[Peter Wieck]

eponymous cowherd wrote:
Is the input/driver tube and output tube terminology analogous to the
preamp/power amp terminology used in SS amps, or is it something
completely different?

Yes and no.

There are driver transistors and output transistors, just as driver
tubes and output tubes. "Input" tubes and "Driver" tubes are not the
same thing always. A "Driver" tube typically handles line-level input
voltages to the output tubes. An "input" tube typically would be the
case in a phono-pre-amp, or some such. Howsomever, if you take a
pre-amp as an input device for a power-amp, then all the tubes in a
pre-amp are "input tubes", and therefore meet your analogy.

Confused yet? Pre-Amp (Input) to Power-Amp (Driver + Output). The
driver resides in the power-amp, not the pre-amp.

Start simple. It ain't nohow rocket science rumors to the contrary, but
some tubies get really defensive and quite nasty about terminology.

Peter Wieck
Wyncote, PA

[Lost'n Found]

I am new to tube design, but here is my view:

I was checking the 12AX7 datasheet, and they take input of 0-5 volts, and
give lots of gain, easily reaching 15 RMS, enough to drive output tubes.

In other words, a CD player should be enough, if it's output is something
like 1v or more. What tubes are in the driver stage?


"eponymous cowherd" wrote in message
...
In article .com,
"Peter Wieck" wrote:

Confused yet? Pre-Amp (Input) to Power-Amp (Driver + Output). The
driver resides in the power-amp, not the pre-amp.

The part that was confusing me is that I am looking at some cheap tube
amps and couldn't decide if they had no preamp or if I misunderstood the
terminology. It seems that everyone agrees that with CD players you
don't need preamps, mebbe the cost reductions from that will enlarge
interest in hifi.

[Peter Wieck]

Lost'n Found wrote:
I am new to tube design, but here is my view:

I was checking the 12AX7 datasheet, and they take input of 0-5 volts, and
give lots of gain, easily reaching 15 RMS, enough to drive output tubes.

In other words, a CD player should be enough, if it's output is something
like 1v or more. What tubes are in the driver stage?

The part that was confusing me is that I am looking at some cheap tube
amps and couldn't decide if they had no preamp or if I misunderstood the
terminology. It seems that everyone agrees that with CD players you
don't need preamps, mebbe the cost reductions from that will enlarge
interest in hifi.

Caution: The CD player must have a variable output, or the power-amp
must have a volume-control.

One of the truisms of tubes is that a first-timer should not start 'on
the cheap'. Tubes may be done so, but in direct proportion to the
skills of the user. A person well-acquainted with the care, feeding,
maintenance and (potential for) modification, construction & design of
tube equipment may do things for relatively low cost. Those who don't
know one side of a soldering iron from the other and/or are boggled by
terms such as SE, SET & PP had best purchase stuff ready-to-go.

Peter Wieck
Wyncote, PA

[[email protected]]

Hi RATs!

Yes, French and German both have words for stupid. No, they are not
exactly the same word. Yes, they mean the same thing, to some people.
Not much is exactly the same in every language, except, perhaps,
Hamster. Hamsters act as if being an electrical engineer is as
interesting as being a Flamenco dancer. Hamsters are pretty easy to
live with, if you don't need applause or anything, but, don't practice
your Flamenco dancing if the Hamster is not safely in its little home.
Hamsters are much too easy to stomp the **** out of, even accidently
.... even if you aren't really a Flamenco dancer. Life is a bitch,
sometimes.

Happy Ears!
Al

[Peter Wieck]

wrote:

Happy Ears!


Al:

With all due respect to your illness and whatever recreational
pharmaceuticals as might be in play, that was even more of a pretzel
than usual.

Peter Wieck
Wyncote, PA

[[email protected]]

Peter Wieck wrote:

Al:

With all due respect to your illness and whatever recreational
pharmaceuticals as might be in play, that was even more of a pretzel
than usual.

Peter Wieck
Wyncote, PA

Hi RATs!

OK, sorry. Analogy and identity are oftened mixed up.

Tube and SS amps both increase the level of an electrical signal to a
level which can power speakers.

Tubes generally multiply the voltage and then use an output transformer
to get it back to something the voice coils can handle.

Solid State keeps it current, as it were.

I don't know why I like tubes more, but, it probably has nothing to do
with anything that has been documented. Just a whim, OK ?

Happy Ears!
Al

PS Neither voltage nor current have anything to do with Music. It is
just a gizmo we do with them.

[robert casey]

The part that was confusing me is that I am looking at some cheap tube
amps and couldn't decide if they had no preamp or if I misunderstood the
terminology. It seems that everyone agrees that with CD players you
don't need preamps, mebbe the cost reductions from that will enlarge
interest in hifi.

The term "preamp" can take on a few different meanings. I've always
thought of it to be the phono RIAA equalization/gain stage. Some people
call the bass and treble tone controls a "preamp", as in "before the
amp", in amps where these controls are ahead of the first tube.