Hi Leo,
You will need to remove the LM4562 as I cannot predict what will happen to the internal circuitry of the LM4562 chip if you apply power to the output terminals with the non-inverting inputs floating.
Regards
Paul
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Hi Leo,
You will need to remove the LM4562 as I cannot predict what will happen to the internal circuitry of the LM4562 chip if you apply power to the output terminals with the non-inverting inputs floating.
Regards
Paul
Thats fine Paul thanks, think I'll do it the cut pins and remove the remaining bits on the pads technique, don't you just love ROHS solder:eyebrows:Quote:
Originally Posted by Paul
Cheers,
Leo
Try this: http://www.wbtusa.com/pages/0800.htmlQuote:
Originally Posted by leo
There are UK sellers on ebay who supply it. :)
Of course, it's no help if you are de-soldering stuff thats been assembled with ROHS stuff. :(
Hi Mike,Quote:
Originally Posted by Shian7
The Sabre uses 90% SMD parts, the Solder used looks to be ROHS, previous experience tells me removing SMD parts soldered with lead free solder can be a pain in the arse depending on track quality, rather than the risk of any track lifting I'll cut the op-amp out up to its body and carefully remove each remaining leg on the pads with solder wick
I've no problem working with SMD parts, especially soldering with leaded or lead free solder:)
Cheers,
Leo
The separate IVY output stage board will be very easy , the +/-v regs are separate and supply the input socket
We'll have to see best place to run the grounding wires, the onboard regs and the input socket are connected to the same top ground plane
Could maybe run them to unused VA socket GND or to the existing pads of the removed parts
http://i273.photobucket.com/albums/j...alo_layout.jpg
I've now changed the input comparator for the SPDIF (marked as IC2 above)
, the fitted one was a LMV7239, these are too slow for 192k so I've changed it to LMV7219 which is a faster part.
Surprising that SPDIF even from my modded Squeezebox3 sounded better with the faster comparator in the Buffalo
This thing is really starting to sound damn good!
Just a note of caution, the comparator is bloody tiny so should only be replaced if your confident working with very small SMD components
Heres an update after two weeks of upgrading the dacs regs to Paul Hynes shunts and series
The ones fitted are
1 x Z1A-3v3 positive shunt regulator set to 250mA which supplies main 3.3v and onboard Crystek 80mhz XO
1 x PR3G-1v2 positive series regulator supplying Sabres core and VDD1.2v
2 x Z1703v3 50mA positive shunt regulator supplying the Sabres left and right AVCC (VREF)
1 x Z1A-15 150mA positive shunt regulator set to 150mA supplying the +15v of the IVY I/V stage
1 x Z1N-15 150mA negative shunt regulator set to 150mA supplying the -15v of the IVY I/V stage
http://i273.photobucket.com/albums/j...busoms/032.jpg
Fitting the new regs for the IVY was quite easy as the outputs are wired straight to the IVY pcb input sockets.
The ones replacing the dac pcb's oboard LDO regs required desoldering the SMD LDO's and wiring the output of the new regs to the pcb pads
The AVCC (VREF) was more tricky as it required removing the onboard LM4562 SMD used as a voltage buffer, I wired the output of the Z1703v3 shunts across the local SMD decoupling caps which are right next to the dac pin, I tapped their input from the now removed LM4562 supply, I did manage to damage one of the onboard capacitors so had to replace it, I'd advise keeping these caps to help with any inductance from the wiring, the AVCC supplies are critical ! Just be very careful if working with SMD parts
http://i273.photobucket.com/albums/j...soms/mods1.jpg
After powering up and having a quick sound check revealed much more detail, it sounded a little light though so I resisted temptation to listen too much at this early stage so left it alone to burn in, a few hours later the sound was far better, bass had much more depth but most of all was the improvement in the midrange !!!
Over the next few days it continued to improve to a point I was struggling to pull my self away from it, focus,detail with extremely clean and clear highs, unlike a lot of digital sources I've heard ,this unit had a total lack of HF distortion and sibilance, no grain!
The biggest plus for me was now the midrange purity which I felt was originally lacking with the standard Sabre, its actually infront of my TDA1541 dac at the moment, I now need to do some more work on the TDA dac and see just how much further it can be pushed, I'll add any updates as soon as I do on the other thread to see if it can be improved to regain top rank
Conclusion is compared to standard three pin regulators, the Paul Hynes discrete regs have FAR better performance, their impedance is lower over a much wider bandwidth , quality of the regulation in any audio equipment is important and will have an influence on the sound, these regs are much more effective than relying on boutique capacitor changes IMO
My advice, when first fitting these regs you have to be patient , give them a few days/ a week running in time as I felt their performance greatly improves as they settle down
Big thanks to Paul for giving me the opportunity to evaluate these regs, they get the big thumbs up from me
I have three DEM reclocking boards arriving soon if you'd like to tinker with one?Quote:
Originally Posted by leo
translated link.
Sorry Yomanze, I totally missed this:oQuote:
Originally Posted by Yomanze
I once tried DEM reclocking, the results was very promising but I had some HF noise ,probably caused by having it built on a piece of vero board or maybe the choice of chip.
If you have one spare I'd love to revisit the DEM reclocking, I think in this case a pcb would be better
Cheers,
Leo
Hey Leo,Quote:
Originally Posted by leo
Did you replace the XO? The supplied one is of very low quality. With 20-50$ you should have already something v. good.