BOM Update
Hi X. Here's an updated BOM for review. I filled in the rest of the items and also made some substitutions for out of stock items. The only thing that's really unavailable right now are MELF resistors. Once you have a look I'll take a crack at separating for HPA vs. Preamp. Thanks!
Hi X. Here's an updated BOM for review. I filled in the rest of the items and also made some substitutions for out of stock items. The only thing that's really unavailable right now are MELF resistors. Once you have a look I'll take a crack at separating for HPA vs. Preamp. Thanks!
No problem X! Let me know if you have any comments or feedback.
Wow! Those are some beautiful boards! Thanks TimS, X, and JP!
Wow! Those are some beautiful boards! Thanks TimS, X, and JP!
Hi Jwarch,
I will look through the BOM, and probably try to place an order on Mouser and details of any adjustments will come out of that. If you have a sharable "shopping cart" link that would be helpful. I am looking to building the amp to verify it works.
Thanks,
X
I will look through the BOM, and probably try to place an order on Mouser and details of any adjustments will come out of that. If you have a sharable "shopping cart" link that would be helpful. I am looking to building the amp to verify it works.
Thanks,
X
Thank you Jwarch for making the comprehensive Mouser shopping cart! It is a huge undertaking and the one you put together is quite inclusive and has options and choices for different pots etc. I am still trying to wrap my head around the critical parts needed for a HPA build, which I believe, is the more popular application for this project.
Related to this is the ultralow noise TPS7Axxxx voltage regulators made by LDOVR.COM - member Badboygolf16v has been in contact with the vendor and says he can secure a 15% discount for us - not sure of the details if this is a GB or a coupon code. I will let him handle it if indeed it is a group buy. But thanks for your efforts Badboygolf16v!
I will send out the boards to everyone this weekend.
Related to this is the ultralow noise TPS7Axxxx voltage regulators made by LDOVR.COM - member Badboygolf16v has been in contact with the vendor and says he can secure a 15% discount for us - not sure of the details if this is a GB or a coupon code. I will let him handle it if indeed it is a group buy. But thanks for your efforts Badboygolf16v!
I will send out the boards to everyone this weekend.
X, jwjarch you may be interested in this -
I came across this while investigating other power supply options: End-to-end Custom Circuit Designs | WEBENCH(R) Tools | TI.com
Basically you input parameters and it will spit out a few different designs with details of efficiency etc.
I came across this while investigating other power supply options: End-to-end Custom Circuit Designs | WEBENCH(R) Tools | TI.com
Basically you input parameters and it will spit out a few different designs with details of efficiency etc.
Thanks for pointing that out. I think JPS64 might have been using this to design the voltage regulators that we are using on this amp.
I am making some progress going through the "HPA" version of the BOM that Jwarch prepared and placed an order with Mouser for the parts to build everything except the input selector panel. Hopefully will get the PCBs verified in the coming week, but will send them out this weekend.
X
I remember you saying that some resistors should be high tolerance (0.1%?)
Does the BOM show these options?
Thanks
I remember you saying that some resistors should be high tolerance (0.1%?)
Does the BOM show these options?
Thanks
I'll double check those badboy, and edit if needed. I also have to add comments regarding transistor matching. For reference I have included tabs at the bottom of the spreadsheet that include the schematics, silkscreens, and renderings that JPS provided.
Here's the text from JP's schematic:
R115-R118 & R135-R138: 2R2 for 145mA bias; 2R7 for 115mA
R106/108 & R126/128 matched (or use 0.1% for performance)
V101/V102 & V121/V122 matched 1% (2mA) for best DC offset
V103/V104 & V123/V124 matched 5% for lowest DC offset
Here's the text from JP's schematic:
R115-R118 & R135-R138: 2R2 for 145mA bias; 2R7 for 115mA
R106/108 & R126/128 matched (or use 0.1% for performance)
V101/V102 & V121/V122 matched 1% (2mA) for best DC offset
V103/V104 & V123/V124 matched 5% for lowest DC offset
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X, any chance of posting the final schematic? the one on the first post is just one channel at the moment.
It’s posted as PDF on post 96. All production data is there including stuffing guide and interconnect block diagram.
http://www.diyaudio.com/forums/grou...led-class-hpa-sub-ppm-thd-10.html#post5479429
There is a typo on schematic: it says that MOSFETs can be substituted with Toshiba 2SK2013 and 2SJ3131. No 2SK2013 since all are P channel. Just 2SJ3131. Also, Fairchild equivalent FQP can be used too.
Just wanted to let everyone know that I am dealing with my basement flooding from a malfunctioning sump pump and rain storm. It’s quite a mess and will take me some time to sort out and recover.
Not to worry. That has to be your priority right now. I hope you didn't have much damage, and can get things sorted without too much grief. Best of luck X.
We have had several deluges here in the past week from the same storm system, no doubt. The creek on my property totally jumped its banks for the first time since I moved here 4 years ago. Sorry about your basement. I hope your amps and speakers are safe!