One thing to note about many of those AC wall warts - they seem to be wound with a fair amount of impedance so that the output voltage at light load is shockingly more than expected. This is an example of an "impedance limited" transformer. With a Class A design like this one, the heavy constant load quiets things down. However, the first filter cap and the caps on the voltage multiplier (and inverter) and the capacitance multipliers will need to be rated to take the hit while the capacitance multipliers delay the onset of loading..
If you use a more normal transformer type to power the amp, this should not be an issue. I'm looking at some of my smaller toroids to see if I have one that is up to the job, though they lack the convenience factor (and low cost) of the plug-in transformers.
If you use a more normal transformer type to power the amp, this should not be an issue. I'm looking at some of my smaller toroids to see if I have one that is up to the job, though they lack the convenience factor (and low cost) of the plug-in transformers.
I got my regulator circuit with cap multipliers up and running, and it's time to hook it up to the finished headphone amp to try and pump some tunes.
On a speculative note, here's the second "buffered SIT" circuit configured as a line amp. Gain is ~6X, and distortion is not too shabby... Some folks might like this simpler circuit.
On a speculative note, here's the second "buffered SIT" circuit configured as a line amp. Gain is ~6X, and distortion is not too shabby... Some folks might like this simpler circuit.
Attachments
I think I have picked out a case for the amp (a repurposed portable hard drive enclosure). If I can fix the back panel and drill some holes, I may be able to mount my amp into the case this weekend and actually try it out with some tunes. Due to the way the case is set up, all the jacks and controls will be on the back.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.