cspirou

I have good news. Song Huei responded saying that they can make up to 99 pots for $4 each depending on the shaft we want. It seems cheap but when I converted the price from The Audio Guild site they cost about $6 for the stereo pots. From the email it seems like this is leftover material from bigger orders which is why they can do a small order. Here is what they said: Okay.. we have element stock for making 99pcs. But I am not sure your shaft length. If you need 20mm round shaft (20KQ) : 57 pcs. 25mm round shaft (25KQ) : 99pcs available. So... please let me know what is quantity you need ?? RK2142G-A10K L-20KQ or RK2142G-A10K L-25KQ @USD 4.0 each. Terms : Exwork. - - - Have a nice day ^^ Since I have been communicating with them I don't mind doing the order.

I got a response and they said they are going to check what they have in stock. So there's a possibility of a small order. Will keep you guys up to date.

I don't having a smoking gun but I have some circumstantial evidence that leads me to think this. I spent quite a bit of time trying to find a source to buy these pots and the 21mm size isn't very typical of Alpha. I managed to find this site which list them as Alpha/Song Huei http://theaudiocrafts.com/electronic-parts/potentiometers/alpha-songhuei-2122g-series-a10kx2-potentiometer I guess Song Huei could be cloning these pots but considering how hard the Song Huei pots are to find as well, it doesn't seem likely. Better off cloning ALPS. Looking at the Song Huei site I found this pot http://www.song-huei.com.tw/product.php?mode=show&cid=19&pid=93 This has the exact dimensions and pinout as the 21mm 4 gang pot on the following Alpha site. http://alphapotentiometers.net/html/21mm_pot_4.html Even further the parts numbers are extremely similar. With the Alpha site using 3RP/2142G and the Song Huei site showing RK2142G. Both have 2142G in common. Again this could mean that Song Huei is just cloning Alpha but I think it's more likely that they have a common manufacturer and that one supplies the other. But even if they aren't the same pot, the fact that they have the exact same pinout makes it a viable alternative.

I am pretty certain that the Alpha pots are relabeled Song Huei potentiometers. http://www.song-huei.com.tw/product.php?mode=show&cid=19&pid=93 might be a way to source a smaller amount from them edit: i just sent Song Huei a message inquiring what a minimum order is. I'll let you know what I find

There should be a way to make a interfacing PCB with a potentiometer on top and pins sticking out the bottom that are compatible with the Alpha pin configuration.

Just received my boards today! Thanks Soren!

The data sheet I found says one of the rows is a tap, similar to a transformer tap. In the PCB that row of pins isn't wired to anything.

I'm too late for the pots but I would like to join in for the boards including the RK27. I tried to add my name to the sheet but it wouldn't allow me to edit. Could @MLA add my name in and interest for 3 of the three pot boards?

Did you figure something out for the heat problems? where can I source some Alpha pots for this?

Are Gerbers available? I don't mind making a bunch because almost all my projects need international compatibility.

Thanks. But I meant where could I get the PCB?

Where can I get more info on this board?

You are right. I was going off the first page where I saw an alps/tkd board. It wasn't until later I saw that the pcbs were modified and tkd only.

I already did. But for the moment I have more Dynalo boards then I want so I prefer to barter for another GRLV.

There is also a group buy for TKD quad pots with PCB. I believe the PCBs are also compatible with ALPS quads

I ordered it as 139mm x 78mm. Measured with my caliper they are a half millimeter short in both dimensions so perfectly fine. Send me a PM if you are interested. Got one pair on hold for you. I read somewhere that KG recommends 3oz copper for the GRLV, is that what you are doing? For the ALPS board I think you can get away with less copper because it's low current. Let me know when you get the boards.

I haven't built any yet. I made a project list on mouser to order the parts for two channels but I haven't ordered any yet. https://eu.mouser.com/ProjectManager/ProjectDetail.aspx?State=EDIT&ProjectGUID=f3a20e6c-4a70-42d5-8238-8780fd13c25b My money is a little tight for the moment so I am just keeping the PCBs for now. When I do start I want to make the power supply and amp in separate chassis so that they can stack and take up a smaller footprint. so I can't totally vouch for easyeda but they did pass testing and i have no reason to doubt their functionality.

They are the v9 boards which should be the latest. I posted a pic on the dynalo mk2 thread.

I have some extra Dynalo mk2 boards if you are interested. 2 oz copper. If you end up making the GRLV and the ALPS board I'd be willing to trade.

I ordered some PCBs from easyeda.com to build this with the following specifications. 139mm Max* 78mm Max; - Layers: 2; - PCB Thickness: 1.6mm; - PCB Color: Green; - Surface Finish: HASL(with lead); - Copper Weight: 2oz.; - Material Details: FR4-Standard Tg 140C; - Smallest Holes: 0.30mm↑; - Min. Tracing/Spacing: 6mil↑ / 0.152mm↑; After reading through many pages here I am pretty sure my boards will be fine but someone can correct me if I am wrong. I ordered 10 boards which makes 5 pairs for 5 amps. I plan on keeping 2 pairs so the other three are up for grabs. I got a discount code since it was a first time order so they workout to about ~$10 a pair. If anyone is interested in the three remaining pairs just send me a PM. I will only charge exactly what it cost me + shipping. I am based in Europe so anyone from the US will have to pay more, but the boards are so cheap that it might be worth it. I will also consider trades for a GRLV PCB, 3oz copper. Edit: got a picture

The Google spreadsheet doesn't have any prices for shipping(at least not for me). Is it assumed that regular mail is included in the price of the boards? If not then how much is it so I can avoid being a deadbeat?

I have a general question on sharing info. If I reverse engineer a product and draw an electrical schematic based on it, are there any legal repercussions against publishing said schematic? If they already have a schematic and I scan it then I can see an issue, but if it's my own drawing then I am not so sure. Same thing goes for the PCB. If I use their exact same layout then I can see an issue but not if I make a different layout.

Do you really need to connect the output jack with the power supply ground? Don't they share the same ground plane? Is there a checklist for voltages at certain points we should be getting for troubleshooting purposes?

Could the Dynalo be used as a preamp instead of using the unbalanced/balanced board? I'd like to wire the output to a switch so I can choose between headphone output and balanced preamp output.

For the V6 board with the 3 bridges, is it meant to work with all three bridges or are you suppose to use either one or two depending on the configuration you are using?