Helium

Hi starcat. What are P/N of the connectors and housings and pins you are using? I'm tempted to try these. As far as my quick search revealed, pins and wire entry seals don't come in bundle and are sold separately, aren't they? My concerns is that CPC series seems to be rated for 250VDC/VAC only, and that there is no space between the thread and the gasket, which means that the gasket itself will be outside the panel/case. Any considerations?

Where are you? I've got lots of them, new, maybe 20 of each.

Lol the above board seems to incorporate amb's sigma22)) Unlike Kevin, Ti is definitely not happy when this happens))

Check this video by Haas: You may want a special tapping drill to make thread go deeper in the limited depth of blind hole.

Thanks, I've already start thinking angle grinder FTW to butcher my nice completed T2 PCB. Just kidding, I would do it on CNC if that happened. Kevin, so how do I wire, simply each PS board to each channel (=half T2 board)? I'm afraid I will encounter heavy ground loops.

Quick question. Do I need to cut T2 PCB in halves to separate GNDs if I'm making dual PS, one for each channel (double the number of PS boards and double the number of transformers)?

If you are making a separate +15/-15VDC power supply board (GRLV), you can do with two Bias GRHV PCBs.

If you use MLCC C0G/NP0 grade, I doubt the difference will be audible. Or, MLCC will be even better. At least amb votes for them: https://www.amb.org/forum/about-building-beta24-t3688-10.html?hilit=mica#p34356

Beautiful! Kerry, how did you treat the chassis to achieve polished surface? Seems to be steel, not aluminum? Is is mechanically polished or galvanized?

Can you keep the physical size and standoff hole placement same to GRLV with RS402L (goldenreference6d.zip)?

Just wanted to share one of my most favorite acquisitions among hundreds of manual and electric tools. Heinrich deep throat is capable to punch holes in the center of 400mm panel (hello large enclosures like Modushop Slimline). No burrs, very clean holes, any hole is perfectly perpendicular to surface, and waaayy more accurately positioned than made by drill bit as you can never avoid drill bit wandering. Precision is close to CNC milling. I also use smaller punch Roper Whitney XX with smaller throat.

Apparently a good tool, will get one. Wish it had No-mar teflon face like some countersink microstop limiters.

You will need 1 x HV board with bias section and 1 x HV with +/- 15VDC low voltage section. If you populate +/- 15VDC low voltage section on one of HV boards, you don't need separate GRLV board. If you go with separate GRLV board (more luxury solution), you can use either single GRLV board producing both positive and negative 15VDC, or split boards, each producing +15VDC and -15VDC. Also, if you go with separate GRLV board, you can do with 2 x HV boards with bias section (saves money if you order boards at PCB house). You need to populate bias section on one them only. Correct. Nothing required. It will accept unbalanced input as well, sound volume will be less. 7815 is noisier than GRLV. GRLV presumably produces cleaner +/-15VDC. Piece of advise: go with amb's Sigma22 for low voltage. Much cheaper than GRLV to buid. That is single +/- GRLV. You can go with split positive and negative GRLVs, as mentioned above. Not recommended IMHO. What if you need to upgrade your DAC in the future? Not needed for Carbon (=no tubes). Leave unpopulated. Use GRHV onboard low voltage section, if you want to cut costs. Or use Sigma22 instead of GRLV, and order 2 x HV bias boards instead of 1 x HVbias + 1 x HV w/low voltage. Really not many options to save money. Most expensive parts are main filter caps (40 USD/ea, and you need 4 of them), balanced potentiometer of your choice, transformer(s) and casework. None can be dropped out.

Actually it depends of user's cables. If these are highly capacitive, it may start to oscillate, who knows. Ferrite _may_ help with it.

For me it doesn't look like IC (THAT) related issue. Does the hiss increase as he turns the volume up? If yes, then it's likely to be some grounding issue. Otherwise it may be oscillation (though I don't know if dynalo is prone to oscillation). Let him try to temporarily fasten hinged ferrite cores on either headphone cable or input cables or both and see if it makes difference.

Digikey? Bought from them 1 week ago 50 pcs, still available.

Hmm, Mouser has C2M1000170D in stock. I bought 12 pcs week ago, and they are still available. Am I missing anything?

There is plenty of 1N4007 diodes. P/N E3/54 you provided is just a package type. Search another one, this generic diode cannot be out of stock for sure. https://www2.mouser.com/ProductDetail/Vishay-Semiconductors/1N4007-E3-54?qs=sGAEpiMZZMtbRapU8LlZD0HbIjlpuZ44RKYLoMCkjXw%3d Same for 0.1uF 50V. There are tons of alternatives. If you would like to stick to Kemet, try searching Kemet 315, 320 series as well. 100V is OK also. Just mind lead spacing.

What's wrong with these boards? By new boards do you mean published a week ago?

Question to Mr. Gilmore: Any chance to see your photos linked in this thread? Particularly about T2 build progress (making enclosure, stuffing the boards etc. Actually I'd love to see all of them). Could they be uploaded somewhere?

amb explained here, same for susy dynalo: https://www.amb.org/forum/susy-dynahi-v2-t2868.html#p26515

Payment sent. Thanks!

Thank you jose and spritzer. Thanks for the hint to have valve inserted. I usually do the same when soldering Mill-Max DIP sockets in order to prevent pins from moving when socket plastic is heated.

Stupid question. Now searching for tube socket for KGST, GG and BH. Lot's of options. Aside from the material they are made of (bakelite, ceramic, teflon), I'm stuck at terminal type. https://www.ebay.com/itm/301444050005 https://www.ebay.com/itm/301838302161 Are these gold pins really intended to be soldered into PCB? Will solder adhere to gold plated surface? Or better look for sockets with leaf terminals?

Hi Steve, any idea what price will be for TKD 4CP-2500 10K if I add 4 units? If it's not too late of course. Total count will be 7+4=11, which is over 10.