A classic Conrad Johnson PV10 has got a 12AU7 in the line stage. It is a simple common cathode + cathode follower without bootstrapping and distortion is 1% at about 20V RMS. At 1V output it is 0.02-0.03%. The SRPP cannot do this with a 12AU7 for sure. Actually I have found the same with the ECC88. I have tried many times in all possible manners.
In a line amplifier I have never had the necessity of twice the current of the SRPP as I don't need to drive strange animals. I also have all types of valves you want, even better than the 6CG7. It is not the point. The point is about the circuit and you can make a very good one even using a 12AU7 but this is not the SRPP. Or if you like, the best circuit you can make is not the SRPP for any given device.
Having said this I normally use solid state gear at signal level, especially phono preamp. I find it better from any point of view.
10k //10nF to absolute maximum of 20Vpp.
Normal maximum signal level 6Vpp (CDP and similar)
I am not quite sure where you are trying to go with this. As I said before "Whether it is 'better' than an SRPP depends entirely on what you want to do with it."
If you want a line amp then I agree, an SRPP is not a good choice, but if you want a headphones amp then a cathode follower is not a good choice. To be honest, I cannot understand what you have a problem with.
P.S Name one tube with better intrinsic distortion than a 6CG7.
Cheers
Ian
Last edited:
I don't have any problem. It's just that I think the cathode follower is better. For a headphone amp you can still use a cathode follower with a gapped output transformer which is more linear and there is no necessity of rather big capacitor in series which creates a resonance anyway. It might be damped but phase won't be that good.
6P5GT, 6E5P, 6H30, D3a. Are these enough?
Without taking into account directly heated devices.
The 6SN7/6CG7 is one of my favourite as cathode follower. It really shines in this application.
Last edited:
Ruff,
which post from you, or any others, showed a changed answer, or any answer, after I answered your question?
Did the extra information make my requirement any different?
Sorry Andrew, I missed your answer. Let me think about it. The 10K is no probrem. Whewre does the 10nF come from.
Cheers
Ian
Stressing the ratings causes microphonics, however 
.....it's a fate shared by more famous valves. Will the heaters be damaged by misusal (they're lifted max by 100Vdc)? Left the pre running last night at full throttle (FM radio) and I must confess this lil' plinker is not bad at all. I'm in the dark for numbers as a dissident non-simulate type but the old ears don't lie. Has anyone seen curves for these // why won't there be any?
.....it's a fate shared by more famous valves. Will the heaters be damaged by misusal (they're lifted max by 100Vdc)? Left the pre running last night at full throttle (FM radio) and I must confess this lil' plinker is not bad at all. I'm in the dark for numbers as a dissident non-simulate type but the old ears don't lie. Has anyone seen curves for these // why won't there be any?An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
... but it's a little too rich to stand for listening more than half an hour.
Back to the roots again with a simple CF and some more current this time.
For me it is yes. I just don't like SRPP as I have always found a better solution.
I have nothing to post. I don't use a computer to measure distortion. It's an "old" HP analyzer.
You will find the same results in other places like Bartola Valves website by my friend Ale. Actually you will find the actual curves as well.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.