Separate DACs for each halfwave ?

[rfbrw]

any hint how to obtain a pair of AD1862?

Buy them ?

 

[till]

at reichelt?

 

[rfbrw]

at reichelt?

You tell me, you're in Germany.

 

[Bernhard]

PCM56-K are highest grade, no need for upgrading these.

Do you have PCM56-K or PCM61-K ?

Could use the 56 in my Technics and the 61 for parallel try.

 

[jean-paul]

PCM56-K if I'm correct. AD1860 too, no PCM61 here.
What's with the paralleling ? Like in piggybacking ? Bipolar chips ?

Will it be better ? Maybe on the analyzer because it really sounds worse in most cases. Piggybacking that is.

 

[guido]

AD1860

18 bit PCM audio DAC.

Digital part: cmos by ADs BiMOS II process.
Analog part: bipolar, MOS and thin film restistors.

"industry standart pinout"

Got the datasheet on paper, it's in the Data converter ref manual from AD, volume I (1992).

Actually got the whole lot.. vol2, amplifier and the audio/video one. And the BB IC data books, data conversion products from 1994 and lin products.

Worked in a hospital back then and they ordered the whole lot for me. Could not use it that much in those days, but it seems the stuff gets more interesting as years pass

Sorry, no electronic copies and i dont have a scanner

 

[guido]

* Not yet.

* I plugged the PCM61 into the socket of the PCM56 in the CDP.
Sound was distorted strongly.
Data sheet say that these are pin compatible.

PCM61 is 18 bit, PCM56 is 16 bit as you can see from the datasheet. So when you clock the PCM61 with only 16 bit you don't define bit 17 and 18. So what are they set to when the chip does the conversion, might be random

And if there is an external MSB adjust circuit, you need to readjust that (also if you swap one 56 for another).

pin compatible != equal

 

[rfbrw]

16bit LSB-justified data != 18bit LSB-justified data.

 

[Bricolo]

PCM56-K if I'm correct. AD1860 too, no PCM61 here.
What's with the paralleling ? Like in piggybacking ? Bipolar chips ?

Will it be better ? Maybe on the analyzer because it really sounds worse in most cases. Piggybacking that is.

You should add a crown to your avatar, that would make it even more hype

 

[jewilson]

The Burr Brown DAC are much better parts than the Analog Devices DAC. Also, there are no missing codes on the BB DAC's, when switching negative, that complete non-sense. In addition there no cross over distortion in DAC that a function of biasing in amplifiers output.

 

[Bernhard]

What does that mean : PCM61-L ? Low quality ?

My Tecnnics is only balanced. This chip between digital filter and DAC is for data line inversion.

 

[carlosfm]

any hint how to obtain a pair of AD1862?

If you buy my Audio Alchemy DDE v3.0 Dac, it comes with two of them inside.
If you don't know it, I'll describe, along with the mods I made.

- Ad1862 and PMD100 digital filter (HDCD)
- Non-regulated PSU, transformed by me for regulated (big difference).
- Changed some PSU caps inside.
- Changed the OP176 op-amps at the analogue stage for OPA627 (huge difference).
- Changed the 6th order filter for a second order. (huge difference).
- Changed the BNC input plug with a Supra Trico coax cable soldered inside (the BNC had contact problems).

This is high-end.

But after making my TDA1541A NOS Dac, tuning, LISTENING...
It's what I have on my main system.

Whant to buy my AA, till?

 

[Lgrau]

In addition there no cross over distortion in DAC that a function of biasing in amplifiers output.

The crossover distortion, is coased by the shift between 1MSB -> 15 LSB bit.

This happens at Zero, so a tiny change in the MSB value will give distortion.

Of coarse this is not the crossover distortion we see in amplifiers.

 

[till]

Whant to buy my AA, till?

all the peripherie does not really help me, only the chips. $$?


i woul trade against TDA1541

 

[carlosfm]

all the peripherie does not really help me, only the chips. $$?
i woul trade against TDA1541

Well...
The chips are on sockets (not by me, AA put them this way).
But I won't scavenge a very good sounding Dac (now) just to sell the chips.
The AA is now connected to my son's PS2 , where I watch some movies and live concerts.
Very good sound indeed.
Yes, the PS2 is on my main room, connected to my main system.
No cheap DVD for me, thank you, the PS2 does it for me while manufacturers are still fighting for new formats/standards.
No crap DVD-A or SACD has convinced me yet.

For CD, I have now my Philips CD650 + TDA1541 NOS Dac, with I2S connection.
S' beautiful.

 

[rfbrw]

What does that mean : PCM61-L ? Low quality ?

My Tecnnics is only balanced. This chip between digital filter and DAC is for data line inversion.

You sure about that? You do not need a 40-pin monster just to invert a data line. What markings are on the 40-pin ic?

 

[Bernhard]

You sure about that? You do not need a 40-pin monster just to invert a data line. What markings are on the 40-pin ic?

Don't remember the marking. MN&something.
The board is back in the player and chip is on bottom side of pcb.

It is more thn simple data line inversion IMHO, what I wanna say is that one DAC output is inverted.

Scope shows full sine.
Output to ground 0,7V each chip, 1,4V chip to chip.

 

[guido]

What does that mean : PCM61-L ? Low quality ?

My Tecnnics is only balanced. This chip between digital filter and DAC is for data line inversion.

Mmm,

databook only has P-P, P-J and P-K version.

The big chip might convert the coding of the data from ?? to two's complement (and invert). What's the decoder ?

 

[rfbrw]

Don't remember the marking. MN&something.
The board is back in the player and chip is on bottom side of pcb.

It is more thn simple data line inversion IMHO, what I wanna say is that one DAC output is inverted.

Scope shows full sine.
Output to ground 0,7V each chip, 1,4V chip to chip.

There are 4 dacs.Do they all have individual BCLK,LE and DATA pins?

 

[Bernhard]

The PCM61-L are doublecrowns ?

Only individual data lines.
Decoder also MN&something.
Don't want to remove the board again...