DC Tube Amplifiers

[SY]

Synchronicity- as I've been back and forth to my bench on a coupling issue in my new phono stage, Bembel sent me some scans of an old French article on DC coupling methods.

DC Amplifiers

The French is not too imposing, but Bembel or other francophones can help us slow folks through the rough spots. The schematics and equations are self-explanatory.

In any case, the ideas are basic and interesting. There's no capacitor as good as a nice, clean piece of wire, but we also have to think through the dynamics of coupling issues and whether or not we just substitute one problem for another.

[Brian Beck]

Hi Stuart,

I converted and merged the three images into one PDF file, but the size is around 2.5MB. Someone more capable than me would have to compress the images further.

[bembel]

Hey guys,
theses photos were done as test. they have been shoot in less then 30 sec and then gimped to be readable and small sized.
I can doo far better if someone wants to do the pdfs, i'll be glad to send better ones.
to be continued...

[Wavebourn]

I use bi-polar power for such purposes. It is cheap today.

[Netlist]

Originally posted by bembel
, i'll be glad to send better ones.

I can try.

/Hugo

[bembel]

Hugo,

I'll try to take some pictures during this week, then send then to you to be acrobated, what mail size fits better to you ?

This article comes from a collection of "Radio plans" & "le haut parleur" that I bought to a friend at a flea market. these are famous french electronic magazines from the 30's to 80's.

I'll try to scan in groups interresting articles (but there's a lot dedicated to radio receivers, not very interesting here).

[Netlist]

Don't make it too big, we'll have to resize anyway.
hugorx at hot mail. +/-20Mb of space.

/Hugo

[wa2ise]

Fig 12 looks a lot like an SRPP circuit, except the output is connected to the bottom plate and not the top cathode. And I'm not sure what to make of R4 and R5 other than having an inverted signal present there. I don't know this foreign language, so all I can do is look at the diagrams....

[bembel]

OK, I think I'll mail it to you during the week Hugo.

Regards

[Wavebourn]

Originally posted by wa2ise
Fig 12 looks a lot like an SRPP circuit, except the output is connected to the bottom plate and not the top cathode. And I'm not sure what to make of R4 and R5 other than having an inverted signal present there. I don't know this foreign language, so all I can do is look at the diagrams....

I believe connecting output to the bottom anode decreases distortions against SRPP.