i'm on a roll... the kgsshv

[Laowei]

Yes, 18VAC X 2.  

Probably overkill. But I don't believe the Golden Reference LV to be a low dropout design. 

[samsie]

I completed my Carbon using boards from Spritzer.  I wanted one small amp next to my bed.  

It is compact.  A lot of heat is coming out from it.  I am considering to make a second one with bigger heat sinks.

I think I deserve a big cup of tea, don't I?

Edited September 3, 2015 by samsie
I think I deserve a big cup of tea, don't I?

[chinsettawong]

That's a nice little amp you have there.  How do you fit the boards and transformer in there?

[samsie]

It was not a tailor made case and I am not as talent as Kerry who modified the design with sm parts

I trimmed the boards a bit and they were tightly fitted. The bottom plate was used as a heat sink for power supply (Spritzer's PS boards are intended to be fitted this way).

 

Edited July 28, 2016 by samsie
I should tidy up the wires later

[headinclouds]

That's smashing Samsie!  You're getting good at this. 

 

[spritzer]

Those heatsinks are at least 50% too small for the carbon so it would be a good idea to reduce the current a bit. 

My mini Carbons should be ready in a day or two.  Massive heatsinks to soak up all the power. 

[sorenb]

It was not a tailor made case and I am not as talent as Kerry who modified the design with sm parts

I trimmed the boards a bit and they were a tightly fitted. The bottom plate was used as a heat sink for power supply (Spritzer's PS boards are intended to be fitted this way).

Congrat on your build! very tight indeed.

What PSU are you using for this?

For how long how you had this powered on?  are you running at 20mA? ... I have build my carbon using the same boards, and decided to move the CSS to their own sink and cascode those  ...noticed that the current climbed up while heating up ... not quickly but steady 0.05mA/min or so ...turned out that the sink first chosen was too little

Massive heatsinks to soak up all the power. 

0.15K/W?

[spritzer]

Not sure sure, there were no specs with these.  They are 3 times the size of the KGSSHV mini sinks though... 

[Pars]

Nice build samsie! Even if the sinks are too small. Where did you come up with that case? Also, I see TKD... is that a CP2500 or the smaller CP601? And where did you source it from?

[samsie]

I am happy to share the sources of the components.

I live in Hong Kong so some of them may not be available for you guys.  (same here. sometimes I envy you guys that can source reliable parts without worrying too much about the shipping charge).

the potentiometer is a TKD 2508S ,  I used one in my KGST and I find it quite good so I used it again.  I think it is a special type with metal plate to separate channels to reduce noise (I am making this up as I do not read Japanese either- perhaps someone can tell me what is the use of the metal plates between each channel.  I connect the plate to the ground this time but I leave them out while I built my KGST.  I do not notice any difference but it was a different amp)

 Here is the link

http://www.kaijin-musen.jp/109_6501.html

Edited September 4, 2015 by samsie

[nopants]

it's the tkd 2508 with shields I believe

[samsie]

Congrat on your build! very tight indeed.

What PSU are you using for this?

For how long how you had this powered on?  are you running at 20mA? ... I have build my carbon using the same boards, and decided to move the CSS to their own sink and cascode those  ...noticed that the current climbed up while heating up ... not quickly but steady 0.05mA/min or so ...turned out that the sink first chosen was too little

0.15K/W?

PSU boards are from spritzer,  It is the one he supplied with his KGST pcb set (good quality boards, survived with de-soldering.  good for newbies like me). I think he used them for mini- KGSS

I powered it on for 7-8 hours.   It becomes steady in two hours then I start to do some fine adjustment to the offset, balance and bias (it was so difficult to adjust the bias- that is the price to pay for small case like this).  I followed the printing value on the pcb but I have no idea how much current in there. I am a newbie, I have to figure out how to measure the running current first.  

I shall listen to this little amp for a few days and start to test it and modify it over the weekend.

Those heatsinks are at least 50% too small for the carbon so it would be a good idea to reduce the current a bit. 

My mini Carbons should be ready in a day or two.  Massive heatsinks to soak up all the power. 

The case was so nice that I do not want to mess it up (No screw can be seen from outside, the finish is so good for the price). 

so current reduction is an option.  any recommendation on how much reduction shall I start with (without seriously affect the sound quality) ? 

 

Nice build samsie! Even if the sinks are too small. Where did you come up with that case? Also, I see TKD... is that a CP2500 or the smaller CP601? And where did you source it from?

 

the case is from taobao, the Chinese version of ebay.  they even  cut a stepped hole for me for the stax socket

http://world.taobao.com/item/39957531066.htm?fromSite=main&spm=a312a.7700846.0.0.Fa8iz2&_u=421pt7g7143

Edited September 4, 2015 by samsie

[Victor Chew]

Nice and the case is good value too. Do they charge for cutting extra holes?

Edited September 4, 2015 by Victor Chew

[samsie]

yes, 1.5 dollar for the hole.  I am sure there will be quantity discount if you want to cut more.

Edited September 4, 2015 by samsie

[Kerry]

That is a nice looking case. Welcome to the world of DIY Stax amps.

Enjoy.

[Pars]

I am happy to share the sources of the components.

I live in Hong Kong so some of them may not be available for you guys.  (same here. sometimes I envy you guys that can source reliable parts without worrying too much about the shipping charge).

the potentiometer is a TKD 2508S ,  I used one in my KGST and I find it quite good so I used it again.  I think it is a special type with metal plate to separate channels to reduce noise (I am making this up as I do not read Japanese either- perhaps someone can tell me what is the use of the metal plates between each channel.  I connect the plate to the ground this time but I leave them out while I built my KGST.  I do not notice any difference but it was a different amp)

 Here is the link

http://www.kaijin-musen.jp/109_6501.html

Those are pretty reasonable compared to US prices, and the fact that you can't find the 4 gang TKD pots in the US. They do have the 10K and 20K as well.

[spritzer]

First mini Carbon up and running.    I also built an identical full size one so I can see of the proximity of the PSU/AMP sections has any effect. 

Two more coming including one with an R-core. 

[sorenb]

First mini Carbon up and running.    I also built an identical full size one so I can see of the proximity of the PSU/AMP sections has any effect. 

Two more coming including one with an R-core. 

Nice 

Similar to the Samsie configuration amp/psu?

[samsie]

Congrat on your build! very tight indeed.

What PSU are you using for this?

For how long how you had this powered on?  are you running at 20mA? ... I have build my carbon using the same boards, and decided to move the CSS to their own sink and cascode those  ...noticed that the current climbed up while heating up ... not quickly but steady 0.05mA/min or so ...turned out that the sink first chosen was too little

0.15K/W?

I measured the voltage across the 150ohm resistor and it was about 18mA.  Am I doing the right thing?

[palchiu]

I measured the voltage across the 150ohm resistor and it was about 18mA.  Am I doing the right thing?

I found this, maybe can help.

[samsie]

I found this, maybe can help.

I used the Carbon boards sets from Spritzer.  A bit difference from the one u referred to. 

[spritzer]

The 10M90 is an IC so they are far from all being identical.  That's why I test them before they go in the circuit. 

[JoaMat]

/

Edited November 11, 2015 by JoaMat

[Kerry]

First mini Carbon up and running.    I also built an identical full size one so I can see of the proximity of the PSU/AMP sections has any effect. 

Two more coming including one with an R-core. 

They look beautiful

I am interested if you can hear or measure a difference based on the case size.

I'm looking forward to building one.

Looks like you have a Blue Hawaii in the works too.

edit: Swipe type is awesome unless you don't proof read.

Edited September 5, 2015 by Kerry

[spritzer]

Yeah, there is a BH or two coming.