• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

1000W tube amplifier

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Philips EL6471 with QB3.5 750 as end tube. This a cool amp:cool:
qb35750_1.jpg


YouTube - 1000W Amplifier Philips EL6471 at full power

YouTube - Philips EL6471 playing stereo part 3

power test glow QB3.5
YouTube - Philips EL6471 3,2 Kv on 250 Ma

more music
YouTube - 1kW Philips EL6471 Tube Amplifier from 1955 demonstrates its original sound - listen!

Enjoy
 
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More info on the tube and a link to the data sheet pdf file (1.29M) here-

QY4-250

Heaters at 5V at 14A! Might be a task for an old PC power supply?
I have a couple of these tubes if anyone wants one for experimentation, nice bottles in Pyrex glass (I think) and lovely solid graphite anode.
Les
 
This Philips EL6471 Power Amp is the smallest one , there is another two model with 10 and 20 KW of out. power .

Found in Philips EL6471 design two characteristic typical solution :

1) Use of three phase PSU ,which is typical for professional Audio power amps when input power consumption exceed 1 KW .

2) Use of two EL34 (triode strapped) DC coupled drivers for two QB3,5/750 output power tubes to obtain the best audio performance,output power efficiency and rock solid output power stage stability .

Best Regards
 
Here is one more original old document for Misissippi colection, related to Philips EL 6471 tube Power Amp.

Please read the bottom of this document , there is signed that customers can demand Power Amp with 2 KW , 10 KW or 20 KW of output power from Philips AG Deutschland .

Best Regards
 

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Hi Sansuii !

My hat down for your Gu81 Amp ! :up:

I never made really serious schematic analysis of this Philips Power Amp but I guess that -3 value is about - 240v , but not 100 % sure since the -3 Voltage network include strartup/protection 60sek. thermorelay B16 .Any way schematic Nr. 2 (with SS HV rectifier ) in that pdf file is more accurate than schematic Nr.1 since the secondary S4 is shorted over SS rectifier via S4 CT in schematic Nr.1 ( error in drawing ) .

All the Best !
 
I would love to see the 10 and 20 KW versions! :eek:

Sorry but until yet I have nothing else except the few more picture of Philips EL 6471 1Kw Power Amp .

Best Regards
 

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