Looking at ECL84 triode section's datasheet values for mu of 65 & gm of 4000, I want to wonder what single or dual triode (7, 8 or 9 pin) has a similar triode.
I can find plenty of mu = 70 triodes, haven't compared gm yet, because I realize there are several other differences like Pd and voltage limits that prevent direct comparison.
Rather than work in a vacuum (yeah) and draw my own naive conclusions, I thought I'd ask.
Thanks
I can find plenty of mu = 70 triodes, haven't compared gm yet, because I realize there are several other differences like Pd and voltage limits that prevent direct comparison.
Rather than work in a vacuum (yeah) and draw my own naive conclusions, I thought I'd ask.
Thanks
12AZ7 is the most similar that comes to mind. mu = 60, 65 or 70, not much practical difference.
There are many with mu ~ 70. But few when we look at Gm, 😀
Use the original tube, or just slightly change the values around the triode.
Example, a 12AT7 comes to mind:
u ~ 60;
Gm 5,500
If you can not easily re-adjust the resistive values and get very similar performance out of the amplifier . . .
Then perhaps you need to either use a completely different circuit, or a better circuit.
Just my opinions
Example, a 12AT7 comes to mind:
u ~ 60;
Gm 5,500
If you can not easily re-adjust the resistive values and get very similar performance out of the amplifier . . .
Then perhaps you need to either use a completely different circuit, or a better circuit.
Just my opinions
Where I'm headed with this is having a box full of 15DQ8/PCL84's. In addition to standard circuits I want to explore other configurations. I've read Tom Schlangen's pentode as triode data (and rest of his paper) and also wanted to consider as much info about the characteristics of the triode portion as I could find.
The triode (and pentode) data in the older Philips data sheets may be more relevant and accurate, than my pursuit of what the _CL84 triode compares to. That's just to be aware of what kind of circuits the 'similar' single triodes are used in.
Kind of a case of already having enough information to use the pentode triodes but being curious what else is possible.
The triode-connected pentode portion of the _CL84 looks like an interesting path to follow. I think, simply for experiment's sake, a cascode using two PCL84 triode sections would be worth trying.
Because it's possible (not necessary).
Thank you.
The triode (and pentode) data in the older Philips data sheets may be more relevant and accurate, than my pursuit of what the _CL84 triode compares to. That's just to be aware of what kind of circuits the 'similar' single triodes are used in.
Kind of a case of already having enough information to use the pentode triodes but being curious what else is possible.
The triode-connected pentode portion of the _CL84 looks like an interesting path to follow. I think, simply for experiment's sake, a cascode using two PCL84 triode sections would be worth trying.
Because it's possible (not necessary).
Thank you.
I used a 6LU8 to try both triode & UL SE connected pentode section in a project about 20 yrs ago.
Connected as FB pairs with NFB from the OPT secondary, all cathode biased.
All written up in an issue of Glass Audio / AudioXpress with lots of test data.
They 'sounded OK', about as good as we would think limited by the speakers used. 👍
😀
Connected as FB pairs with NFB from the OPT secondary, all cathode biased.
All written up in an issue of Glass Audio / AudioXpress with lots of test data.
They 'sounded OK', about as good as we would think limited by the speakers used. 👍
😀
This is a good resource for traced tube data. Note that the P-variant of an E- tube is not always exactly the same, E/PCC84 being an example.
MV Audio Labs tube data
MV Audio Labs tube data
