#37
Hello Gerd, forum
when I was a boy, I thought same.
Today I know that this is an 'excuse' for those
who are not able to put all parts 'internal'.
This is why I agree with kuroguy and pointon #4 #5
Since 'internal' is much more demanding than 'external' a few 'extra points' are not enough.
Darius
Originally #37 posted by gerd
...
IMO is an external PS the better solution for such small designs. You get better noise margin, less humming (stray effect from the mains transformer) and you can use the PSU also for other things.
Gerd
Hello Gerd, forum
when I was a boy, I thought same.
Today I know that this is an 'excuse' for those
who are not able to put all parts 'internal'.
This is why I agree with kuroguy and pointon #4 #5
Originally #35 posted by fergs1
Actually Poynton as the originator of this thread I have stated that external ps is ok, just extra points for internal, but I do agree that it must be able to drive typical speaker loads and no hybrids. ... cheers fergs
Since 'internal' is much more demanding than 'external' a few 'extra points' are not enough.
Darius
Re: #37
and now you are a girl?
oldeurope said:
...when I was a boy, I thought ....
and now you are a girl?
Hey man. I was just pointing out that the power supply was external. Doesn't matter much to me since it still has to plug into a wall socket.
The cool part is the really tiny package the amp has. Internal or external, I'd still like to build one of these tiny amps just as a conversation piece. Both of these little amps look really cool and I'd be delighted to tell others I built one of them.
THe fact is, these tiny amps build interest in our hobby and that is a good thing.
Great job guys.
Kuroguy
The cool part is the really tiny package the amp has. Internal or external, I'd still like to build one of these tiny amps just as a conversation piece. Both of these little amps look really cool and I'd be delighted to tell others I built one of them.
THe fact is, these tiny amps build interest in our hobby and that is a good thing.
Great job guys.
Kuroguy
kuroguy said:...
The cool part is the really tiny package the amp has. ...
THe fact is, these tiny amps build interest in our hobby and that is a good thing.
Great job guys.
Kuroguy
Yes,
I like Gerds design #2
Darius
The Kolibri was the prototype for this little beauty I think...
www.greatech.de
An externally hosted image should be here but it was not working when we last tested it.
www.greatech.de
"hummingbird"
Yes, this is written in the text
(web site translator)
"...In May 2005 I left the hummingbird for a few weeks Peter Grundig (GREATECH),..."
aquapiranha said:The Kolibri was the prototype for this little beauty I think...
http://www.greatech.de/tube_amp_05.jpg
www.greatech.de
Yes, this is written in the text
(web site translator)
"...In May 2005 I left the hummingbird for a few weeks Peter Grundig (GREATECH),..."
Attachments
Smallest !?
This one with psu and russian sub-miniature tubes:
http://www.jogis-roehrenbude.de/Leserbriefe/Drehko-Stefan-Miniamp/Miniamp.htm
This one with psu and russian sub-miniature tubes:
http://www.jogis-roehrenbude.de/Leserbriefe/Drehko-Stefan-Miniamp/Miniamp.htm
Some of these are getting big enuff to warrant me posting mine...
http://t-linespeakers.org/tubes/SEP_50EH5.html
dave
http://t-linespeakers.org/tubes/SEP_50EH5.html
dave
Re: Smallest !?
this is a really nice thing and a perfect mechanical work.
But it would be much better with the right tubes and OPT´s .
The used tubes are low power RF tubes Ua max 150V/Ia max 8mA, and the used OPT´s (little mains transformerss) are not really HiFi. With an 1P24B (power pentode with Qamax 2,5 W / Uamax 300V / Iamax 25mA) instead the 1Sh29B he would get the 1 Watt per channel.
With this direct heated tube in push-pull 5-6 Watts are possible, I have tried this for a contest to build an amp with the best ratio of power/volume. Here are more informations:
Zwerg
translated link
userguide said:This one with psu and russian sub-miniature tubes:
http://www.jogis-roehrenbude.de/Leserbriefe/Drehko-Stefan-Miniamp/Miniamp.htm
this is a really nice thing and a perfect mechanical work.
But it would be much better with the right tubes and OPT´s .
The used tubes are low power RF tubes Ua max 150V/Ia max 8mA, and the used OPT´s (little mains transformerss) are not really HiFi. With an 1P24B (power pentode with Qamax 2,5 W / Uamax 300V / Iamax 25mA) instead the 1Sh29B he would get the 1 Watt per channel.
With this direct heated tube in push-pull 5-6 Watts are possible, I have tried this for a contest to build an amp with the best ratio of power/volume. Here are more informations:
Zwerg
translated link
#49
Fair play please ...
The text does not say that little mains transformers are used.
... Das teuerste waren die AÜs von Conrad (100 V AÜs, Best. Nr. - 516104-12. 4,58 Euro/Stck ...
...The most expensive part was the output transformers from C...
(100V output transformers order code 5... is 4,58 EUROS/each)...
BTW: The two hundred thirty five thousand Euro "hummingbird" project
isn't HiFi( DIN 45500),too.
Originally #49posted by gerd
...
But it would be much better with the right tubes and OPT´s .
... the used OPT´s (little mains transformerss) are not really HiFi. ...
Fair play please ...
The text does not say that little mains transformers are used.
... Das teuerste waren die AÜs von Conrad (100 V AÜs, Best. Nr. - 516104-12. 4,58 Euro/Stck ...
...The most expensive part was the output transformers from C...
(100V output transformers order code 5... is 4,58 EUROS/each)...
BTW: The two hundred thirty five thousand Euro "hummingbird" project
isn't HiFi( DIN 45500),too.
oshifis said:Ha anybody used the Russian pencil-stiley double triodes 6N16B, 6N17B or 6N23B with solderable wire terminals? I know they are low power, but still... Paralleled or whatever...
I think this is possible, with paralleled 3 tubes (6 systems) you get a 5W-Triode with 30mA/V. With Ua 200V and Ia 25mA this should work for about 1 Watt on 5k Rp in single end config.
But you can also use the 6P30B, looks like the 6N16B, only some longer bulb. Pentodes are better for more power ;-)
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