Debugging Over/Undershoot Issues with Aleph30

[hifimaker]

I appreciate the forums insights and suggestions to square off the waveform on the output of my Aleph30.

The input is a square wave from a signal generator set to 2vdc at 10khz. Scope setting is 1 volt per division.

The boards and parts are from the Aleph GB using BrianGT's boards.

Attached is a picture of the scope's display.

Thank you again for any insights.

-David

[hifimaker]

Just like when I tested my BOSOZ, I realize the neg phase input needs to be grounded.

Here is the scope measurement with a 10khz square wave at 1volt, and 1 volt per division.
Neg phase is grounded.

-David

[hifimaker]

Here is the scope measurement with a 10khz square wave at 2 volts, and 1 volt per division.

Neg phase is grounded.

-David

[hifimaker]

Here is the scope measurement with a 1khz square wave at 2 volts, and 1 volt per division.

Neg phase is grounded.

-David

[Nelson Pass]

Something odd is going on there, but I don't know what it is.
How does it change with and without a load?

[hifimaker]

The previous measurements were without a load. Here's a set of measurements with an 8 ohm 100w non-inductive load.

10khz, 2 volt square wave on positive phase, neg phase grounded. Scope set to 1 volt per division.

-David

[hifimaker]

Measured with an 8 ohm 100w non-inductive load.

10khz, 1 volt square wave on positive phase, neg phase grounded. Scope set to 1 volt per division.

-David

[hifimaker]

Measured with an 8 ohm 100w non-inductive load.

10khz, .5 volt square wave on positive phase, neg phase grounded. Scope set to 1 volt per division.

-David

[hifimaker]

Here's the amp's schematic.

[Netlist]

Do both the Aleph current source and gain devices work properly? What is the bias current?

/Hugo