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AudioSector-chip amp kits, dacs, chassis

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Destroyer OS. said:
That is USB with SPDIF signal.... uh if I am not mistaken a lot of external devices use raw data so then jitter means nothing. Also SB's use ethernet for raw data, so no Jitter involved. The only jitter should be between the SB's input and DAC. That is all I can think of....

I disagree, but I wont say any more about this in the AudioSector thread. Keep your eye on that link - there are more measurements coming.
 
i like SPDIF as it is. welcome to my bulky mp3 server. not finished;)

i never was a big fan of usb being a tech for 10 years. usb can be a pain in the butt:rolleyes:

but when it does work im sure it sounds good;)
 

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Peter, a friend of mine who purchased your LM4780 board has asked me to kindly post this question.

On the first time he completed the board, his brother turned it on when he was not around and one channel of the amp blew together with 4 pcs of the MUR860. He doesn't know what actually happened, as he did not have first hand information but he suspected it could be a faulty chip. He has now replaced the chip and the MUR860 and powered it up and it seems fine. No smoke or smell. :D He measured the output for DC and found it had negative voltage on both channels, -125 mv on one and - 18.7mv on the other. Is this acceptable and or normal? he is worried and have not attached speakers to it. Maybe tomorrow, after your response. BTW, the LM3875 boards arrived and are as beautiful as the LM4780 boards. You sure put out high quality stuff. :up:

Thanks.
 
So far nobody reported a faulty chip yet. It could be short connection on the board (from assembly) that destroyed the diodes.

What configuration is used for LM4780 (parallel, stereo)?

-125 mv on one and - 18.7mv on the other is still acceptable in a way that it should not damage the speakers. The offset should be measured with source connected.

While 18.7mV is perfectly fine, -125mV is a bit high, that's why I was asking about configuration and if the source was connected.
 
Peter, the chip was not from you. You are most probably right about the assembly part.

On the negative dc voltage on the output, the amp is in parallel config and no source was connected. BTW, which are the coupling caps for this amp? I am about 80% completion of my LM4780 from your board too. Actually the amp and PSU boards are completed but not wired together yet. I'll have eveything come togther in my case as soon as it's completed. In my parallel config, I have remove the zobel (cap and resistor) as you have suggested. Dying to hear how it sounds.

Thanks for the reply. Looking forward to more guidance or test procedures.
 
Peter, he just hooked up some satellite speakers and the amp is playing well. DC at output on both sides is 35mv. I guess everything's fine.

Hell, no. I am not going to put any coupling caps into the LM4780. After listening to my previous LM3886 GC without the coupling caps, I don't think I ever want them in my amps. :D

Thanks Peter. I'll try to post up some pics of my friend's implementation as he used a car audio amplfier enclosure for this and it looks good. Great stuff.
 
Peter, can I buy the 22k and 220R caddock Reistors and the 680R Rikens from you? Since I have heard so many good things about LM3875 amp, I thought I wanna go all th way for this that I am going to build after I complete my LM4780. You can send me a mail, if you prefer on the pricing and sending to Malaysia.

Thanks again for the great support and Good night. It's late over here now.
 
Peter, I just wanted to let you know how good the LM4780 sounded. We were able to try it out today.

Source were a Marantz CD16 and a Rega P25 (25th Anniverasary) turntable, pre is a Musical Fidelity F22 (I think) and speakers were the Vandersteen 1A. The LM4780 floored everybody including the owner of the system and he is using a pair of highly rated monoblocks. The resolution was good, ambience was good, soundstage was good and I don't know where to stop or start. :D I found the best part was that it was very musical and addictive to listen to. This is a level above the LM3886 that I had. The GC drew respect from all who were present as nobody expected the GC to perform this well.

We credit that it must have been due to your excellent implementaton and we are looking forward to building the LM3875 as so many has commented that the LM3875 is the most musical of NS Overture range of chips.

Thanks a lot for all the support and probably will need more in building the LM3875.
 
jleaman said:
Here is a dac that a friend of mine is working on. Really nice too. And sounds good.

An externally hosted image should be here but it was not working when we last tested it.

I second Destroyer OS. Recently I added Peter's NOS DAC in between a modded SB2 and a Patek, and the result has been fantastic. Strings, pianos, bassoon, cellos, percussions, vocals have never sounded this realistic. A warm yet fast, detailed and dynamic presentation of music left me not wanting for any further tube or ss or digital upgrade. Except, maybe a second Patek would help empower my 89db speakers a bit further in the future. Plus, I have instant access to hundreds of CDs ripped from time to time, using SB remote or better yet a laptop. The 300GB HD is going to fill up its full capacity with growing ripped CDs, so I plan to get another HD to Fi-Wire chain it to the existing disc.

I end up buying more and more piano and string CDs, the two instruments I used to think would never be reproduced right on my stereos.
 
I recently received an order for two assembled premium DAC kits, so I decided to compare receiver chips (CS8412 vs CS8414). I'm slowly running out of DIP pacakage and whatever is assembled now uses adaptor boards and SMD chips. Soon, I will redesign the board to be compatible with SMD package only.

There is definitely a difference between those two chips. SMD package of CS8412 sounds the same as DIP version, however CS8414 sounds different. I got the impression that music flow is much more liquid and coherent with CS8412. The musical notes with CS8414 seem somewhat disjointed and I'm having problem concentrating and following the presentation.

The impression is so pronounced that I actually have to remove the CS8414 chip and install CS8412, as otherwise I would be hesitating to send such DAC to a customer. The bass may be slightly better with CS8414, but I'm not sure about it yet.
 

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DAC Receivers

Peter Daniel said:

There is definitely a difference between those two chips. SMD package of CS8412 sounds the same as DIP version, however CS8414 sounds different. I got the impression that music flow is much more liquid and coherent with CS8412. The musical notes with CS8414 seem somewhat disjointed and I'm having problem concentrating and following the presentation.

The impression is so pronounced that I actually have to remove the CS8414 chip and install CS8412, as otherwise I would be hesitating to send such DAC to a customer. The bass may be slightly better with CS8414, but I'm not sure about it yet.

Peter,

That is very interesting. I compared the SMD CS8414 to the DIP CS8412 in my Budget Greenboard DAC (post #714) and could not hear a difference. I can't do the comparison in my two Premium All-In-Ones, because I have the DIP CS8412s hard wired.

Could there be enough difference between the Budget Greenboard and the Premium All-In-One to cancel out the difference in the receivers that you are describing....or are my ears just that bad?

Robert
 
It's hard to say if budget version prevents noticing the differences. I think it's more a matter of getting used to a certain sound signature. I'm listening to that setup for almost a year now and any small changes are easily noticable right away.

If I put a freshly built DAC in a system, even if it's not broken in yet, I recognize the same sonic virtues. Here however, the sonics had different "virtues", the ones I'm not being used to.

The difference may be subtle, to me however is quite important.
 
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