• 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.

6V6 line preamp

diyAudio Chief Moderator
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this one reply from Shirley seems to so.
Shirley noted 4.5W parafeed in his video. Line preamp 6V6 with OPT they ask about. Such with OPT and especially with NFB must be specifically tested to recommend a type. See first about squarewaves, gain, Zo, bandwidth, preferred load etc. 6V6 power amps featuring OPT there are many examples. Especially small guitar amps.
 
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Salas sounds superb.

Asap pics of inside the 6V6.
 

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diyAudio Chief Moderator
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Star ground I see, coax signal wire, local signal grounds, fine. Surely better than before. Better wiring led to no hum result as we projected. Congrats.

What are those black plastic things with a red center on the heater boards? Fuse holders? What is your final power Tx arrangement and what is the raw DC and B+ it finally allowed?
 
diyAudio Chief Moderator
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Could be 5K?
What? OPT load value? Possibly. But I never recommend something as a good outcome without having applied it, measured it, listened to it, first. Especially when there's significant cost involved to get it. Like a good output Tx nowadays. Its DIY and you can experiment of course but its not based on my experiment. No possible info from me on what to get how it will go or how to tweak etc.
 
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Star ground I see, coax signal wire, local signal grounds, fine. Surely better than before. Better wiring led to no hum result as we projected. Congrats.

What are those black plastic things with a red center on the heater boards? Fuse holders? What is your final power Tx arrangement and what is the raw DC and B+ it finally allowed?

Are fuse holders, the red color is the paper where is marked the fuse power: in my case 0.5A.

The custom power tx 275V 0,3A spends minimum 1 week to make it.

PSU 310-313V so Vin for SSHV2
B+ 290V

Thanks for you design, guide, advice & help as usual Salas.

Best personal regards
Felipe
 
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Thanks for the info. You are welcome.

*New higher voltage Tx will be locally made? Toroidal or EI?
I don't like toroidal for B+, other mania: I don't like to share the same powwr tx for B+ & heaters, I like R-Core for heaters but never tested for B+.

Here is difficult to get people making custom transformers & only for mains power, and the only few that I know always EI, the last maker of custom transformers is retired and recommended a new one, let's see how he does, I asked electrostatic screen to connect at chassis ground.

The prices as all things are skyrockets.