Unlike DSD T1 does not have bulk smoothing power caps or inductors on the rails, so opamps and buffers power would be a bit noisier and may not be able to handle peak current as easily, but it should not be too tricky to add smoothing/filtering caps to opamps and even transistors supply pins (I considered the latter but could not find time to implement).
So the bulk sanyo ft caps (and other nichicon gold caps) are really affecting the sound? I knew that the T1 won't sound the same as the DSD (a friend of mine says the T1 'loses something in the process of the circuit").
It's also a bit sad that the there's not much of capacitors for modifying.
He actually removed the power caps and both high and low pass filters along with the outcaps and inductors and stated on the Zishan Corner he wasn’t looking back in favor of Op amps as buffers, filters, inductors, etc. It’s odd that he would flip his position on this in comparison to the T1 circuitry??
Not sure if the Opa1622 is Class D Amplifier but I'm guess this was his approach??
”So how does a Class-D amplifier work, then? The answer is that they grab the bull by the horns and instead of moving the frequency UP, they move it DOWN. Using a sigma-delta modulator a Class-D amplifier remodulates the incoming signal to a lower sample rate than that of DSD, but to preserve the integrity of the signal it uses a bit depth of more than 1-bit. I don’t want to get too technical at this point, but how it does that takes it into a different realm. It increases the effective bit depth not by using it to encode the intensity of the pulse in the waveform, but instead the width of the pulse. In effect it encodes the output of the sigma-data modulator not in with “Pulse Density Modulation” representation (which is what DSD is) but with a “Pulse Width Modulation” (PWM) representation.”
However, the MSOP and filters deal with higher frequency in the Delta Sigma DAC like the DSD Zishan circuitry does.
The peak current isn’t limited nor regulated by the power caps anyway. The stability of the limited bh Msop 8 pin on the DSD DAC is what limits the current peaks on what ceramic outcaps minimum requirements usually needs low esr ceramic caps to make the chip stable at 0.1-1uf depending what the datasheet says it needs. It's the same with the LDOs as well btw with the ceramic outcaps as well like the lp5907 mod.
”The LP5907 is a low-noise LDO that can supply up to 250 mA output current. Designed to meet the requirements of RF and analog circuits, the LP5907 device provides low noise, high PSRR, low quiescent current, and low line or load transient response figures. Using new innovative design techniques, the LP5907 offers class-leading noise performance without a noise bypass capacitor and the ability for remote output capacitor placement.
The device is designed to work with a 1-μF input and a 1-μF output ceramic capacitor (no separate noise bypass capacitor is required).
This device is available with fixed output voltages from 1.2 V to 4.5 V in 25-mV steps.”
