Hi guys
when the ampli arrived the first thing was connected and play for reference a cd that I know very well (the dark side of the moon)
really a tank, wharm sound, but.......
shit! bass was zero!
So... five minutes and the ampli was naked.
I've cut the two tiny cables of subsonic filter, connected as you noticed and play again music.
shit(x2)! bass is still zero!
Are you sure you have the subsonic filter block removed correctly?
But even then, that is only the beginning of the journey to make the AU999 a great performer.
I highly recommend you do the pre-amp modification. It brings the whole sound of the amplifier into another level of performance. You can read at the end of the thread a few guys did it and love it....
Check the thread here..
http://www.audiokarma.org/forums/archive/index.php/t-466545.html
the au999 isn't famous for bass response, but this is too poor!
managing the bass pot on + 4/+6 at 100hz is bit better. But I need for the 20-100 band.
In the manual I can read under Control " BASS +12db / -8db at 20hz.
but there isn't any way to menage the 20hz! where is the control?
May be that he need of a total recap?
May be that I use to listen music with valves ampli (a simply rogers cadet III) ?
A re-cap may help a little, it is hard to say without knowing how bad the caps in the amplifier are.
The tone controls are a bit shit on these amplifiers, especially the bass control.
The "centre frequency" for the bass control regardless of whether you have 200hz or 400hz selected, is 20hz.
This means that 20hz is boosted 12db when the bass is set to maximum.
The 200hz and 400hz is determined by a capacitor which controls the width of the boost/cut from the 20hz centre frequency, and if I remember correctly, the boost of 200hz when the control is set to maximum is only +6db.
But because this control is a Shelving filter, the frequency goes from 200>20hz or 400>20hz depending on which is selected.
The slope is too gradual, you cannot get enough of the "right bass" before you have the unwanted frequencies coming through.
This tone control (bass) is actually pretty much useless in my opinion.
I have modified mine, I have made the "slope" a lot steeper than factory, and increased the response.
I get +12db at 100hz now if I want it, which is a much more useable area of bass....
The slope is a lot more steep, more like what you would find on a professional mixing console, which is what I am used to.
I will post some pictures of which resistors to change, and the values of resistors to do this.
But you will need to modify the preamp as in my other thread, otherwise the pre-amp will not have enough headroom to handle this mod....
I may be able to do this over the next few days.....
There is 4 resistors to change to do this, it will take about 10 mins..
I can tell you, that this mod is brilliant, you will have all the bass you want, and more......
Hopefully you can understand my English enough to get the idea.....
I will post this in a new thread...