Good news, the mafia v4 amp boards work 

 

Powered up my new (much smaller) HV and there's sound coming out of it. I had to lower the 2kOhm resistors before the offset pot to 1.74kOhm to get it to zero though. Once I get a replacement for this buzzing toroid I'll take a few pics.

That's good to hear.  :´)

The latest onboard (Production Rev 0.63) has a couple of new surprises I haven’t seen before.

I dang nearly missed that jumper for the BJT current sink.

 

Why the need for the 18V zeners for the Mosfet option?

because if you clip the output like you would do with testing with scope and

signal generator, the top fets blow due to reverse bias on the gate.

 

mosfets on the output are a bad idea, but some people want them.

Edited August 3, 201411 yr by kevin gilmore

I'm having difficulty trying to source 1968's for reasonable prices (bdent has only few of them left for $14.95). Any places that might stock some NOS units that aren't too pricey or fake?

Nope.

There is this place in japan somebody had volunteered to do a group buy from but it never happened. If somebody speaks Japanese and lives in Tokyo, this is the time to speak up

Arnaud?

Edited August 6, 201411 yr by eggil

Some here, but not sure if they are any good.

 

http://s.taobao.com/search?initiative_id=staobaoz_20140806&js=1&stats_click=search_radio_all%253A1&q=2sa1968

Ok bdent is out of stock and on backorder, don't think they will get some anytime soon which means my build is halted to x time interval i.e I'm fucked unless another source for A1968's pops up. 

 

I wouldn't touch transistors on taobao with a 50 feet pole. 

Edited August 6, 201411 yr by DefQon

second row, second and 4th are pictures of the real item

 

if it does not have the slits in the plastic by the pins it is not real

This would be a good example of not real... 

 

http://item.taobao.com/item.htm?spm=a230r.1.14.274.VYCKXq&id=35575378373&ns=1#detail

 

 

 

I might have cleared out that place in Japan as I just bought a lot of 1968's.  1967's also work but then you have to insulate them.  See here:

 

http://www.diyaudio.com/forums/swap-meet/34929-fs-sanyo-2sc3675-2sa1967-hi-voltage-transistors.html

My first all black KGSSHV:

 

 

Soft white power light... 

Nice!

Digging the black spritzer.

 

@kevin: Thanks for the note on identifying fake 1968's.

 

Now what agent should I use for buying stuff on Taobao?

 

These are the ones I'm going to go forth with:

 

http://item.taobao.com/item.htm?spm=a230r.1.14.36.9sqmKb&id=38581330445&ns=1#detail

 

or

 

http://item.taobao.com/item.htm?spm=a230r.1.14.78.9sqmKb&id=39994327207&ns=1#detail

 

or

 

http://item.taobao.com/item.htm?spm=a230r.1.14.162.Xu7U33&id=36290880273&ns=1#detail

The black looks great, Birgir.

Nice work Spritzer.

Indeed. Quite nice!

Very nice.

I like the Soft white power light.

Beautiful work as usual Birgir.

 

Just powered up my new on-boards tonight 

 

Edited August 7, 201411 yr by johnwmclean

John where do you get your wire terminal blocks from? I've been looking around for 600v rated parts for decent price but no luck. The green cheap ones on ebay rated for 350vac and no good.

I don't think there is a terminal block out that that can take 600VAC. 

 

Nice work John. 

400V rating on the ones I used;

 

Mouser 651-5452261

Today I received my recently ordered 2sc4686. Looks like i got 50 instead of 48 in an original? bag.

 

I guess they should be real then?

 

Any one?

Is it through that ebay seller something like 6gbp for like 12 pcs? Let me know if they are real as I purchased 4 lots same as you and would not be a happy Jan if they turn out to be fakes.

Yes its from that ebay seller. At the moment I have no way of testing them. I just thought I'd buy some, if I ever wanted to build another KGSSHV. 

Is it through that ebay seller something like 6gbp for like 12 pcs? Let me know if they are real as I purchased 4 lots same as you and would not be a happy Jan if they turn out to be fakes.