polyester or polypropylene or other??

[jcx]

cut the BS, you have to spec "ceramic" by dielectric material class, whether smt or thru hole

NP0/C0G are excellent, beat many film, just don't make it to uF size, mostly up to a few 10 nF

but quite acceptable as Silver Mica substitute, will be a parameter upgrade for all specs

 

[soulmerchant]

ok, so since nobody wants to stick their neck out on this...

I don't much like the way the EF86 bias is done. I don't want to sound too foolish, but I would like to see a way to not have to use C11...

This is one way I successfully used EF86:

This post is just to stir up some ideas

Its a lot of work to mod a printed circuit board... but if the original poster is looking to improve this amp then I agree that changing caps won't make much difference. Changing the ecc99/6H6N part of the circuit might be a greater challenge...

Ian

 

[elektroj]

Good starting point would be the table below and this data sheet:

http://www.4tubes.com/DATASHEETS/SCANS-Original/E/EF86_RT.pdf

 

[crazymechanic]

But why would I want to change the 6H6N tube , many say it's a well made tube doing it's job properly , I mean the input could be better maybe but overall if a tube is a good tube and working in a decent circuit (not saying the priboi's the best) what would it change to have a different tube ? much like you said about different capacitors.

isn't this much like the anecdote about the anarchists ? When one was asked what would be better after all institutions and government would be destroyed he replied not better just different.
I kind of feel much the same goes with amplifiers and " sound" people mod stuff then listen to it sounds bit different nd they kind of feel they have reached some excellence.although i believe the total harmonic distortion stays pretty much the same.



P.S. is there a device that could be attached to an amplifiers output and input at the same time , much like a scope and that could record for a given time the waveform of the signal and then much like the recording of a cardiogram could be compared , the input signal vs the output.
because music is a rather complicated waveform and simply testing an amplifier on fixed frequency sines and squares doesn't show the full picture although I admit if it does well on various frequencies of sine square triangle whatever it probably will on the rest.

 

[Nikolas Ojala]

Natural test signal

P.S. is there a device that could be attached to an amplifiers output and input at the same time , much like a scope and that could record for a given time the waveform of the signal and then much like the recording of a cardiogram could be compared , the input signal vs the output.
because music is a rather complicated waveform and simply testing an amplifier on fixed frequency sines and squares doesn't show the full picture although I admit if it does well on various frequencies of sine square triangle whatever it probably will on the rest.

Mr. Kalervo Kuikka is very enthusiast about the "natural test signal" he invented. He claims that the test signal fits that kind of purposes quite well.

 

[crazymechanic]

still hoping to hear wavebourn's input about the Priboi schematic's
or anyone's for that matter.

 

[Merlinb]

the Priboi schematic's

Which are those?

 

[Wavebourn]

still hoping to hear wavebourn's input about the Priboi schematic's

You heard my opinion.

 

[crazymechanic]

"Why I suggested it, capacitors are not the weakest point of Priboy. Schematic is."

This is what you said on the matter and I was just hoping you would elaborate.