[niknik]

Hi there!

I'm gonna go for Wayne's analog mod (I really like the simplicity this mod offers) on a SB2(or3)  and run directly into my amp.

I read that it is very important to check the output impedence and voltage of the modded SB2/3 to make sure it's compatible with the amplifier. I have no clue if it will be compatible to my amp. I have a Musical Fidelity P270 (designed by Tim de Paravicini)
http://www.whelan888.com/p270_5.jpg
-but I have no clue on the specs on this thing and how to know what to look for to determine if it is compatible with a modded SB2/3?

Can anyone help me on this?

Regards,
Nik

[Wayne1]

What's more important is the input impedance and sensitivity of the amp.

The efficiency of the speakers also comes into play.

The DAC chip of the SB2/3 is rated to work with amp input impedance's over 5K. The higher usually is the better.

The DAC chip has full output of 1.1 volts. The amp should be spec'ed to deliver full rated power with 1 volt input.

Hopefully the speakers are around 88 db efficient or greater.

All of this is relative to achieving a volume level in your room that will be adequate to your listening preferences.

[robert1325]

I'll save that information, It could come in handy for me to sometime....     I'll see how the modded SB fares with my cambridge amp.   

Any updates about my SB, wayne?     

[Wayne1]

It hasn't arrived yet, Robert.

[robert1325]

OK,   can't wait to receive this thing         ,     Holland is so small compared to the US ,   Takes 1 to 2 days for something to arrive....

[niknik]

What's more important is the input impedance and sensitivity of the amp.

The efficiency of the speakers also comes into play.

The DAC chip of the SB2/3 is rated to work with amp input impedance's over 5K. The higher usually is the better.

The DAC chip has full output of 1.1 volts. The amp should be spec'ed to deliver full rated power with 1 volt input.

Hopefully the speakers are around 88 db efficient or greater.

All of this is relative to achieving a volume level in your room that will be adequate to your listening preferences.

Thanks Wayne,

I guess I have to study this a little more before I get the idea fully.

But one question:

I would like to use the SB2/3 analog outs straight to one of the small "class T" amps.. I'm thinking of the "Charlize" from diyparadise.com:
http://diyparadise.com/charlize.html
http://202.186.86.35/audio/story.asp?file=/2006/3/30/audiofile/30charlize&sec=audiofile
(hope it's ok to post these links?)

- Is there anything I should consider in this setup? Will it be "ok"?  Right now I have a pair of Kef 104/2 speakers which are 92dB -and I am in the middle of getting(building) a pair of speakers that are 94/95dB

[Wayne1]

niknik,

Looking quickly through the data sheet for the Tripath TA2020, it appears the chip should reach full rated power at 0.745 V RMS input.

This is with RI and RF equal. http://www.tripath.com/downloads/TA2020.pdf

Check with DIYParadise to make sure this is so. 

Anyway, the modded SB3 should work with the Charlize just fine. You will have plenty of volume from the SB3 to the amp.

Some speakers are happy with the 10 or so watts the Tripath can deliver. Others need a bit more current to really get going.

[niknik]

Thanks Wayne!

I'll write DIYParadise and ask just to be sure

I look forward to hear this combo - I think it could be quite good maybe (and compared to the costs maybe very good)

Regards