Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: frank57 on January 23, 2013, 02:04:56 pm

Title: Is this Schematic correction right?
Post by: frank57 on January 23, 2013, 02:04:56 pm
Just want to get this Hiwatt schematic more accurate.
Is the OT CT in the wrong place on the original?
It should be behind the 100 ohm resistor?
Title: Re: Is this Schematic correction right?
Post by: stratele52 on January 23, 2013, 02:15:36 pm
IMO your red pencil line is the good one.

I look only the scematic
Title: Re: Is this Schematic correction right?
Post by: Willabe on January 23, 2013, 02:18:15 pm
I would say no, not if the schematic and layout drawing line up the same.

Notice how they "T" off a 470R going to 2 @ 100R for the screen grid B+ node?

But 5w/100R might not be enough of a safety margin. If not then the problem is can you get a 10w to fit on that PCB?


              Brad      :icon_biggrin:
Title: Re: Is this Schematic correction right?
Post by: frank57 on January 23, 2013, 03:43:40 pm
So it was wrong on the original schematic?
I can probably cram a 10 watt in there.I don't think the dissipation is that great there.
Looking at the phase splitter I think if you readjust the parts you get something that makes more sense although it might not be exactly what they did.At least on most Hiwatt schematics that's where you would find those values.
I assume they're performing the same function here.
Title: Re: Is this Schematic correction right?
Post by: stratele52 on January 23, 2013, 03:59:26 pm
IMO 5 watts is enough.
Title: Re: Is this Schematic correction right?
Post by: Willabe on January 23, 2013, 04:56:58 pm
So it was wrong on the original schematic?

No I'm not saying that. I'm saying that the schematic could be right. I would compare the schematic to the layout drawing. If there are the same it's probable right. I can't make heads or tails out of that PCB layout drawing.

IMO 5 watts is enough.

Stratele is probably right. He's much better at the math than I am.


                Brad     :icon_biggrin: