KGSSHV Carbon Build Thread

[wink]

As long as he doesn't blackball the project...........  

[P3t4]

10 hours ago, mwl168 said:

Hard to tell from the rendering the size of the heat sinks. The Carbon runs hot, make sure the heat sinks are adequate. 

I am going to run a controlled test when I get the heatsinks. My backup plan is to go with normal vertical heatsinks which I have already modelled after the conrad design. I decided to go with a cool winged heatsink because Conrad heatsinks never replied to my emails.

10 hours ago, Pars said:

I wish I could use modelling software like that

Everybody can do it! This is my first ever 3D-model .

[Whitigir]

1 hour ago, wink said:

As long as he doesn't blackball the project...........  

This reminded me a pool game where sinking the 8 ball was an automatic lost  good time, and good quote

Edited November 22, 2017 by Whitigir

[gepardcv]

Where are you sourcing the heatsinks?

[bui501]

Finally got off my ass and started to populate the boards for my Carbon build... I’m on a roll now... I just hope I don’t run out of scotch before the boards are finished...




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[Blueman2]

Looking great!  I see you are following mwl168's advice and elevating the resistors.  Smart.  Looking very good so far.  So you will be finished my morning?  I mean with the Scotch.  

 

[bui501]

Looking great!  I see you are following mwl168's advice and elevating the resistors.  Smart.  Looking very good so far.  So you will be finished my morning?  I mean with the Scotch.  
 

I ran out of scotch. I’m going to bed :-D


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[sorenb]

4 hours ago, bui501 said:

Finally got off my ass and started to populate the boards for my Carbon build... I’m on a roll now... I just hope I don’t run out of scotch before the boards are finished...




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3 hours ago, Blueman2 said:

Looking great!  I see you are following mwl168's advice and elevating the resistors.  Smart.  Looking very good so far.  So you will be finished my morning?  I mean with the Scotch.  

 

elevating resistors and caps are not needed on those boards, as the boards do not have any ground plane on top. (so the only resistor needed to be elevated is the power resistor on the PSU board).
Probably easier to populate the SMDs and socket before resistors, as the resistor sort of get in your way now

[Whitigir]

 I was reminded by the experts here to only use 600V and 1/2W rated Resistors ?

 

 

Edited November 23, 2017 by Whitigir

[sorenb]

1 hour ago, Whitigir said:

 I was reminded by the experts here to only use 600V and 1/2W rated Resistors ?

link or context please

Edited November 23, 2017 by sorenb

[bui501]

3 hours ago, sorenb said:

elevating resistors and caps are not needed on those boards, as the boards do not have any ground plane on top. (so the only resistor needed to be elevated is the power resistor on the PSU board).
Probably easier to populate the SMDs and socket before resistors, as the resistor sort of get in your way now

That’s ok. I remembered the advice you and others gave me for my KGSSHV build and just continued with that.

Having the components slightly raised made it a lot easier to check every joint on both sides of the board.

About the resistors getting in the way of the SMDs: DOH!!!!


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Edited November 23, 2017 by bui501

[bui501]

I’ve been trying to find a source for the PZTA42 transistors for the Carbon V5 boards, but everybody seems to be out of stock on them.

Would this be a suitable substitute?

Diodes Incorporated, ZETEX, Manufacturer part FZT657  — it’s a 300V NPN transistor with a collector current rating of 0.5A:

https://www.mouser.com/Search/ProductDetail.aspx?R=FZT657TAvirtualkey52230000virtualkey522-FZT657TA

[Pars]

That one might work. Also I came across this as a replacement: PBHV8540Z

[sorenb]

mmbta42 and mpsa42 are still available

 

[bui501]

mmbta42 and mpsa42 are still available
 

Awesome! Thank you.


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[P3t4]

22 hours ago, gepardcv said:

Where are you sourcing the heatsinks?

I will have all of the parts custom made in a cnc-shop. Since it's unclear whether I will make more than one I will have the heatsinks milled and not made with a mold. It will be expensive but beautiful

[Blueman2]

It has taken me about a week to understand why so much of the music I am listening to on the KGSSHV Carbon seems distorted and overmodulated.  Until last week, I had never heard of the term 'Dynamic Range' or 'loudness wars'.  I was unaware of just how poorly much (most?) of the music recorded in the past 15-20 years was mastered.  Not really a topic for this thread, but just thought it was worth mentioning as I wasted quite a bit of time and effort doing measurements on my amp to ensure it was correct, doing similar tests on my SRX-Plus, and then going back to my HD650s as a reference.  Turns out it is the source material that was poorly mastered.  In fact, this is a general issue with much of the music recorded in the past 15 years or so.  One of the worst offenders is a favorite of mine: Beck.  Morning Phase and Colors are both horribly over modulated and distorted. Luckily, there has been a re-master of my very favorite Sea Change which addressed the issue, but just a word of warning to those like me who are new to using Stax earspeakers with really good amps like the Carbon.  If something sounds bad, it is probably the source material, not the DAC, Amp or earspeakers.  

Unfortunately, the source material is the one thing we have no way to address!  Depressing.  

Edited November 30, 2017 by Blueman2

[eggil]

go back to Bach man!

absolutely no distortion...with instruments of the period and all...

[Blueman2]

1 hour ago, eggil said:

go back to Bach man!

absolutely no distortion...with instruments of the period and all...

Hmmm.  Never a big fan of BTO, but worth a try I guess

[bui501]

Would this work as a substitute for the LSK389? Mouser doesn’t carry the LSK389. This the closest I could find from them for dual JFETs:
https://www.mouser.com/Search/ProductDetail.aspx?R=2N3958virtualkey58900000virtualkey106-2N3958


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[kevin gilmore]

you should buy the right thing from a company that sells linear systems parts

[Skooby]

3 hours ago, bui501 said:

Mouser doesn’t carry the LSK389.

Check Trendsetter, this was where I got mine.

[bui501]

Check Trendsetter, this was where I got mine.

Thank you for the tips, Skooby and Kevin.


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[Pars]

Would it be a better idea to use the LSK489 (and LSJ689 for those needing 2SJ109)? And BTW, does anyone actually have the LSJ689 in stock?

[spritzer]

I got mine from Trendsetter but it was a while ago. 

No problem using the LSK489 in most of our circuits and some other dual monolithic units will work just fine, just have to check the specs.