SY said:
Hi,
why?
Yes, I have strong objections to using LED biasing,
solid state CCS, and source followers for screen drive,
this is why I didn't do that in my triodelington amplifier.
If I can get the triode I want, I don't need a triodelington.
I was not able to get 20 Telefunken NOS ECC82. 😉
In the OTL I'll take a 6080 or EL500 triodelington ...
Darius
I'm curious to see that as well. Having a transistor that is as transparent as possible would seem to be the primary goal. A similar topology using a CFP may be a worth while experiment too.
At least the ECC82 is working as a cathode follower, so the distortion should be fairly low . The majority of the coloration/distortion is likely to come from whatever voltage gain stage is placed before it.
It's not really a cathode follower unless you connect the composite as a follower. In the example circuits, the plate is connected to the load, along with the collector. Now, the distortion spectrum is interesting because it will reflect how much the composite acts like the tube as opposed to like the bipolar. If it's different (other than scale) than the tube, that's a good indication that the circuit is no different than the well-known FET-lington. If it scales and is the same, then the claim of "works perfectly" could be supported.
Ahh, I didn't see the whole schematic, just this:
http://bp3.blogger.com/_oCEpds9YoPw..._9o/s1600-h/ausgangskennlinienfeld+triode.png
I assumed it was going to be used as a follower.
http://bp3.blogger.com/_oCEpds9YoPw..._9o/s1600-h/ausgangskennlinienfeld+triode.png
I assumed it was going to be used as a follower.
Had to simulate the rather bizarre triodeling...
The reason for using transistors at output must be to eliminate the OPT. Otherwise it is better to use powertubes as these don´t need cooling.
So I did a simulation around a standard circlotron arrangement. As the stoneage ECC82 is a total deadend in my audioworld, I used a 6H30 that has rather good linearity at low voltages.
The transistor are biased at 500mA each, so if done IRL this would be hot as hell as each transistor dissipates ca 25W.
The current drawn through the 6H30 is then (too)low at just above 4mA. If wanting more drivercurrent, transistors with lower hfe must be used.
Output power is just above 35W/8ohm at 1% distortion. Above that clipping is rather soft and shows 5% at 75W/8ohm and 10% at max power 100W/8ohm.
Zout ca 0,6ohm.
The thermal sim shows a quite acceptable slowly rising Iq that probably could be compensated for with the NJLs built in diodes.
Now remember this is a Spice simulation so the results are NOT reliable at all. They just point in the direction that the circuit will probably work.
But will it sound good?
And please "oldeurope", let go of your besserwisser attitude! No wonder you get thrown out of some forums 😉.
The reason for using transistors at output must be to eliminate the OPT. Otherwise it is better to use powertubes as these don´t need cooling.
So I did a simulation around a standard circlotron arrangement. As the stoneage ECC82 is a total deadend in my audioworld, I used a 6H30 that has rather good linearity at low voltages.
The transistor are biased at 500mA each, so if done IRL this would be hot as hell as each transistor dissipates ca 25W.
The current drawn through the 6H30 is then (too)low at just above 4mA. If wanting more drivercurrent, transistors with lower hfe must be used.
Output power is just above 35W/8ohm at 1% distortion. Above that clipping is rather soft and shows 5% at 75W/8ohm and 10% at max power 100W/8ohm.
Zout ca 0,6ohm.
The thermal sim shows a quite acceptable slowly rising Iq that probably could be compensated for with the NJLs built in diodes.
Now remember this is a Spice simulation so the results are NOT reliable at all. They just point in the direction that the circuit will probably work.
But will it sound good?
And please "oldeurope", let go of your besserwisser attitude! No wonder you get thrown out of some forums 😉.
Attachments
#45
Oh, but I am so sorry to tell you that you made lots of fundamental mistakes.
Maybe Jeb-D. gives you some help if you are able to ask him politely.
D.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1561794&stamp=1216059759revintage said:
Oh, but I am so sorry to tell you that you made lots of fundamental mistakes.
Maybe Jeb-D. gives you some help if you are able to ask him politely.
D.
oldeurope, did you think I was interested in your amp-circuit? I am not, as it is not useful for OTL.
I used the combination triode+BJT to be used for OTL as this is what the thread is all about.
I used the combination triode+BJT to be used for OTL as this is what the thread is all about.
OT Signature edited by moderator
Hi Hugo,
I didn't give you permission to delete the
technical forum rules in my signature 😡
Technical forum rules:
µ = hfe_
hie = 1/hoe_
triodes don't change their characteristic at positiv grid voltages_
anode current is independent from g2 current in a pentode_
calculating the gain of a triode cathode follower you have to ignore the influence of µ_
Loftin White is cathode feedback_
[D]ignore the fourth circuit topology[/D]_
tubes should be replaced by mosfets_
neutralisation is forbidden_
continued 😉...
D.
link annoyed must read!
Netlist said:
Hi Hugo,
I didn't give you permission to delete the
technical forum rules in my signature 😡
Technical forum rules:
µ = hfe_
hie = 1/hoe_
triodes don't change their characteristic at positiv grid voltages_
anode current is independent from g2 current in a pentode_
calculating the gain of a triode cathode follower you have to ignore the influence of µ_
Loftin White is cathode feedback_
[D]ignore the fourth circuit topology[/D]_
tubes should be replaced by mosfets_
neutralisation is forbidden_
continued 😉...
D.
link annoyed must read!
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