amp32-ps mods

[wadoka]

Hi,
My 'number 3' amp32-ps is now working and being left to burn-in. I have doubled the smoothing cap to 24000 by adding a second 12000, the same type as in the kit. I'm running it from a torroid.

I'm wondering what other mods I could do, I was thinking...
...Snake oil input caps of 3.3mf...
...Nice earthed two box aluminium cases, one for the transformer, one for the amp...
...alps blue volume pot, wired as a shunt though an expensive resistor..
...all internal wiring by 0.4mm silver wire..
...double the 470mf output caps, should give a stronger bass...

Any comments/suggestions?
Thanks!

[Mr T]

Hello,

It would be interesting to let us know if you noticed any improvement over the standard AMP32-ps whith doubling the caps value.

For the rest I have no clue, my own AMP32 is so sweet as it is that I won't mod it : http://tinylink.com/?Node5sG5gg

Mr T

[krilli]

Caps: I haven't tried it myself, but I'll go to these pages when I do:
http://www.ecp.cc/cap-notes.html
http://www.humblehomemadehifi.com/Cap.html

From my PIMETA headphone amp, I know that a bad pot is bad. So yes, good pot.

About the output caps - hmm. Are you talking about the capacitors that are the output filter, along with the inductors? Those have a rather complex effect. They're part of a lowpass filter, which should leave the low frequencies untouched, and are unlikely to give you stronger bass ...

... unless I'm mistaken! Which I might be!

Here's a Google spreadsheet with the output filter calculation in it:
http://spreadsheets.google.com/ccc?key=pjFYoIAgm0aAF-tih_y3bWw&hl=en
You can type in different values for the components and driver impedance to see what happens when the filter's values are changed.

A finer grade of capacitors might help there, however. If we believe in different-sounding input capacitors, we may surely believe in different-sounding output caps, given the same value. Jan's output filter caps are pretty good quality, I've heard.

Oh btw, having amps in two boxes is definitely cool. People like to see it. I assume it might be good for sound too :)

[wadoka]

quote:Originally posted by Mr T
[br]...

It would be interesting to let us know if you noticed any improvement over the standard AMP32-ps whith doubling the caps value.


...


If I had a scope I could see if it helped damp a little ripple from the dc, but I dont. My ears tell me that balance of the amp is a little more towards the bottom end, which has filled out a bit. I checked this by doing an a/b test with my other amp32-ps.

[wadoka]

quote:Originally posted by krilli
[br]
About the output caps - hmm. Are you talking about the capacitors that are the output filter, along with the inductors? Those have a rather complex effect. They're part of a lowpass filter, which should leave the low frequencies untouched, and are unlikely to give you stronger bass ...

... unless I'm mistaken! Which I might be!

Here's a Google spreadsheet with the output filter calculation in it:
http://spreadsheets.google.com/ccc?key=pjFYoIAgm0aAF-tih_y3bWw&hl=en
You can type in different values for the components and driver impedance to see what happens when the filter's values are changed.



Thanks for the advice, I was told by my electronics tutor (also a diy hifi nut) that increasing the value was likley to improve the bass at the expense of the treble, but he could be wrong :)