gepardcv

Have you ordered from Conrad Heatsinks recently? The prices on the site all date to 2008. I sent an email requesting some clarifications and updated quotes a few days ago, and have not heard back.

Clarification request: to run the Carbon with that 20mA output, you recommend using the 400V PSU, rather than the 450V?

I've been thinking about making a completely custom enclosure for the Carbon from scratch. The problem is finding heatsinks to use as the chassis sides. I have some dimensions in mind, but am having a hard time finding sources that don't want to make runs of 2000lbs. There is http://www.heatsinkusa.com, which has good prices and sells in small quantities, but none of the profiles there work for me. Then I found Aavid, which has good profiles, but has an order minimum of $800 (i.e., one 300mm sink costs $800, and 10x 300mm also cost $800). I sent out a few emails to various vendors I found by Googling, but so far, no good replies came back. Does anyone have experience ordering small quantities of extruded aluminum heatsinks, and can suggest a vendor?

What is the 9V winding for? My notes for secondary windings, gleaned from everything I saw posted on the main KGSSHV thread and the Carbon group buy thread, have the following specs (primary windings probably should probably be 2× 115V for everywhere except Japan for maximum flexibility): For a 400V PSU: 2× 335VAC @200mA16-0-16VCT (anywhere from 15-0-15VCT to 18-0-18VCT should work fine) @500-700mA (the higher amperage is way overkill)For a 450V PSU: 2× 360VAC @350mA16-0-16VCT (anywhere from 15-0-15VCT to 18-0-18VCT should work fine) @500-700mA (the higher amperage is way overkill)The higher the amperage, the higher your transformer's VA rating, obviously — I haven't contacted SumR or Toroidy for quotes yet, so not sure what either one will say. Also not sure about the size of the resulting transformers.

I'm in for a set.

My boards came in also. Thanks!

Thank you much!

Do you have any photos or instructions or even just tips on how to plug the ports? I'm loving the new 007A stock, but all this praise has me wondering! I remember reading somewhere that replacing the earpads is tricky..?

Nice build, @samsie! Are you noticing any noise on your Carbon from having the transformer so close to the amp boards, inputs, and outputs?

Speaking of mounting (pun intended, sorry!), does anyone have recommendations for finding appropriate angle brackets? I don't have easy access to a machine shop to make my own, and it doesn't look like attaching transistor tabs directly to the heatsinks is an option here.

No LV windings on that one. Looks like it's still worth getting a Toroidy.

What's a three layers deep laceration?

Which one? Thank you!

Any updates on potential Carbon transformer group buys?

Mirror in the lid of the box? And the pads look like they would only fit the ears of a small child. Doesn't really look like an HE90 to me.

I've been playing with my KGST and noticed something: when I power it on, the offsets measure crazy high. Like ~350V. In about 3-5 seconds, they drop to the expected 1-2V and stay there. I guess it has to do with the way the tubes turn on, maybe the heaters?

It's totally fine to run +20V over on the bias, probably quite a bit more. I'm asking more out of curiosity. FWIW, I use a DY294 to pick zeners with the closest tolerances, and replace 100V with 91V versions, but that's my OCD talking more than any real need.

I have found that zeners tend to run at a higher voltage than rated when warm... plus there's the 5% spec. Did you hand-pick them to be as close to the called-for voltage as possible? Do you find that the bias gets up to >600V after warming up?

Also paid. Thanks for arranging this.

Any chance FT Cap can be convinced to make these caps 70mm tall instead of 76mm? It would make using 2U cases for the Carbon trivial.

Great. I'm in for 12, since that costs less than 4 Mundorfs (or 4 Kemets for that matter). I'll take your and JDineshk's word that they're similar to Mundorfs. Maybe you should ping the Carbon GB thread? I think many more people follow that one. Are you sure about the height? I thought the Mundorfs were 100mm, not 76mm.

Yup, sorry, missed that completely the first time. Can I just switch to that cap order instead of the original Mundorfs? I'll get more than 4 then, $38/piece was pretty steep.

Is it reasonable to change my mind from the original Mundorfs to the FTCaps? I'd rather not pay $38 when I can get the same thing for $12.

Interesting. So you don't use servos in your builds at all, or you use something other than the OP27?

After swapping the 470uF/35V capacitors for 2200uF/35V (yay overkill!) on the LV section of the BH PSU I use with my KGSSHV mini stereo build, the screeching noise on turn-off went away. Thanks for the suggestion, Spritzer! I've been readjusting the amp, and two other questions came up. One: the offset is pretty high when the amp is cold. Like 40-50V. Is it bad to have headphones plugged in with the offset that high? Two: the servo seems to make the balance and offset somewhat less stable. I was able to get the balance to <500mV on both channels, and the offset to ~1V after an hour or so of running the amp. Both fairly stable. After placing the servos back, both balances and offsets started fluctuating between 1 and 5V. This doesn't seem right. Could I have faulty OP27s?