half power

ggk · Goldfish Joined: 28 Apr 2003 Posts: 58

Hi,
another question, maybe stupid... I red somewhere that is possible to half the power of the amp by removing couple of tubes..i.e. 100W (4 tubes), removing two tubes is possible to run the amp at 50W without damaging the trasformer. What's up with 50 watt amps? 2 tubes, push pull configuration...you can't just remove one tube, right?...the amp wil play in the same way but stressing only one tube...I'm right or completely not?
thanks in advance for reply

bye
ggk

TimC · Posted: Tue May 20, 2003 5:50 am Post subject:

ggk- How's it going? If you read the last post on the thread started by Walter, I've asked about the same thing. I know for an amp to work right, the impedances have to match. At input and line levels, I don't think anything will suffer but the tone. At the voltages and current found in the output section, I think damage can occur. Maybe someone in the know will read this and reply. I know the tubes have to be removed in pairs, one from each side of the push- pull.

ggk · Goldfish Joined: 28 Apr 2003 Posts: 58

Ops, Tim, you right...I didn't follow the walter questions...
sorry again and thanks.

gg

Guest · Posted: Sat Jun 07, 2003 8:57 pm Post subject: amp phsyics

By pulling the two outside or inside pairs of poweramp tubes you can effectivly reduce the output by half the wattage. Don't expect a big change in loudness. Remember 1 yes one watt is 1/4 as loud as 100 watts when percieved by the human ear, 10 watts is half as loud as 100 so 50 is still up there over 3/4's as loud as 100 watts. The impedance is changed but it has very little effect on the output xmer in cases where the amp is speced well. Van Halen does it with his 5150 amps which are essentially Soldano SLO 100's. Peavey is great at repackaging stuff and selling it cheaper. There is a slight change in tone but it is very slight and most will not be able to tell.
For the record, I'm not a fan of this practice. If you want to reduce the output of your amp safely, do it with a big clean impedance ie; power brake aka power attenuater, aka power soak, aka choke. What these units do is safely redirect some of the load that would normally go intirerly through the speakers through an resistance in series and between the amp and speakers ( before the speakers ) and then the energy is expelled as heat.

Craig

khingpynn · Posted: Sat Jun 07, 2003 8:59 pm Post subject:

OOOPS I forgot to login, that was my brief explanation above.

Take Care
Craig
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