mwl168

Thanks Kevin and Craig! I plan on using exactly that - 18AWG wire, 600V rated, PTFE stranded wire I bought from Apex Jr. I will be using a star-schema grounding tying the IEC ground and the regulator ground to the chassis. In this case, should I still tie the 7th wire to the chassis on both sides? On the amp side, how should I handle the grounding? Will tying the 7th wire to the chassis be sufficient? I did not go into all details - I am actually planning to use the same PS unit for my Blue Hawaii and, in the future, the Grounded Grid. I plan to have a separate 4 pin connector and wires for the 6.3 vac filament supply which I will twist the wires. I also plan to install a separate switch (together with thermistors) for the transformer secondaries for the HV. This switch will function as a manual delay for the HV supply for the BH and GG. I'll leave this switch in the "ON" position when I use the PS with Carbon and HV. When I use it for the BH and GG, this additional switch will be in "OFF" position when I turn on the main power switch and be flipped on after 30 seconds or longer. EDIT: I forgot to mention that the reason I am doing the HV delay this way is because I use the off-the-shelf Antek transformer (AS3T-325) which has the 6.3vac and 325vac secondaries on the same transformer.

I need some advice with the construction of a power cord. I am ready to case my Carbon finally and it will be a two-chassis layout; one chassis for the power supply (GR HV, LV and transformers) and one chassis for the amp. The power supply connection will be through a 7-wire cable (ground, +580 VDC, +400 VDC, -400 VDC, +15VDC, -15VDC and one wire will be unused for now). I plan for the cable to be about 3 feet long to provide flexibility in placement. My questions are: 1. Is 3 feet too long? If so, what's the appropriate length without causing problems or degradation in power supply quality? 2. Should the 7 wires be braided, twisted or just leave them parallel to each other? Thanks in advance for your thoughts and advice!

I am in for 5 Alpha/Song Huei pots.

To clarify, is the price quoted for a balanced stereo pot or single-end stereo pot?

Will do. Hopefully Seeed will respond to your e-mail now that weekend is over.

Thanks to cspirou for your rational. Interestingly Song Huei's web site mentions collaboration with TKD but not Alpha. I can visit the factory next time I visit home and maybe even strike a deal of some sort for a batch. But the nearest plan I have won't be till November time frame.

Care to elaborate?

We will offer this new board along side the 4CP601-only and 4CP601/4CP2500 boards as a third option if there is enough interest. Please state your interest here in the thread and I'll ask MLA to add another column to the spreadsheet if necessary.

I am also interested in how the Elear compares to the Utopia being at 1/4 of the price.

Can confirm UFN's answer based on my own builds - 1.7V red LEDs on my KG designed Dynalos and ES amps.

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!