And of course check out the product page: http://focus.ti.com/docs/prod/folder...t/pga2320.html

[builderandy]

I found another link using the pga2311 a while ago.

http://www.dh3ben.de/html/electronic...1_preamp.shtml

The files in the link above could be imported into Eagle and thereafter it is possible to update the schemtic and board after your own opinion.

This is rather expensive and complex solution, my opinion, so I haven't looked into it further.

/Andy