OTL guitar amp?

Amp tinkerers and people who aren't afraid of 700 volts or so in here....

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tubeswell
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Re: OTL guitar amp?

Post by tubeswell »

sean k wrote:I'll have to look at some data sheets on the EL84's and ballpark the voltage I'd want with a 6.6k OT.
FWIW I make that (Va) to be somewhere between 280 and 285 if you're going to be scientific. [ Zout = Va/(Pa/Va) ]

But I don't think it'd even do them much harm to run the plates at 300 or 320 with 6k6 Pr Z.

That is between 1/6 - 1/7 of the (assumed) plate resistance of 38-40k, so it will sound a wee bit less distorted than an 8k Pri Z, for a wee bit of compromise in output power.

Interesting about your technique for regulating voltage in a choke input filter - I never thought about that.
He who dies with the most toobs... wins

sean k
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Re: OTL guitar amp?

Post by sean k »

I looked up a schematic of the blues juniour and they're running 330 volts on the plates plus -10 to the grids for a total of 340 so maybe I'll go for about 350 and cathode biased. Who knows... first I gotta bend aluminium and do a rough layout... figuring out the fine details can come later! Starting with the hard work always gets things done faster than havin' a plan!

Cheers tubeswell... whether it it be tubes well or tube swell...

tubeswell
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Re: OTL guitar amp?

Post by tubeswell »

sean k wrote:Cheers tubeswell... whether it it be tubes well or tube swell...
well, its tubeswell (ha ha)
He who dies with the most toobs... wins

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