diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Audio Sector (http://www.diyaudio.com/forums/audio-sector/)
-   -   The CD Transport (http://www.diyaudio.com/forums/audio-sector/160373-cd-transport.html)

Peter Daniel 31st January 2010 07:34 PM

The CD Transport
 
3 Attachment(s)
It's been a quite some time since I opened a thread on building an affordable CD Transport: http://www.diyaudio.com/forums/digit...one-story.html

The majority of the most useful info is scattered now in this long thread so here I will post instruction how I build my units, which became quite successful.

Peter Daniel 31st January 2010 08:12 PM

6 Attachment(s)
I start with a copper plate bottom, size 5.8 x 8 x 3/16". The wooden frame (Wenge) is 6.4 x 8.8 x 1.5". There are 6 screws attaching plate to a frame and 3 spikes acting as feet.

I cut out the display opening later, after top acrylic plate is trimmed. There's also an RCA socket and opening for an umbilical cable in a rear panel.

There are 2 pairs of standoffs (1" long) mounted to a plate: two 3/8 are for mechanism support, the other two for buttons pcb.

Peter Daniel 31st January 2010 08:38 PM

5 Attachment(s)
I modify the original display board next: it's trimmed, and what (needed) traces have been cut, they are now replaced with hookup wire. Unnecessary components in top layer are also removed. I also trim plastic display board housing. It can be removed by taking out 2 screws and desoldering IR receiver, LED and display pins.

There are 5 connection points to the switches:

2 common for all buttons
S stop
P play
B back skip
F forward skip

The buttons are spread 0.7" apart. The display is attached to wooden frame with a single, isolated head, screw. There is additional TOC switch mounted on a side (normally closed type).

Peter Daniel 31st January 2010 08:44 PM

2 Attachment(s)
This is the current mods I perform on mechanism:

I remove the choke and caps C916, C952

Peter Daniel 31st January 2010 08:46 PM

3 Attachment(s)
I also remove ceramic bypasses for those two electrolytics, altogether 5 parts.

Peter Daniel 31st January 2010 08:56 PM

6 Attachment(s)
The schematic show external PS. Two wires from PS are connected to the pads where choke was. Since BG FK is hard to find these days, I use BG STD with BG N 4.7uF bypass.

I add two output resistors: 300/100 Dale (you may also consider S102/Caddock) and in place of C916 I instal BG N, either 47/50 or 33/16 depending on availability.

Peter Daniel 31st January 2010 09:30 PM

6 Attachment(s)
I mount the mechanism, power supply and wire everything.

brianco 31st January 2010 09:36 PM

Thank you Peter.

Like so many threads here it is the nature for the truly useful stuff such as construction guidance to get lost within a morass of comment and questioning. Then someone new joins the thread and repetition is added!

That you have chosen a topic out of your many contributions which has the lowest commercial return for you is noted and admired!

Peter Daniel 31st January 2010 09:56 PM

7 Attachment(s)
Well, I just follow my signature: “Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” ;)

Getting back to the transport, the last thing is a top panel. I was initially using 1/4" acrylic, but after I tried thin metal top, I though that 1/8 acrylic would be nicer. Most common choice is clear frosted type, as it's easiest to maintain, but recently I was tempted to go with darker color and tried tinted acrylic. The shiny finish is quite impressive, but any fingerprints show right away, so I hand brushed it with quite good results. The look is similar to brushed, anodized aluminum.

I cut out the laser opening first and align it over the wooden frame, then figure out where 4 mounting holes should be placed. After attaching slightly larger panel on top, I trim the sides with a router.

The buttons are 0.314" dia. and I got them years ago surplus. When I run out, I will be making them out of aluminum rod.

I was initially using a bit more complicated front panel which was made out of aluminum with acrylic insert, but later figured out that simple piece of tinted acrylic fits here much nicer and is way easier to make (3.25 thickness). It's also clear enough to provide good visibility.

Peter Daniel 31st January 2010 10:04 PM

5 Attachment(s)
That concludes the commercial version of a transport, which performs very well based on comments I'm receiving from end users.

Recently, I was experimenting with clocked output and the idea is certainly worth pursuing.

While checking some of the Lampizator ideas: http://www.diyaudio.com/forums/digit...ml#post1926921 I had a chance to compare the clocked output of CEC TL0 vs a simple resistive divider output. In the end the clocked output appeared to be better and for some time I was thinking on trying it with Shigaclone. The guys on Audiostereo Forum made more experiments already, but nothing so far has been documented well: Robimy shigaraki transport / CD Flatfish - Do It Yourself - Forum Audio - Audiostereo.pl

So let's start from the beginning.

Attached is original CEC TL0 clocked output schematic and pics of the boards. "The master oscillator (a crystal which looks like Citizen) controls not the transport mechanism but the output stage, a flip-flop chip that could be considered a 1-bit FIFO. The output data thus have the maximum timing precision, which is where it is needed. The mechanical drive is slaved to the output stage".


All times are GMT. The time now is 11:04 AM.


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