BLZS and SOZ problem

[Adams_Leo]

I want to build BLZS preamp and SOZ amp.
1.My CD player no balance output and the SOZ need balance input.so I want modify the BLZS preamp.input unbalance signal but balance output.it can work well,the attach file has modified BLZS SCH.
2.if build 10W SOZ,the 8 Ohm resistance use dale 50W is OK?

 

[mefinnis]

The BLS article tells you that the circuit can be used as an unbalanced-to-balanced converter by simply grounding 1 of the input leads ...... so, yes, this will work.

50W Dale's will be quite sufficient at 10W.

Regards

Mark

 

[jh6you]

In addition, I recommend to replace R3/R4/R5/R6 with constant current sources (CCS), for a reliable set of symmetrical output swings. There are many guidances how to make simple CCS in this forum.

 

[eLarson]

I used the current source (sink) that NP showed in his A75 front-
end: a zener being fed by a resistor attached to the positive rail,
and filtered with an RC. This establishes a relatively stable
voltage which I used to drive the gate of an IRF510 (two,
actually: each gain MOSFET gets its own in mine.)

It works well, but in my can't-leave-well-enough-alone mania I'm
thinking of cascoding the gain devices.

Erik

 

[kenbeyond]

Question

Follow this circuit, unbalance input and balance output, i imitate one and test, but the +output level and -output level is difference, near 0.2V(input 0.5V), is problem? i remember Son of Zen document also same like this. (photo is + - output level addition)

 

[wuffwaff]

Kenbeyond,

this is the normal behaviour if you don´t use current sources. Since the output differential is ok I wouldn´t worry about this.

william