spritzer

Voltage doubler off the built in switcher.

It's been a while since I bought some but the RN65's are almost twice the length so yeah, creative lead bending would be needed. It's a 1W part though so utter overkill with so many 1/2W units available.

RN65 resistors won't work, they are huge. The RN numbering is milspec so a 1/8W resistors is actually 1/4W, 1/4W is actually 1/2W and so on. Here is the diode, use it: 511-STTH512FP This is the resistor you want: 71-RN60D1743F

Just try the 5A one. It should only blow the fuse if something is shorted on the board. I've seen all manner of KGSSHV psu failures but never a full short.

The fuse rating for torodial has very little to do with the actual current draw of the circuit. The inrush current is the problem that needs to be accounted for.

You're in the US? Then a 3.15A fuse might be on the small side of things. Try 4AT and see if it holds up.

That post shows a huge lack of knowledge of how the tube industry operated back in the "good old days". Manufacturing tolerances were crap to say the least and everything was done to keep costs down. There is also a huge difference between just about works and works comfortably. Let's also look at what was happening in the early 50's, that's when the improved novals are being phased in so they had to find some use for their obsolete octal tubes. A manufacturer "inventing" new ways to use an existing product when the market place shifts, perish the thought... that would never happen.

If you are using a TRS plug then I'd uprate those resistors massively. A lot of current will be flowing through them. Better yet, use a 4-pin XLR.

My problem with the 6SN7 comes from not finding any evidence that the tube was actually redesigned to fit those parameters. Sure they altered the filament a bit so you can series wire them in TV's but other than that they seem to be bone stock 6SN7's. Call me a cynic but it smells of "sure we can push to that" as we have millions of these tubes in stock. The ECC99 spec sheet is very lacking but it's a sort of a hybrid between the 6n6pi and the 12BH7A. No need for peak voltage in those as it's only applicable in TV use. It's a worthless measurement for our use.

Some are real, some might be Chinese copies. That is true, especially of the 2SC1815. Nothing wrong with using MPSA units though

If you are really bored as there are hundreds of revisions, some tiny but also some major ones.

The amp board is different. It's a bit smaller to suit my needs.

I've been keeping this circuit in the back of my mind and it could work to use ECL82's with it. That is a true 600V tube so triode strap it and use the built in triode for the second stage. I'm going to do something similar for a mini megatron to match what I did with the Octave.

I've never come across fake 2SC4686A's but I'm sure they will surface once supplies dry up. I bought thousands of them from Japan and I've been selling them with the boards.

It has already been changed on the new boards: Been like that for months. There is a good and a fairly obvious reason why we did it like this though.

Yup, nothing here will need more than 1A.

Has to be debris inside the driver so they are defective. I'd just return them and get a new set.

The 717 is a modified KGSS so far superior to the Exstata. The latter was always a bit of a bastard and with roughly 1% THD the sound isn't for everyone. I tried to fix it the best I could on those boards but it's still a very warm and thick sounding amp. Some people like that sound and it will work well with the older 009's but it isn't the last word in fidelity.

Have a great day Doug!!

Happy Birthday little one!!!

It's only the Changstar fucktards who think it is bright so nobody with any sense.

With those AC levels it is easy to get pro bias. The 350VAC tap pushed right up against the 1000V rating for most of the parts so you'd need 1200V caps and diodes and then a voltage divider to bring it back down to 600VDC. The B+ in that amp might be in the 600V range for the the last tubes. What is the voltage on the tie points for those 27K resistors?

You can modify the stock bias supply too as it its run off the same line. Replace all the resistors though, they are all passed it. I put the pro bias supply in the middle of the tags as they aren't connected to anything. The filter cap goes between B+ and ground, from it goes a 22K resistor to a junction. One 220K resistor goes from that to ground and also the 4M7 resistor to the output. The diodes should all be changed and the caps too.

They aren't connected. This is from a great software update which caused some major fuckage on a number of boards.

The point is that it isn't unusual. For the amps I did not account for part changes due to supply or obsolescence just fundamental changes to how they were built. Your argument is made even worse as it doesn't account for the general mentality at Stax. Constant changes are the norm and there is no looking back, new is always an improvement. It's been like that from the 60's.