gepardcv

Are these Alphas 50k pots?

That makes my KGST look like a beast in comparison. Very cool. Any plans to shrink the PSU as well?

Looks terrific. Thanks!

If new board versions are in the cards, I'd much appreciate one without a line of angle bracket holes. That should make it possible to mount the boards vertically on a 100mm heatsink, making a nice "2.5U" enclosure.

Are you thinking of this exchange? With all our love of overkill, it certainly sounds like encouragement to use the 680uF caps. The group buy came along soon afterwards.

The board is labeled for 680uF/550V, which purk used here. Looks like these caps came from the GB. What small caps do you mean?

Such as? (Not being sarcastic, genuinely interested in opinions.)

I'm going to order cut aluminum angles from OnlineMetals. Since I'm not too familiar with metallurgy: which alloy is preferred for attaching to heatsinks, the 6061-T6 or 6063-T52?

I use this: http://www.amazon.com/gp/product/B004SPJP5O, supposedly 99.9% isopropyl alcohol. It takes several rounds of scrubbing and drying to get boards clean enough. Birgir posted on the T2 thread that he uses Electrolube Safewash 2000, but I haven't yet found it in the US.

Bug report: I haven't been getting emails for PM notification in the last couple of days. Double-checked my settings, and the email flag is turned on. Checked my spam label on Gmail, and it's empty. Did anything change in email infrastructure?

Your choice of words clearly shows your priorities. :D

I like Tony Kuphaldt's Lessons in Electric Circuits series: https://www.ibiblio.org/kuphaldt/electricCircuits/ — he has not finished all the chapters, but the basic stuff is solid and easy to read. After reading his coverage of a topic, it pays to go over the same topic in AoE. The different presentation made a few things sink in for me that did not make sense from just one book. iCircuit is a pretty nice little circuit simulator to see what happens without going through the work of building it.

Carbon CC? I'll post my Carbon case design when I finish it, it might match what you're thinking of for some of the amps. That Fischer SK56 is already available in different heights, 75mm, 100mm, 150mm, and 200mm (and 1000mm, but that's clearly not for DIY amplifier builders). The Dynalo doesn't need external heatsinks, though, and the Circlotron has way too much going on for the footprint I'm designing for the Carbon. For the Dynahi, KGSSHV, KGST, and Carbon, it should work. Not sure about the Megatron or BHSE, I never looked at the size of those boards.

I would love to design some custom profiles, but I can't imagine anyone, Fischer included, wanting to deal with that for a small order. I don't mind paying for an extrusion die, but I don't want to deal with minimum orders of 1000kg.

Following up on my own heatsink question, in case anyone else is looking: after failing to get a response from Conrad, I discovered Fischer Elektronik, and found that it makes excellent extrusion profiles for the casework I plan to do. This, for example, is the 300x40mm heatsink, available in several different lengths including 100mm, that I ended up buying. As far as distribution goes, I ordered two of these heatsinks from Newark Element 14. Another heatsink I considered is a smaller 100x40mm unit, and putting three of them side-by-side (so the fins run horizontal to the case), but decided against worrying about the dissipation behavior of this system. The large sinks arrived today, and they look and feel fantastic. I'm sure they will handle the Carbon easily. I'm too lazy to post pictures, but can do so if anyone wants.

Thank you so much for taking care of this. Dealing with a GB of this size is sizable organization task. I'm sure we'll all appreciate it even more once we have finished our amp builds.

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!

The Sommer Galileo 238 cable?

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?

All this chatter about the Yggdrasil, even here... and I thought this place is sane, compared to the others. Maybe I should try to borrow one and see what I think after a couple of weeks. Never heard much of a difference between DACs, so care about ergonomics and desk fit more than anything else. (I was also vaguely considering making a γ3 once that becomes available.)

Gorgeous build, thank you for sharing!

This one?

Based on your description of how hot the transistors run, I wonder how toasty the chassis will get if you use it as a heatsink.

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

I tried the port plug mod on my 007A. As others observed, it definitely increases the incidence of the Stax fart, which is mildly but not overwhelmingly annoying. Bass does seem tightened up, but I think I may have lost some mids and treble; both sound more muted than I remember (though it's hard to tell without comparing to a stock 007A). Is this expected?