wquiles
500+ Head-Fier
- Joined
- Dec 8, 2007
- Posts
- 727
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- 33
I just completed my own High Performance mini^3 !!!
I read everything twice, got my bench ready, etc.:
And I have done other projects like the CMoy and even this fancier amp:
HeadWize - Project: A DC-Coupled, Selectable-Gain Headphone Amplifier by Chester Simpson
I even made sure I had a "dead" 9V battery to solder the connections to make sure I would not damage the circuit:
I had the schematic and layout prints ready:
And did the metal work before I started, like amb suggested in the instructions:
I then assembled the parts in the sequence amb suggested:
I was very careful with the OP-Amps:
I even checked each resistor packet to make sure the values were correct before using them:
and I marked off each part before moving to the next one:
Of course, I did mess up on the very last step: I got the battery polarity backwards!. Sure enough, there was some damage and I had to swap both the TLE2426 and also U5 (AD8397). Once I did, I got normal values as expected:
- Quiescent current (with battery): 29.4mA
- Rail splitter check (with battery):
1) End to End voltage: 7.91V (cell was not new/fully charged)
2) Mid point voltage: 3.92V
- Output DC offset (with battery):
1) OG to IG= +0.23mV
2) OL to IG= -0.57mV
3) OR to IG= -0.11mV
- Battery charging current (with DC supply, no-load=15.5V DC): 16.5mA
- Charging voltage at battery terminals (with DC supply, no-load=15.5V DC): 12.39V
I still have not put some labels, but here is how it looks so far:
How does it sound? Great! Compared to my old CMoy and Chester Simpson's desktop amp, this has extremely low noise floor - I can hardly hear anything, even at max volume. I will be listening for a while to get everything burned-in, but so far I think it really sounds good!
Will
I read everything twice, got my bench ready, etc.:
And I have done other projects like the CMoy and even this fancier amp:
HeadWize - Project: A DC-Coupled, Selectable-Gain Headphone Amplifier by Chester Simpson
I even made sure I had a "dead" 9V battery to solder the connections to make sure I would not damage the circuit:
I had the schematic and layout prints ready:
And did the metal work before I started, like amb suggested in the instructions:
I then assembled the parts in the sequence amb suggested:
I was very careful with the OP-Amps:
I even checked each resistor packet to make sure the values were correct before using them:
and I marked off each part before moving to the next one:
Of course, I did mess up on the very last step: I got the battery polarity backwards!. Sure enough, there was some damage and I had to swap both the TLE2426 and also U5 (AD8397). Once I did, I got normal values as expected:
- Quiescent current (with battery): 29.4mA
- Rail splitter check (with battery):
1) End to End voltage: 7.91V (cell was not new/fully charged)
2) Mid point voltage: 3.92V
- Output DC offset (with battery):
1) OG to IG= +0.23mV
2) OL to IG= -0.57mV
3) OR to IG= -0.11mV
- Battery charging current (with DC supply, no-load=15.5V DC): 16.5mA
- Charging voltage at battery terminals (with DC supply, no-load=15.5V DC): 12.39V
I still have not put some labels, but here is how it looks so far:
How does it sound? Great! Compared to my old CMoy and Chester Simpson's desktop amp, this has extremely low noise floor - I can hardly hear anything, even at max volume. I will be listening for a while to get everything burned-in, but so far I think it really sounds good!
Will
