KGSSHV Carbon Build Thread

[Kerry]

Nice work!

The output accuracy is also controlled by the resistors in the voltage divider, which are only 1% for the dale/xicon.

For our purposes, this is not an issue.

[mwl168]

Thanks Kerry. 

Onto the headers and wire housing for the servos on Carbon V5 board; the Molex 22-11-2022 part in my previous Mouser project/BOM and jdineshk's Mouser project does not work for me for the position next to the 4N25 - it collides with the 6P DIP socket. I've updated my BOM and project to use 3M 961102-6404-AR which is also a 2.54mm pitch. Based on the data sheet this part should fit the board. I cannot be 100% sure without having the actual part on hand to try. Hope others can chime in.  

Edited October 14, 2015 by mwl168

[insanity]

I think I used exactly this part, without being able to compare the part number. It works perfectly in that spot.

[mwl168]

Thanks. Very good to know.

[Laowei]

My custom p/n 1380R001 R-Core arrived from Custom  Magnetics this afternoon. 

 

Primary: 120VAC X 2

 

Secondaries: 360VAC@350mA X 2

                      18VAC@200mA X 2

 

Expensive at $250, as I paid the development cost. Anyone can contact Mike in Technical at Custom Magnetics and inquire for copies or a group buy of #380R001. They should be less expensive, but have not confirmed.  

 

[mwl168]

Very nice! Did you specify the size to fit your layout? How do you plan to secure them in position?

Also, what capacitors are you using for the .47uf/50V positions? Any partcular reason you pick them over the ceramic caps?

Edited October 15, 2015 by mwl168

[chiguy]

Doesn't the low voltage winding need to be 30VCT (15v 0v 15v)?

[Laowei]

Very nice! Did you specify the size to fit your layout? How do you plan to secure them in position?

Also, what capacitors are you using for the .47uf/50V positions? Any partcular reason you pick them over the ceramic caps?

Seems to be a very nice big hunk of steel and copper wires. Another plus: the house smells like fresh varnish.

I'll have a better evaluation once its powered up.  

There are quantum steps in R-Core sizes for rated power, so I kind of knew what I wanted. I simply specified to be <5.25 inches to fit the chassis/PCBs. Custom Magnetics was easy to work with. It will be tied down with screws thru the 4 gold transformer base plate hole to the chassis bottom plate. Easy peasey.

The 0.47uf@63V caps are Wima MKS, Mouser p/n MKS2C034701C00JSSD. I used them there because I tend like film caps, and they fit. No other reason. 

http://www.mouser.com/Search/ProductDetail.aspx?R=MKS2C034701C00JSSDvirtualkey50520000virtualkey505-MKS2C034701CJSSD

 

Doesn't the low voltage winding need to be 30VCT (15v 0v 15v)?

It should 15-0-15 CT be to used on the onboard LV supply on the Fat PS PCB.

I have early GRLV PCBs that use 2 separate AC supplies. Kevin's newer boards (after the GB) can use a center tapped secondary. 

Plus I do not know the drop needed for the GRLV voltage regulators. So I added a few extra VAC compliance to the LV supply. 

Edited October 15, 2015 by Laowei
Corrected Mouser p/n and added link

[Pars]

Thanks Kerry. 

Onto the headers and wire housing for the servos on Carbon V5 board; the Molex 22-11-2022 part in my previous Mouser project/BOM and jdineshk's Mouser project does not work for me for the position next to the 4N25 - it collides with the 6P DIP socket. I've updated my BOM and project to use 3M 961102-6404-AR which is also a 2.54mm pitch. Based on the data sheet this part should fit the board. I cannot be 100% sure without having the actual part on hand to try. Hope others can chime in.  

Shouldn't the board layout be fixed to allow the Molex connector to be used? Better connector (locking) than the simple 3M one.

[insanity]

How are you guys progressing with your builds? I am almost done. I am just waiting for the caps of the GB, still have to do some minor chassis work and all the cables. 

[gepardcv]

I'm not that far along. Ordered a transformer earlier this week and finally found good heatsinks for the chassis I want to make.

[GeorgeP]

Dropped the current back down to 15ma on mine (had to put the 182ohm resistor back).  The highs seemed a bit too intense at 20ma, seems better now.  The drop may have impacted the soundstage some, making it more compact.  I am really interested to see what others think/discover.  I may try going back up a little more.

Andy, where did you end up landing on this? Anyone else?

Still waiting for my caps and traffo, but expect to be firing up by the end of the month.

 

 

[blubliss]

I'm at 17ma right now.  But, we will be going up to 450v when the caps arrive.  Sounds really good, especially with the SR-Omega.  It's not at the T2 level, IMO, but close.

[insanity]

This is my progress so far. Waiting for the caps. Rest is more or less done. To answer some questions before they are asked:

My transformer has 15-0-15 and 2x 18vac windings, because I was undecided which lv psu to use, when i ordered it. As you can see, I have decided which one to use, and connected the 15-0-15 just to prevent the wires from dangling around. I will clean up the transformer wires when I finish it. 

Any other questions are welcome ;-)

Edited November 2, 2015 by insanity

[GeorgeP]

I was going to go 450v as well. Did you use the trimpot or change the resistor to increase the ma?

And good news on the sound. Was hoping to use this in place of my T2 as my bed-side rig, but man does the T2 ever sound glorious. 

[gepardcv]

Looks sweet.

1. Floating signal ground?

2. What kind of wire/cable did you use for the connections from the XLR jacks to the pot?

3. Where did you get the angle brackets for heatsink connections?

[insanity]

Looks sweet.

1. Floating signal ground?

No, its actually connected to chassis and earth through the xlr connectors. I will also add a connection from iec earth the gnd (which is not yet established).

2. What kind of wire/cable did you use for the connections from the XLR jacks to the pot?

I used double shielded sommer galileo cable. I had some lying around.

3. Where did you get the angle brackets for heatsink connections?

I bought them off ebay from a german vendor precut to 10cm. Drilled and tapped the holes myself.

 

Edited November 3, 2015 by insanity

[gepardcv]

The Sommer Galileo 238 cable?

[insanity]

The Sommer Galileo 238 cable?

Yes exactly. Do you have any experience/comments on that? I have been using it for my XLR interconnects. 

[gepardcv]

No, I was just wondering what you used so I can try to buy some in the US.  All my questions were about decisions I need to make for my own Carbon build. For the input signal, the Carbon calls for something nicer than my usual approach of just twisting ordinary wires.

Thanks for the tips!

Edited November 4, 2015 by gepardcv

[insanity]

I have assembled all the parts and it everything works but I have one problem. HV Voltages are fine 402V -402V. Offset was around 200V to start with for both channels, but I cannot get offset below 70 / 80V on both channels. The current sources are set to 1V across the 50ohm resistor. 

I cannot reach the +20 requires to engage the servo. 

What shall i do? I am thinking of replacing the 182ohms resistor with 150ohms. 

Edited November 8, 2015 by insanity

[JoaMat]

 

Edited November 11, 2015 by JoaMat

[spritzer]

Yup, try that as a number of factors you have to factor into the offset string.  The value is based on my builds which are very different to the boards from the group buy. 

[insanity]

I changed the resistors and it works like a charm. Just listened a few minutes with the 007A. 

Am I the first one from the GB who has it running? I wonder if others need the change the resistors too. With 150ohms I could just reach +20V, but I think it wouldn't reach down to 0. So maybe for those who have not started yet, order some 150ohms and 120ohms resistors just in case. 

Edited November 8, 2015 by insanity

[JoaMat]

Well done. Congrates.

The blue electrolytics, are they from the group buy?