Comments to PCB of Hiraga PrePre

[masag]

Hallo to everybody,
I am not very expierenced in Audio Electronics but did some tweaking before (Philips CD880 new analog stage, Jung line stage in my Rotel preamp.)
This is after a long break my first project. The four 2SB737R had to wait 15 years for their performance.
Powered with two 6 V batteries. I am using nonmagnetic dales, 4700uF Panasonic FC, and 1,5uF Mcaps from www.schuro.de

The input and output and battery ground are fixed to the star point.

Maybe the more expierienced diy-ers could have a look on it?

I don't know where I should mount the load resistor for my DL103?

Thank you

Sam

 

[masag]

Schematic Hiraga PrePre

and here is the original schematics

 

[jan.didden]

Hi Sam,

The simplest way for the load resistor is across the input connector...

But what is the value of the load resistor? The input impedance of this prepre is VERY low (couple of ohms) so do you need that load resistior?

Jan Didden

 

[masag]

Load resistor

Dear Jan,

thank you very much for the fast replay.
I know your articles well from AA.

My friend is using a 100R or 68 R Load resistor.
Do you think I should try it with out a load?

Sam

 

[euro21]

Hi Sam,


Hiraga prepre designed for DL-103 loading.

DON'T try any parallel resistor!

It's working fine with old, and new DL-103 series (aprox. 26 and 40 ohm) too.

 

[masag]

Hallo EURO21,

Thank you very much for your help.
Now I understand what you mean.
The input resistance itself is very low, and does not need a parallel resistor.

Herzlichen Dank,

Sam