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Closed - Megatron and GRHV PCB GB


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Got my boards today. Thank You! I have posted pics before but here are some more of my build. I noticed these boards have a 12 V for the filaments. The old board did not have it.  

12v filament version posted pretty sure the original was done the way it was to accomodate the 6dj8 tubes for those that wanted to do that edit: the filaments of the output tubes are tied to

All international-destined packages have been sent too. I'll PM each with the postage. Happy building!

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The group buy is closed. Here is what we have:

                  AMP board         GRHV split

Jose                 2                         2

PICaudio          2                         3

Whitigir             1                         1

gwrskien           1                         1

Looser101        2                         2

gepardcv          1                         1

mypasswordis   0                         2 Neg.

chiguy               1                         1 

samsie              0                         2

sbelyo               1                         0

 

Base on the vote, the amp board will be 2mm/4oz from PCBnet, $36 per board. The GRHV splt will be 2mm/3oz from Seeed, $30 per set (2 boards).

Participants please PayPal me the board cost to my Id below before end of day Friday, 5/12. I will place the orders on Saturday.

If you choose to not use PayPal gift please remember to add the applicable PayPal fee. Thanks! 

 

 

PayPal ID.JPG

Edited by mwl168
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I have a late thought about the GRHV split PSU. 

Kevin also published a version with CPC1117N switch on the boards (but no control logic). This allows builders to implement a timed delay to the HV supply. You would have to supply you own control/timer unit which is abundantly available on eBay for very reasonable price (less than$10 US). The board is slightly larger (139 x 103mm vs 139 x 99mm) but the cost will be the same.

I should also mention I am not personally aware of anyone who has successfully built this version. Maybe Kerry and others can chime in.

What does everyone think?

Sorry for this late curve ball I throw you but I thought it's worth a debate since most will be using the PSU for the Megatron.      

EDIT: found a version of GRHV with switch Kevin posted that is the same size as the original: 139 x 99mm

Edited by mwl168
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Thanks again Kerry!

Also, found a version of the GRHV with switch that Kevin has posted and it is the same size as the regular one - 139 X 99mm.

I propose we use this version for this GB. Again, you can simply leave out the CPC1117N opto switch and the 600R resistor if you don't plan to implement a HV delay.

Please let me know if there are objections.

GRHVRightSWS.JPG

GRHVLeftSWS.JPG

Edited by mwl168
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I would definitely prefer the version where the L bracket mounting holes are on the side, like on my positive rail boards. I suspect I'm in the minority, though, so will go with whatever people agree on. Is everyone else mounting this vertically with L bracket or horizontally directly on the heatsinks? 

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24 minutes ago, mypasswordis said:

I would definitely prefer the version where the L bracket mounting holes are on the side, like on my positive rail boards. I suspect I'm in the minority, though, so will go with whatever people agree on. Is everyone else mounting this vertically with L bracket or horizontally directly on the heatsinks? 

The mounting options for the switched version should be the same as the non-switched version. I will be mounting vertically with L bracket.

Forgot to mention that the CPC1117N relay also provides soft-start and soft-off.

For reference, here are images of the non-switched version:

GRHVRight.JPG

GRHVLeft.JPG

Edited by mwl168
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Ah, I should have paid more attention and checked the files... probably have an earlier version of the board then. That version is longer and narrower along with the L bracket holes being on the side, which meant it made more sense to mount directly on the heatsinks. That wouldn't work on this version, which forces me to buy a 100mm+ tall case either way I mount it which was exactly what I was trying to avoid :/ 

Edit: I will just have to buy smaller caps to use instead of the ones I got from Soren's group buy, so no objections to any board

Edited by mypasswordis
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1 hour ago, mypasswordis said:

Ah, I should have paid more attention and checked the files... probably have an earlier version of the board then. That version is longer and narrower along with the L bracket holes being on the side, which meant it made more sense to mount directly on the heatsinks...

Sorry, I should have been clear from the get go about the version of GRHV. I was just going by the version I've been getting many requests on since the original GB was completed.

I am guessing the version you had in mind is the one below. 

 

GRHVSkinnyRightSWS.JPG

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I have received payment from most. Thanks all for the prompt responses.

I will be placing PCBnet amp board order today. The Gerber file used will be the megatron12v.zip with 12.6vac filament for the front end tubes. Board size is (229 X 229 mm or 9" X 9")

I will place the Seeed GRHV board order this weekend (it's 9:30pm Friday night in China now). The Gerber files used will be kgsshvpssicfetsinglenewrightfatsws.zip and kgsshvpssicfetsinglenewleftfatsws.zip.

These are the boards with the CPC1117N opto relay and the builders can opt to implement a HV delay if desired. Board size is 139 X 99 mm or 5.5" X 3.9").

I will update everyone when I receive order confirmations.

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Forgot to mention: the Megatron amp uses 2 2SC1815 which I have quite a few on hand and happy to provide them free for the GB participants. Please let me know if you need them and I'll include them when I send the boards.

 

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8 minutes ago, gepardcv said:

The 2SC1815 seems to be available from Digi-Key: https://www.digikey.com/product-detail/en/Central-Semiconductor-Corp/2SC1815/2SC1815-ND/

But if that's not the right part, I'll gladly take a pair.

That's the right part. Thought they were unobtainium many years ago. I stand corrected.

Regardless, I am happy to provide them if just to save shipping charge from having to place additional parts order.

Edited by mwl168
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