Ptownkid
Well-known member
The thoroughness is just awe inspiring Chunger...
[BUILD] VC528 ST2+ 500/51x Support Thread...aka The Missing Link!
- Thread starter jsteiger
- Start date
Help Support GroupDIY Audio Forum:
chunger
Well-known member
Next on the menu is the sub-ST2 board. Details about this board can be found in:
"8_04-1x24 Rev A_Sub-ST2 Rev A.2 Overlay.pdf"
and
"7_Classic VC528 Sub-ST2 PCB BOM.pdf"
in the build documents.
The components for the Sub-ST2 board can be found in this baggie:
Note, in the stereo kits, you'll find 2x pcb's and a closely matched set of resistors in this baggie.
Next, I identify and sort the electronic components. For our build, even though I'm doing a stereo pair, I'm showing components for a single board in the photo. . . just to keep things consistent.
These resistors are very easy to identify because the values are all printed at a pretty reasonable size. I double check them all with my multimeter just to be safe.
Here's a little trick I learned from the draft instruction PDF jsteiger wrote up to make clean, consistent bends on the resistors using the shaft of a small screwdriver. Worked great!
and, we're populating.
and, a shot showing my resistor values more for personal reference later if I have a problem.
Next we install the 3 position toggle switch. . . the instructions say to make sure and seat this one flush to the PCB and straight. I lightly clamped the threaded shaft of the toggle switch like so. . .
Then, it was a bit of a juggling job, but not too bad. I chose one of the center solder lugs, pressed down with the soldering iron lightly and soldered the joint. . . immediately when the solder melts into the joint, and with the soldering iron still on the joint, I let go of the solder wire, and press the PCB down firmly with my fingers. . . easy. Then, remove the soldering iron and hold the joint until the solder hardens.
It would have been awesome to have a picture holding the PCB with my left hand, and with the soldering iron actually on the joint, but it was logistically difficult having only 2 hands ???
Verify that everything is fully seated. . . nice and straight:
doesn't get much better than that, so I went ahead and soldered the remaining lugs on the switch.
Then, per the instructions, I cut the leads on the switch close to the PCB
OK. . . instruction set says to leave the L-header, LED, and Grayhill switch off for later steps, so we are done with this component for now.
"8_04-1x24 Rev A_Sub-ST2 Rev A.2 Overlay.pdf"
and
"7_Classic VC528 Sub-ST2 PCB BOM.pdf"
in the build documents.
The components for the Sub-ST2 board can be found in this baggie:
Note, in the stereo kits, you'll find 2x pcb's and a closely matched set of resistors in this baggie.
Next, I identify and sort the electronic components. For our build, even though I'm doing a stereo pair, I'm showing components for a single board in the photo. . . just to keep things consistent.
These resistors are very easy to identify because the values are all printed at a pretty reasonable size. I double check them all with my multimeter just to be safe.
Here's a little trick I learned from the draft instruction PDF jsteiger wrote up to make clean, consistent bends on the resistors using the shaft of a small screwdriver. Worked great!
and, we're populating.
and, a shot showing my resistor values more for personal reference later if I have a problem.
Next we install the 3 position toggle switch. . . the instructions say to make sure and seat this one flush to the PCB and straight. I lightly clamped the threaded shaft of the toggle switch like so. . .
Then, it was a bit of a juggling job, but not too bad. I chose one of the center solder lugs, pressed down with the soldering iron lightly and soldered the joint. . . immediately when the solder melts into the joint, and with the soldering iron still on the joint, I let go of the solder wire, and press the PCB down firmly with my fingers. . . easy. Then, remove the soldering iron and hold the joint until the solder hardens.
It would have been awesome to have a picture holding the PCB with my left hand, and with the soldering iron actually on the joint, but it was logistically difficult having only 2 hands ???
Verify that everything is fully seated. . . nice and straight:
doesn't get much better than that, so I went ahead and soldered the remaining lugs on the switch.
Then, per the instructions, I cut the leads on the switch close to the PCB
OK. . . instruction set says to leave the L-header, LED, and Grayhill switch off for later steps, so we are done with this component for now.
Something I forgot to mention before... I do not recommend using a freshly built DOA in the receiver stage during the CMRR adjustment, unless you are 100% sure the opamp is functioning correctly. A stable and correctly operating DOA is a must for the CMRR adjustment to be right!
I added the above note to the first post. I should have thought about mentioning that before. :-[
Cheers!
Jeff
I added the above note to the first post. I should have thought about mentioning that before. :-[
Cheers!
Jeff
gar381
Well-known member
chunger..
As usual FIRST CLASS !!
carry on !!
GARY
As usual FIRST CLASS !!
carry on !!
GARY
chunger
Well-known member
Sorry about the delays. A little more progress tonight.
Next up in the build is the Elma switch sub-board. The parts are contained in this baggie:
There are a lot of resistors to sort in this little board. Here are the parts identified, sorted, and ready to go.
and, we're populating in the order specified in the build manual. . .
and, all resistors are placed.
Next, I check resistance between J1-2 and J1-3 looking for 1K ohm to make sure I did not bridge any solder joints.
and we're good to go.
The Elma switch is placed. . . a few pins needed to be slightly nudged into position before pressing into the PCB.
And, here is how I set up to solder the switch
And, Elma switch is in.
I checked resistance again between J1-2 and J1-3 to confirm we are still at 1K ohm, and this sub-assembly is ready to go. We set it aside for now.
Next up in the build is the Elma switch sub-board. The parts are contained in this baggie:
There are a lot of resistors to sort in this little board. Here are the parts identified, sorted, and ready to go.
and, we're populating in the order specified in the build manual. . .
and, all resistors are placed.
Next, I check resistance between J1-2 and J1-3 looking for 1K ohm to make sure I did not bridge any solder joints.
and we're good to go.
The Elma switch is placed. . . a few pins needed to be slightly nudged into position before pressing into the PCB.
And, here is how I set up to solder the switch
And, Elma switch is in.
I checked resistance again between J1-2 and J1-3 to confirm we are still at 1K ohm, and this sub-assembly is ready to go. We set it aside for now.
sea_man
Member
i finish my VC528 ST2+ ( thanks chunger , your pics and advices are very useful) now i need calibrate but i'm a little confused what i need apart of the resistors and the tone generator ( i have here a DMM and the resistors only :-[), or maybe is another way ( more easy) to do it this step ?
Some pics:
http://www.flickr.com/photos/mar1o_bross/sets/72157627033770651/
Some pics:
http://www.flickr.com/photos/mar1o_bross/sets/72157627033770651/
sea_man, you can use your DAW as a generator. You can also set an input of your DAW to record ready and then monitor those levels during the calibration process.
Besides the cable with resistors, you only need 2 other things. A signal generator of some sort and a device to monitor the output level of the receiver amp. Can be a DMM, scope or DAW inputs.
A very important thing is to use a known, good DOA in the receiver stage when you make this calibration.
BTW, nice pics! ;D 8)
Cheers, Jeff
Besides the cable with resistors, you only need 2 other things. A signal generator of some sort and a device to monitor the output level of the receiver amp. Can be a DMM, scope or DAW inputs.
A very important thing is to use a known, good DOA in the receiver stage when you make this calibration.
BTW, nice pics! ;D
8)Cheers, Jeff
sea_man
Member
Done ! Whit a little of patience , a digi 003 , and many cables and alligator clips my first unit reach -72.1 and the second -71.8 dbu !
Thanks again for your help !
Thanks again for your help !
Nice! Congrats!
sea_man said:
Your gonna love them!
johnny dance
Member
- Joined
- Jan 15, 2010
- Messages
- 22
Hey guys loving putting this together. Chunger. Any more updates?
I was wondering about 'Chung as well. From his Facebook updates, I think he may be buried under the sand on a volleyball court at some beach. :'(
indamix
New member
I have built two of these vc528's and they sound incredible. "The missing link" says it all. Great work on these Jeff! Also, thanks for the pictures as these were a great help during the build.
Daniel Ovie ask me if I had a recall sheet prepared for the VC528 module. My answer was "no" but now I can say I have whipped up 4 different ones. These links have been added to the first post of this thread as well as the product pages at my site.
************************
Recall Sheet pdf downloads:
1 module
2 modules
4 modules
6 modules
************************
Cheers, Jeff
************************
Recall Sheet pdf downloads:
1 module
2 modules
4 modules
6 modules
************************
Cheers, Jeff
chunger
Well-known member
Ok. . . sorry about the extended delays, folks. Trying to get ready for 1st baby coming late October, so my workspace has been in chaos. So, little progress today, but onward none the less
Time for the main PCB. Time for a little parts identification. . . diodes are up.
Watch out for the 1N914 CR1, CR2, CR3, and CR4. . . these look like this:
Also, watch out for 1N5243B CR9. . . it's marked:
24
3B
Next, I placed the components on the PCB as marked.
And, soldered the components in from the top side.
And, diodes are done.
Time for the main PCB. Time for a little parts identification. . . diodes are up.
Watch out for the 1N914 CR1, CR2, CR3, and CR4. . . these look like this:
Also, watch out for 1N5243B CR9. . . it's marked:
24
3B
Next, I placed the components on the PCB as marked.
And, soldered the components in from the top side.
And, diodes are done.
chunger
Well-known member
Next up, I use a printout of the provided resistor sorting PDF to sort the main PCB resistors.
Note: R7, R8, R9, and R10 are packaged together and are .1% Vishay. . . R22 is the same value, but 1% Xicon
I then place all resistors on the PCB.
and solder from the top side cleaning up joints as needed from the back side.
Note: R7, R8, R9, and R10 are packaged together and are .1% Vishay. . . R22 is the same value, but 1% Xicon
I then place all resistors on the PCB.
and solder from the top side cleaning up joints as needed from the back side.
chunger
Well-known member
Next up, I use a printout of the provided film capacitor sorting PDF to sort capacitors.
Due to possible confusion on the various labeling conventions on these capacitors, I'm including pictures of the markings. I ended up having C21 (.047uf) and C25 (.47uf) mixed up on the first pass, so please double check!
Due to possible confusion on the various labeling conventions on these capacitors, I'm including pictures of the markings. I ended up having C21 (.047uf) and C25 (.47uf) mixed up on the first pass, so please double check!
chunger
Well-known member
Having sorted the film capacitors, it's time to stuff them into the PCB. On this point, I think there are better ways of doing things, as I'm not 100% happy with how straight my caps ended up lining up on the PCB, but for what it's worth, here's how I did it.
First, I bent the legs of the caps a little.
Then, I inserted into the PCB and soldered 1 leg (I can seldom get the caps to seat firmly against the PCB by bending the legs).
Then, with the PCB on it's side, I solder 1 leg of the film cap.
(note: no picture of the next steps because i couldn't figure out how to do it without hurting myself or breaking something).
Next, I re-heat the 1 soldered leg while applying pressure to the cap with my finger seating the cap. . . then, with the cap secured in position, I flip over and solder the 2nd leg.
At any rate, here is the board populated with the film caps. (not as straight as I'd like, but nothing wrong with it either)
First, I bent the legs of the caps a little.
Then, I inserted into the PCB and soldered 1 leg (I can seldom get the caps to seat firmly against the PCB by bending the legs).
Then, with the PCB on it's side, I solder 1 leg of the film cap.
(note: no picture of the next steps because i couldn't figure out how to do it without hurting myself or breaking something).
Next, I re-heat the 1 soldered leg while applying pressure to the cap with my finger seating the cap. . . then, with the cap secured in position, I flip over and solder the 2nd leg.
At any rate, here is the board populated with the film caps. (not as straight as I'd like, but nothing wrong with it either)
johnny dance
Member
- Joined
- Jan 15, 2010
- Messages
- 22
Hey Jeff, trying to troubleshoot my VC528's all set up but not passing noise... would love some help on where to start looking... with the DMM
JD
JD
JD, first off, what opamps are you using? They need to be known good. Maybe pull a pair from a preamp or something and we'll go from there. Also make sure the rack slot and associated cabling are trouble free.
