TKD 4CP-601 & 4CP-2500 4-gang volume pot and PCB GB

[UFN]

On the other hand, it might be the cheapest shaft extension we'll ever be offered so I'm at least very excited

//UFN

[Voltron]

@swt61 Paging Dr. Wood. Paging Dr. Wood.

[eggil]

who do I send the payment to? 

[sorenb]

21 minutes ago, eggil said:

who do I send the payment to? 

being lazy?

[MLA]

35 minutes ago, eggil said:

who do I send the payment to? 

Me

[email protected].

[eggil]

payment sent. Thanks!

[UFN]

Paid the last "installment" and updated the sheet.

 

//UFN

[MLA]

4 minutes ago, UFN said:

Paid the last "installment" and updated the sheet.

 

//UFN

Great, thanks!

 

[MLA]

 

The POTs section of this GB is now officially closed.

Entries for pot boards (type and quantity) can still be updated and edited.

 

Also, if you need your shaft(s) extended, now is the time to make that known I will be placing the order tomorrow.

Edited September 2, 2016 by MLA

[mwl168]

Many thanks to Pars that we should now have the final Gerber files ready for the pot PCB boards. The board sizes were shrunk further from earlier versions.

Also a reminder for the GB participants to double check your order quantities in the GB spreadsheet for the PCB boards.

There are two version of boards:

4CP601-only:  36.3mm x 31mm

4CP601and 4CP2500: 46.5mm x 38mm

Both boards have provisions for Phoenix and Molex connectors.

[LemPyle]

Hi..i am a new user here. As per my knowledge i think i fits, though a bit on the large size, maybe the alternate spacing could be changed to fit the 4cp-2500 instead of the Alps. It has a separate ground for each channel and can be cut in half for stereo mode without cutting through any traces. Maybe Pars could add his molex connectors to the existing gerbers.

pcb+assembly+services

[MLA]

STATUS UPDATE: TKD has confirmed the GB order including the pots with extended shafts, and started production. So now we wait

 

[Pars]

For the dual CP401/CP2500 pot board:

I went downstairs and measured the pins on a 2CP2511 I have (never used), and the width on the pins was 3mm, not the 2.5mm shown in the datasheet.

The datasheet you guys sent does show 2.5mm, but an older datasheet that I had shows 3mm, so they must have changed these at some point.

I think I should enlarge the slots to 3.1 x 0.8mm just in case, and to accommodate older pots.

Thoughts? I attached both datasheets.

 

TKD cp2500ps-e.pdf

2CP2511.pdf

[MLA]

Better safe than sorry in this case I think...

[GeorgeP]

6 hours ago, Pars said:

For the dual CP401/CP2500 pot board:

I went downstairs and measured the pins on a 2CP2511 I have (never used), and the width on the pins was 3mm, not the 2.5mm shown in the datasheet.

The datasheet you guys sent does show 2.5mm, but an older datasheet that I had shows 3mm, so they must have changed these at some point.

I think I should enlarge the slots to 3.1 x 0.8mm just in case, and to accommodate older pots.

Thoughts? I attached both datasheets.

 

TKD cp2500ps-e.pdf

2CP2511.pdf

Good catch! I measured the ones I have that were produced around May of this year and they are 3.04mm on my Mitutoyo. 2.5mm is cracked out - not sure why they would do that.

[mwl168]

Yes, agreed with MLA it's better safe than sorry - I vote to go with the 3.1 x 0.8mm.

On the same topic, I've got quotes from the fab houses and decided to go with SeeedStudio for cost reason. I've corresponded with SeeedStudio to make sure they can handle the rectangular plate-through holes.

For 1.6mm and 2oz copper the 4CP601-only board (36.3 x 31mm) will come to about $3 per board and the 4CP601/4CP2500 (46.5 x 38mm) will be about $4 per board after figuring in the shipping from China to me. The higher cost of 4CP601/4CP2500 board is due to the lower quantity.

Many thanks again to Pars for the great work and for your patience in dealing with my repeated requests for modification  

With Pars's permission here are images of the boards:

 

   

 

Edited September 11, 2016 by mwl168

[Pars]

OK, changed the slots from 2.6 x 0.8 to 3.1 x 0.8.

MLA: can you check with your TKD contact regarding the pin size?

Michael: can you check with seeed to see what the final dimension for a 3.1 x 0.8mm slot will be once plated? I was just guessing in terms of final dimension and how much additional size to plan for on the slots.

For the CP601, the datasheet shows the pins at 0.8mm. On the part I created in Eagle, I used a 1mm drill, so we should be good there i think. I could up the drill to 1.1 if needed. Going any larger on the pad size would risk clearance issues between pins 4, 6, 7 and 9 on the CP601 and 2 of the output pads on the CP2500.

Edited September 11, 2016 by Pars

[MLA]

I can ask, but I got the CP2500 data sheet directly by e-mail from TKD when discussing pot setup, and it's same as the one posted above, indicating 2.5 mm pin size, so I think that's what they think it is now at least

I have a 601 that was produced in may this year, I can check pin size on that one one I find my caliper and see if it matches the data sheet.

update: I've measured, and the 601 does indeed seem to be 0.8 mm pin size.

Edited September 11, 2016 by MLA

[Pars]

If you can ask if they can measure one, that would be great. Thanks!

[MLA]

Will do!

[Zashoomin]

So I already noted that I was really really late to pay and I already said this in the note in paypal but better put it here as well.  I sent the payment.  If my order was omitted because it was so late than we can figure it out.  Otherwise better late than never and thanks for doing this group buy.  

[MLA]

3 hours ago, Zashoomin said:

So I already noted that I was really really late to pay and I already said this in the note in paypal but better put it here as well.  I sent the payment.  If my order was omitted because it was so late than we can figure it out.  Otherwise better late than never and thanks for doing this group buy.  

Sorry to say, but I closed the GB and placed the order a few days back, and for various reasons its not possible for me to add more pots to the order (I've sent you a longer explanation over PM). I'll refund the paypal payment as soon as it shows in my account.

However, if you look in the audio gear for sale post, I think JohnWMclean posted a bunch of different quad pots for good prices yesterday (an updated spring sale post), so I would recommend having a look there unless they are gone already.

On 2016-09-11 at 5:34 PM, Pars said:

If you can ask if they can measure one, that would be great. Thanks!

So, it turns out that TKD just now are changing pin size for the 2511 because they are switching production materials for the internal pot PCBs.

The former type (green color) has 3.0mm width terminals, while the new type (black color: injection molding) has 2.5mm terminals. We will get the latest type for our 2511 order, so 2.5mm is the correct pin size.

Advice on the change of the resistor board 3-1.pdf

Edited September 13, 2016 by MLA
New info

[Pars]

My intent was for the board to support both old and new pots.

My concern is what is the convention for how much extra space to leave, i.e., what will the finished dimension of a 3.1 x 8 mm slot be after thru-plating and manufacture.

I ran across the attached document the other day regarding IPC-2222 and IPC-2221 standards. Level A is for general production, and is what I think I should shoot for, but results in the most additional and the largest pad size. Unfortunately, it doesn't discuss slots.

For the holes and pads for the CP601, the pins are 0.8mm. So, for Level A, the hole size would be:

Minimum Hole Size = Maximum Lead Diameter + 0.25mm (for Level A of IPC-2222)

0.8 + 0.25 = 1.05. This isn't a std. drill, so 1.1. I already have this at 1mm, so can bump up.

Pad Diameter = Minimum Hole Size + 0.1mm + 0.60mm (for Level A of IPC-2221)

1.1 + 0.1 + 0.6 = 1.8mm. Pads are already at 1.934, so good there.

For the slots for the CP2500, I think I should bump them to 3.2 x 0.8mm

If you could ask Seeed what the approx. finish dimension of a 3.1 x 0.8 and a 3.2 x 0.8mm slot would be, I'd appreciate it. I don't think I could go beyond the 3.2, as the pad would be getting too small, and there isn't room to bump the pad size up much, at least at Eagle's std. values.

Let me know what you guys think.

http://www.pcb-3d.com/knowledge-base/pth-dimensions

[Pars]

As I feared, I can't go larger on the CP-2500 pad size without clearance issues between the pads noted in a previous post. Just a bad relationship between the 601 and 2500 pad locations.

The only other think I could do would be to define the pads in the part as SMD pads, which I can control the x/y size and roundness on. You have to place these on both the top and bottom layer, and then drill them (or the slot) to get them to do a through hole part and plating. Might confuse Seeed.

Here is the new gerber file(s) for the CP601 only board using 1.1mm drill on the pot holes. No change in board size or anything else.

The dual board will not change size either once we have determined slot size.

TKD 4CP601 only mod.pdf

[sbelyo]

is the bigger board compatible with the alps RK27 quad pot?