Closed - SRX Plus board set Group Buy

[mwl168]

A few of us over at another thread started by Blueman2 are contemplating getting SRX Plus PCBs fabricated. See this thread: http://www.head-case.org/forums/topic/12445-plan-to-build-srx-where-to-find-bom-boards/

Discussion of the SRX Plus design can be found here: http://www.head-case.org/forums/topic/11996-srx-revisited/

I've checked with PCBNET and we can get the cost the amp board to $25 if we order at least 15 boards. The board will be 2mm thick with 3 oz copper, the board size is 9.35" x 6.85" ( 2 channels on one board ).  Kevin has recently updated the board with teardrops enabled. We have not decided on the PS to use yet. The SRX Plus needs a +/- 340VDC and -20VDC supply in addition to filament supplies for the 12AT7 (x 4) and 6SN7GTB (x 2). JimL is working on a PCB of the shunt regulator he used and published on Audio Xpress. I think a GR HV configured for those voltages will also work.

No promise, but if we have enough interest to start a GB, I will run it following similar process and logistics as we did on the Carbon GB earlier this year.

Please state the number of boards you like if you are interested as well as your thoughts/preference of the PS. If we cannot reach consensus on the PS to use I am inclined to confine this GB just to the amp board.

Thanks and Happy Holidays!

EDIT 1/9/2015:

Kevin has laid out a PCB for the shunt regulator JimL designed for the SRX Plus and added the 580VDC bias. The PSU board measures 8.9" x 5.05" and requires off-board heatsink. I have also upgraded the boards to 2mm thick and 4 oz copper.  The amp board will be $25 each and the PSU board $20 each PSU if we can reach the quantity of 20 boards each. 

Here are the board counts:

MLA: 2 AMP 2 PSU

UFN: 1 AMP 1 PSU

blueman2: 2 AMP 2 PSU

gepardcv: 1 AMP 1 PSU

jose: 1 AMP 1 PSU

palchiu: 1 AMP 1 PSU

charlo89: 2 AMP 2 PSU

DefQon: 1 AMP 1 PSU (please let me know if your friend is interested and how many)

JimL: 2 AMP 2 PSU

sorenb: 2 AMP 2 PSU

mwl168: 2 AMP 2 PSU

eggill: 1 AMP 1 PSU

Samsie: 1 AMP 1 PSU

b0bb: 1 AMP 1 PSU

GeorgeP: 1 AMP 2 PSU

Rodeodave: 1 AMP 1 PSU

Bdrew: 1 AMP 1 PSU

Edited February 7, 2016 by mwl168

[MLA]

Interested in 2 amp boards!

As for PSU, I would prefer JimL's version or none, as I already a few suitable PSU boards from the KGST and Carbon builds laying around waiting to be used.

[UFN]

Interested in one amp board and matching PSU.

 

//UFN

[Blueman2]

Put me down for 2 of Amp and 2 of PSU.  For the PSU, I lean towards whatever is a simpler to build and less expensive to buy parts for option, but will go with whatever the group prefers.  

[gepardcv]

In for 1 amp board and 1 of Jim's PSU. 

[jose]

I´m interesting in a amp (amp+psu) too.

[palchiu]

Interested in 1*amp + 1*psu.

 

Is that possible add/modify thought holes for 0.1uf cap's pitch from 10mm to 15mm?  I thought 0.1uF/15mm were common with KG's board, and stock in hand as usual. Thanks!

[charlo89]

Interested in 2 sets.

Thanks for the GB

[gepardcv]

If we go with Jim's PSU, should the GB also include a bias power board?

[Blueman2]

2 hours ago, gepardcv said:

If we go with Jim's PSU, should the GB also include a bias power board?

Agreed.  I am still torn between the StaxPlus PSU and the KGBH PSU.  I prefer to go with whatever is smaller and easier to build/buy parts for.  But I will absolutely commit to 2 sets of whatever boards are in the GB.  

[DefQon]

In for 1 set personally but a friend of mine may be interested in 10. Will get back to you.

[JimL]

I'm in for 2 amp board and 2 PSU plus two bias boards

[eggil]

I am in for 1 of each

[mwl168]

Here is the count of sets of boards so far. Please correct or update.

Looks like we have enough for a GB. I will get quote for the PSU board and report back with cost.  

Each set will be one amp board and one of JimL's shunt regulator board with bias circuit added. 

I will also change the title of this thread to indicate that we are moving forward with a GB. 

 

EDIT 1/10/2015: List of GB participant and board count moved to first post.

 

Edited January 11, 2016 by mwl168

[samsie]

I am in for a set, please

[eggil]

I did not see my name in the list. I am in for 1 set.

Thanks

 

[mwl168]

1 hour ago, eggil said:

I did not see my name in the list. I am in for 1 set.

Thanks

 

My bad, I mssed your entry. 

[b0bb]

I would like a set (amp + psu).

Thanks

[mwl168]

I received quote for the PSU and response to an upgrade inquiry yesterday.

We'll be able to get one set of amp + PSU boards cost at $45 US with 2 mm thick PCB and 4 oz copper.

I have visually traced the PSU board against the schematic JimL provided. It looks good to me but additional pairs of eyes to verify will be great and much appreciated.  

Edited January 6, 2016 by mwl168

[Rodeodave]

I would like one set of amp + PSU boards.

Thanks!

[mwl168]

I moved the board count to the first post for ease of access.

Also, there are requests on the other thread to not have to order the AMP and PSU board in sets. That's no problem with me. We just need to keep in mind board cost is affected by quantities fabricated. 

Those that like to order different quantities of AMP and PSU boards please state your request on this thread.

I plan to close the GB in the next few days and start collecting payment toward the end of the week of Monday 1/11.  

[palchiu]

mwl1688

Please remove my boards, thank you.

Pal

[nopants]

I'll take a power supply board if possible, I already have an amplifier pcb

[charlo89]

I am not sure to built it. Please remove my board.

Thank you

[Blueman2]

On 1/9/2016 at 3:30 PM, mwl168 said:

I moved the board count to the first post for ease of access.

Also, there are requests on the other thread to not have to order the AMP and PSU board in sets. That's no problem with me. We just need to keep in mind board cost is affected by quantities fabricated. 

Those that like to order different quantities of AMP and PSU boards please state your request on this thread.

I plan to close the GB in the next few days and start collecting payment toward the end of the week of Monday 1/11.  

mwl168,

If we end up being below 20 boards on either the AMP or the PSU, I will agree to buy the amount needed to get us up to 20 boards.  Otherwise, I confirm my commitment for 2 of each board.