mwl168

Sorry, but the shipping charge for GeorgeP and s_r is incorrect. The $6.8 USD flat rate only applies to the US shipping address. The Canada shipping will be determined based on weight and will for sure be quite a bit higher.

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:

All US-bound boards were shipped via USPS Priority Mail this morning. Two remaining packages will be shipped pending remaining payments.

Most USA/CA-bound boards should be shipped out tomorrow.

Beautifully done John. What's the "thing" fastened to the back panel between the IEC and XLR sockets?

Beautiful work as always Kelly. Those front panels look seriously thick. How does it sound?

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.

@joehpj: did you try measure the voltage drop on the current limiting resistor on the B+ side through the power-up and voltage sagging lapse? Just a thought.

What value volume pot are you using with the SS Dynalo? SS Dynalo has BJT input not JFET and requires using a pot that's no higher than 10K.

TKD no longer sells to US directly without going through their US distributor which quoted a much higher unit price. That's why we decided for MLA to order directly from TKD in Sweden, he'll then send the North America orders to me and I'll handle the shipping to individual GB participants in North America.

Cannot help you if you already have or decided to use quad RK27 for volume pot. but there is a GB going for TKD pots that also include PCB board for mounting the pot.

Sorry being late to response. A couple of things: 1. Pars has been nice enough to create a smaller, 4CP-601 version of the boards which I will get quotes or both version of boards soon. 2. I am interested in the 4CP-2511 myself ( like Jeremy Clarkson, I believe "bigger is better" ) and can commit to 2 units - that's 3 units between obiwan and I. If we can get 2 more units we'll meet the minimum quota for production. Anyone interested?

I second Birgir's comment. In fact, a friend of mine like the Dynalo as a preamp so much he uses it as his main preamp in his speaker system and asked me to build him another SS Dynalo for his headphone use.

Sorry for being thick - but why would a short on the B- header take out the LV regulator?

I am easy but smaller board is better. If you can send me the Gerber you currently have, I can use it to inquire the fab house how they like the slots for the 4CP2500 indicated and their ability/option for the slots. Thanks!

Hi Pars: If you are happy with the layout, please send me the Gerber file and I'll check with the PCB fab house. Thanks!

Kevin already laid out an indicator LED and its current setting resistors on the PCB. Going by memory, it's the two 2K resistors and the LED at the very front edge of the GR LV PCB. The resistor values may need to be adjusted based on the regulated output voltage and choice of LED.

If Pars doesn't mind doing the heavy-lifting creating Gerbers with slots, I am happy to work with fab houses to get quotes Personally, I like the option of using the TKD CP2500 series. they seem to have a good reputation for sound quality and the cost is not outrageous.

I did not know Kevin already laid out a Gerber for volume pots. Thanks to gepardcv and GeorgeP for pointing it out and confirming it. I did not see an alpsquad2 but found a alpsquad3 Gerber file on Kevin's site and looked at it through a Gerber file viewer and it looks exactly like the photo GeorgeP posted. I second the motion to alter and fit the TKD 4CP-2500 series given that RK27 does not seem to have a good reputation for sound quality.

Thanks Pars! That would be great.

I think we have enough interest to warrant a GB. I am working with MLA to confirm availability and cost. Re: the PCB, I think we should make it versatile in utility, minimizing the board size would be the second priority. Does anyone have the means and know-how to layout the PCB and create the Gerber file? Below is the link to the datasheet which includes the dimension information. http://www.tkd-corp.com/products/att/pdf/cp600as-e.pdf

Are people also interested in having a custom PCB for mounting the volume pot if we proceed with a GB?

I think this will be the way to go if there are enough interest in the US. TKD Japan did not give me the option to buy directly from them probably because they now have an US distributor. According to the US distributor, we cannot even get close to the $42 unit price even with 100 units.

Hi All: I inquired TKD Japan directly about their 4-gang volume pot 4CP-601 and they referred me to their US distributor. Long story short, looks like I can get the 10K pot for $65 a piece plus shipping. The cost may be slightly lower if total quantity is high. I am still working out some detail information. Any interest?

No, except for the 120R tail resistors (182R on V5 board) of the offset trim pot John pointed out. Although I believe I made this update in the V5 BOM in the previous GB already. The 120R provides greater adjustment range that allows for 20mA output device current.