View Full Version : SB3 as Preamp

2007-05-20, 11:26
Hello, i have been trying to use the SB3 as a preamp to my Trend Audio 10.1 but when i am playing it does not sound so good in the bass region. It
sounds like the bass is coming like 1 second after everything else in the music.

As soon as i just use the amp as a standard amp and not with the sb3 as preamp the souns is amazing.

Is there any way to get this problem fixed?

I have a friend who is building a new power supply for me at the moment and hopyfully it will fix the problems.

But is there any more modification i can do to get more power to the sb3?

2007-05-20, 23:37
you may find your answer here: http://wiki.slimdevices.com/index.cgi?ConnectToPowerAmp



2007-05-21, 01:33
There's a couple of problems here.

If your setup in conventional mode sounds 'amazing', why do you want to change it? Having tried an alternative setup and found that, in your case, it doesn't provide an audible improvement, why not just switch back?

In my experience, problems with bass can often be improved by changing speaker placement. If you have a subwoofer, changing its position, phase, gain and rolloff can all make an enormous difference.

The last thing you want is 'more' power to your Squeezebox. What you want is 5.0V, with enough current available (a factor which is determined by the design of the SB3 - having more available from a PSU doesn't mean it ever gets used), and as little noise as possible. Forcing more power into the SB3 would mean it gets hot and then breaks - neither of which would make it sound better.

2007-05-21, 08:15
the problem is that i want to use two trend amps, and not use two volume pots.

I will gett a pre amplifier when i can afford the one i want.

The powersupply is going to be 5.0V and 2A so it will not mega powered.

I think it has to do with this.

it is essential to ensure the source output level is matched to the amplifier input senstivity (the input level that achieves maximum power).

2007-05-21, 08:45
OK - your PSU is correct, though I'd have thought that any improvement would be subtle at best.

A new PSU won't affect the output level from the SB3, though - it's not clear to me from your posts whether or not you expect that it will. A new PSU certainly wouldn't be the first thing I'd try to cure a problem with poor bass.

There's more to matching sources & power amps than just making sure you can get maximum power. I'd suspect that maybe your amp is a fairly heavy load (low, possibly non-linear input impedance), and so the signal from the SB3 is getting distorted trying to drive it. In that case you really do need a preamp.

The wiki page talks a lot about level matching, but doesn't even mention this potential issue, which is surprising. Maybe it was deemed to be one layer of complexity too far.