starcat

Hey JoaMat, this note from ONsemi with mounting considerations Craig posted earlier states 8 inch-Lb for TO-220 package which is about 0.9 Nm. The only thing I fear is the metal ring on the holes of the board potentially touching the inox screw and also the bracket. Need to investigate as I do not want to use plastic screws. I am using these PPS insulation washers on top, might throw in one from below for peace of mind. I am also using belleville disc spring washers from below to hold it safely in place.

Started with the PSU board, half through, made first test fit into PSU chassis in order to properly adjust and fix the brackets to the board and make sure everything fits perfectly. Up to the transistors for now...

Piling up lately all parts for the absolute original DYI T2. When I say original I mean even in the Gilmore case. Last package come in today as well as the transformers.

Very nice pictures, fantastic work! Next would be to integrate a roon endpoint with a Raspberry Pi and add a network port to it 🙂

Hmm, you might be right Jose, but the fins of the small enclosure Michael used above doesn't look like being much more of actual real estate... Btw, which one is it exactly? This might fit in the two balanced boards, the BH mini PSU and a transformer in the back. Bit too high probably but for the sake of bigger sinks. Chassis dimensions in mm are: outside W320xD315xH120, inside W220xD300xH112

So you are using the R-core transformer for the preamp? Very nice indeed!

Indeed the 621-KBP201G is available, just ordered a bunch, thanks.

This looks like a very nice case for a dual chassis design for the static CFA3. PSU chassis: mount the kgsshvpssicfetsinglenewrightsws and kgsshvpssicfetsinglenewleftsws GRHV boards on the sinks together with goldenreference6d GRLV in the middle/front and a transformer in the middle/back. Might be even room for two GRLV and two transformers for total symmetry. Amp chassis: two balanced CFA3 boards mounted on the sinks. Will be pretty empty in the middle. The internal hight of 73mm might get tight but probably enough to fit the 63.5mm wide balanced boards; or mount them horizontally with some L-brackets. What do you think? I think I might go for it. Chassis dimensions in mm are: outside W360xD270xH86, inside W280xD255xH73 Or just use single chassis with both CFA3 boards mounted on the sinks and a kgbhultraminipsv4 board in the midfront and a transformer in the midback.

Happy birthday, dear Craig! Cheers!

As you can see I have spent more than some time and even posted the link above. It is simply that I do not find a 1U enclosure with sinks on the sides. Might be that it is discontinued or whatever. If you don't want just don't bother answering. Doesn't mean I have not researched the whole site already. Exactly, the left is the SlimLine with the profile sides and 10mm milled front as in the shop. The right however looks identical in hight but with sinks and a sinked version isn't available in the shop. Might be that he had it modified though with the sinks. Doesn't really look to me like being 2U.

Very nice indeed. I can however find the Modu Slim line only with profile sides but not with sinks. Do you have a link or model number for the one on the right (with the sinks and milled aluminium front)?

I suspect using here the 1/2w Xicon 273 50PPM resistors shouldn't be a problem instead of the 1/4w Vishay 100PPM from the BOM? I have a couple of the Xicon's laying around...

Hey Jose, very nice amp. Mind asking which cases are you using here? Is the sink estate enough to cool all the transistors for CFA3 balanced with 4 channels? Can someone please point me to the latest gerbers for the CFA3 balanced amp - looks like here in this post is the latest revision? Appreciated, thanks! As for the PSU the GRLV is it, right. Some building it with 24 or 30 volts? Here in this post BOMs for the CFA2 and GRLV 30V.

Phoenix Contact indeed makes 400V rated terminal blocks where the usual green colored ones are only 250V rated.

Thanks guys. I'll try the Rectron MDA201G. It looks pretty much identical to the 3N254, same pinout, size and specs. Only diff is the 3N254 is max rated at 60amp vs 50amp for the MDA210G. The 621-KBP201G doesn't seem to be available soon from Mouser. Just found, the VS-2KBP01 looks like a new direct replacement from Vishay.

Question regarding the bridge rectifier 3N254 - both alternative parts 3N254-E4 and 2KBP10M-E4 seem to be unavailable as well. Anyone used successfully any other replacement? Thanks.

LoL, yes

Yeah 🙂 Michael above was making some balanced cables for his HD800.. Cheers

Any good starquad cable makes a perfect balanced cable for headphones. Like the Mogami or Belden. In fact the way overpriced Black Dragon is a starquad as well.

C2M1000170D would be available end of April at Farnell and mid of June at Mouser. I have backordered already a pile. Here to check availability across all distributors. Would be nice to have a BOM next to each of the PSUs James has put together above. I will send some shortly.

Any non-obsolete replacement for the 3N254? Thanks! Adding to the above BOM: Here the Mouser basket as well (which is missing the obsolete 3N254 bridge rectifier): https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=9472151902 I would also exchange the 220uF/500V cap with a Nichicon LGN2H221MELB45 as it is rated up to 105°C and even cheaper.

Which PSU is this exactly? Can link to any schematics with details? Thanks

Any update on the CFA3 amp anyone?

The C2M1000170D will be available soon here https://at.rs-online.com/web/p/mosfet/1456660//?cm_mmc=aff2-_-at-_-octopart-_-Outofstock1456660 and here https://www.newark.com/wolfspeed/c2m1000170d/power-mosfet-n-channel-4-9-a-1/dp/12X8366?CMP=AFC-OP

So, what's up with this dedicated GRHV thread? No one building yet a GRHV 🙂