The Phonoclone and VSPS PCB Help Desk

rjm

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Joined 2004
Paid Member
Today I shipped the first batch of Phonoclone PCBs. Its appropriate I think to switch gears, and threads, from the design phase to the build phase.

Component selection, soldering, mounting, wiring, cases, power supplies, mods and varients. All that good stuff, Q&A, FAQ, Discussion... and pics pls! ... goes here.

First an update for Batch 2. This will be a mixed order of VSPS and Phonoclone boards and I'll be taking orders for these up until Sunday, May 22.

Reviewing the Phonoclone PCB, it came out as I had imagined it might. Looks good. The only changes I would make are purely cosmetic, so I'm not going to bother with an update right now. Batch 2 Phonoclone PCB will be exactly the same (ver. 1.5e Beta) as Batch 1.

Just so you know, Batch 3 will be in 6 months, September-October. I want both projects to go through a full build cycle before continuing.

-R

Relevent Links:

PCB Ordering Information

Phonoclone Page

Hint page for the Phonoclone PCB

VSPS Page

Hint page for the VSPS PCB
 

rjm

Member
Joined 2004
Paid Member
Two "issues" came up during the manufacturing process of Phonoclone 1.5e, both related to the silk screen layer.

1. The text font came out much bigger than it looked in Eagle, so the RJM Audio label got offset and chopped off. The board is now RJM Audi. I hope I don't get sued by the car company! :D

2. The other point is slightly more serious: the component values layer didn't get printed. (Olimex doesn't print this by default) Please use either the table of components or the Eagle-generated images of the board as a guide to match the component (C2, R4 etc) with the required value. The regulators ended up unlabelled, but it should be clear that the 7912s go beside V- at the bottom and the 7812s go near V+ at the top.

Also, I notied the edges of the boards are cut quite roughly, so you may want to sand them down before you start. In any event, since the boards are fibreglass please take appropriate precautions when handling the edges.

-R
 
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Joined 2002
rjm said:
1. The text font came out much bigger than it looked in Eagle, so the RJM Audio label got offset and chopped off. The board is now RJM Audi. I hope I don't get sued by the car company! :D

Set all fonts to vector, that way they will appear full size. I also use freedfm.com to check my gerbers look correct before I send them out.
 

rjm

Member
Joined 2004
Paid Member
Glad to hear your packages are showing up.

>With vector fonts the Eagle results match the Olimex end product. Good call. VSPS layouts have been updated accordingly.

>Those caps are actually polypro, and given their size might be film-foil. They ought to be ok. I haven't tried them yet.

I was using some itty-bitty cheapo metallized polypro things before and they weren't all that great. Lent an, um, metallic grain to the sound. Using polystyrene since yesterday, seem v. fast and clean but too early to call.

The big revelation was with diodes. I have two power supplies (actually three but...) two at any rate differ only in having a 25A bridge rectifier vs four fast/soft glass passivated diodes. So I can hot swap between the two rectifiers easily. This time around the big bridge was sooo much better. That nagging greyness in the treble which has been bugging me for a some time fell away to black. Moral: watch out for RF, either from the power line or diode-generated.

Anyway, that switch, in combination with the new caps, really pushes it from 75 to 85 points /100 and into the A list.

-R
 
Hi R,

The boards & components arrived safe & sound; thanks for that!

I am now awaiting my Russian teflon caps, & hope to put it all together soon thereafter. I look forward to comparing it to my other equipment.

I intend to play with opamps & powersupplies as well. One step at a time though!

Regards,
Phil
 

rjm

Member
Joined 2004
Paid Member
See attached for a photo of the VSPS board. Olimex really did a nice job on this one.

Judging from the emails, many of you are agonizing over the component selection. Is brand X better than brand Y? While its understandable that you'd want to make sure its right the first time, my advice is to flip a coin where necessary and just get on with it. I have found it much more rewarding and enjoyable to upgrade bit-by-bit later that to build it all at one and be forever wondering if, you know, you made the best choice or not.

Lastly in this game (chip audio) there is just no guarentee, be it price or any other specification you can list, that any given component will sound better than any other.

-rjm
 

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rjm

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Joined 2004
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Board Prep

I have found that after sanding down the edges of the boards its a good idea to wash them in warm water and mild soap, rinse, and dry with paper towels. The white component lettering in particular stands out much more clearly afterwards, plus it gets rid of the last of the glass dust.

-R
 
VSPS PSU Questions

Hello all,
I am after some help with the VSPS PSU, I have a transformer with two 12V secondaries, four wires;
Red,Yellow,Blue and green.
Looking at the VSPS site, it looks like the diagram wants me to wire the Blue and green together to give 12V 0 12V Is this correct?

This leads me onto my next bit of confusion, the rectifiers.
From the diagram it looks like i need two joined together.
I am making the rectifiers from eight sf4007 diodes.
What i would like cleared up is a diagram on how to wire the diodes,and where to connect the red and green, and the + and - outputs.

Do i take the VSPS common from the combined blue/yellow, or is it from the wire joining the two bridges, not sure from the diagram?
See attached file;

Many Thanks in advance,
Ian Webb
 

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Looking at the VSPS site, it looks like the diagram wants me to wire the Blue and green together to give 12V 0 12V Is this correct?
Yep, that would be correct, if the colors are matching!
I am making the rectifiers from eight sf4007 diodes.
I guess you want to go dual-mono from the rectifiers, right? If yes, you connect the secondaries to both bridgerectifiers.
The Common (blue and yellow) goes to both XLR's common! Or whatever connection you use.
Do i take the VSPS common from the combined blue/yellow,
Yes you do.
Cant see your attached file:xeye:

Steen:)
 
Thanks Steeno for the advice. I only have one XLR for the power output.
So how would i wire the bridges for single not dual output?
Is there a good diagram for the bridges and transformer connections?
So the two 12v wires go to one bridge, and that will give me +12vdc and -12vdc?
I can see the file, not sure why you cant?

Thanks
Ian Webb
 
I can see the file, not sure why you cant?
I can see it now,too:D Maybe I was too fast, replying?
That schematic looks ok! But you really dont need two bridges for that! If you use only one, your common will be the two connected wires from the trafo:) There is not much advantage from two bridges, I guess:) Just connect the common to your XLR common:) You can use the two, if you want to, though:)
Take a closer look at Fig2 here:
http://www.geocities.com/rjm003.geo/rjmaudio/diy_pho5b.html

Steen.
 
VSPS PSU Questions

Hi,
If i connect the yellow and blue transformer wires together to form common, the fuse blows every time.
So i am still confused on how to connect the transformer wires to get
12 0 12,

I made the bridge per fig 3 in below link;

http://www.eleinmec.com/article.asp?18

Where exactly should i connect the bridge wires to get +12vdc -12vdc and where to connect the common for the pcb's?


Thanks
ian webb
 
If i connect the yellow and blue transformer wires together to form common, the fuse blows every time.
The colors of your transformer leads arent the same as, RJM's. You obviously connect the wrong leads for the Common!
Isn't there a drawing on your trafo, showing start and finish for each winding? You have to connect the finish (last turn) of one secondary winding to the start(first turn) of the other secondary winding. On the attached picture, you would connect Rot and Braun together to form the Common (or Centertap). Dont do anymore until you have got this right.

Steen.:)
 

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rjm

Member
Joined 2004
Paid Member
Your trouble is that with a dual bridge configuration, the trafo windings are not supposed to be connected to common, or together or anything. Just connect them to the diodes and that's it. Its the output of the bridge thats connected together.

With a single bridge, you do indeed connect the bottom of one winding to the top on the other to make, in essence, a center tap.
 

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