Search found 242 matches

by terkio
Thu Nov 26, 2020 9:51 am
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 62
Views: 49478

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

About digital synthesis, I found this: https://www.analog.com/en/technical-art ... rator.html
Jumping at the conclusion.
They claim: The –120 dBc harmonic distortion figure could be met with a careful design....
by terkio
Thu Nov 26, 2020 8:49 am
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 62
Views: 49478

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

I understand the objective is ultra low THD+N. How does this analog solution compares with digital synthesis. _Synthesis using a high performance sound card, focusrite, evaluation boards. _Synthesis re inventing all from scratch: High speed clock, Ram holding Sinus data, high resolution DAC, appropr...
by terkio
Sun Nov 22, 2020 7:09 pm
Forum: The Peabody Lounge
Topic: The Corona Virus Hoax of 2020
Replies: 297
Views: 25243

Re: The Corona Virus Hoax of 2020

Where have I seen the story of one who had a positive test in a nostril and a negative in the other one ? :D
by terkio
Sat Nov 21, 2020 8:49 am
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 62
Views: 49478

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

I've been able to lower second harmonic distortion by identifying three sources. 1) The VCA. I lowered the input current by 14 dB. It no longer contributes. Is this the VCA from THAT Corp ? Have you figures about the VCA distortions at these low levels. And comments about noise when going to low le...
by terkio
Mon Nov 16, 2020 12:04 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1092

Re: Split Power Supply Load Balancing

From my simulation: Average currents over an exact period. WindingA -463.49mA WindingB 463.49mA Center Tap -926.98mA Loads 10 Ohm and 50 Ohm. 1.2301A and 303.13mA Difference -926.98mA _________________________ Edit. Now, with balanced loads WindingA: 0A WindingB: 0A Center Tap: 0A Loads 10 Ohm and 1...
by terkio
Sun Nov 15, 2020 1:46 pm
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1092

Re: Split Power Supply Load Balancing

I decided it might be a good idea to point out what I'd found. Yes it is. Your study is far more interesting than efforts I have seen on regulated PSU, aiming at sub microvolt noise, ripple reduction beyond 130 dB and output impedance in micro Ohms. :lol: I'd be curious to find a source that just c...
by terkio
Sun Nov 15, 2020 11:31 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1092

Re: Split Power Supply Load Balancing

At the beginning of this discussion, I was confused, then used simulation to figure out what was going on. 4 diodes, 2x 10000uF caps with ESR 0.5 Ohm. As a transformer 2 AC voltage sources, 18V peak with 1 Ohm resistance. Loads 10 Ohm and 50 Ohm. Then all became clear in my mind. I am aware, this tr...
by terkio
Sat Nov 14, 2020 10:35 pm
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1092

Re: Split Power Supply Load Balancing

Exactly the waveforms I get with simulations. And no need to insert 1 ohm resistors ;) Actually there is no need for simulations nor measurements to figure that load imbalance induces DC at the CT. The current load difference flows at the ground track at the loads. This current is near pure DC with ...
by terkio
Sat Nov 14, 2020 10:48 am
Forum: Pro Audio Design
Topic: Bipolar Power Supply Load Current Imbalance And Transformer Core Saturation
Replies: 21
Views: 1092

Re: Split Power Supply Load Balancing

Interesting studies, I get similar results calculating with LTSpice simulations. I am thinking we have millions of center tap transformers used in line level audio. Negative and positive rails are rarely equally loaded in those equipments. It seems to me, nobody cares, nor has ever seen trouble, is ...
by terkio
Thu Nov 12, 2020 7:50 pm
Forum: The Peabody Lounge
Topic: Entropy
Replies: 1157
Views: 450565

Re: Entropy

From a familiar story about an old axe. :lol:
When the pan is worn out, you change it, when the handles are worn out, you change them, but that still is the same wheelbarrow.