ad1955 evaluation board ad1955eb.pdf

[georgehifi]

Hi George,

whats a transimpeadance amp, and why not make one for your new dac? BTW hows the babelfish-x going?

Their input impedance is zero ohms, pic posted,
one day I will,
whats babelfish-x ???????

Cheers George

 

[Luke]

The babelfish is a jfet aleph variant by zen mod and I recall you made a pcb for his xed version to try it out. Sorry if Im mistaken

 

[georgehifi]

AD1955 eval available again at AD

But now they are $475 and called EVAL-AD1955EBZ instead of EVAL-AD1955EB still worth it, one of the best sounds I've heard, just a little more laid back compared to my heavily modded Harman HD970 (also a AD1955 dac) but just as smooth and just as detailed, and extremely versatile even does sacd, below is a printout of what it can do with the multitude of links, switches and bridges.

Cheers George

 

[b-square]

Are you certain it is the same, just more expensive? Would hate to order one and then discover they made changes and it is both more expensive and not as good.

 

[georgehifi]

With each one you get a very good comprehesive manual and switching instructions on CD

The 1st post has a circuit diagram/manual of an earlier revision B, which was a little different to mine which is revision C, I would say this newest more expensive one will have to be revision C and have some stuff that mine may have not, but all do the same job, just I would say each later one will have more versatility than the previous one, like mine has the cradle for a 4 pin oscillator where the revision B did not.

Cheers George

 

[arekkl]

Please help

Hello everybody.
I'm sorry for off-topic. I'd like to ask georgehifi user about symbol of laser unit to my CD-player Pioneer PD-77 (PEA ????, PWY ????). I didn't find it in web. Please help me. Thank you.

arekkl@wp.pl

 

[georgehifi]

Re: Please help

Hello everybody.
I'm sorry for off-topic. I'd like to ask georgehifi user about symbol of laser unit to my CD-player Pioneer PD-77 (PEA ????, PWY ????). I didn't find it in web. Please help me. Thank you.

arekkl@wp.pl

The laser you want is the PWY1004, below are two places I found within 2 mins of serching.
Cheers George


http://www.partstore.com/Part/Pioneer+Electronics/Pioneer/PWY1004/New.aspx

http://parts.pioneerelectronics.com/part.asp?productNum=PWY1004

 

[arekkl]

RE: laser

Thank you George!

Best Regards
arekkl

 

[georgehifi]

With each one you get a very good comprehesive manual and switching instructions on CD

The 1st post has a circuit diagram/manual of an earlier revision B, which was a little different to mine which is revision C, I would say this newest more expensive one will have to be revision C and have some stuff that mine may have not, but all do the same job, just I would say each later one will have more versatility than the previous one, like mine has the cradle for a 4 pin oscillator where the revision B did not.

Cheers George

Typo above
Sorry this newest one would have to be revision D

Cheers George

 

[dday_one]

Hi George,

What Power Supply did you use? I just have ordered an EVAL-AD1955EBZ DAC in the Netherlands, it won't be here the next two weeks... so I'm deciding on the PSU to use.

thx. Lennert

 

[georgehifi]

I wanted something already made (kit form) so I went with this Russ White one, very good.

http://www.twistedpearaudio.com/lcbs/lcbs.aspx

But with a 15-0 15-0 secondary toroidal that I had here, I had to change the + regulator for a low drop out one as the + rail sagged because of the extra load on it from the DA eavl board, and it sagged very close to the dropout point of his supplied + regulator.

Cheers George

 

[georgehifi]

lol...

I know another evkit that would be suitable for you but i rather shut the **** up

I just saw this previous post by flshzug, what was the purpose behind it?
does he want to keep all the boards for himself?
or is he a cronic poster?
or is he a, I've got one one but you can't have it kinda guy?

I can't work it out?

Cheers George

 

[JonPike]

??? I don't get it... Are you saying you made your own ladder DAC and it sounds better? Or, is there some secret other eval board that you think is better?

It also makes it sound like buying an eval board from Analog is ripping them off somehow... I don't get that either, most are offered at cost or better. It's not like abusing the samples network by getting parts lots of parts for free, then selling them...


Oh well, this "new" board is still officially "in stock soon" and I can't find any documentation on what the new one has that the old one dosen't...

Getting back on topic... or completely off... George, have you any listening experience with Twisted Pear DAC's? Wondered how they compare with the AD1955... Or other kit type ones that you ACTUALLY CAN BUY from someone?

 

[georgehifi]

[B
Getting back on topic... or completely off... George, have you any listening experience with Twisted Pear DAC's? Wondered how they compare with the AD1955... Or other kit type ones that you ACTUALLY CAN BUY from someone? [/B]

I haven't, but I have a friend who has heard one, on his system he said it was very good, but that my AD1955 eval board on his system was better, and my modded HK HD970 was better again, he said the modded HK seamed to take the reins off and let loose the dynamics like he's never heard before.
I can listen to both the eval and the HK, if I'm in a close the eyes and drift off into the music frame of mind I listen to the Eval board, but if I want to be shocked and startled in between the close the eyes drifting off by the dynamics, it's the HK all the way, it seams to have a built in dynamic range enhancer (DBX Unit) without all the nastie's, I believe it's the (LC) Transimpedance I/V amp and discrete output amp that's doing this.


Cheers George

 

[georgehifi]

??? I don't get it... Are you saying you made your own ladder DAC and it sounds better? Or, is there some secret other eval board that you think is better?

Jon, the moderators have seen fit to gag flshzug, I don't think you will get an answer.

Cheers George

 

[georgehifi]

Get a life!!!!!!!!!!!!

 

[JonPike]

I just want to get a halfway decent DAC, for not a lot... right now I'm using a $50 DVD for a source.

Shouldn't take much to get beyond that... I like the Twisted Pear stuff, but the whole balanced thing is a bit more than I need, since most of my gear is unbalanced, and I'd need yet another board to get back there.

Thinking about some lower end designs... but want to keep a decent final cost/quality vs effort of building a kit ratio, if you know what I mean...

 

[georgehifi]

I just want to get a halfway decent DAC, for not a lot... right now I'm using a $50 DVD for a source.

Shouldn't take much to get beyond that... I like the Twisted Pear stuff, but the whole balanced thing is a bit more than I need, since most of my gear is unbalanced, and I'd need yet another board to get back there.

Thinking about some lower end designs... but want to keep a decent final cost/quality vs effort of building a kit ratio, if you know what I mean...

This is what I'd do, get a second hand Harman HD970 they only come in 220-240volt, then use a 240v to 110v 1 amp step down transformer in reverse, for your 110v
I've seen the HD970 in Australia second hand on ebay for $399aud, and they are factory seconds that were dead out of the box, then fixed, they still came with 1 year HK warrenty. I think there are many in Europe also, and Asia

Cheers George

 

[georgehifi]

Here's one in Europe as we speak.
http://cgi.ebay.com/Harman-Kardon-H...ryZ27782QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Cheers George

 

[JonPike]

Yeah, that's the thing... they're all overseas, and 200-400 Euro...

I have read a bit more, seems like an Opus DAC can be run single ended w/o the buffered adapter board.. with some loss of signal amplititude. So what I said earlier wasn't true.

I appriciate the tip, though... I've been looking/learning the DIY speaker/electronics/audiophile world from the DIY side out... don't know much about the commercial stuff!