6BQ5 Sweet Spot?-Charts for other than 250 Screen Volts? - diyAudio
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Old 13th December 2010, 02:49 PM   #1
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Default 6BQ5 Sweet Spot?-Charts for other than 250 Screen Volts?

I'm working on designing a SE 6BQ5 amp. I have built several from old Magnavox amps (see attached) but when compared to commercially available SE 6BQ5 Amps there output is a little weak.

Do you know where I can find charts on this tube with different screen voltages?

I have looked at a lot of different schematics. Most set the screen voltage at other than 250 Volts.

Perhaps a simpler question is what would be the (Sweet Spot) optimum Plate, Screen and Grid Voltages?

I'm using 5k-8 outputs (Edcor GXSE10-8-5K). I can go up to about 300V on the plate. I want to stay around 10 watts at the plate. The rating on my power Tx is 100ma. The other tubes I plan to use are a 6CA4 and a 6CG7

Thanks for any input

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Old 13th December 2010, 03:00 PM   #2
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Default tube manuals

There is plenty of great information on operating points in the data sheets from the tube manufacturers. Read the appropriate pages from the tube manuals here:

electron Tube Data sheets - E
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Old 13th December 2010, 05:57 PM   #3
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Thanks Palustris,

Some of those data sheets have more info on them than the ones I have. The Mullard one is very useful.
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Old 3rd February 2011, 02:06 PM   #4
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Could be your output transformers are a bit on the small side, so could be good for one or two watts.
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