[ScottieB]

Yeah I get why to do it - just need details on HOW - I know it's been illustrated here before, I just don't recall... thanks

 

[dacavalcante]

Hi guys, I'm wonder if doing that will do any harm on Zero ?

The mean reason for this is to try to identify bass loss with 3 HDAMs setup.

That way I'll use a flat 40Hz wav and check both at the same time.
I already did it swaping both, but really couldn't come to a conclusion.... They seem to produce the same SPL.

The other option is to find the spot on the pcb where I can mesure with a voltimeter the head amp section output, that way with a flat 40hz signal, I can check which one got the higher voltage on the output for this frequency. the high voltage will have more bass.......


Diego

 

[AudioPhewl]

Bump for buying links in my signature.

~Phewl.

 

[sharpi31]

Can anyone help me to identify all of the coupling caps in the zero? I've swapped over to OPA627 + 2xLM4562, cut out the 4x ceramic caps and now I want to turn my attention to the caps in the signal path....

 

[grkn]

What do you guys think about doing the Lampizator bypass to the line out and installing a couple of LT1364s for the headphone amp? Wouldn't this be the cost effective route to go? Why bother with HDAMs if you can bypass?

Cheers.

 

[Pricklely Peete]

Quote:

Originally Posted by grkn /img/forum/go_quote.gif What do you guys think about doing the Lampizator bypass to the line out and installing a couple of LT1364s for the headphone amp? Wouldn't this be the cost effective route to go? Why bother with HDAMs if you can bypass? Cheers.

Well if you bypass the entire analog section (Lampy's passive out mod) you loose the voicing of the Zero's output section. I like the Zero's voicing.

Go ahead and try it by all means...this is an equal opportunity tweak for all thread

Most have the LT1364 opamps in the H/Amp already, that's one of the standard features of the "Head Fi members deal" setup from Lawrence Chan.

Peete.

 

[Pricklely Peete]

Quote:

Originally Posted by dacavalcante /img/forum/go_quote.gif Hi guys, I'm wonder if doing that will do any harm on Zero ? The mean reason for this is to try to identify bass loss with 3 HDAMs setup. That way I'll use a flat 40Hz wav and check both at the same time. I already did it swaping both, but really couldn't come to a conclusion.... They seem to produce the same SPL. The other option is to find the spot on the pcb where I can mesure with a voltimeter the head amp section output, that way with a flat 40hz signal, I can check which one got the higher voltage on the output for this frequency. the high voltage will have more bass....... Diego

Hi Diego,

I don't think you'll harm it in the short run......I was alarmed by the heat of the analog regs when running 3 HDAMs as you know. I can't imagine that kind of heat is good long term. For all I know they could be fine (at that temp) and I'm just a big worry wart

CC or Alex (hey where is Alex these days ? ) calculated the current draw on the stock PSU as being too much. I forget the exact number....anyway it was the reason why I went looking for a solution (as you know

)


Peete.

 

[taso89]

Sorry to bring this up again, but if I'm using the Zero strictly as a DAC/pre-amp can I unplug the headamp section and will I benefit from doing this?

 

[Pricklely Peete]

Sure taso89. Just unplug the black 3 wire connector that powers the H/Amp pcb. Your done

I'm not sure you'll hear a difference. Taking unused circuity out of the loop is always a good idea in practice.

Peete.

 

[Currawong]

I didn't notice a difference disconnecting it, except that regardless of whether the head-amp was being used or not, it got hot, which was a waste of energy. The more power in reserve for the HDAM, the better I think.

 

[ccschua]

Just read some infor on Lampizator site regarding CD transport and the connection to the ZERO DAC.

The Lampi infor is inline with good practice as with audio-gd , that the best connection is still coaxial cable (75OHM) with BNC plug. Coaxial with RCA plug gives higher jitter. The BNC connection gives constant 75 ohm resistance throughout the load range, while the RCA can fluctuate between 32 ohm to 100 over ohm. That is bad for audio signal.

AES/BSU has good reliability but still higher jitter than BNC.

The least favour connection is Optical, it gives a jitter 20 times that of BNC. If u have AT&T, that would be good but $$$ = ZERO DAC.

I dint trust all this until I saw lampi oscilloscope results and conclusions.

CD_transport_DIY

 

[ccschua]

I cant understand, if BNC connection is so good and cheap, why is not provided in most of the DAC ?

. This is a joke.

Audio-gd uses the BNC plug (Les than USD 2) for one of its DAC, the clarity is better than those expensive coaxial RCA. Good news. Replacing the ZERO stock coaxial plug by BNC can be done directly without the need to drill hole.

Please see the photo of the premium grade BNC. This BNC cost USD 12 each. (boy, look at those red WIMA. audio-gd really make me drooling, the amount of caps, the isolation of tranny from the signals,etc)
This type need to drill hole.

 

[Currawong]

A lot of high-end gear still uses RCA for digital. Many professional DACs though have BNC.

Hmm, about 17 pages of this thread have disappeared for me...I wonder what happened?

 

[MuuMuu]

Just got one of these Zeroes through a seller on ebay. It sounded terrific -- except for the fact that there's a huge amount of hiss on the left side.

A suggestion within the thread of re-seating the op-amp seems to have done the trick -- had to fiddle with it for a while, but eventually the bad left side did one last buzz that faded away and is now completely clear. Couldn't have figured it out w/o the thread, and I'm extremely thankful for that, but is the opamp placement really THAT picky? Looking at it the amp it seemed like it was seated completely to begin with, and I had to reinsert the thing several times before it was happy with the position.

 

[viscosity]

How would replacing the coax plug result in any improvement being as it's a digital signal? I mean for peace of mind sure... but I doubt it would make much difference

I think im gonna keep the Earth in DAC and LT1364 in amp section.. need all the bass i can get with my akg k701s.. untill i upgrade to a seperate tube amp