audioPT PreAmp

[audioPT]

I've started a thread here, but I think it becomes off topic in the subject.

So, I started this one.

Here is the schematic:


Legend (from portuguese to english):

Groups:
do selector -> from selector
6 canais dvd -> dvd audio channels
condicionador de entrada -> input conditioner
controlo de volume -> volume control
para o controlo de volume -> to volume control pcb
para o filtro do subwoofer -> to subwoofer filter pcb

Channels:
E -> Left
D -> Right
FE -> Front left
FD -> Front right
LFE -> Low frequency effects
C -> Center
SE -> Surround left
SD -> Surround right
Sub -> Sub output

The RE1 selects between L+R and FL+FR as I have a source selector and I'll use the same front speakers for movie and music.

The SW1 selects between LFE (from dvd) and low frequencies taken from the sum of left and right channels when in both dvd or music listening.

Comments?

[ThorstenL]

Konnichiwa,

Originally posted by audioPT
Comments?

Hmm. All the stuff we love in quality audio. Poor sounding, nasty VCA's, the many beloved NE5532 all over.... And to think I'm criticising the Burr Brown PGA2310 & Cirrus Logic CS3310 Volume control chip's fopr their poor sound quality.

Now if all you are interrested in is usinging generic parts and having the fucntionality, with no regard to good sound your design is sufficiently equipped to do that.

If you are interested in at least a minimum level of sound quality I'd suggects trying the Nat Semi Volume control Chips (no on-board Op-Amp's, much better choice than either BB/TI or CS) and discrete J-Fet buffers on the input and between Volume Control Chip and output stage. Then consider an output opamp with "cojones" and good speed (Nat Semi LM6181 or AD811 or more modern equivalents would be my choice).

Anyway, my view.

Sayonara

[audioPT]

Yep, you're right, but this preamp is for my 23 y/old sister.

She can't differenciate from tube or solid state, and I want something sufficient at a low cost.

I'd preferred go passive and buy a DACT switcher, of course

I only want to know if the design is correct