Dear All,
I'm building a setup with minisharc + buffalo III + 4 IVY.

I need 4Vrms out on the single ended output of the minisharc.

Actually I'm having some troubles. Changing R1-R4 to 3kOhm and r13-r16 to 356R the output doesn't seem to change. The output level is very low.

Can anyone suggest me the correct configuration?

Thanks in advance,

Marco.

is it possible that noone can help me with this implementation?

Of course, the 4vrms out refers to IVY, not minisharc.
Since I'm not a big expert, I'm trying to follow guides and manuals.
Therefore, from IVY Maual I found out that:
Changing R13-R16 from 180 to 356 will give 4Vrms

Moreover, from buffalo Integration manual i found that:
In 8 channel configuration R1-R4 should be changed from 750 to ~3k.

I tried to follow both changes, but with bad results (signal low and audible distortion).

Than I found a thread where Russ suggests to change R13-R16 x4 for 8 channel configuration 2Vrms.

Now the question is:
What is the best Resistors configuration to use IVY+Buffalo III, in 8 channel configuration and ~4Vrms?

Noone that can help me with this configuration?
Noone has used buffalo in 8ch with 4 IVY??

Ok for doubling the voltage out.
But i think it works for a 2ch configuration.
I read that 8ch configuration needs more modification on ivy because buffalo ouput is lower... can u tell me the correct change?

I have only done 8 channel with Legato not IVY, but the principle is the same in that you will need to quadruple gain in order to get the same volume per channel as a stereo config.

Doing both mods suggested by avr300 would appear to achieve 4 times gain:

Increasing R21-R24 to 4.4k will double the voltage gain in the SE stage (from 2v to 4v).
(halving R17-R20 from 2.2k to 1.1k will do the same)

(2 X 2 = 4 times the gain)

Why do you think you need 4vrms? Do you need balanced or single-ended outputs?

R21-R24 and R17-R20 are participating in a 'differential amplifier' circuit

Doubling the resistance of R21-R24 will double the voltage gain. Quadrupling the resistance will quadruple the voltage gain, and so on (theoretically)

Similarly, halving R17-R20 will double the voltage gain. Quartering the resistance will quadruple the voltage gain, and so on (theoretically)

Google 'differential amplifier'and you will find ample explanations as as to how this circuit works and how to calculate the values you need for 8 times gain

see e.g.: http://www.electronics-t...ls.ws/opamp/opamp_5.html

BTW: I have not used the MiniSHARC but have had problems with some other MiniDSP products as they suffered from lock dropouts when mated with a Buffalo DAC (you will hear random clicks and gaps in the sound if it happens to you too). Let me know how you go.

Poss

Most importantly, the resistors should be matched to at least 0.1%, especially parallel parts in the balanced signal feedback loops.