NAD DAC M51 vs. Philips TDA1547 DAC

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Hi forum

I've now had my NAD M51 DAC for 1 year and i'm pretty tired of the sound or should i say, i'm missing a more open and detailed sound. The NAD is very closed ...like it's filtered and oversampled to much. :confused:

I've ordered a new Philips TDA1547 Assembled DAC from ebay, because i've had a DAC for a couple of years ago ( unfortunately dead ) which contained several TDA1541's and it was very open and detailed.

What's your opinion, could this be a better solution, when it's said that i like open and detailed sound ?

Signal: streaming from pc's in wav format = 44,1 khz via coax or usb.

PS: I've got both 2x16 vac + 2 x 9 vac transformers + enclosure + 2 x opa2132 for this build !
 
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What's your opinion, could this be a better solution, when it's said that i like open and detailed sound ?

IMHO definitely ... but to make DAC7 combo to shine, everything has to be done properly, starting with the selection of the input receiver and digital filter, through several stages of reclocking, proper PSU for digital and analog part, grounding, PCB art, choice of opamps, etc. Only in this case SAA7350/TDA1547 combo is capable of really outstanding sound.


Info:

If i understand this thread http://www.diyaudio.com/forums/digital-source/20133-tda1547-dac.html , we are talking about DAC-7 ( when combining TDA1547 + SAA7350 ).

IIRC, Philips guys use to call TDA1307/TDA1547 combo DAC7 as well.

I almost forgot ... the SAA7350/TDA1547 combo can be converted into a non-oversampling dac also, you just have to bypass digital filter and supply I2S directly to SAA7350 from input receiver.
 
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hi aparatusonitus

thanks for the answers

It seems i've found one of the good DAC's then. what do i have to buy/get for making what you call several stages of reclocking ? is it possible to find schematics or tutorials ?

I'm going to put two seperat trafos to the digital section and a seperat trafo for the analog. i checked the voltageoutput on several trafos yesterday. i got some "okay" ones that gives 17-0-17 vac and 10 vac. but even better, i've got some "quality" ones that has an output of 22-0-22 vac and 12 vac. i looked at the specs of the dac and it only allows +/- 20 % of 16-0-16 vac and 9 vac.

This dac has 317/337 voltageregulators, so i guess it should manage the 22-0-22 vac and the 12 vac input ( or maybe not, without adding better heatsinks ? )

about the op amps, should i go for 5532, 2132/2134 or maybe some 627's ? i only got the 2134pa in stock, so if they are okay i would be happy !

exactly ...i want to have the conversion possibility for non-oversampling. where do i find a schematic, so i know which pins i should use for bypassing ? can i do it with a simple contact or should it be done close to the digital components with a relay ?
 
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Hi KrammeAcoustics,

How good (or not) your dac is remains to be seen/heard. At this stage I would not recommend to buy anything extra, just what is essential to get it work.

About reclocking...don't lose you sleep over it for now, it's is already implemented in some way or another in you dac pcb, it seems.

As for transformers, use lower voltage one for start, if nothing (LM317/337) is hot, you may use higher voltage ones, regs will become slightly hotter.

For opamps, use what you already have, OPA2132, at later stage you can experiment with another ones.

Without schematic and/or circuit board, it's almost mission impossible for an amateur to do non-os mod, sorry.
 
hi again aparatusonitus

again thanks for quick replying. okay i will start simplistic and then we will see if some add-ons and tweaks is necessary :)

i will definetely get back when i'm ready for the non-oversampling operation !

obs: if anyone else has something related to subject, please feel free to tell.
 
Hi again

The stuff has arrived and offcourse as a little boy at christmas, i quickly had to crank the new DAC up. In the junkbox i've found a toroidal transformer with 15-0-15 vac + 9 vac and after mounting this and soldered the L+R input signal i was ready to listen. First impression is wauuuw ( some simple guitarmusic from Adam Raferty ). I discovered that there actually is mounted 2 pcs. of 5532 from JRC om the board, even if it was said that there were no op amps included in the price. Okay offcourse i just have to be satisfied with this extras. Anyway i think i'll mount some Burr-Brown OPA 2132 or 2134's of my own in a couple of days.

After a couple of hours listening with one transformer giving all the different voltages needed, i now tried to play with the PS. So now it's supplied from 3 transformers. One toroidal 15-0-15 vac and nr. 2 also a toroidal 1 x 8VAC and nr. 3 is equal as nr. 2. ( i observed that it's only 16 VDC electrolytics after the rectified 9 VAC inputs ). Does it then sound better with 3 transformers ...well i can't say yet. It's obvious that this DAC as any other electronics has to be burned in first. I will try later ...maybe after some weeks to try again comparing 1 vs. 3 transformers and give a review.

An important thing i've noticed is the 7809 reg. is getting very hot ( it has a cooling sink ). but the 7808 does not get hot ....is this normal ? i would had thought these two regulators would get nearly the same temperatur !

Last but not worst, is this DAC worth 75 US $ ? Yes i think so ...i'm glad to have one more DAC to make comparisons with vs. my NAD M51. It has something that the NAD not have and vice versa ( they're night and day up against each other ).

I'm ready for some mods. very soon and if i can get some help from you guys, that would be nice !
 
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Judging by the barely visible schematic, there are 6 Regulators on board: LM317/337, LM7812/7912 (or LM7815/7915) and LM7808 and LM7909...am I right?

Following is what i found ( measurements )

LM317 = 7 vdc
LM337 = -6,4 vdc

LM7805 = 5 vdc
LM7905 = -5vdc

LM7805 = 5 vdc
LM7805 = 5 vdc
? = 6 vdc ( this one i can't see because a coolingsink is blocking the view, it must be a LM7806 )

:mad: ...arrggh, i just found a loose connection = bad soldering for one of the terminals
 
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Judging by the barely visible schematic, there are 6 Regulators on board: LM317/337, LM7812/7912 (or LM7815/7915) and LM7808 and LM7909...am I right?

Which schematic are you refering to ? I would like to see this schematic ...please ! Link ?

I think you should measure all voltages on all the chips to see if they are within specification ... be VERY careful not to make a short circuit. Consult datasheet to identify exactly on which pins you need to measure.

Okay i'll try that if i can find the different datasheets !
 
btw, this is what I bought for Christmas:)

Looks great, nice goodies inside ( congrats ) :D


SPDIF/AES input using YM3436
Second PLL using Fujisu VCXO
Yamaha YSF210B digital filter and sample converter
Philips SAA7350 x 2 pcs 1 bit converter
Philips TDA1547 x 2 pcs 1 bit DAC chips
Op-amp filters and buffer – JRC2114, JRC5532
Nichicon, Elna, Sanyo OS-con, Soshin, Panasonic Electrolytic or film capacitors
RMA or Film resistors for signal path
Linear power supply and regulators

Price ?
 
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