if you go forth with the GB.

 

There are two negative reasons: I am not interested in having an extra KGST set, and, secondly, I live in Spain and this will increase the final price because of the shipping cost if no most of the interested people live in Spain, or at least in the EU, and because the PCBs coming from China have to pay custom duties in Spain.

I am out. Thanks

I've been working with Bay Area Circuits, and am not getting much of a discount over their specials (e.g. the "Golden Gate" for 15 boards/$300), so it seems to be better to stack up a number of specials, but then why do the group buy at all in that case? Basically I'm finding it more expensive to get a custom quote rather than one of the specials, which are geared toward smaller quantities. So the group buy isn't working out as well as smaller individual buys, at least with the route I'm taking. Also as this is the first time I've done a board run I'm cautious as to how well it would work out.

 

Rather than risk unhappy group members I did a special one run of five sets. I'll get the boards back and report back here to how well it went, then people can decide if they want to club together in smaller groups to do a buy, or try another vendor. If it works out I'll have a few extra sets to sell. 

 

I should get these back next week so will report then as to how well it went. 

PCB fab houses can be such an epic pain to deal with. 

 

I have some KGST boards up on my site if anybody needs a set.  These are the slightly smaller version I use and the PSU is the super small KGSSHV mini unit. 

Hmm, no, but I'll check. Is a greater thickness preferred? Why?

Absolutely.

Absolutely.

 

I checked with the hardware engineers on my team (I'm in R&D and we do the highest performance measurement instruments on the planet). These guys have worked in HV too, like 5kV! Anyhow none of them could think of why thicker traces are important, 1oz is standard and what you want most of the time. The only difference is that for some high frequency circuits you want 1/2 oz, but that's up in the GHz range. 500VDC is bush league  

 

The only rational reason I've heard so far is that it's easier for DIY work.

On another thread KG recommends 2 oz traces for the tube filaments - makes sense because those are relatively high current - 0.6 amps each for the 6S4A (KGST) and 1.5 amps each for EL34s (Blue Hawaii).  Since the filament traces are part of the board that means the whole board needs to be 2 oz.

The filament traces on the KGST PCB are only ~18mm long and IMO should not require 2oz traces there. But if you want to pay extra for it, couldn't hurt.

You could always solder a piece of copper wire along the filament traces.

 

Doesn't look too pretty, but boosts the track current carrying capacity.

It would be very Rudistor though.    He had "silver reinforced" traces... 

Edited March 2, 201511 yr by spritzer

Greenwire is pure bush league ladies ... no self respecting engineer would touch it (well, if they can help it )

I got the boards back from Bay Area Circuits and so here's my report

 

• Turnaround was about a week
• kgstmini05 and kgstpsu21
• For the KGST mini boards the best deal is the "Golden Gate".
• You can get custom quotes, but people here were squirreling and they needed a number, so gave up and just ordered one special. For up to 15-20 boards it seemed like getting multiple specials was better than a custom quote. 
• $300 for up to 4 board types maximum 352 sq inches, you can pick color 
• I received 5 PS boards and 10 Amp boards, for a total of 5 amplifiers, which works out to be $60/set
• The online software is first rate. Upload your files over the website and you can view them before submitting. Note that oddly Kevin has the PS board in .rar format and the amp in zip, but the ordering process wants all zip so I converted it. 
• They are US based and nice folks, I talked to them on the phone (see below) to get some special help
• Last minute I found that there was some opinion I should be getting 2oz, where the Golden Gate special is 1 oz. I called last minute and they were nice enough to give me 2 oz for free (I recommend specifying it in the comments or contacting them beforehand)
• The boards look professional and first rate. Blister packed and look great

 

So I recommend trying BAC, highly recommended. You might pay a less going with a Chinese manufacturer, but the service and quality of BAC looks worth it to me. 

 

I'm not selling any extra boards at the moment, I'm going to build two amps at least, so I recommend interested parties in clubbing together and buying the Golden Gate 5 board special. 

Edited March 6, 201511 yr by Earspeakers

I use Bay Area for my one offs since my edu email still works. pretty nice and they usually give extras

Got my board from last GB, I would definitely be interested in a power transformer GB.

why can't you use the antek

why can't you use the antek

Oh well didnt see that 275V one.

I was looking for 280V all the time.

I think 300 dual works fine, and there is a dual 18v as well, two pieces

So, since earspeakers apparently isn't doing the group buy anymore, is anyone else interested in doing it instead?

So, since earspeakers apparently isn't doing the group buy anymore, is anyone else interested in doing it instead?

 

Correct, my vendor (BayAreaCircuits) didn't offer better pricing for a group over the 5 board store special they have, so I gave up trying to get a decent quote. 

I think 300 dual works fine, and there is a dual 18v as well, two pieces

Just did a power-on, the 300 Vac unit will give you 368 Vdc or so on the rails

Just did a power-on, the 300 Vac unit will give you 368 Vdc or so on the rails

 

The output voltage is set by the zener string reference unless the secondaries are too low

Yes I'm just providing the resultant voltage because I suggested using that transformer

.. b-but, you... I... waitwut?

Does anybody have any boards up for sale?

^Ditto.