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10m45s

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Hello I'm having some troubles finding the 10m45s from ixys. But is it possible to use the dn2540 wich i have without any change to the circuit of the tubelab SE or do I need to chnange something.
Or is there maybe anybody here who has some of those for sale and is willing to send them to Europe?

Kind Regards and thanks...

A desperate Tubelab SE builder...
 
I had problem with purchase of 10m45s in eu, so made dn2540 cascode daughter boards for sse - not sure if it is safe, because B+ should be around 450 volts - that exceeds max voltage specification for dn2540. can't try it out, because I am still waiting for opt's from edcor. hopefully board will not burn during breadboard tests.
 
I have used the DN2540 in a TSE. I think I used a 180 ohm resistor. The DN2540 is rated for 400 volts but you will always drop at least 50 volts in the 5842, usually 150 to 200. That way the DN2540 sees about 250 volts.

The 5842 will dissipate too much power if cranked to 27 mA. I aim for 10 to 15 mA which keeps the dissipation to 3 watts if the plate voltage drifts to 200 volts with age. The 5842 has a wide tube to tube variation and does tend to drift with age.
 
Copied from an answer I posted about the SSE in another forum. THe same thing applies here except the choke can be rated for less current if you are building for 45's:


Just about any choke that can handle 150 mA or more will work. Aim for 5 to 10 Hy and a DC resistance between 100 and 250 ohms. I used a 1 Hy choke with 60 ohms of DC resistance in one of my amps because I didn't have space for a bigger choke. It still works better than a resistor.

The aux cap should be a motor run (NOT motor start) cap. Motor run caps are made for a very low ESR and work synergistically with the electrolytic to form a very good low cost solution. These are usually rated in AC volts and should be 370 VAC or higher. Any capacitance value from 40 uF to 100 uF will work. I usually shop for 80 or 100 uF motor runs on Ebay and have found them for $15 to $20.

Matched tubes are important in some P-P amps. Fanatics want them in SE amps but exact matching isn't needed. On the other extreme grossly mismatched tubes can make the two channels sound different.
 
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