ad1955 evaluation board ad1955eb.pdf

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Finaly got to pay for and order one, can take up to 4 weeks to get to Australia I was told by AD Australia

Here is a pic I found after much searching.
Circuit and Data sheet is in the first post of this thread.

Cheers George
 

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I wanted the AD1955 because it's sacd ready as well, and I have no idea how to build from input that's aes/ebu or 75ohm spidf ready with all the other components that are involved before and including the dac chip, also it's all Cirrus Logic at the front were the HD970 is all AKM, this also will sound different.
To me the output analog stage is by far the least complex part of this eval board and I'm confident playing around in this area, but all the digital stage, I may as well be looking at Hieroglyphics.

Cheers George
 
Mine arrived today, not bad 16days from payment to delivery, hope to find the time soon to mount in a nice case, and a separate case for 2x 12vdc recharable batteries with charging system. It's quite a big board, you do get your money worth, very nice quality components.
This is some more stuff that comes with the cd when you purchase one, the circuit diagram was it the very first post
http://home.tiscali.cz:8080/saudio/AD1955EB.pdf

and I posted a picture of it on post 21
http://www.diyaudio.com/forums/attachment.php?s=&postid=1315495&stamp=1191364151

But here is some switching info some mite like to know about.

Cheers george
 

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georgehifi said:
Mine arrived today, not bad 16days from payment to delivery, hope to find the time soon to mount in a nice case, and a separate case for 2x 12vdc recharable batteries with charging system. It's quite a big board, you do get your money worth, very nice quality components.
This is some more stuff that comes with the cd when you purchase one, the circuit diagram was it the very first post
http://home.tiscali.cz:8080/saudio/AD1955EB.pdf

and I posted a picture of it on post 21
http://www.diyaudio.com/forums/attachment.php?s=&postid=1315495&stamp=1191364151

But here is some switching info some mite like to know about.

Cheers george


Hi George,

I'm gald you like your board as well. AD spared litte expense with the passive components. There might be opportunities to upgrade the PSU regulation, but it's quite good as is.

A prior post mentioned batteries. TNT audio did a very interesting evaluation of batteries and found them noiser than well regulated supplies. The AD3303 LDO regulators after the LM3xx's on the AD1955 eval board are very nice and they come mounted on the board. Just a thought to consider.

I wish the other DAC vendors took this much care in building eval boards.

-David
 
Hi David, I did read somewhere that the lead acid rechargables are slightly noisy, but the gel cell rechargables are dead quite, maybe the bubbles in the liquid of the lead acid make noise?

Do you have a good supplier of cases, I had one but it looks as thou he's gone out of bussiness, it was
ATI Research Company Limited
www.atiresearch-anodized.com

This is a archived cached link, it takes a while to load, he had some great cases and they were well priced.
http://web.archive.org/web/20070707142522/www.atiresearch-anodized.com/products.html

I used to get these nice cases 320x300 mm from them, does anyone know where I still can get these from?
 

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georgehifi said:
Mine arrived today, not bad 16days from payment to delivery, hope to find the time soon to mount in a nice case, and a separate case for 2x 12vdc recharable batteries with charging system. It's quite a big board, you do get your money worth, very nice quality components.
This is some more stuff that comes with the cd when you purchase one, the circuit diagram was it the very first post
http://home.tiscali.cz:8080/saudio/AD1955EB.pdf

and I posted a picture of it on post 21
http://www.diyaudio.com/forums/attachment.php?s=&postid=1315495&stamp=1191364151

But here is some switching info some mite like to know about.

Cheers george

Well, hell!! I've been trying to get one of those for months... sent emails for months... got someone at Analog to answer, they said they're out, but will have some by May, which turned to June, which turned to August... then they kinda refused to promise them ever showing up. They removed the link with the price a while ago.. and I gave up. Figured they decided it wasn't cost effective, weren't going to produce any more, and didn't want to come out and say it.

I'm even in the US, dealing with the home office...

So, spill the beans, how/where did you order one?
 
OK, just made a quick check... there is a eval board in the list of things for sale, not linkable from the greyed out "Eval Boards" link though...

It says they're available from 9-06 (??) but to actually put one in the basket results in it saying they're out of stock now, 8 week wait.

Guess that's an improvement, but I wouldn't want to plunk down to wait two months, and hope they didnt' become 4-8mo, or longer...

I might try a more local sales office...
 
georgehifi said:
I paid up front with my local AD dealer here in Australia, Avnet Electronics. They are in stock, took 16 days from payment to my door step.
Cheers George


We do have Avnet here in the States... I'll try them, and other vendors that "do" Analog.

Was looking at the EZdac board... nice having a AS reclocker, and the TI/BB later design DAC ain't shabby... but the comments about the vendor themselves probably doing exceptional layout on their eval board to properly display their industry topping product, are well taken.

And, the thing uses AD797 op amps for the output!! :cool: How cool is that?

Quick question for you guys, what're the dimensions of the board. outside and hole spacing?
 
AD-1955 Evaluation Board

Finally found the time to get it together with a supply, and it does sound very very good.
It beats my favorite standard non modded Harman HD-970 (also a AD1955 with discrete class A output). It sounds just as detailed and as smooth, but with a little more drive and dynamics.
But it still can't match my benchmark a Harman HD-970 with a discrete transimpedance I/V stage and a discrete class A transistor output stage, powered by a shunt regulated supply, this Harman is almost scary to listen to, it has all the smoothness of the standard HD970 and the AD1955 Eval Board but when the crescendos build or drums get hit hard it is very scary to listen to, it's as though it has a DBX (dynamic range enhancer) built into it, yet still stays smooth and airy when needed.
I really believe now that a transimpedance amps as I/V stages who's input represents a short to output of current output dacs such as the AD-1955, is the only way to go, it is a massive change to my ear for the better, especially dynamically, that said on some systems that have problems with slight hardness's or harshness it could be detrimental to those systems.
I'll post 3 pics of the AD-1955 with it's power supply and box.

Cheers George
 

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