Well, the off board amplifier is working again as there was nothing wrong with it except for the blown toroid which I replaced early with Jwzhan's extra transformer.

Richard from SumR told me he will build a replacement toroid, which will go back to Jwzhan Thank you man!

I also disconnected the relay and the e24 replacing the momentary switch with a latching one.

That's excellent news!!!   

 

Speaking of offboard... say hello to the new super tiny KGSSHV's....

 

 

This is a new version of the offboard design I did for my own use.  Cut down in size as far as it can go and 2SA1968 only. 

 

The power supply in the pics is a version of the BH supply as even the KSSHVk PSU is roughly the same as the entire chassis.  That said, I'm putting the finishing touches on a version of the HV psu which will fit in there... 

Is that a custom chassis? It looks stunning.

Nope, bought off ebay. 

Beautiful job. I like that it is a stock chassis. This really reduces build time.

It looks taller than the dissipante cases I have used.

Edited January 27, 201412 yr by eggil

Think I've got the same case which I originally bought for my F5 project but no time. 

 

Speaking of offboard, I've still got John's (johnmclean) boards half populated.....

A F5 in this chassis would run very hot indeed....     There is a larger version of the same chassis which might work with the bias turned way down. 

 

For the HV, chassis like this means I can turn up the current and I have some even smaller ones in mind which would have to use a simpler PSU and lower voltages.  Running at +/-400V opens up plenty of options for output devices in current production and MOAR CURRENT!!!! 

Finally, I got the three boards to work.

I'm going to build the chassis and the panel the next week.

For the psu board.the out put is +506V, -506V, Bias +586V, +14.82V, -15.15V

For the amp board. : L+,L- :24V,  L+,GND:6V,  R+,R-: 34V, R+,GND:9V.

Some notes for this build:

1)At first I forgot to connect the GND cable between the amp board and the psu board. I met a strange issue that the LED(D13) was dark when turn on the power. And then when I turn off the power,It starts to light again.

2)If I don't setup the jumper for neither the local or the gobal feedback. I got the o+,o- with about 1500V. Oh, my god!I turn off the power immediately and setup the jumper and now I get about 20~30V. 

Is there a better way to spend a Saturday than with a pile of KGSSHV boards? 

 

 

I did confirm my suspicion that BUL216 doesn't work without serious mods as an output device.  It's a shame as it can just about take +/-450V. 

 

There is another pile of boards that was supposed to be tested today but I've run out of parts at the moment.  That pile will include a documented and tested way to run it at +/-400V but at higher current with the onboard sinks which should be interesting. 

Wonderful work spritzer. I cannot stop staring at this picture. So many boards!! 

I like to do things in bulk. 

 

Another thing of note, a comparison of the old KGSSHV boards and the new HVk boards in the same chassis...

 

 

have you found any success upping the current at 400? this is a pretty attractive proposition since the edcor 330v/200ma and any 15v is super cheap compared to sumr

It's next on my list but I've run out of parts.  It will be complete Mouser amp too with Fairchild output devices so part sourcing is made far easier.  Also a 400V design is cheaper to build as we can go back to single caps in the PSU. 

 

Those Edcor transformers are excellent plus it's easy enough to remove the endbells and mount them sideways. 

Edited February 3, 201412 yr by spritzer

Some further news, the first use of the new power board:

 

 

Sorry for fucking up the focus...    Works like a charm and fits perfectly in the spot it was designed for.  No more flying wire connections for voltage selection and primary connection. 

 

Part of this:

 

 

My personal amp... well until somebody pleads with me long enough and I sell it.  That transformer is from my bulk order and it is seriously awesome.  Can't tell if the amp is on with an ear right next to it... 

Edited February 3, 201412 yr by spritzer

That's just beautiful!

Great news on both the board and transformer.

Very nice work as usual, Birgir.  I really need to find a better home for my KGSS.  I'm hopeful that they'll move me into an actual office and if so, it may become my work rig as absurd as that would be.

Every KGSS needs a good home.   

 

I was just doing some inventory and I have just about enough parts for two more KGSS and then I'm out.  Now I have the strange urge to build a Blue Hawaii though... 

I've been toying with the idea of moving my kgsshv into the office, but it might be more economical to move the megatron to cut down on my power bill

Makes a note to design something even more inefficient... 

Very nice Birgir. I like that power board.

Some further news, the first use of the new power board:

 

My personal amp... well until somebody pleads with me long enough and I sell it.  That transformer is from my bulk order and it is seriously awesome.  Can't tell if the amp is on with an ear right next to it... 

For the parts hoarding crowd that likes to pretend they will build stuff eventually, is there a spec for this transformer on file with the company and available for order?  Especially since 48x 4686A just arrived and the sumr keep having issues?

That's alot of toroidials back there.