Hi-Fi, low power, medium-voltage plate tube
RF
Hello All, I am new to the group.
Is there any good sound tube with voltage plate at about 220V or
less? I am newbie and I am trying to avoid those risky voltages
and expensive power supply transformers. I have never heard a
tube before, so I only want to try. (1-2 Watts is OK.)
Greetings from Spain.
PS: Apologizes for my english.
Gregg
6AS7/6080 is a good tube to start with using lower voltage/higher
current output stage. But you'll still need 250 to 300V for your
preamp stage, lest you quickly run out of headroom. Tim can give you
lots of good circuits/math regarding those :-)
The transformers for generating HV need not be expensive, you just
have to look a little harder. A common trick is to put two common 12V
transformers back to back to generate a line-isolated 120VAC and use a
full wave voltage doubler. The 12V secondaries teid together are also
a source for your filaments.
Having been into tubes since I was 12, I actually find them easier to
design and get useful results from, rather than those
three-legged-fuses (what we call transistors here) ;-)
We try to be a helpful bunch here, so feel free to ask questions and
come take a boo at the forum we also hang out at (in my sig.)
--
Gregg
*It's probably useful - even if it can't be SPICE'd*
Check out the cool electronics forum at:
http://www.dutchforce.com/~eforum/index.php
Henry 007
so you would only need a couple for stereo. There are some good schematics
around...
"RF" <lis...@terra.es> wrote in message
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Tim Williams
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> less? I am newbie and I am trying to avoid those risky voltages
> and expensive power supply transformers. I have never heard a
> tube before, so I only want to try. (1-2 Watts is OK.)
You can try line-operated tubes such as 50C5 and 35EH5 and just
about anything else beginning with two digits, one or two 'lower'
letters (i.e. closer to A) inbetween, and ending in a 5 or so...
I recommend some sort of isolation. Don't want to shock yourself
eh? And especially being where you are, that would be one nasty
shock!
Hmm. Good point. Classic line-operated tubes won't be a whole
lot of good to you. 150VAC is a lot to burn away.
Could start with a 6V6 SE or 6BM8, as others have sugested.
http://www.tubesandmore.com ships internationally, you can get pretty
much everything you need from them. I'm sure there's a better, more
local source, of course. (Hey Igor or Choky...)
> Greetings from Spain.
> PS: Apologizes for my english.
Your English is better than some English-speaking people I've seen!
Tim
--
"If God didn't want us to eat in Church, He would've made gluttony a sin."
- Homer Simpson
Mike Lewis
amp? That is what I'm doing as I slowly gather all the parts for my
amplifier. It is quite cost effective and gives you that tube sound.
Mike L.
Don Robinson
read a good review of it somewhere. http://s5electronics.com/.
Nothing40
The 60FX5 might be a tube to check out.You could make a stero PP
amp,and wire the fils in series for the 240V line. (or series-paralell
for 120V)
I think the max plate voltage is 150V. They have quite alot of
gain,and are sometimes microphonic. Neat little tube though,I made a
SE headphone amp with a pair.. Sounds pretty good for just a watt,but
with headphones too much more would be suicide! ;-) Just 1 tube per
channel. I have the schematic around here somewhere,if you're
interested.
iga
6C45P one tube amplifier with 220V on plate will give
you about 1,5W power.
Saludos,
--
Igor
http://www.arrakis.es/~igapop
"RF" <lis...@terra.es> escribió en el mensaje
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Ronald Pit
You can use power trannies as output tranies with Push Pull .
Little beefy 0-110-220 sec. and about roughly 8V for a 8 ohms load .
If you take a 16V tranny that fits you mains (220 V ?) and another 220V to
16V and use the sec as pri , then you have 16V for heaters and 220V for
the HV.
Should be cheap this way if you can find the trannies in a dump store .
"François Yves Le Gal" <fle...@aingeal.com> schreef in bericht
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> On Sun, 06 Oct 2002 22:31:16 +0200, RF <lis...@terra.es> wrote:
>
> >I have never heard a
> >tube before, so I only want to try. (1-2 Watts is OK.)
>
> One of the easiest tubes for beginners is the 6BM8/ECL82, a
> triode/pentode designed for such applications. One tube in SE gives
> around 2 W.
>
> Check, for instance, http://www.bonavolta.ch/hobby/en/audio/ecl82_1.htm
> for the schematics of a Mullard amp.
>
>
RF
Thank you all for the replies.
I take note about the 'double-transformer' (220-12)<->(12-220)
power supply trick.
Where I live I can't find vendors for some tubes (50C5, 35EH5,
60FX5, 11MS8). 6V6 and 6AS7/6080 amplifiers that I have found
on the net usually needs voltages greater than 220V.
6BM8/ECL82 and 6C45P looks very attractive. I have found very
simple single-tube amplifiers using them. In the schematics I
have seen 6C45P needs less +B voltage than 6BM8/ECL82 and
requires lower OPT impedance (7 Kohms 6BM8 vs. 5 Kohms 6C45P).
And 6C45P datasheets looks very linear.
Thank you again. Very nice newsgroup :-)
Gregg
>Thank you again. Very nice newsgroup :-)
You are very welcome and do come back and let us know how it turns out
:-)
Tim Williams
news:3da23b9f...@news.telus.net...
> On Tue, 08 Oct 2002 00:51:00 +0200, RF <lis...@terra.es> wrote:
>
> >Thank you again. Very nice newsgroup :-)
>
> You are very welcome and do come back and let us know how it turns out
> :-)
Only if you have pictures.
Otherwise, get lost.
:P
Kidding!
FWIW, I don't see why 6AS7/6080 (likewise to some extent, 12B4 too)
can't be used at voltages more within their ratings. ( ;)
6AS7 bottoms out at say, 50V or so, for a practical amount of current -
so you should be able to get a good bit of power from one in PP or SE
at 200V. Could even go down to 100V, though you have alot more heater
power consumed than output. :)
RF
> > >Thank you again. Very nice newsgroup :-)
> >
> > You are very welcome and do come back and let us know how it turns out
> > :-)
>
> Only if you have pictures.
> Otherwise, get lost.
:-)
> FWIW, I don't see why 6AS7/6080 (likewise to some extent, 12B4 too)
> can't be used at voltages more within their ratings. ( ;)
> 6AS7 bottoms out at say, 50V or so, for a practical amount of current -
> so you should be able to get a good bit of power from one in PP or SE
> at 200V. Could even go down to 100V, though you have alot more heater
> power consumed than output. :)
Yes, I have found a low voltage (+150V) doble tube amp with 6922 and
6AS7. I have to do more searches.
Ronald Pit
"Ronald Pit" <r....@home.nl> schreef in bericht
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