Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp
New Posts  All Forums:Forum Nav:

Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp - Page 404

post #6046 of 9361
Quote:
Originally Posted by Pricklely Peete View Post
LOL sure why not I have some very nice cable from DIY HI FI Supply I can use !!!

Peete.
Hi,

Just got 1 easy way out about the regulator mod. (not the best, and keep my fingers cross)

1. Remove the +- 15V on the stock tranny going to the OPA. That would give more power supply to the DAC and receiver chips. A great plus.

2. Disconnect the stock 3pin regulator.Connect the new power supply +- 15V in place of the 3pin regulator.

voila. what do u think.
post #6047 of 9361
Hi PP,

I hope to offer some help.

Here is another way of giving the power supply to the OPA (more technical though). See the diagram first before cont.

Normally there is a resistor and a coupling cap to each supply rail. The resistor is normally there but can be omitted due to sound tuning, cost cutting or the designer dunno the circuit design requirement. Wheareas the purpose of coupling cap is below (return path)

Coupling Capacitors in Op Amp Circuits

So u can trace back the from the OPA (pin 4, 8) back to the coupling cap and the resistors to connect up the +15 and -15.

Which way will you prefer.

ps. It is a nice picture but i have problem to fill it up in this room.
rgds.
LL
post #6048 of 9361
My original wire for the OPA-Sun is getting shorter by the minute I will have to get another one.

What type of wire should I use for this?
post #6049 of 9361
i am quite new to external dac and hi-quality music...
I have connected the zero through coaxial to the mainboard.
i'm using foobar. with flac files

what i have to do with output settings? (16, 24, 32 bit)?
do i need a plugin (i've seen "asio" written in many places) what's this?
what do i have to put in coaxial output (44.1, 48, 96 or 192 KHz)?

thanks for the info, i hope to understand something
post #6050 of 9361
Quote:
Originally Posted by ccschua View Post
Hi,

Just got 1 easy way out about the regulator mod. (not the best, and keep my fingers cross)

1. Remove the +- 15V on the stock tranny going to the OPA. That would give more power supply to the DAC and receiver chips. A great plus.

2. Disconnect the stock 3pin regulator.Connect the new power supply +- 15V in place of the 3pin regulator.

voila. what do u think.
Quote:
Originally Posted by ccschua View Post
Hi PP,

I hope to offer some help.

Here is another way of giving the power supply to the OPA (more technical though). See the diagram first before cont.

Normally there is a resistor and a coupling cap to each supply rail. The resistor is normally there but can be omitted due to sound tuning, cost cutting or the designer dunno the circuit design requirement. Wheareas the purpose of coupling cap is below (return path)

Coupling Capacitors in Op Amp Circuits

So u can trace back the from the OPA (pin 4, 8) back to the coupling cap and the resistors to connect up the +15 and -15.

Which way will you prefer.

ps. It is a nice picture but i have problem to fill it up in this room.
rgds.
Hi CC,

Excellent !!!

I will have a look at what your proposing and try and figure it out. I just want to add the DAC HDAM has a 1uf PIO paralleled on V+ V-...as per the Burson tweak...just an FYI. I don't see it's function being altered with this mod, enhanced maybe

Thanks for all the great ideas and help !!!

Peete.
post #6051 of 9361
Quote:
Originally Posted by fdbf View Post
i am quite new to external dac and hi-quality music...
I have connected the zero through coaxial to the mainboard.
i'm using foobar. with flac files

what i have to do with output settings? (16, 24, 32 bit)?
do i need a plugin (i've seen "asio" written in many places) what's this?
what do i have to put in coaxial output (44.1, 48, 96 or 192 KHz)?

thanks for the info, i hope to understand something
With ASIO driver you'll avoid processing steps in the operating system (bad)/onboard SC chip...and you'll want to output a "bit perfect stream" meaning no resampling,oversampling,upsampling to alter the flac files original coding (16 bit/44.1 khz...CD's are all this bit/sample rate). If you have a driver set capable of "bit perfect" output (google the term, check your mobo sites FAQ WRT the onboard sound card to see what options it has). Bit perfect will automatically set the output to the FLAC files original recorded standard as mentioned earlier (CD's are 16/44.1). It sounds far more complicated than it is

What model modo and what is the SC chip please ?


I'm sure I've just confused you further.......it sounds far more complicated than it is. Google ASIO and "bit perfect" playback for detailed explanations of each. That should get you started in the right direction.

Peete.
post #6052 of 9361
i have asus p5q mobo with realtek HD Audio. The asio control panel tells me that the output is 8-192Khz, 32bit.

i connected the zero directly to a coaxial input in my mobo.

the question is... connecting to the coaxial bypasses the audio card? (this is what i want)

do i need asio?
i suppose no... if i understood well... direct coaxial output will send to zero the audio file "as it is"...

Am i right? in the mean time, thanks for the help
post #6053 of 9361
You may be right...it may be passed as is. I'm not familiar with that mobo...I have the Asus Maximus Formula, but use an Auzen Prelude for digital out via Auzens ASIO driver.

I'm not 100% sure the way your doing it is untouched. I may be wrong about that. Is there anything mentioned in the mobo manual WRT to how the SPDIF out is handled in hardware by the P5Q ?

Peete.
post #6054 of 9361
Quote:
Originally Posted by Pricklely Peete View Post
Your right CC and AP, thanks to both of you....I've made the changes to my order and now have the correct reg and toroid on the way.

AP what's your thoughts on this latest question raised about the coupling caps on the main pcb ?


Peete.
The two caps immediately below the DAC opamp? Could remove them and feed your power supply directly at that point, which would also then be fed over to the headphone amplifier board, if my memory serves me correctly...

Sorry if I've missed the question - it can be hard to keep up in this thread!

~Phewl.
post #6055 of 9361
Does anyone have or where I can find the sun/earth pin map(diagram)? I mean I need to know what exactly meaning of every pin?
Thanks.
post #6056 of 9361
Not to be the opportunistic weasel of the threat but what are you guys doing with your old OPA627's?

I still haven't taken the plunge on the Discrete OPAMP and am still rolling through what I have.

If someone was looking to get rid of their 627's on a brown dog adapter I would gladly buy them to add to my collection. Blast me a PM.
post #6057 of 9361
no mention in the manual, only "through coaxial you can link an external audio device", not so useful. But coaxial is treated apart from audio table in the manual... and in windows changing volume of the sound card nothing happens, so i think it is bypassed...
post #6058 of 9361
CC

Two things come to mind after reading the link.....the first being...the coupling caps (stock ones) are there to scrub dc offset on the vcc/2 lines correct ?
The second is to measure the new reg board for this component in the supply lines, if there is then deal with it via the onboard coupling caps (on the Zero mainboard) or try and scrub it with further bypass caps on the large electrolytic caps on the new reg board ?

I plan on adding to all 8 filter caps on the new reg board 8 WIMA FKP 1 2200pf bypass caps anyway. We'll have to see what the new reg board does first via its measurements on the +15 -15 lines.

Here is the link to the reg board and tranny plus schematic...

Welborne Labs PS1 Regulated Supply

The idea of tapping in where the LM 337T 's are (in effect taking them out of the circuit ) isn't what I want to do. I want to keep that part of the topology intact. The real idea behind the mod is to not leave a permanent footprint, it has to be reversible with minimal tools, to unbolt the toroid etc...no soldering or pin cutting on the HDAMs. I have that worked out already, it's simple and elegant.

The idea that has most merit to me is an external chassis to offload the transformers and the new reg board to. This will have two immediate benefits, isolating the power supply and reg board to another chassis and thus getting it's magnetic field, ac noise and other nasties away from the analog board. Second it will allow room for all the modules to be installed and use the stock cover in the Zero (with room to spare for future tweaks...like isolating the 3.3V line). I'm toying with bolting the 2 chassis's together either stacked or side by side. Direct wiring with no umbilical cables between the 2 chassis's. Simply route the power lines through one hole and keep the V+ V- line a couple inches away through there own hole. Of course I plan on using shielded cable for this...for good measure.

I'm thinking of using the Lite Ah chassis for this...it can be had from DIY Gene for under 30 dollars and is perfect for this purpose. Simple, utilitarian and best of all will yield a superior SQ result...I hope

What do you think CC and AP...Alex...is this the best overall approach ?

One other question that comes to mind is where to locate the PS1 reg board ground...to what ground plane...the audio ground or the chassis ground ? My guess would be audio ground on the main pcb ...Would that be correct ?

Thanks for all the great help you guys...this is far easier to understand with all your help....big thumbs up from Peete !!!

Peete.
post #6059 of 9361
Hello all. I have a problem (I think) because I can adjust the windows volume when I use ASIO4ALL with foobar2000. Does that mean that I am not getting perfect playback ? Thanks.
post #6060 of 9361
Quote:
Originally Posted by fdbf View Post
no mention in the manual, only "through coaxial you can link an external audio device", not so useful. But coaxial is treated apart from audio table in the manual... and in windows changing volume of the sound card nothing happens, so i think it is bypassed...
I think you are correct about that.

You have a direct out...how does it sound to your ears ? Usually you can detect signal loss and degradation with careful comparison vs a dedicated CDP using a familiar track for reference.

Peete.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Review: ZERO 24 BIT/192KHz DAC/Headphone Amp/Pre-Amp