Magnavox 8602

a 3W single ended EL84 amp for home, work & school

Magnavox 8602

Postby markshan » Tue Aug 19, 2014 5:23 am

So, I have a really old Magnavox 8602 console pull which I am told is a really good sounding amp with the right mods. I'm not at a skill level to understand much of what I am reading about the mods, and the case is VERY small and is challenging my soldering skills. Would the power and output transformers from that amp be good candidates for the budgie se? It would allow me the chance to use what are supposed to be excellent sounding OPTs, and it would also make this project very inexpensive. TIA.
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Re: Magnavox 8602

Postby Shannon Parks » Tue Aug 19, 2014 7:32 am

markshan wrote:So, I have a really old Magnavox 8602 console pull which I am told is a really good sounding amp with the right mods. I'm not at a skill level to understand much of what I am reading about the mods, and the case is VERY small and is challenging my soldering skills. Would the power and output transformers from that amp be good candidates for the budgie se? It would allow me the chance to use what are supposed to be excellent sounding OPTs, and it would also make this project very inexpensive. TIA.


Those lack the UL taps, so you'd have to do the trioded EL84 build that will cut the power in half - but you could do it without a problem.

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Re: Magnavox 8602

Postby 20to20 » Tue Aug 19, 2014 8:37 am

Magnavox uses a 2.4K R to feed screens from the B+ on another of its SE amps. This may be the way to do it to keep it in pentode mode. Tie that to the UL solder pad. ??

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Re: Magnavox 8602

Postby markshan » Tue Aug 19, 2014 3:47 pm

Okay, I'm open to either of these options but will need talked through it a bit. I don't know what a UL tap is and wouldn't be sure where to add the resistor.

The power loss shouldn't be an issue, I am driving either Hereseys or Universal 6201 coax drivers in Barzilay cabs. Either way, it is a high sensitivity affair. I am more interested in doing which ever will give me the better sound. The Magnavox pulls are supposed to sound fab, so if adding the resistor would keep me closer to that build, that is probably what I would favor.

Thank you both.
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Re: Magnavox 8602

Postby Shannon Parks » Tue Aug 19, 2014 5:02 pm

Easiest would be to just hook up the plates as normal in the schematic and solder two 1W, 100 ohm resistors between pins 7 and 9 on V2 and V3. Also omit R9, R10, C5, and C6 (i.e. zero feedback in triode mode).

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Re: Magnavox 8602

Postby markshan » Tue Aug 19, 2014 9:51 pm

Thank you, I think I can follow that. Would easiest also be good sounding, or would some slightly more difficult option result in much better sound?

And when you say "solder two resistors", I assume you mean one on each tube, not two on each tube. Correct?
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Re: Magnavox 8602

Postby Shannon Parks » Wed Aug 20, 2014 7:13 am

markshan wrote:Thank you, I think I can follow that. Would easiest also be good sounding, or would some slightly more difficult option result in much better sound?

And when you say "solder two resistors", I assume you mean one on each tube, not two on each tube. Correct?


One resistor per tube. Easiest will sound fantastic - pseudo triode with good damping. Pentode operation is a whole other untested design (and what you have already).

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