DX-1 Cards

[Robh3606]

I was lucky to get a DX-1 from Mike Cadwell. It powers up and looks in perfect shape however it is missing the crossover cards. In this thread I hope to be able to show how too make the cards from readily available sources such as Radio Shack. The only skills you will need are how to read a schematic and soldering. I will also link as much as the DX-1 information already on the site into this thread. I am able to do this because to the generous contributions of Pasadena, Giskard and others in threads that I will link that provide the information required to make the cards.

Basic Schematics for the cards are here:

http://audioheritage.csdco.com/vbull...highlight=DX-1

Unit Schematic

More Later

Rob

[johnaec]

Let me know if you need some pics of DX-1 cards for the XPL200 - I could probably do that if it helps at all...

John

[Robh3606]

Hello John

Thanks I have pictures of the boards already. Thanks for the offer.

Rob

[Robh3606]

I got the cards built today and did some measurements with Clio to see how the voltage drives looked in both channels. They look very good and compare with the other set of drives we have posted in the other thread. I don't have the 1000pf Polystyrenes yet or I would be closing it up to see how it sounds. I will post more later about making the cards and where I sourced the parts.

Rob

[Robh3606]

Here are pictures of the cards. I used Radioshack Component PC Board as my cards. They are available in several sizes and the 276-149 is almost an exact match for the size of the original cards. The componenents were primarily sourced from Ocean State Electronics. It had the 1% resistors, Mylar caps and polystyrene bypass caps. The connectors are .100 spacing and any female connector that can accomodate the pins size should work fine.

https://www.oselectronics.com/


I didn't try to use a charge coupled topology for these cards but will at a latter date. The PCB's made assembly very simple as the cards are predrilled on .100 center and have solderable copper lands around each whole. There are a couple of issues that came up and both were mistakes in the DX-1 schematic. R104 and R106 are switched on the HF side and the right and left side LF blocks are also switched. The best way to verify the actual pin connections is to use photo's of the boards.

Rob

[Robh3606]

Attached are simplified schematics for the cards. Please note that there are .001 Uf Polystyrene caps in parallel with all capacitors.

Rob