[Kurotetsu]

This has probably been asked several times before and I just can't find the posts...

Payday is Friday and I plan on making a purchase (hopefully, provided I don't chicken out). Is the shenzhen Audio store/wsz0304 a good, reliable source for Zero DACs? He sells the upgraded version with the OPA627 opamp (it doesn't mention what's on the headphone section though):

ZERO 24/192 DAC DA CONVERTOR, HEAD AMP(Upgrade Version) - eBay (item 110287180536 end time Dec-06-08 13:00:00 PST)

He has 100% good feedback which looks like a good sign.

 

[crzystng]

wsz0304 is who I purchased mine from and am pretty sure he is owner or at least partial owner of little dot. He was very helpful in my purchase of the I+ and ZERO combo.

 

[sandchak]

Quote:

Originally Posted by crzystng /img/forum/go_quote.gif wsz0304 is who I purchased mine from and am pretty sure he is owner or at least partial owner of little dot. He was very helpful in my purchase of the I+ and ZERO combo.

I second that, although my amp came in defective, he is a really nice guy and he is trying to help me out too just like people on the forum specially Peete, to get the Zero up and running..

 

[fdbf]

Hi there guys!

Have someone of you tried the "cap snipping mod" cutting off those capacitors in the Dac and Pre-amp sections?

I'd like to do it but i fear bad consequences, like sound becoming TOO bright for my ears.... anyone giving me some advice?

Thanks

 

[BigTony]

Quote:

Originally Posted by AudioPhewl /img/forum/go_quote.gif I ordered a DAC from Lawrence a few months back, which turned out to be faulty(think I might have been the first on here to get stung by him, he ignored me completely and I ended up instigating a chargeback against PayPal for the amount via my bank). Anyway, the DAC PCB was the cause of the fault. My recollection is that there was no hum from the transformer, but it was several months ago now. I've still got it here, you can have it for the cost of post and a pint of Guinness if you want? ~Phewl.

Many many thanks, pm sent!! Buzzin is driving me (and therefore my family crazy)!
Anyone else remove the batteries from clocks in their listening room due to the infernal ticking!! or is that just me?

 

[Currawong]

Quote:

Originally Posted by fdbf /img/forum/go_quote.gif Hi there guys! Have someone of you tried the "cap snipping mod" cutting off those capacitors in the Dac and Pre-amp sections? I'd like to do it but i fear bad consequences, like sound becoming TOO bright for my ears.... anyone giving me some advice? Thanks

One person had undesirable consequences from doing this, which was that he found out how bright Grados are! Another, who already had a lot of hiss in his system, afterwards had more, as the caps are presumably there to filter out hiss. Unfortunately they also filter out detail.

 

[sandchak]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif I may have spotted something in one of the pics you posted. There are 4 x 47uf 10V coupling caps (Elna Silmic) near the 2 voltage regulators on the lower right hand corner of the main pcb (if the front faceplate is towards you as normal). I can't tell for sure but it looks like one or all of those caps are not installed correctly according to their polarity. The shaded side silk screening on the pcb itself denotes - or negative pole. All electrolytic caps will have a negative indicator stripe (can't miss it ). Check the whole main board to make sure all the electrolytic caps are installed correctly just to be safe. Someone else of late had one those coupling caps installed incorrectly by the factory although he was still getting sound but at reduced output to that channel (it was one of four in backwards). Hopefully that's the ticket. Peete.

Hi Peete,
Today I had the time to see whats wrong with the Zero and I did everything you asked me to do:

1)I opened out the board and inspected the back, I dont see any cold solder or anything shot (pic attached), I did a slight twisting of the board as suggested.

2) The caps you had mentioned to check for polarity - everything perfect, infact I checked ALL caps on the both the boards and everything is soldered as it should be. (Pic attached)

3) I swapped the OP627 opamp with the new LM 4562 - No difference ( Seller had writteb back asking me to check this too)

4) switched from optical to coax - no difference

Observations - When the headphone is NOT attached but headphone switch on the ZERO switched ON ( with coax or optical ON) at very High Volume on the ZERO, I can hear Faint ( very fain) music on the Speakers.

NOW if I attach the headpnone on the ZERO, and SWITCH OFF, the headphone switch on ZERO and Raise the Volume, I can still hear music onmy headphone - again very faintly..

I have a feeling, that when I swiched on the ZERO for the FIRST time, with the Headphones ON, within seconds I heard like something being fried inside the ZERO and the lights dimmed.

I really dont think theres anything more I can do with my level of electronic knowledge...

Let me know, if theres anything else I can..

Thanks Peete and EVERYONE on the Forum !

Sandeep

 

[les_garten]

Quote:

Originally Posted by Kurotetsu /img/forum/go_quote.gif This has probably been asked several times before and I just can't find the posts... Payday is Friday and I plan on making a purchase (hopefully, provided I don't chicken out). Is the shenzhen Audio store/wsz0304 a good, reliable source for Zero DACs? He sells the upgraded version with the OPA627 opamp (it doesn't mention what's on the headphone section though): ZERO 24/192 DAC DA CONVERTOR, HEAD AMP(Upgrade Version) - eBay (item 110287180536 end time Dec-06-08 13:00:00 PST) He has 100% good feedback which looks like a good sign.

I don't know the exact OpAmp number, something like 55532 or something. Needless to say, everyone here has replaced with something Like LT1364 or LT1361, etc. I talked to him and his "upgrades" only upgrade the DAC Opamp. No worries though, just order your free samples from Linear Technology when you order the Zero. You can order 5 sets of free Opamps from Linear as free samples. You may want to listen to the "stock" amps and then replace later to hear the difference.

 

[finax]

(to sandchak)

I had also same kind of problems with the Zero´s preamp section.

My case the problem was with the two wires,that goes mainboard to the headamp section.They were wrong way.They should go 1-3,2-4 (up to down mainboard 1,2 and headamp section 3,4)

 

[sandchak]

Quote:

Originally Posted by finax /img/forum/go_quote.gif (to sandchak) I had also same kind of problems with the Zero´s preamp section. My case the problem was with the two wires,that goes mainboard to the headamp section.They were wrong way.They should go 1-3,2-4 (up to down mainboard 1,2 and headamp section 3,4)

This sounds very interesting, I just opened up the amp, there are 3 connectors on the main board which is attached to 3 on the headphone board, and I am a little confused as to which one should go where, if you can explain a little more, or maybe post a pic, I will be very grateful..

 

[Pricklely Peete]

sandchak,

I also mentioned these wires in the original reply...it was easy to miss I suppose in my huge answer. The 3 wire connector (black wires) are for power only, the two 4 wire sections to and from the pre/head amp board to the main board are the analog (L/R channel pairs of + and - signals) lines...it's possible those are reversed as finax suggests.

How to trouble shoot this section is not easily explained by text alone. Posting pics showing the cable runs and the wiring would help greatly so I can double check the connections. Label the the difference between the two cable runs (of 4 wires each) and to which connectors they are using (of the 4 on both boards)

A really simple test to check pure DAC mode would be to pull the black 3 wire power connection from it 's connector (on the H/Amp board) and see if the line level signal in pure DAC mode will pass to your speakers. This powers down the entire H/Amp section from the main pcb circuit.

Another simple test would be to pull the 2 four wire connectors from the H/Amp board effectively taking the entire H/Amp circuit out of the DAC circuit. The 3 wire power remains unconnected as well for this additional test.

Make sure you note which 4 wire assembly was connected to it's respective slot, that way you'll know the original assembly positions.

I hope that isn't confusing...give it a try

Peete.

 

[finax]

PP,thanks for the extra clarification.I didn´t mention that there is also one power wire.

 

[evangellydonut]

just got one of these to use with the PH100 and got some free LT-1361 and LT-1364 to swap in! i wonder if anyone can find the schematics to this baby =P

 

[sandchak]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif sandchak, I also mentioned these wires in the original reply...it was easy to miss I suppose in my huge answer. The 3 wire connector (black wires) are for power only, the two 4 wire sections to and from the pre/head amp board to the main board are the analog (L/R channel pairs of + and - signals) lines...it's possible those are reversed as finax suggests. How to trouble shoot this section is not easily explained by text alone. Posting pics showing the cable runs and the wiring would help greatly so I can double check the connections. Label the the difference between the two cable runs (of 4 wires each) and to which connectors they are using (of the 4 on both boards) A really simple test to check pure DAC mode would be to pull the black 3 wire power connection from it 's connector (on the H/Amp board) and see if the line level signal in pure DAC mode will pass to your speakers. This powers down the entire H/Amp section from the main pcb circuit. Another simple test would be to pull the 2 four wire connectors from the H/Amp board effectively taking the entire H/Amp circuit out of the DAC circuit. The 3 wire power remains unconnected as well for this additional test. Make sure you note which 4 wire assembly was connected to it's respective slot, that way you'll know the original assembly positions. I hope that isn't confusing...give it a try Peete.

Hi Peete,

I am sure I overlooked that part, even though everything you have suggested, including this one is printed and stuck on the wall right in front of me!
I have decided that, this weekend, I will start from the scratch and try everything suggested once again, and if it still fails work, it will be off to China with love, first thing Monday morning.

Its just too painful to see something not performing, especially something that I had so much expectations, after reading so much about it...

Will be back on Monday, either with the working or shipping status!

Thank you extremely much for all your help, and everyone on the forum for the help..

Sandeep

 

[Kurotetsu]

Quote:

Originally Posted by les_garten /img/forum/go_quote.gif I don't know the exact OpAmp number, something like 55532 or something. Needless to say, everyone here has replaced with something Like LT1364 or LT1361, etc. I talked to him and his "upgrades" only upgrade the DAC Opamp. No worries though, just order your free samples from Linear Technology when you order the Zero. You can order 5 sets of free Opamps from Linear as free samples. You may want to listen to the "stock" amps and then replace later to hear the difference.

Sounds like a plan. I imagine, being socketed, they are easy to switch out? Just remove the case, pull out the old opamp and slide in the new one?

For the free Linear Tech samples, you just sign up for a MyLinear account?