i'm on a roll... the kgsshv

[kevin gilmore]

you want a transformer that has 360vac windings

 

you change the 440k resistors to 390k

[mwl168]

I've been eyeing the stereo board version of the KGSSHV, and debating between building it next, or a KGST. Decisions, decisions.

 

For the lower-voltage versions of the KGSSHV (like the 400V stereo), a couple of things I never quite understood (and would appreciate a link back upthread, since I seem to have missed this info previously):

 

1. What transformer specs do I need for a 400V version?

2. What parts need to change on the PSU board (I'm looking at kgsshvpsminifinal)?

 

The Tsar has already spoken but since I just built a 400V KGSSHV using a similar PS (kgsshvpsminifinalstn9360) I can also share my experience. You can also referred to my earlier post #4321 which has the exact value of resistors I used based on availability at Mouser at the time.

 

The formula to calculate the B+ is ((R29 + R5)/R6 + 1) x 10V (V out of the LT1021 voltage reference) and similar for the B- side of course. I also read that you should configure the pre-regulate Zener string to 50V above your desired voltage, in this case, 450V.  

 

In my case, I have been getting a very steady +408V/-406V output from my PSU.

 

Hope this helps.

[kingofsnake]

that schematic is close enough

 

 

 

Thank you.

[gepardcv]

Perfect. Thank you Kevin and mwl165!

[gepardcv]

For the Antec transformer, I assume you (mwl165) used this one? Any downsides to it — like buzzing? This price is pretty tempting compared to a custom, but I'm a bit leery of noise.

[nopants]

The one I use in the KGST has a slight self hum but none of this makes it to the headphones. Similar to the part you linked, it's only drawing a small portion of the available current

[mwl168]

For the Antec transformer, I assume you (mwl165) used this one? Any downsides to it — like buzzing? This price is pretty tempting compared to a custom, but I'm a bit leery of noise.

 

Yes, that's the one I use.

 

I have not experience any hum nor buzzing and it runs cool. The downside is the size - this thing is HUGE )

[Laowei]

i'm redoing the kgsshv-carbon board for current parts, i added the cascade current source,

is there anything else people might want?

I have a pair of unstuffed v0.9 Carbon PCBs. Tracing the circuit, it appears the outputs are grounded gate, kind of like a SS Blue Hawaii. Is this correct?

[kevin gilmore]

yep grounded gate.

[nopants]

Have you guys given up on the pbmf input fet option?  Mouser lists this as EOL

 

The only other thing I can think of off the top of my head is perhaps a hole/some holes near the output section, to have some options for wiring. Not sure what everyone else's experiences are but snaking wires to terminal blocks over the resistors gets kind of crowded for me (kgsshv offboard). This might be a pain given the size of the board though. Maybe I'll just start using molex connectors

Edited April 21, 2015 by nopants

[spritzer]

Yup, it's EOL and with plenty of K170's out there it doesn't make any sense to use them.  I still have a couple of hundred of them so they might find some use... 

[JoaMat]

/

Edited November 11, 2015 by JoaMat

[gepardcv]

I see two 0.1uF caps with traces to the servo. Which of the two did you remove (or both)?

[JoaMat]

/

Edited November 11, 2015 by JoaMat

[Laowei]

i'm redoing the kgsshv-carbon board for current parts, i added the cascade current source,

is there anything else people might want?

Smaller board with more SMT?

[spritzer]

Using SMT resistors will make it much more expensive to build. 

[nopants]

Maybe he was referring to the active parts? Are the smd versions of the mps*6 devices also EOL? I don't remember the power handling off the top of my head, but seems like a possible option

[JoaMat]

/

Edited November 11, 2015 by JoaMat

[kevin gilmore]

the version of the carbon board i am working on has

pzta42,pzta06,pzta56

and at the moment mpsa06 and mpsa56

all of these parts are current fairchild production

i have been told that all these parts have at least 5

years more life left.

i have also been offered this really nice bridge in SF

recently painted...

the stn9360 lay down because they need to dissipate a bit more heat

the pzta parts stick up vertically, and are therefore real easy to

solder in.

i have also added the cascode to the carbon.

should be 100% mouser parts except for the lsk170/lsk389 which are easily

available.

with 20ma per leg, should make the current crazies happy.

and 32 watts of heat per channel

getting kerry's servo in there is going to be fun

Edited April 22, 2015 by kevin gilmore

[nopants]

any issues with laying them horizontally? maybe put the pads on the back of the board? Either way I'm glad I don't have to go treasure hunting on ebay

 

Are you trying to maintain the same board size? This version sounds pretty dense- kgsshv diamond? haha

 

or maybe it's "this version sounds pretty buff- kgsshv cabron edition"

[Laowei]

Sorry I was not clear. I was thinking of SMT for the active parts.

[kevin gilmore]

its getting pretty tight...

 

http://gilmore.chem.northwestern.edu/kgsshvcarbon.jpg

 

laying the rest of them horizontal is going to be a bit of trouble.

[luvdunhill]

Should that be 55 years?

[kevin gilmore]

50 years is the golden anniversary

 

55 years is ??

 

in 5 more years, 60 years is??

 

and this is what happens when you edit an edit of an edit of an edit...

[nopants]

60 years is diamond, it's a sign