Other tubes in KG's Blue Hawaii...

[spritzer]

It's an EL54 so similar to the 34 but not the same. Might work in the ES-1 but the BH would have to be modified.

[luvdunhill]

Elephas:

I can check it out for you if I can get a pin out of the adapters. Also, remember that the BH connects the the cathode to G3 (suppressor grid)... personally, I wouldn't plug anything in until someone looked at the datasheet and the proposed pin out.

[kevin gilmore]

KG:

Is it possible to put two IXCP10M45S in series and get double the current, but the same voltage rating as a single IXCP10M90S? I don't see why not, but figured I'd ask.

You would put 2 of them in parallel, not in series. In parallel with suitable heatsinking you can

get to about 100ma.

You could put 2 in series to get twice the voltage swing (say 1800 volts) but then there

are going to be voltage breakdown issues and they have to be heatsinked very carefully and

probably with berylliumoxide insulating washers. (which are toxic if not handled right)

[luvdunhill]

You would put 2 of them in parallel, not in series. In parallel with suitable heatsinking you can

get to about 100ma.

You could put 2 in series to get twice the voltage swing (say 1800 volts) but then there

are going to be voltage breakdown issues and they have to be heatsinked very carefully and

probably with berylliumoxide insulating washers. (which are toxic if not handled right)

I wasn't going to get that extreme! I was just going to buy a bunch of the 450v and put them in series and stick them on 500-550v rails, instead of buying the 900v parts. So, 10m45s 2 in series * 2 per board * 2 boards with 500-550v rails.

Looking at the 10m90s datasheet, it seems that you can get 100mA per device, so would sticking them in parallel get up to 200mA total? or is this one of those things that the datasheet doesn't tell you, i.e. 50mA per device is what you can get in the real world? Looking at the 10m45s graph on the last page, it seems that you can get over 100mA per device, like in the 400mA range, but at the top of the spec sheet it clearly lists 100mA... any idea which is correct? of course, all of this is assuming lots of heatsinking

thanks again!

[luvdunhill]

... and one other question. By upping the +- 400v rails, do I need to make sure I change the components required to keep the 300v, 350v, and 380v reference voltages on the schematic, or will these values become -100V, -50V, and -20V with respect to the new rail voltage?

[kevin gilmore]

Buy the 900 volt parts. Really. You should not run them at more than 50ma each.

You can try the 450v parts, I have not tried this. Getting 3 of them in series to

correctly voltage share might be tricky.

If you raise the voltage rails past +/-400 you have to change out the 2sa1156 with a

2sa1486. Then you can probably go to +/-550. Everything else references the two

rails, so there should be no other changes.

[luvdunhill]

The project is coming along slowly. I just sent off the plans for the case. I'm going to try out the new case option at Front Panel Express. I'm going to try and cram things in a 42mm high enclosure, with the heat sinks and tubes top mounted. If that doesn't work, then I'll go for the larger 56mm option, which will definitely work with no problems. Since I hadn't decided about this, I didn't order the front and rear panels this time around. I'm getting a sample of the blue colored material from FPE as well, perhaps I'll go with that for the front panel.

I'll post pics once the case gets here

[luvdunhill]

Kevin:

Are there any decent subs for the 2sj79 and 2sk216 parts? I'm assuming the benefit of these parts are the low capacitances? Are the lower voltage versions possible substitutes? Any subs that use the higher rated case like the 2sa1968 to avoid heat sinking these parts, perhaps 2SJ313 and 2SK2013? I guess I don't really have a good reason for asking these questions, just curious...

[luvdunhill]

[img width=150 height=113 alt=P1010236]http://www.head-case.org/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=1494&g2_serialNumber=2&g2_GALLERYSID=bb4f68f8f9ee575f1b358536d1e7f287