Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on May 15, 2015, 02:33:17 pm
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Is the ECL84 effectively usable for audio purpose as her bigger sister the ECL86 ?
and the ECL82 is the smaller of the serie ?
Thanks
K
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They are all similar. None are pin compatible with the others.
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Many thanks Steve
All are usable for audio purpose ? (doubt solved - the ecl84 can be used as audio tube - sometime my brain refuses to collaborate)
Franco
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The ECL84 is equivalent to the 6DX8 and the Russian 6F4P. They are quite capable of being used for audio purposes.
(http://i497.photobucket.com/albums/rr333/valvetone/6DX8.jpg)
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Ciao Darryl
I've found something on my archive that remembered me they can be used for audio
(http://i497.photobucket.com/albums/rr333/valvetone/impact/impact00.jpg)
:icon_biggrin: (http://www.diyitalia.eu/forum/images/smilies/lol1.gif) :icon_biggrin:
and not only for the use indicated:
The Philips ECL84 is a triode output pentode amplifier designed for class A1 use.The triode section was designed for a variety of uses including sync separation. The pentode was designed for use as a video output stage. Introduced in 1958 when the UK had a 405 line VHF television service and a video bandwidth of 3 MHz maximum.
Source National Valve Museum (http://tdsl.duncanamps.com/link.php?target=112577E0)
Franco
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I've found something on my archive that remembered me they can be used for audio
Perhaps you should update your archives . . . :wink:
(http://i497.photobucket.com/albums/rr333/valvetone/impact/Mk%20II/impact_MkII.gif)
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Archive updated :thumbsup:
Many Thanks Darryl
Franco
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Franco,
Look at reply #5 on this thread about low watt push/pull amps:
http://el34world.com/Forum/index.php?topic=12526.0 (http://el34world.com/Forum/index.php?topic=12526.0)
I built the SoLow Watt using p/p ECL84's. Nice amp & it had an amazing bass response for such a small tube, IMO.
And there is a fairly lengthy thread on this amp on TAG complete with pictures and soundclips of different guys building the amp:
http://ampgarage.com/forum/viewtopic.php?t=17599&highlight=solow+watt+amp (http://ampgarage.com/forum/viewtopic.php?t=17599&highlight=solow+watt+amp)
The TAG guys that built the amp were fairly complimentary of the tone/design.
with respect, Tubenit
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Many Thanks Tubenit
Those schematics and links are really as cacio sui maccheroni :grin:
Have you an idea on the output power of the ecl84 in PP ?
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I was thinking to the 3 tubes in order of power to be ecl82 - ecl84 - ecl86 but evidently I was wrong
the right progression is ecl84 - ecl82 - ecl86
(http://www.mif.pg.gda.pl/homepages/frank/short/001/e/ECL84.gif)
(http://www.mif.pg.gda.pl/homepages/frank/short/001/e/ECL82.gif)
(http://www.mif.pg.gda.pl/homepages/frank/short/001/e/ECL86.gif)
ecl84 has a plate dissipation of 4W - elc82 has 7W - ecl86 has 9W
Again Thanks
Franco
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Franco,
The amp had about 3-4 watts of power with ECL84 p/p. The thing that surprised me was the amount of rich bass tone that those tiny tubes had. They sounded like a bigger tube at a very low volume. Pretty easy to overdrive the tubes, IMO and not a lot of headroom.
IF you added LNFB (local negative feedback) around the second gain stage, I think you could get a reasonably decent clean tone. You could probably try the Dumblish style of LNFB to see if that worked?
With respect, Tubenit
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Thanks for the answer Tubenit
3-4W is enough for a small amp
I've ordered some 6Ф4П (6F4P) on ebay and now I'm waiting for it :smiley:
Did you used a recovered OT or one among the Hammond's ?
Franco
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I don't remember for sure? It may have been one of the Hammonds? Shortly after I built the amp, someone wanted to buy it and I sold it.
With respect, Tubenit
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someone wanted to buy it and I sold it.
:thumbsup:
Franco