[Sathimas]

I am currently gathering materials for my exstata and want to integrate a bassboost.
(Which will be bypass-able per switch)

I am using a STAX SR303 - most of the time I really love their sound but sometimes the low end is just a little too thin.

I know next to nothing about filters of this kind but found the circuit used in AMBs M³ amplifier.
Its a 6bB/octave lowpassfilter which would fit my requirements.
The only problem is that it is designed for a single-ended amp while the exstata is a balanced amp.

It would be really nice if someony could give my a circuit scheme.
I don't know the final "shape" of the filter yet because I first want
to build the amp and then test some different values using a
parametric eq on my computer. (But 6dB/octave will be fine, just max. boost and corner frequency aren't defined yet.)
At the moment I only have the phones but no amp.

Some more information on my setup in general:
My exstata will use XLR-inputs - connected with adaptors to my cd-player with RCA-output-jacks.
I am planning to build a balanced DAC in the future.

 

[Emooze]

AMB's bass boost is built into the feedback circuit. On the eXStatA, there's 2 feedback loops per channel so I'm thinking that's where they'd go.

I'd really PM runeight though and see what he has to say on the matter.

 

[pabbi1]

If it is of any relevance, I didn't notice any lack of bass with the SR303 on the eXStatA prototype - just don't remember if it was the SS or hybrid, though it was only a brief impression on just a few selections.

Am definitely interested in your research, and how the bass boost impacts other frequencies. One real strength of eXStatA is the balance of presentation, so this should be really interesting.

 

[Beefy]

Quote:

Originally Posted by Emooze /img/forum/go_quote.gif AMB's bass boost is built into the feedback circuit. On the eXStatA, there's 2 feedback loops per channel so I'm thinking that's where they'd go.

The amount of negative feedback applied in the M3 is much higher than that used in the Exstata. I don't think it is a particularly good idea to try and implement it in the same way.

 

[Sathimas]

Quote:

Originally Posted by pabbi1 /img/forum/go_quote.gif If it is of any relevance, I didn't notice any lack of bass with the SR303 on the eXStatA prototype - just don't remember if it was the SS or hybrid, though it was only a brief impression on just a few selections. Am definitely interested in your research, and how the bass boost impacts other frequencies. One real strength of eXStatA is the balance of presentation, so this should be really interesting.

"Lack" of bass is a very subjective thing.
I'm not a basshead at all but some of my CDs just sound too thin with the 303, not many but enough to think about a bassboost.

About the implementation of the bassboost - I never said I wanted to integrate the M³-boost into the exstata.
Just the shape of the filter is what should be "copied" in any case.

I think I would prefer some kind of extra circuit that I can simply switch "in and out" of the signal pathway.

I wouldn't like to run wires across the boards or whatever.
This is more like a standalone passive EQ I think.

 

[luvdunhill]

Quote:

Originally Posted by Sathimas /img/forum/go_quote.gif This is more like a standalone passive EQ I think.

so, let me get this straight. You want a passive EQ circuit to "add" more bass?

 

[Sathimas]

I do not want to "add" more bass but substract the higher frequencies - just what a lowpass-filter does.
If I begin at 25Hz - 50Hz will be 6dB qieter than 25, 100Hz 6dB quieter than 50Hz.

Simply said I want to make mids and highs quieter - bass gets "louder" relatively.