tentlabs heater supply current draw

richardcooper2k · Post by **richardcooper2k** » Wed Oct 22, 2008 3:07 pm

question for people with experience of tentlabs supplies

i have ordered some of these but nick at hifi collective told me they self destruct if you feed them too much voltage.

my heater supply is 9V AC. i am using 300B which draw 1.2A @5V. so my question is how much extra current (if any) above 1.2A will the tentlabs supply draw ?

this is so i can work out the resistor value i am going to have to put in to drop the voltage to the unit

pre65 · Post by **pre65** » Wed Oct 22, 2008 3:19 pm

Tentlabs chart would suggest that the ideal input voltage for a 300b would be 6.2v,so a suitable 6.3v heater supply would be ideal.

If using 9v you need to drop the extra !

http://www.tentlabs.com/Products/Tubeam ... _chart.pdf

richardcooper2k · Post by **richardcooper2k** » Wed Oct 22, 2008 3:25 pm

yes philip, i need to know how much current the valve and supply are going to draw to work out the value of resitor i need to drop the voltage

pre65 · Post by **pre65** » Wed Oct 22, 2008 3:26 pm

Another thing to think about,Phil Ramsey advised me to run 300b at 4.8v,not the full 5v !!

richardcooper2k · Post by **richardcooper2k** » Wed Oct 22, 2008 3:31 pm

yes i heard a similar thing. the tentlabs supply has adjustable output voltage so i can easily try it out

pre65 · Post by **pre65** » Wed Oct 22, 2008 4:15 pm

I looked on the hi-fi collective site to see how much their 5A Tentlab modules were-£146.88 shock horror !!

Should have got a pair from e-bay for $220 (inc post) when they were last on offer.

I did not realise that Nick was their service department now,is that the new day job ?

Post by **Nick** » Wed Oct 22, 2008 4:30 pm

I did not realise that Nick was their service department now,is that the new day job ?

Just the odd email, no major effort involved.

Just a point about the prices. At the moment 220.00 USD =135.003 GBP, so not that big a difference for ebay.

richardcooper2k · Post by **richardcooper2k** » Wed Oct 22, 2008 8:42 pm

i'll start off asuming the current draw is 1.3A and see what i get

so i recon i'll need about 2.6 ohms at 13 watts ! since i need to bring it down from 9 to about 5.6V

as long as its only on long enough for me to measure what i'm getting it should be alright i hope

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