Hi, Stalker , note that in the original transformerless, the schem claims for 145V just after the diode, and feeded from an unknown wall socket, while I've got measured 132V at the same point.(under load). Why do You think this guy Rosen used a single diode?
To found some 400V caps is not a problem , but It's worth it to do so?.
Maybe in a second unit. I started this one more like a joke, and never suspected that the sound could be as good as it is.
To found some 400V caps is not a problem , but It's worth it to do so?.
Maybe in a second unit. I started this one more like a joke, and never suspected that the sound could be as good as it is.
Ok, I did the math 120 × 1.4 is 168 volts. Too much for your caps. Worth it?
Who knows, in any case too soon for mods in my opinion.
Rosen left that diode as it was, no mod there.
This amp is no joke and no toy. Sounds better than some expensive "HI-FI" amps out there.
I am happy to hear you're enjoying it.
Who knows, in any case too soon for mods in my opinion.
Rosen left that diode as it was, no mod there.
This amp is no joke and no toy. Sounds better than some expensive "HI-FI" amps out there.
I am happy to hear you're enjoying it.
This site shows prices in AR$ (pesos) the $100 SE Tx is actually around U$S 26.- I do not know nothing about the quality , nor how is their business. Get a trip to Rosario some day, and taste personally. If nothing else, Rosario is said to be a City with a plenty of awesome girlies🙂
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Fleabreeze V.2
Well, I would like to try a variant on the Fleabreeze amplifier.
A full wave tube rectifier(CV574),16GK6's at the output, and the 12BZ7 as input tube (I like their tone a lot, it rape my mind)
So, by first thing I go and check that the filament current where the same for the three tubes, in order to use the the series filament string ( I already got a Power Tx with a 50V secondary)
Obviously there is a separate 6.3V secondary for the rectifier
I'd Done the right math, or there is something missing?
Thanks for any guidance..
Well, I would like to try a variant on the Fleabreeze amplifier.
A full wave tube rectifier(CV574),16GK6's at the output, and the 12BZ7 as input tube (I like their tone a lot, it rape my mind)
So, by first thing I go and check that the filament current where the same for the three tubes, in order to use the the series filament string ( I already got a Power Tx with a 50V secondary)
Obviously there is a separate 6.3V secondary for the rectifier
I'd Done the right math, or there is something missing?
Thanks for any guidance..
Attachments
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Fleabreeze completed
Finally completed and as the original design.
250K pot (thanks to Littlerick) permits an usable turn range of the volume knob.
First tube now is a HP 5751, as the original design call for.
A really good sounding little amplifier.that dare to drive 84 dB, two way ,4 ohm mini bookshelf speakers, not only high efficiency single drivers.
Finally completed and as the original design.
250K pot (thanks to Littlerick) permits an usable turn range of the volume knob.
First tube now is a HP 5751, as the original design call for.
A really good sounding little amplifier.that dare to drive 84 dB, two way ,4 ohm mini bookshelf speakers, not only high efficiency single drivers.
Attachments
Hi, It's an old series 20 Nad 3020, I believe it was released for the german market, almost exclusively. Some informed collector maybe would tell us if this is right.
Regards
J
Regards
J
Interesting Amps. I bet they would work great for computer speaker amps. where a lot of power is not needed.
Hi, yes, this can be a destination. Conversely I'm working on a 2 way mid/high efficiency system around a WB Betsy K (whizzerless)
My wife has been complaining about her computer speakers (she listens to a lot of music while on her computer) and was asking if she could hook up a set of bookshelf speakers to it (she was eying my Kenwoods but they are too large). I told her it would take an external amp since computer speaker sets have amps built in.
A small set of nice bookshelf speakers and a 3W SE stereo amp might work out nice for her.
I've gotat least a pair of 25C5s, and a pair or more of 50C5s plus some other low watt tubes like them, so this might make for an interesting project.
I presume that the WB Betsy K is a speaker, but I can't find any info on it. Who is WB?
I've just found that there is the even cheaper 50B5 tube
http://www.mif.pg.gda.pl/homepages/frank/sheets/137/5/50B5.pdf
PD (Wild Burro on the Manufacturers forum)
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Interesting. Not as many 50B5s on ebay as 50C5s so I wonder how plentyfull they are?
The 50B5 has a much lower plate voltage and 21% less power. Still interesting.
There are lots of low power (less than 10W) tubes out there that would work well in these small amps.
The 50B5 has a much lower plate voltage and 21% less power. Still interesting.
There are lots of low power (less than 10W) tubes out there that would work well in these small amps.
50EH5 (and other heater variants)
A bit less power, but if you have good drive, you can hook the grid of the power tube to the input.
http://www.t-linespeakers.org/tubes/SEP_50EH5.html
dave
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