[MaloS]

Quote:

Originally Posted by radical_tyro /img/forum/go_quote.gif The output signal level has changed from voltage 1.2 Vrms (DA100) to 2.4 Vrms (DA100S). Why would they do that?

That leads me to guess that the internal circuitry is balanced ONLY, and to produce the single-ended output they run a summing amp.

 

[radical_tyro]

Huge pics here April Music

 

[SirMikeAloT]

Just an update: As my DA100 Sig is breaking in I am going through torment (I should probably just be burning in and not listening)... the DAC seems harsh, foward and edgy.

It seems to be backing off now and becoming easier in presentation.
Mike

 

[radical_tyro]

Mine sounded great right out of the box and haven't noticed anything over time. Maybe they burnt it in first or burn in is simply psychological

 

[SirMikeAloT]

Quote:

Originally Posted by radical_tyro /img/forum/go_quote.gif Mine sounded great right out of the box and haven't noticed anything over time. Maybe they burnt it in first or burn in is simply psychological

Maybe.. Not sure. But now it sounds really great. Relaxed, detailed, and one of the most amazing things to me is the imaging with a nice width and depth. Ive tried the different sampling rated and the upsampling to 192 is in another league all together. Just amazing body to the sonics, where the others are flattened a bit. Im doing this with speakers so Im not sure how that translates to headphones.
Mike

 

[elcee]

Some tech issues cleared up by April Music regarding DA-100 Signature:

Balanced outputs are true balanced ( + signal, - signal, signal ground: not sure which pin is hot).
At first, thought that doubling the output voltage from 1.2Vrms (DA-100) to 2.4Vrms was due to balanced circuit topology. Turns out, output voltage is 2.6Vrms for Balanced and 2.4Vrms for single-ended.
DAC does not invert polarity.
Upsampling LEDs:
No LED - Bypass upsampling. Red LED - 96kHz. Green LED - 192 kHz.

elcee

 

[Asr]

Quote:

Originally Posted by radical_tyro /img/forum/go_quote.gif Huge pics here April Music

Those pics are definitely worth looking at. There are JRC NE5532s in the analog stage! What is it with this op-amp?! IMO, those looking for a balanced DAC should keep looking because that op-amp isn't optimal for balanced output.

 

[radical_tyro]

Quote:

Originally Posted by elcee /img/forum/go_quote.gif Some tech issues cleared up by April Music regarding DA-100 Signature: Balanced outputs are true balanced ( + signal, - signal, signal ground: not sure which pin is hot). At first, thought that doubling the output voltage from 1.2Vrms (DA-100) to 2.4Vrms was due to balanced circuit topology. Turns out, output voltage is 2.6Vrms for Balanced and 2.4Vrms for single-ended. DAC does not invert polarity. Upsampling LEDs: No LED - Bypass upsampling. Red LED - 96kHz. Green LED - 192 kHz. elcee

Thanks for the details. Are you sure about the upsampling colors though? Mine cycles from no light, green light, red light. That would correspond to bypass, 192 kHz, then 96 kHz which seems out of order to me.

 

[gracky]

Quote:

Originally Posted by elcee /img/forum/go_quote.gif Some tech issues cleared up by April Music regarding DA-100 Signature: Balanced outputs are true balanced ( + signal, - signal, signal ground: not sure which pin is hot). At first, thought that doubling the output voltage from 1.2Vrms (DA-100) to 2.4Vrms was due to balanced circuit topology. Turns out, output voltage is 2.6Vrms for Balanced and 2.4Vrms for single-ended. DAC does not invert polarity. Upsampling LEDs: No LED - Bypass upsampling. Red LED - 96kHz. Green LED - 192 kHz. elcee

Considering the pictures, I think DA100S's output stage is not fully balanced as DA220. Only one push-full TRs pair per channel is seen on the board, while it has a pair of opamps (on the sockets) which are not on the DA100 board. So I think that cold signals of DA100S are generated by opamps. So single-ended output might be better I suppose.

I think NE5532 opamps are used in what April calls digital filter. Also there should be opamps for DC servo.

 

[Andrew_WOT]

Quote:

Originally Posted by gracky /img/forum/go_quote.gif Considering the pictures, I think DA100S's output stage is not fully balanced as DA220. Only one push-full TRs pair per channel is seen on the board, while it has a pair of opamps (on the sockets) which are not on the DA100 board. So I think that cold signals of DA100S are generated by opamps. So single-ended output might be better I suppose. I think NE5532 opamps are used in what April calls digital filter. Also there should be opamps for DC servo.

Kind of make sense from marketing perspective, who would continue buying D220 otherwise.
But does that also mean that the only functional advantage the new one has is just I2S input and getting it without matching I2S CD transport is jut blowing extra $200?

 

[elcee]

Correction to balanced tech specs:
output voltage:
pin 2: 2.6Vrms
pin 3: inverted 2.6Vrms
Output voltage from XLR outputs: 5.2 Vrms.
Upsampling LED sequence seems to be designed descendingly:
Green - 192Khz; Red - 96Khz; no LED - bypass upsampling.
Using single ended outputs, which are rated at 2.4Vrms, expected more than marginal increase in gain from linestage compared to Nixon Tubedac (1.6Vrms). Anyone know why?

 

[radical_tyro]

Umm how can you guys say the balanced out is worthless/worse than SE-out simply based on the opamp? I don't have a balanced set up so I can't try it, but that seems terribly closed minded unless you've heard it. If you have some compelling data on why this op amp is so bad send it my way. I believe there is more than just the opamp to consider and I trust the engineers at april music know what they're doing.

 

[MaloS]

Quote:

Originally Posted by radical_tyro /img/forum/go_quote.gif Umm how can you guys say the balanced out is worthless/worse than SE-out simply based on the opamp? I don't have a balanced set up so I can't try it, but that seems terribly closed minded unless you've heard it. If you have some compelling data on why this op amp is so bad send it my way. I believe there is more than just the opamp to consider and I trust the engineers at april music know what they're doing.

If there is an op-amp used in the balanced section it would be worthless strictly because we would be giving up discrete class A output, but I think that is a confusion.

The next consideration to why the balanced would not be all that in DA100sig is the suggestion that the balanced out-puts are actually in push-pull mode, as opposed to true balanced mode with separated channels. That would actually be not interesting at all, making the $200 premium pointless (I can just get an amp with phase splitter to do that).

 

[bozebuttons]

Quote:

Originally Posted by SirMikeAloT /img/forum/go_quote.gif This is my first post at Head-fi as I am not a big head gear guy...yet Mike

Hey Mike,
Welcome to the Dark Side,sorry about your wallet.

 

[radical_tyro]

Quote:

Originally Posted by MaloS /img/forum/go_quote.gif If there is an op-amp used in the balanced section it would be worthless strictly because we would be giving up discrete class A output, but I think that is a confusion. The next consideration to why the balanced would not be all that in DA100sig is the suggestion that the balanced out-puts are actually in push-pull mode, as opposed to true balanced mode with separated channels. That would actually be not interesting at all, making the $200 premium pointless (I can just get an amp with phase splitter to do that).

Hmm this is interesting. Could someone more informed on this issue than me email april music about these concerns to clear up the confusion?