ask godluv to put you in the next bulk..

the problem is the next bulk stil 0 ppl now -.-

guys,, which opamp is best to pair with opa sun in pre amp section? LT1364? need to swap both opamps in head amp section right?

Aiya, I was too busy to come in to check and missed the BU part. Guess I'll have to wait till your next upgrade Chua. I really have a lot of catch up to do. Hope the year end holiday season will give me the required time to sit down and do the moddings.

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Added on December 3, 2008, 4:59 pmBTW, I've been running in my second Zero in the office. Even though this unit also have the transformer hum, at least office is too noisy to hear it instead of at home.

My mini review on second unit:

Setup is Notebook -> HA Mini USB to Digital Coax converter -> Zero -> headphone out with adapter -> Altec Lansing 2.1 multimedia speaker.

Initially, it sounded clearer than direct notebook out but bass was hard and boomy and top end treble was harsh.

Between 50-60 hours, the clarity suddenly kicked in and everything sounded more detailed. The bass is smoother without boom and the soundstage opened up.

After 100 hours, clarity continue to improve. Details of instruments and vocal is very apparent. Soundstage is wider than before!

After 200 hours, clarity is almost silky smooth. Excellent details and separation. Bass is tight and low and the soundstage... they went beyond the speakers. Hard to believe such sound coming from RM149 2.1 multimedia speakers. OK, surely my first Zero with Earth OPAMP is a bigger improvement but as it is, the sound quality is much better than the Creative external processor that my friend has, which cost more than the Zero.

My colleague just bought the Klipsch GMX A-2.1 which are very good speakers and compared to my system, the clarity is almost on par but the Zero has better details, separation and soundstage. Bass obviously lost to Klipsch since it has a much bigger driver and an amp that's 3x more powerful.

Bottom line? Improving your source can make a huge difference in SQ and Zero can definitely give you that. For the price, it's a big improvement.

Next, I'm gonna swap in my 827 to compare, and then to 627.

This post has been edited by RAV4: Dec 3 2008, 04:59 PM

nice review bro.. why dont you try to use the RCA line out instead of the headphone jack? i guess it would be much better. by the way what opamps do you use for the head amp section?

I will post the photo here about the BU2 mod. It seems very easy depending on what level of details to be changed.

I believe in Kingwa can come out something really good, which he told me. I also confirm adding a buffer between has improve it further in that it is more analogue feel and more neutral, in that the sound opens up.

Hi rav,

let me know how to send the items to you or meet up. Have u got the caps for the Franken mod as well ?

This post has been edited by ccschua: Dec 3 2008, 06:51 PM

ermmm ..... my DAC kena static charge soo cant connect coaxial already
soo now waiting my new amp ....
i just finish DIY my preamp for my new amp



This post has been edited by abel: Dec 4 2008, 06:04 PM

so you thrown away the old one?

That's a lovely journey. I can \recall the days I was running back and forth changing opamps. It was fun.
Try OPA Sun and see whether u can get better bass response.

With the buffer, I hope the sound will be more extended, wider soundstage and better dynamics. Which I already can get using soundstage 1.5 as buffer.

For the BU2 mod, it is easy. if u connect the OPA Moon to the DAC socket, cut the output wire. Bring the half opamp output wire to the BU2 buffer (with some RC components) and then output the buffer to the other half of wire that gos to the RCA and headphone amp. The buffer needs power supply which u can tap from the pin 4 and pin 8 of DAC OPA socket. Nice and clean.

Yeah, I'm doing a proper burn in with my second unit so I can hear the difference as time goes. Was not able to do that with the first unit. I will move to discreet OPAMP once I'm done with the 827 -> 627.

Ahh, don't have to touch the board. Looks like I will do the buffer mod before I add the caps! Hehe...
Oh, so the output bypasses the board's circuit? Ooooo.... I can't wait for them to arrive... this should be another jump in improvement since Lampizator considers the Zero's output stage to be low grade. Thanks for sharing this upgrade Chua!

I think the cap bypass + franken is good to do. it will add more ommp to the output power/

actually those are not call bypass is call decoupling

Ceramic capacitors, which are often used for decoupling have the property that for higher capacitance, the ESR (Equivalent Series Resistance) and ESL (Equivalent Series Inductance) is also higher. To provide adequate decoupling for both low and high frequency components, a high value capacitor (with high ESL) is used to take care of the low frequency components for which the higher ESL is insignificant. Another lower capacitance capacitor is connected in parallel to take care of the high frequency componets for which a lower Xc is acceptable, but a low ESL is required.

Two capacitors of equal value in parallel, will, in general, have lower ESR and ESL values thatn a single capacitor with twice the capacitance as each of the lower value capacitors.

guys, the best to connect aego m to zero dac is through its rca jack or through it's headphone jack?

RCA jack

allright,, thx,, by the way, i just swap my stock opamp in dac section to opa sun, what should i change in headphone section to pair with the opa sun in dac? LT1364 would be good?

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Added on December 5, 2008, 1:41 pmBy the way, i have 1 spare unit of opa sun for sale. anyone interested let me know.

This post has been edited by Dybre: Dec 5 2008, 01:41 PM

Yeah, the green sausages are connected in parallel so bypass is more a coin word but it's technically wrong.

Abel, so what you're saying is "decoupling" is an easier way to upgrade but it's still best to replace the cap?

I dont follow technical jargon, cause I am no technical men. I follow noob language.

follow this for your buffer mod, hope to end up like DAC 100 loh.

This is DAC 100 circuit diagram



This is BU2 mod for ZERO. The box in Black is the additional circuit. Remember to add in the R (2k2) and C (2200p) before the cap.



This post has been edited by ccschua: Dec 5 2008, 09:49 PM

if can replace cap and decouple with green sausage will reduce the noise ... if to big can buy lower volatage

anyone wanna sell their earth HDAM with extension wires?

Interest to swap with OPA Moon?