Hello!
I was looking at the PCC85 curves, simulated a simple common cathode triode stage using an ECC85 model, and noticed that the anode voltage for the given bias was way off chart. First I blamed the model, but looking at the ECC85 datasheet I saw the curves are different from the PCC85, and both models I used matched the ECC85 curves. Both datasheets seem the original Phillips. Is that a fact that the tubes are that different, other than the obvious heater requirements?
Below the difference in anode voltage for a -3V bias, Ia 7.5mA, 262V vs 215V. I keep looking for the stupid mistake I may be doing but can't find it.
Regards,
Jose
I was looking at the PCC85 curves, simulated a simple common cathode triode stage using an ECC85 model, and noticed that the anode voltage for the given bias was way off chart. First I blamed the model, but looking at the ECC85 datasheet I saw the curves are different from the PCC85, and both models I used matched the ECC85 curves. Both datasheets seem the original Phillips. Is that a fact that the tubes are that different, other than the obvious heater requirements?
Below the difference in anode voltage for a -3V bias, Ia 7.5mA, 262V vs 215V. I keep looking for the stupid mistake I may be doing but can't find it.
Regards,
Jose
Thank you guys!
I'm a bit surprised, because for other cases where P and E versions differ, like the example in #2, there is plenty of information on the net stating that these are very different tubes. I could not find anything about the E vs P for the CC85.
I got some PCC85s from e-bay, will check whether they match the P-specific curves.
I'm a bit surprised, because for other cases where P and E versions differ, like the example in #2, there is plenty of information on the net stating that these are very different tubes. I could not find anything about the E vs P for the CC85.
I got some PCC85s from e-bay, will check whether they match the P-specific curves.
Do you know that it is a variable mu triode, developed for UHF stages with AGC? Not ideal for audio. My favourite is ECC88.
ECC85 and PCC85/UCC85 are a different tube. This has been documented in the past. As example, this is stated on Funkschau issue 1054/03 at page 45 when the ECC85 tube was first decribed. At the end of the description, they wrote the caution that UCC85 does share the data with the previously described PCC85 (Funkschau 1953/18 page 355). The radioumuseum web site does not list PCC85 as tube with different heater than ECC85, but as an entirely different tube.
I know. But using a CCS as load gives pretty good linearity, I marked some of the areas in my original post.
One of my favourite tubes, the PC86, is also not designed for audio but it is very linear.
The ECC85 is more linear than the 12AT7 which is not uncommon in audio, though I don't know how the PCC85 compares.
For those interested, @cogsncogs has posted a PCC85 model in https://www.diyaudio.com/community/threads/vacuum-tube-spice-models.243950/post-7245906