AD1865N-K availability.

[Jocko Homo]

I stand by my claims.

As rotten and wretched as the 1541 is, the SAA7220 is just as bad. It has a zero in the transfer function to cancel a pole in the post-filter. All it does is let ultrasonic crap through.

Anyone who thinks this combo is good has no idea what good really is.

People ask where I come up with so many "Crowns" to sell. It is easy: I rip them out and put something decent in their place. No one has ever asked to have it put back one back when I'm done.

Jocko

[rfbrw]

Jocko Homo
As a good capitalist, the tenets of capitalism oblige you to pop over to the Audio Asylum and take advantage of the reverential status accorded these devices by offering them at an inflated price to those wishing to build a non-oversampling dac.
As for the SAA7220 it couldn't have been that bad at least not to AD. They have an appnote showing how to connect to their multibit dacs.
One more thing. What do you replace the 1541 with, given that pin compatibility is out ?
ray.

[Elso Kwak]

Hi Jocko,
What did you put back in after removing the TDA1541? You have made me very curious!
I have given up the digital filter a long time ago.
I don't agree the TDA1541AS1 is that bad as you describe, it has a character different from the AD1865.
If you can get two AD1865N-<B>K</B> I will make use of your kind offer to buy these chips. Thanks in advance.

[Jocko Homo]

rfbrw:

I do sell them! Although not always to that crowd. AD probably does think it is bad.......there are a lot of audiophile types designing stuff there. The rep used to live down the street, so I received lots of insight as to what they were up to. They probably showed how to hook it up in order to get people to use their stuff. I have data sheets showing their DACs connected to all sorts of stuff. Sony, Pioneer, etc......

Elso:

Never had to put one back! Which is good, because I sell them as fast as I can pull it. I make a separate board which holds BOTH the DF and DAC chips, and find a way to mount it on top of the PCB. The I/V goes on a different board.

OK........so you want the "K" version. How many? I usually send stuff to Europe labeled as "samples" or "warranty repair". Usually gets it by the morons in customs, without VAT. Always afraid they will take them out and look at them with their greasy fingers, but so far the only thing they ruined was a transformer I sent to Scotland.

How many others want these "K" versions? If I buy enough, there is probably a price break at 25 pieces, knowing AD. The only drawback is that I have to pay shipping, usually not all that much, to get the parts, and then more to send it to you.

Do you want me to start checking on prices for shipping to your country? Probably costs the same to send ten as it would one, but too many might make the VAT man curious.

Why the popularity in the 1865??? Never used them. If I am right, it is a stereo DAC. I usually use the 1862, and sometimes the B-B PCM1702. Both have strengths and weaknesses from a design standpoint. They do sound different, but I have no preference sonically. Both are worlds better than the you-know-what.

I need to get the e-mail address of my buddy Ton Maas. He has a phono stage I built for him. Tried to sneak it past the VAT man, and had to come up with some creative.......well, shall we say....LIES......so that he did not have to pay it. (They wanted VAT on the shipping too! Which was $150 US!) If I can get it, you need to give it a listen. He was in Amsterdam last I heard. Unemployed, probably. Starving artist type.

Jocko

[capslock]

Jocko:

why do you complain about I2S? Nice thing about I2S: it'll take any number of bits from 16 to 24 without having to deal with status registers and stuff. Many of the newer AD parts even use I2S as default. Makes me think whether for my next project I want to convert from right justified 16 bit to I2S by using a shift register, a digital receiver or whether it's easier to install an extra PIC just to get the AD1853 to accept right justified 16 bit format.

By the way, the TDA 1541A will accept right justified simultaneous mode (the output from most digital filters) .

Greetings,

Eric

[Elso Kwak]

Hi Jocko,
If I understand you correctly you put in a AD1862 and keep using a digital filter? I stopped using a digital filter. What is the digital filter you are using?.
The AD1865 seems ideally suited for the non-overdampling 16 bit red book format as the CS8412 can output 18 bits, that are really 16 bits with two zero's stuffed in. In this way the two lowest bits of the AD1865 are not used resulting in better linearity. This can be seen easily on the scope comparing the 16 bit AD1851 with the AD1865 on a -60dB signal.

Will mail you about the buying of two AD1865N-K.
Thanks again.


I never heard of Ton Maas, but will give it a try as know a few DIY people here in Holland.

[Jocko Homo]

Eric:

I like I2S, just not the 1541. It sounds awful, they break all the time, operates in a unipolar mode, and well......they are just old technolgy. The AD and B-B DACs sound much better.

All my current designs use I2S, even ones that are fed from a RX chip.

Elso:

I found Ton Maas' address........email me for it.

As for technical stuff........

I only use the SAA7220 for the clock and the digital output. You could make your own clock, but since I want the digital output, I leave it. I take the outputs from the decoder chip, in good old I2S format, and run it into a modern digital filter. Some NPCs take left-justified data, so I offset the data by one clock pulse with a "D" flip-flop. The new Burr-Brown filters will take I2S direct. Neat, huh?

But........you can use the newer filters to upsample to 8X and get 24-bit resolution. All it takes is just a few more parts. (Well, maybe more than a few if you do it my way.) All it takes is money, space and time. Yeah, I know there are only 16 bits to start with, but good interperlation filters make a big difference in sonic performance. Trust me gang........I've done lots of this.

Jocko

[capslock]

Jocko,

for I/V conversion on the AD1862, do you use the on chip 3 k resistor or an external resistor? Providing an on-chip gain resistor is very common in instrumentation DACs because its temperature drift will track that of the other internal resistors. But in audio, one does not bother about slow gain drifts but about LF thermally induced distortion. (1 mA)^2*3 k = 3 mW is not much for a real resistor but may be a lot one of those little on-chip resistors...

Eric

[ALW]

Elso,

All items from the Newark catalogue are available via Farnell in the UK.

May get you round the shipping problem.

Andy.

[Elso Kwak]

Hi Andy,
Thanks for the reply and I discovered Farnell as a good supplier. Unrfortunately they don't have this part!