gepardcv

Notifications definitely don't work right for me. Example: I follow the "i'm on a roll... the kgsshv" thread. It has had several posts in the last day. They don't show up in the notifications list (when I click the bell icon). On the plus side, at least I don't get notification emails anymore (though the thread that sent them out — the parts advice thread — hasn't had any posts since the last email notification). In addition, clicking a thread or a thread's last page doesn't take me to the first unread post. That used to work, made reading new content much more efficient. Now I have to scroll from the top of the last page and look for the blue divider line.

I'm looking at the notification options (http://www.head-case.org/forums/notifications/options/), and the "Someone comments on something I follow" setting is locked to Email on, notification list off. I want to change it to be the opposite, but the form hover says "the administrator has disabled this option from being toggled". Any particular reason (or is this a bug)? I liked the old behavior, where all email notifications could be disabled.

Also paid. Thanks!!

C'mon guys, doesn't anyone else want to build Dynalos?! It's pretty much the best amp for non-electrostatics out there, might as well pair it with the slick Golden Reference LV singles.

Past advice on the LV winding seems to have been 500-700mA. Not 1A, certainly, but quite a bit more than 100mA.

Oddly, I find my KGST ready to play faster than my KGSSHV. The HV's transistors don't work very well with the heatsinks cold, and warming them up easily takes 20 minutes. The offset changes considerably during this period. The KGST is ready to go in a minute or so. That said, I don't recommend forgetting to turn off any tube amplifier, or being careless with it in general. To be honest, my HV runs pretty warm, too (mini stereo board), so I try not to neglect that one, either.

I chose the fat boards because they fit easily in a 300mm-depth Modushop Dissipante box. The skinny boards are longer, and IIRC require a 400mm-deep box. It'd be nice to use 2U, but I can live with 3U in exchange for less depth.

As far as lead length goes, I had a feeling it might cause problems and asked for specific lengths for each wire, and Toroidy delivered.

Thanks. I've been thinking about whether I want to use a 400 or 450V PSU for my Carbon build, and honestly don't know. Not sure how much output current to go for, either. Given the height of the caps, I'll probably use a 3U Dissipante case (the 300mm deep version, though, not the 400), so plenty of heatsink area. Any guidelines or suggestions on the tradeoffs? I will primarily use a 007A (the recent "Mk2.9"), and I don't listen very loud.

The 360VAC primaries under discussion are for the 450V version, right?

+1

From the data sheet (http://www.mouser.com/ds/2/427/cmfind-239942.pdf): “Vishay Dale Model CMF is also available as Military Qualified Styles RN and RL. See Vishay Dale’s CMF (Military RN and RL) datasheet (www.vishay.com/doc?31027) for the MIL-SPEC ratings / attributes. (Except for marking, the Industrial and Military versions are exactly the same).” (Emphasis mine.) After reading this, I started buying whichever of the two is cheaper and available.

I was at that meet, and agree with @TMoney — Frank's amp (1) sounds gorgeous, and (2) looks gorgeous. Best-looking piece of audio equipment I have ever thought to see. Reminds me of the woodwork I have seen in palaces in Europe.

I'd like to know that, too. Though with the large-quantity quote, it looks like they end up cheaper than Kemets. Also, the spreadsheet doesn't specify which capacitances to sign up for, just a raw count.

How tall are they at each capacitance? The spec sheet you posted earlier didn't specify, just gave a range.

When you say use one or the other, you mean (1) zero the balance and offset with both servo jumpers pulled, and then (2) try putting back either of the jumpers, but not both, and see what happens?

I finished a mini-stereo KGSSHV build yesterday. It sounds pretty nice! One problem: when I turn it off with headphones plugged in, there is a pretty loud crackle in the headphones. Not deafening loud, but disconcerting, especially since my KGST doesn't do this. There is no noise on power on. Any idea what might cause this power-down problem?

To make sure I understand the exact connections required: - IEC earth to chassis - Transformer to chassis - XLR input grounds (pin 1) to XLR output grounds (pin 1) - Pot input grounds disconnected - Pot output grounds to amp boards - PSU grounds to amp boards The KGST has two ground points on its two terminals — I assume only one of these needs to be connected to the PSU, and one to the pot output?

Seriously?! So after painstakingly setting my bias to 580V from the test point, it turns out I'd biased for ~400V instead? Live and learn!

@luvdunhill: The IEC module I use (Schaffner FN1394-10-05-11) has its earth line connected to the chassis through its body, according to my multimeter. @Earspeakers: You mean something like this? I have plenty of matched tubes, it's easy enough to swap them and see what happens. But is that probe really necessary? It seems to be designed for thousands of volts, not just 580.

Full list of connections (other than the obvious ones without which the amp wouldn't work at all): - XLR input: pin 1 to chassis - XLR output: pin 1 to chassis - Star ground (SG) to chassis - IEC ground to SG - Transformer to SG - PSU ground to SG - Pot input and output grounds to SG - PSU ground to amp ground (both HV and LV lines) I also daisy-chained my power front switch LED from one of the amp boards +15V (through a 3k resistor) and ground lines. I thought that might be bad, and tried disconnecting it, but it made no difference.

Thanks for the suggestions. I rotated the toroid to point directly at the back panel, but it didn't help much. Anyway, this is more of a theoretical problem than a real one. The hum disappears once I plug in a source, and the amp sounds terrific. Many thanks to Kevin and Birgir for sharing this design and helping with the build. Thanks to everyone who helped me with parts — @headinclouds for the transformer and matched 6S4A quads, @luvdunhill for input JFETs. Thanks to everyone else who answered my endless questions. If the Carbon can improve on this, I'll be exceedingly impressed. Looking forward to building one.

Nice! What do you think of the sound?

Pin 1 to chassis.

I did twist the heater wires pretty tightly. They're the orange and pink ones in the image below. Not sure how to keep them away from the rest of the wiring, short of running everything else all the way around the case. Suggestions much appreciated.