| Megaboss |
Hi.
I'm looking for ideas how to best make use of PL 519 in PP arrangements. ( not interesded in OTL's )
I'w been trying to find information regarding recomended B+, Ia and plate load.
I'm thinking triode strapped but maybe UL is the way to go...
Anyone got any ideas or schematics ???
// Niclas |
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| SY |
If you're really, really ambitious, you might consider using these in a screen drive arrangement. In this topology, you tie the control grid directly to the cathode, then drive the screen. The tube acts like a zero-bias triode. Downside is that you need a driver that can source current, like a cathode or source follower. Upside is that you can run very close to class B without sacrificing linearity. With 2000 ohms plate to plate impedance and a 700V B+, you can get 150 watts out of a pair of 519s.
Go over to David Berning's website and take a look at the schematics for some of his older amps like the BA-150, EA-2100, and EA-230 to see a few implementations. In my amps, I use a source follower to drive the screens; Berning uses emitter followers or cathode followers, which are also good choices. |
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| sajti |
| quote: | Originally posted by Megaboss
Hi.
I'm looking for ideas how to best make use of PL 519 in PP arrangements. ( not interesded in OTL's )
I'w been trying to find information regarding recomended B+, Ia and plate load.
I'm thinking triode strapped but maybe UL is the way to go...
Anyone got any ideas or schematics ???
// Niclas |
UL is not really good with the '509s. Tetrode connected with 450V anode, and 150V screen gives some 100W, when use 2.2kohm output transformer.
Another possibility to use it as triode (22-100ohms screenstopper necessary!). With 300V anode, and 2200ohm gives 30-35W, but it needs high driving voltage due the low mu. So for 100mA bias (class AB) You need about -75V for first grid. I made this amplifier, and it sound nice, even without nfb. This is possible because the low plate resistance.
I have some tested schematics for this valve, but I need time to scan it.
sajti |
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