I've tested a whole load of high mu triode strapped pentodes. Try searching for "gm70 driver'
The 6j9p is capable of heroic performance if you run it hot
I believe these tubes can run a2 with little grid current demamds allowing huge voltage swings. The more current you run through them the lower the distortion, certainly much lower than a 5687 or 807. My tests were done with mosfet loads, best were gyratory.
The 6j9p is capable of heroic performance if you run it hot
I believe these tubes can run a2 with little grid current demamds allowing huge voltage swings. The more current you run through them the lower the distortion, certainly much lower than a 5687 or 807. My tests were done with mosfet loads, best were gyratory.
I am not sure that E180F are very close to 6j9p with CCS the E180F run at 200v and 16mA -2v red diode, far of the curves of the 6j9p now I alternating the E280F and E180F both -2v at 16mA with single 10m45s the wave square are very good in both 20hz to 20khz a little bit better the Tesla E180F
That's the same kind of bias 6j9p's run at. Infact many hi mu triode strapped pentodes have the same pin out and will work well at that bias, d3a ef184 6j52 etc etc as long as you strap both g2 and g3 to plate you can just roll all these tubes as some have the grids on opposite pins.
Sound wise I preferred d3a but none of them were duds. And all measured better than any small signal 9 pin tube I've tried with the exception of the 6c45pi
Sound wise I preferred d3a but none of them were duds. And all measured better than any small signal 9 pin tube I've tried with the exception of the 6c45pi
What Mu has the 6j9p? I drive the 211 with only one stage the 6j51p do perfectly only is a little dry.. The ef184, e180f and e280f are in the limit but is true that the e180f e280f have a pretty sound and I dont need a lot of watts.
Enzo I thought the same to strapp all g2 and g3 to plate and you can play with all. 🙂
I am finishing all measures with the oscilloscope, my new toy for Christmas, not very good at the moment maybe need to replace the chinese OPT
Enzo I thought the same to strapp all g2 and g3 to plate and you can play with all. 🙂
I am finishing all measures with the oscilloscope, my new toy for Christmas, not very good at the moment maybe need to replace the chinese OPT
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I had high hopes for the 6j9p-e as I hoped it would have the same linearity but a higher power anode to allow the 30ma or so that the 6j9p likes but can't sustain thermaly. I found it disappointing.
I have some 6j51 coming and some 6j11 in a box that I haven't tested yet. Was thinking of using these in a 6cb5a se or pp amp. I use 4p1l as drivers in my dht amps
I have some 6j51 coming and some 6j11 in a box that I haven't tested yet. Was thinking of using these in a 6cb5a se or pp amp. I use 4p1l as drivers in my dht amps
I once run a big test with different tubes with CCS load trying to achieve high output voltages with low THD.
6J9P gave 80 Vrms to 100 k load with 0,58 % THD when Ik = 12 mA, Ua = 220 V.
6J52P gave 100 Vrms to 100 k load with 0.66 % THD when Ik = 20 mA, Ua = 220 V.
6J9P gave 80 Vrms to 100 k load with 0,58 % THD when Ik = 12 mA, Ua = 220 V.
6J52P gave 100 Vrms to 100 k load with 0.66 % THD when Ik = 20 mA, Ua = 220 V.
I saw a report on a Dutch forum that the 6j9p had rather different performance between individual tubes
6j9p Gyrator load 67vrmS 210v 24ma 0.048% jaw dropping surely?!
An externally hosted image should be here but it was not working when we last tested it.
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i had tried Gyrator loaded 6J11P-E with 170v on plate to drive my 6C33CB Set.
Had a good performance and very quiet.
Hello,
3 6j9p on the bench,triode strapped
B+=285v
Ra =12k
Rk=100Ω,no capacitor .
100Ω screen resistor.
3rd grid to cathode.
Ia= around 12,5 ma
Gain = a little more than 30.
It will use for input stage like this,no ccs.
Cheers.
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Is that a benchtop power supply you've made that I can see in the back there for your R&D, it looks interesting ?
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Joined 2009
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Don't want to drag this thread off topic but have you some design information and experience gained (why did you go for this design and what did you learn that will help me avoid learning from scratch?), for your bench supply posted somewhere as you're photo above has now tempted me to build a supply for myself ?
