Leaderboard

Threw together a scrap wood shooting board for the 62. Did the whole Rob Cosman build with the tape to keep glue up from warping the mdf. Seemed to work well.

In progress Amp design by me, power supply designs and circuit board layout by kerry, support by birgir +/-300 volt power supplies. complementary push pull all bipolar design with cmos style multiplying current mirror.

It isn't confined to On-Semi. Rohm did the same thing with all their low noise offerings ages ago, So did Renesas with the J79/K216 - in fact lateral MOSFETs are a thing of the past. Most p-channel jFETs have gone, and many low-noise jFETs of any flavour. The latest to go is the very low noise J107 (another On-Semi casualty). NXP killed off the n-jFET BF862 (lower noise than the K170) and indeed all jFETs, period. Analog Devices has just EOL'd the monolithic dual MAT01, unusual because it BVceo is 45V; every other low-noise dual is 40V. So in one of my applications where the maximum Vce is 41V it is the only part that will do. Hell On-Semi even obsoleted that ubiquitous BC560! OK they still make the SM version, the BC860, but it is tough nuts if you needed the power dissipation of a discrete part. If a part does not go in an automotive, mobile device, TV or other ultra-high volume application, semiconductor manufacturers lose interest real fast. The glimmers of hope are Toshiba, Diodes Inc, Linear Systems and THAT. And LS is the only one with a credible line up of single and dual jFETs and dual bipolars in multiple package choice.

How about 621-KBP201G (Mouser PN). Haven't tried it but same specs. These bridge rectifiers are common parts and shouldn't be a problem to replace. Also a Rectron MDA201G would be another one to look at. 2A 100V bridge rectifier in an appropriate case/footprint and pinout.

I couldn't stop listening to this yesterday I was using my SR-007's. It drives them very nicely. Very rich deep bass and good imaging / sound stage, which is usually where the 007's suffer without the proper amp. This was running this off of a bench supply at 11.1V and it was drawing .4A very consistently. The top board is the +/-300V supplies (with input EMI filtering) and the one below that is the bias supply set to 580V. Each amp section is 1" x 2" and each of the +/- PS sections are 1" x 1". Bias is a little wider.

Switched from Megatron to the Blue Hawaii this morning. Different sound signature but equally as satisfying. This one is not the BJT version but the one that uses 2SK216/2SJ79 with cascoded CCS and adjustable plate current.

There you can use anything that has a minimum value of 100V @ 2A

I've fixed at least five of these over the years, all with bad mosfets so they just fail. Once swapped out the amps spring to life.

Where Are the Iconic COVID-19 Images? https://www.theatlantic.com/international/archive/2021/02/where-are-iconic-images-covid-19-pandemic/618036/

I never really wore my 1861 Speedy much. Why would I; I have a Pre-Moon. I haven’t taken it off since I put it on this bracelet. Highly recommended.

https://www.behance.net/gallery/113377671/EuroPi-Making-EuroRack-Affordable

Ping ponged up a set of Naval Aviator wings and broke in one of my SurfPreps.

Proper funding is mandatory for those DIY projects. Not mentioning killing yourselves with fake sand, along with troubleshooting made impossible not knowing who's who. Saving a few ten or hundred bucks is bullsh*t, common, you are going to play those with top dollar headphones, and they are designed to last decades. Quality remains, prices forgets. And some savings are costly.

I had the same issue a couple years ago with my first amplifier build. I bought some 10m90s and DN2540 from ebay, with the result that my power supplies kept blowing up. I had no idea that there was enough money to be made selling fake parts. But I guess there is. Now everything is from Mouser or DigiKey.

That is just part of OnSemi's quest to obsolete anything remotely of use to audio. They took over Fairchild and Sanyo and have systematically removed many much loved discrete transistors from both their lines. I hate OnSemi with a passion. A big fucking hatred. A big fucking passionate hatred.