"The paradox of simplicity is that making things simpler is hard work!"
--- Bill Jensen
https://www.amazon.com/gp/product/0...de=as2&tag=disrupt-20&linkId=TL3ZSXSEY3KDFDIX
-RNM
--- Bill Jensen
https://www.amazon.com/gp/product/0...de=as2&tag=disrupt-20&linkId=TL3ZSXSEY3KDFDIX
-RNM
Last edited:
For now exist only on drawing board, sorry.
When I finish making layout, I can post gerber, I am kind of slow with soldering
.Regarding layout, please comment if there is something needs changing/improving?
BR Nenad
Output transistors will be mounted beneath the PCB.
Two mount options in my POW:
1. Yours
, fixing to the bottom of the case2. Mini power amp like case with lateral heatsinks, for example:
Douk Audio Amplifier Chassis General Aluminum Shell Pre-Amp Enclosure DIY Box | eBay
internal lateral height needed is 50 mm
With heatsink like this, I believe much higher bias is possible.
Attachments
That's the same case I used for a pass F5 headphone amp...It's called the "2107 chassis" on eBay, etc.
It is way, way more than enough. Even with 300ma bias. Probably more.
Can we find a way to put a hole in the pcb for the output BJT mounting screws when they are mounted on the bottom of a chassis or on heatsinks?
It is way, way more than enough. Even with 300ma bias. Probably more.
Can we find a way to put a hole in the pcb for the output BJT mounting screws when they are mounted on the bottom of a chassis or on heatsinks?
Attachments
Attachments
Jack has matched devices to sell.
If all bets are off, let me know. I can match a couple pairs from my Fairchild 2N5457's and 2N5460's.
pads
Hi,
I bought this PCB about two years ago, but I didn't get any schematic with it.
That wouldn't be a big deal because all the component values are printed on the board. Except I can't find any explanation for the pads called J1 to J4. They look like SOT23 footprints ,which doesn't tell me to much. So I ask here if somebody could explain the purpose of these pads? Thanks.
Hi,
I bought this PCB about two years ago, but I didn't get any schematic with it.
That wouldn't be a big deal because all the component values are printed on the board. Except I can't find any explanation for the pads called J1 to J4. They look like SOT23 footprints ,which doesn't tell me to much. So I ask here if somebody could explain the purpose of these pads? Thanks.
Attachments
I have the same board and kit from Jack. J1 to J4 are surface mount alternatives for the 2N5457 and 2N5460 jfets which are getting harder to get in their TO-92 package(in position J1C - J4C). The surface mount part numbers are MMBF5457 and MMBF5460.
Since this is a published design, you should purchase a print of the article from Linear Audio(https://linearaudio.net/article-detail/2118), which has the schematic and BOM etc. If it is a Rev 2 board, Jack has made provision for a trimmer pot(P2/P4) that may not be mentioned in the original article. I can send you a scan of the package that Jack sent me if you PM me.
PM me
this is the second version of the boards -- it's set up so that you can use the transistors Dick had in his original article, the Toshiba's or SMT devices which are still in current production.
the board also incorporates a suggestion by Dick to allow adjustment of the bias. that's why there are two potentiometers.
As Jack's site is down anyone else here have few spare boards and matched transistors to sell?