diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Digital Source (http://www.diyaudio.com/forums/digital-source/)
-   -   Ultracurve, what can I do ? (http://www.diyaudio.com/forums/digital-source/11508-ultracurve-what-can-i-do.html)

Bernhard 23rd February 2003 01:17 PM

Ultracurve, what can I do ?
 
Hi,

a picture first:

http://www.beautyphoto.de/uc.jpg

this is my old 8000 Ultracurve. I have AES/EBU installed and feed it with spdif.

On the output one hot pin is connected to ground to make it asymmetric.

My questions:

I can not see any OPs, where are they ?

These 14pinICs labeld "Behringer" ?

For shure there are lots of magnetic resistors and cheap caps in the signal path, especially the SMD resistors would be difficult to change, so:

Is there any DIY DAC that can be used with the AES output ?

If I use an external dac, is there any reason to upgrade to 8024, sonically ?

Any rumors about a new model coming ???

Could I built some HQ output circuit direct to the pins of that DAC ?


Thanks, Bernhard

fmak 23rd February 2003 04:46 PM

The opamps are the vertical in line units marked 4580.

In my opinion you should ait for the 24/96 replacement. The 8024 is very cheap and very cheerful and despite claims in this forum requires major surgery to make it sound reasonable.

Problem seems to be in the transformer, dc power supply, clock and many cheap electrolytics. If you have lots of time and patience, may be you can improve it. It will be a major undertaking to change the opamps.

The measured performance of the unit with analog in is not good - from memory thd+n was about -70dB on the 8024.

Bernhard 23rd February 2003 05:55 PM

Wait for 24/96 replacement ? Will they bring out a better one soon ?

Bernhard 23rd February 2003 08:14 PM

Ok, this 4558 is the output stage, but where is it made symmetrical again ?

How about that ?:

Pull out the whole output stage, swap the OP for a socket, desolder all resistors and caps of the filter network, and then put bridges where necessary, so that I have the l+, l-, r+, r- on the socket.

Build a board with a new output stage and plug it into the socket.
Ground comes from the PSU.

fmak 24th February 2003 07:08 AM

Quote:

Originally posted by Bernhard
Ok, this 4558 is the output stage, but where is it made symmetrical again ?

How about that ?:

Pull out the whole output stage, swap the OP for a socket, desolder all resistors and caps of the filter network, and then put bridges where necessary, so that I have the l+, l-, r+, r- on the socket.

Build a board with a new output stage and plug it into the socket.
Ground comes from the PSU.

-----------------------------------------
You will have to create an input board; an output board and connect this to the software switches.

Do you have all this time and is it worth it?

The opamps on the 8024 are 4580, not 4558 which is an improved 741.

Bernhard 24th February 2003 08:27 AM

Quote:

You will have to create an input board; an output board and connect this to the software switches.
Only an output board because input is spdif.

Why software switch if only new output stage ?

My UC is the old 8000 and there is only one piece of a 4558.

Look at the photo, and three 14-pin-I-dont-know-what-behringers.


Maybe the best would be an external DAC, any recomandations ?


All times are GMT. The time now is 02:08 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2