[JoshK]

Well I certainly have been taking my time building my first CDpro kit.  But it looks like it paid off, everything tested out perfectly and the CD is recognized, tracks are listed and it looks to play fine (didn't hook it up to hear the sound yet).  Now I just need to move the display board up and I should have one down.

[JM]

Hi Ken

Thanks, that helped. Actually I needed to add a washer either side of the tray as well (this also helped to locate the screw head as the holes in the tray are a bit large)

The suspension still seems a bit 'stiff' ( but doesn't foul the tray anymore)

I've taken care to centre the spring 'cups' and that nothing is obviously rubbing. Can anyone confirm how 'free' the suspension should feel. I'm used to a sprung TurnTable but I guess the CD will not be this compliant.

Regards

Westiebj    

I used 2 nylon washers per pillar so that the tray is flushed with the top of the aluminum pillars. That leaves enough clearance for the transport to be free of contact from the tray.
The springs are stiff (like a sport car) and they should be able to move without interference from the screws that lock them.

[JoshK]

I successfully chopped off the extra length on the buttons, tapped new holes in the end this weekend and the VFD board fits with the new short buttons.   What a PITA that was though.   A lot of work!  It probably would have been a lot simpler to skip tapping new off center holes and just left a flat back and added double sided sticky tape like another modder did.  I think I will do this in the future instead.  

Two notes that may be useful to others.  Flipping the one post around does not provide enough clearance for the VFD display board to reside between the two posts when the large opamp is installed.  I had dry tested without the opamp in place like a dummy.  I am considering just leaving the post out.   Second point is that when the VFD board is move forward the L bracket now rests directly above one of the cones, so tapping a hole there is not possible.  So this isn't a simple mod.

[JM]

I just wanted to share the grounding scheme I've settled for now:
As per Steve suggestion, I connected one of the grounding screws from the transport PCB (you'll need a Torx key) to the chassis, and the 9V ground (at the Sequential Power-On PCB)  to the ground (3rd pin) at the IEC. This worked well sonically, but I got a ground loop in my system.

One of the alternatives was using a low value resistor between the circuit ground and the IEC ground. I tried 2 methods:
1- connecting the chassis to ground, and 9V ground to ground through a 10ohm resistor. That didn't work so well. The sound was hard and forward in the mid-range.

2- connecting one of the grounding screws from the transport PCB to the chassis, and the 9V ground to the ground at the IEC through a 10 ohm resistor. That worked much better and there was no more hum. And sounded better than lifting the ground completely.

I'll still try other approaches, since there are different ways to connect cicuit ground to ground (earth). Diodes can also be used, as well as a combination of diodes and resistors. This connection has a profound effect on the unit's sound so it is well worth investigating...

[JoshK]

Thanks for the feedback Julien.

[bsyyu1]

I would like share my experience on my cd-pro2 kit.
I am using AKSA 100 power amp and DACT passive preamp. When the cd-pro2 is connected, it did play very good sound. But there is nosie when the power amp is turn on and turn off. Two days ago, my speaker woofer is blown out when cd-pro2 kit is turn on.  For those the amp is without speaker protection should pay attention on this.

After then, I connected cd-pro2 to my Outlaw power amp, cd-pro2 detects the cd and did play, but  stop after about one minuite playing. my cd-pro2 module chassis is free from ground ( cdpro is on the spring to absorb vibration and screw is not firmly fixed.   These problem is corrected When the cdpro module is firmly fixed at screw and is connected to the main ground.

[NoobyBaboo]

Greetings all.  This is my inagural post on these forums.

I have recently taken delivery of a CDPro2M kit and am in the process of building it.  Along with the CDT build, I will be installing a dAck! 2.0 circuit into the empty space of the CDPro chassis.  

Discussion of optimized grounding schemes for the unit is of interest to me.  I am wondering if some sort of star ground topology can be rationalized.  In the past, I have star grounded power supply and signal circuits to separate points.  These were points were connected with a parallel RC network between them, and the PS star ground point was terminated to the IEC ground terminal.  Thus, the signal star point (insulated from the chassis) was at a slightly higher potential than the PS star point.  If I can identify respective signal and power supply ground planes on the CD Pro circuit boards, I would attempt to solder ground wires direct to these.  A routing of power supply leads and ground wires would intend to keep each away from the other.

One thing builders should be aware of is that the anodized surface of the chassis is acutally an insulator, which can be shown with an Ohm meter.  If making ground connections to the chassis, it may be necessary to scrape away some of the surface anodize to get good continuity.  When the various panels are bolted in place, there seems to be continuity between them (as measured at the internal support columns) without any additional preparation, so the chassis should be an effective Faraday cage.

[NoobyBaboo]

Similar to others, I have moved the VFD board to fit in between the front two pillars, but I think I had different results.  This is not a simple mod, but it is one that is easily doable with home tools, foresight and patience.  Concurrent with moving the control board forward, I moved the CDPro2M transport and ancillaries forward also.

I found that the stuffed board, with IC’s fitted, does fit closely between the two support pillars when the rearward one is rotated 180 deg.  I found that when the “L” brackets are mounted forward the board (on the display side of the board) that there is no interference with the cone foot.  The final fit seems almost by-design.

These are some of the steps I took to fitting the VFD board to the forward position between the support pillars:  

To locate the new holes properly, one needs a machinists style “tri-square and scribe.  The tri-square tool has a head and a ruler blade which slides through the head.  I believe these are available at Sears and other hardware stores and have an aluminum (rather than hardened steel) head.  The aluminum head variant is accurate enough for the purpose here.  The tri-square is used to transfer the OEM hole locations in the chassis bottom forward to new locations along straight lines.  These straight lines go through the centers of each of the holes that will be transferred forward, and the lines are perpendicular to the front edge of the chassis bottom plate.  

Remove the chassis front plate if installed and remove all chassis support and CD drive support pillars near the holes of interest (6 of these).  
Using the tri-square, scribe lines through the CENTER of; the VDF board mounting holes, the CD transport support pillar holes, the CD transport “cover” mounting holes, and the CD sensor board mounting holes.  For convenience, the scribed line should extend from the rear most hole on any given line to the front edge of the chassis bottom plate.  The new hole positions will be located along these scribed lines.  

To locate the new holes for the VDF board, first take the “L” brackets and, using a sharp tin snips, cut off about 1/16-3/32 in. of one leg end.  This shortened leg will face and attach to the chassis bottom.  The modified “L” brackets will be located on the front facing side of the VFD board.  To locate the center of the new hole in the bottom plate, place the modified bracket face with slot centered along the scribed line with the cut end of the bracket flush with the bottom plate front edge.  With the modified bracket positioned thus, the location of the new hole is defined by the location of the slot end (the “inside” slot end, away from the front edge of the chassis bottom plate).  Mark the virtual center of the hole with the scribe.  

Once the holes are drilled, fitting the VFD board included these steps:  When stuffing the board, the installed components need to be fitted as close to the board as possible, especially capacitors and IC sockets.  The chassis support pillars facing the board were covered with 3M #33 black electrical tape.  The tape needs to extended around the corners of the pillars.  The soldered lead ends need to be trimmed to their lowest possible height.  Additionally, I used a mill-fine file to file the clipped ends to make them flat and less likely to penetrate the tape on the pillar face, this also helps to make more clearance for the board between the pillars.

To locate the CD transport support pillar holes, the CD transport “cover” mounting holes, and the CD sensor board mounting holes, these are all moved 3/4 in. forward along the scribed lines.  Tin snips must be used to trim the front end of the CD transport cover, and I trimmed 5/8 in. from the front end of this.  Moving the CD transport forward has the benefit of providing more rear clearance and convenience for placing and removing CD’s.

A hand drill can be used to make the holes.  With the hole centers located with scribe marks, first center punch the hole center point, as this helps to prevent drill wander and improve precision.  The OEM holes are some metric gauge, so use the next standard size larger.  Using a size that is slightly larger than OEM has the benefit of permitting compensation for slightly off-center drilling that comes with manual drilling.  Two sizes of drill bits may be needed.  First is a 1/16” pilot hole and second is the final hole size.  The pilot hole is useful but not essential.  It is useful for improving the likelihood of making an on-center hole, but it complicates the process because one must clean the bit during the drilling process because it loads-up with the soft aluminum and then does not cut.  The pilot hole helps prevent wander of the larger final drill size.  In any case, get some scrap aluminum metal and do some practice drills on scribed centers first in order to learn a proper drilling technique.

Especially for the CD transport support pillars, you need to drill accurate holes so the suspension springs fit in their cavities with proper clearance and do not rub or bind in use.

[heathman]

Hello group the problem with my transport running 23 minutes and then shutting down was due to mislocation of the sensor module. There are an extra couple of pins on the PCB right next to where it is supposed to be mounted. Effectively, mine was shorted at both input and output as these pins were apparently for use with another package outline. Anyway, my Luxo circline lamp has been packed away and I miss having it since my eyes are not as good as 20 years ago. I have had the unit running continuously now for about 100 hours. I still have a little quirk with the standby switch itself but hope to figure that out soon. The switch does not seem to do anything at the moment. I have triple checked it for mounting paddle down, center lug to center pad on VFD, lower lug to upper pad, but still nothing. I will try reversing it in the next day or so. On power up both supplies come right up. Thanks for the info and tips. Once I got irritated and started looking it was pretty easy to see that I had 1100 Hz output from the 555 but nothing from the sensor. Then I just had to dig out my magnifier.

[JoshK]

Thanks NoobyBaboo!  

A very helpful and detailed scribe of your experiences.  The devil is in the details it seems.   I knew the VFD board 'could' fit if I had the foresight to have taken more care in component heights relative to the PCB board as you have done.  In my case I am thinking of acquiring a long standoff to put in place of one of the pillars or grinding down the pillar I have.  

I already placed electrical tape on the pillars to insure against an accidental short.  However, I think the most useful point you made for me was,

The modified “L” brackets will be located on the front facing side of the VFD board.

I didn't think of that, but it seems completely obvious now.  Thanks a bunch, you just made my life simpler!

[JoshK]

By the way, what are those two extra long skinny PCBs for?  I see no mention of them in the manual.


Secondly, I think this thread really belongs in the Lab and not in the NY Audio Rave as this kit isn't only for New Yorkers.  

[ken_diyzone.net]

Hi Josh,

They are for the Blue LEDs.  Take power from the 5V board, and use 1K for resistor value, reduce by 20% if you think the LED is too bright, and vise versa.

They fit on the inner tray that I mailed out to you yesterday.

I also included two OPA627 to swap with OPA134.  Please let me know which one you think is better.

Regards,
Ken

[NoobyBaboo]

I also included two OPA627 to swap with OPA134.

What is a preferred source for the OPA627?
What is the correct full identification (some have suffix letters as OPA627##: AM AP AU BM BP SM) for the OpAmp?
DigiKey shows about 18$ ea. for the OPA627  Is this normal cost?
Are these a drop in for the OPA134?, because the data sheet for the two shows the pins for NoConnection and OffsetTrim (#'s 8 & 5) are reversed for the two devices.  Is rewiring of circuit traces needed here?

Thanks.

[tianguis]

Baboo:
        The "BP" is the package which fits into a socket as the kit uses, the "AP" is surface mount. I just swapped them with no problem.
        Check eBay. I bought a pair, still sealed in the TI anti-static bag, for about $10.

Regards,
Larry Welsh

[JM]

Using the OPA627 is a definite sonic improvement over the OPA134.
The sound becomes more analog like, smoother, less grainy and mechanical. It flows better.
I've ordered samples of a few other op-amps from National and Analog Devices to compare.
These op-amps have a definite influence in the sound of this player.
I'll be trying new voltage regulators as well. That was suggested by some users at the diyzone.net forum.
I'll be replacing LM317 with LT1085CT, and LM337 with LT1033CT. That should be interesting.
I'm also using the blue LED diodes network in the tray. I only used one PCB for now, at the back end of the tray, bathing the lens with blue light. I used a 1K resistor and connected it to the 9V supply. I couldn't tell much of a sonic difference, but then again I didn't really listen critically after this mod, I was more worried about the ground issue..., but it certainly looks cool.

[JM]

I also included two OPA627 to swap with OPA134.

What is a preferred source for the OPA627?
What is the correct full identification (some have suffix letters as OPA627##: AM AP AU BM BP SM) for the OpAmp?
DigiKey shows about 18$ ea. for the OPA627  Is this normal cost?
Are these a drop in for the OPA134?, because the data sheet for the two shows the pins for NoConnection and OffsetTrim (#'s 8 & 5) are reversed for the two devices.  Is rewiring of circuit traces needed here?

Thanks.

You can use either OPA627AP, or the OPA627BP, they are both 8 pin DIP.
The BP is a tighter spec version, but I've compared both in a buffer stage and I couldn't find any sonic differences.

[tianguis]

Julien:
       Of course, you're correct. It's the "AU" which is surface-mount.
       JM, I agree with you regarding the sound of the OPA627 vs. the OPA134.

Regards,
Larry Welsh

[JM]

I found this page with many links to CD-PRO2 documentation.
http://www.daisy-laser.com/products/CD/modules/CDPro2/downloads.htm
One interesting fact is that for those using it as a stand alone player (like myself), the absolute phase is inverted. So reversing the polarity on the speaker cables should be a must. I have to try that.
I hope the upgraded internal DAC will correct that...

[NoobyBaboo]

Question:  What is the function of the “Stand-by Switch”?  What does it add over and above the function of the On-Off switch?

I note that the graphic details on the VFD board illustrate both “stand-by” and “power” switch locations.  The builder’s manual indicates the stand-by switch is wired to terminals labeled “power”, and the terminals labeled stand-by are left unused.  

The supplied switch itself has two positions, the default position (held by spring pressure) is “normally closed” (there is continuity through the switch), and the select position (held against spring pressure) is open (no continuity through the switch).  So, “flipping the switch” breaks an existing continuity in order to accomplish its intended function.

[heathman]

Hi Group I think I still have a small problem with the standby mode on my machine. Last night I unsoldered the switch and found that although I have 5V on the top of R37 , there is no voltage on the bottom of it (on the pin going to the PROM). There is nothing I can do either with the remote nor with the switch (assuming it is soldered in place) to raise the pin high. Does this mean I killed the PROM? Thnx, Jim W