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Vintage threads from the first ten years

Hammond 270DAX ?

6/5/2005 6:19 PM
Jones	Hammond 270DAX ? Will a hammond 270DAX handle a pair of 5881s if you dont bias them too hot (cathode bias)? This PT is only rated for 90ma at 260v, I am only wanting to get about 25watts out of the pair. I know hammonds are rated conservative...but...tube manual suggests 2 5881s draw 88ma plus 5ma screen. There is only 1 Preamp tube drawing about 3ma, this is mainly a 6v6 amp but want to be able to switch in some 6L6 types.

6/5/2005 6:19 PM

Jones

Hammond 270DAX ?

Will a hammond 270DAX handle a pair of 5881s if you dont bias them too hot (cathode bias)? This PT is only rated for 90ma at 260v, I am only wanting to get about 25watts out of the pair. I know hammonds are rated conservative...but...tube manual suggests 2 5881s draw 88ma plus 5ma screen. There is only 1 Preamp tube drawing about 3ma, this is mainly a 6v6 amp but want to be able to switch in some 6L6 types.

6/6/2005 8:10 AM
Alexander	Hey Jones- That 270DAX will handle an SE 5881 but forget two of 'em. I use that tranny for 2 EL84's and it struggles with THAT load ! sounds loose and buttery but would be disaster for 2 -5881's. Stick with the 6V6 loads or upgrade to the 270FX(150ma)or HX (200ma) HTH, Alexander http://www.retrodyne-amps.com

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6/7/2005 12:02 AM
Josh	Yes, The hammonds are tough, but they are designed for 115v wall volatge. In the US, wall voltage can be really high(128v+). So you are making it run hard right from the get go. Most of the hammond power transformers I have used run hot. Even when pulling lighter loads (110mA from a xformer with 150mA) they get really hot. I have never had one fail, but I like to get the biggest hammond I can fit just so it stays cool. Now the output transformers.....those really are indestructable

6/7/2005 12:02 AM

Josh

Yes, The hammonds are tough, but they are designed for 115v wall volatge. In the US, wall voltage can be really high(128v+). So you are making it run hard right from the get go. Most of the hammond power transformers I have used run hot. Even when pulling lighter loads (110mA from a xformer with 150mA) they get really hot. I have never had one fail, but I like to get the biggest hammond I can fit just so it stays cool.

Now the output transformers.....those really are indestructable

6/24/2005 9:12 PM
Jones	I have just decided to throw that Tandberg radio xfrmr in it. That thing is bulletproof, nazi construction. actually has a swastika on it...it ran 11 preamp and tuning indicator and VU meter tubes and 2 power tubes in a big tape deck. It dont even get warm with a pair of EL34s and a couple 12ax7s.

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