MagnaTone? Anyone?

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TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

Sorry. Yes, brainfart attack and lack of desire to proofread gang up on me often.
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TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

Maybe a V-front like the stereo Gibson RVT79.
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Smokebreak
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Re: MagnaTone? Anyone?

Post by Smokebreak »

Here's the modern Stereo Twilighter. Fantastic sounding amp but basically 2 Deluxe reverbs in Stereo, with vibrato. Someone had asked about subs, Martin M. developed a varistor subsitute years ago that i tested in a magnatone build, that nailed it. All the info is on the forum somewhere ;)
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martin manning
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Re: MagnaTone? Anyone?

Post by martin manning »

Thanks for posting that. The Maggie varistor replacement thread is here: https://tubeamparchive.com/viewtopic.ph ... 92#p323892
TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

Moving forward I'm using a stand alone stereo KT-66 SE. The components take so much space they are on a separate 12"x17"chassis. I thought this would go in the bottom of the cabinet.

The preamp will have it's own chassis, which I may make removable, to drive two separate larger amps if need be.

I'm conflicted about the cabinet though. I'd like to have the ability to separate the speakers for a wider stereo field. I having difficulty designing a cab to do this while holding the two chassis. As I want 12" speakers, and the chassis are larger, an elegant design escapes me. I might not be able to separate the cab. Might have to Live with just slanted baffle boards. Anyone else on the Maggie quest?
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sluckey
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Re: MagnaTone? Anyone?

Post by sluckey »

I'm a Maggie fan. Restored a M10A several years ago and also built a M2 using a Hammond AO-44 as a donor (same power amp). You can see these projects here...

http://sluckeyamps.com/magnatone/magnatone.htm

http://sluckeyamps.com/lil_maggie/lil_maggie.htm

There is a guy over at Hoffman's forum that is currently building a stripped down Twilighter. But IMO he stripped out all the Maggie juice. He removed the Vibrato and reverb and that pretty much left him with a Deluxe AB763 but with bias vary tremolo. See it here...

https://el34world.com/Forum/index.php?topic=27260.0
TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

Nice job on the M-10A. And your M-2 is the cleanest build I've ever seen. Did you work for Hiwatt in a previous life?
I am parsing the circuit also. I'll use a preamp design of my own into a stereo effects loop, into the full stereo FM Maggie trem, then to two SE KT-66 power amps, each driving a 12.
Lots of real estate for one cab.
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TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

sluckey wrote: Thu Apr 08, 2021 2:43 pm I'm a Maggie fan. Restored a M10A several years ago and also built a M2 using a Hammond AO-44 as a donor (same power amp). You can see these projects here...

http://sluckeyamps.com/magnatone/magnatone.htm

http://sluckeyamps.com/lil_maggie/lil_maggie.htm

There is a guy over at Hoffman's forum that is currently building a stripped down Twilighter. But IMO he stripped out all the Maggie juice. He removed the Vibrato and reverb and that pretty much left him with a Deluxe AB763 but with bias vary tremolo. See it here...

https://el34world.com/Forum/index.php?topic=27260.0
Where is the reservoir of Maggie juice? I assumed the major part was the FM vibrato, and the stereo of course. Would you dup other parts of the circuit?
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sluckey
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Re: MagnaTone? Anyone?

Post by sluckey »

His basis is the standard twilighter, not the stereo twilighter.
TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

Shot from some utube vids showing the chassis. The varistors on display are brown, some other vids show bright blue varistors. They're cleaned & stamped with the M logo to make our job harder.
Screenshot_20210508-112237_YouTube.jpg
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TUBEDUDE
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

Amongst other projects, and demands of my time, I am getting the poweramps built for the Maggie project. Dual KT66 SE amps. Lots of filtering so I hope it will be quiet. Should see ~9 watts a side. Still have to do the preamp chassis. This amp will be large and heavy, damnit.
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Colossal
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Re: MagnaTone? Anyone?

Post by Colossal »

TUBEDUDE wrote: Wed Aug 11, 2021 4:20 pm Amongst other projects, and demands of my time, I am getting the poweramps built for the Maggie project. Dual KT66 SE amps. Lots of filtering so I hope it will be quiet. Should see ~9 watts a side. Still have to do the preamp chassis. This amp will be large and heavy, damnit.
Super cool. Looking forward to seeing this one. Some years back, I built what started life as a Jones Octal One with a 6SJ7 driving a KT66 SE using a great set of Heyboer iron. I ended up revoicing the 6SJ7, then changed the preamp for a 12AX7 in cascade, similar to Mark Huss' Beast (that sounded great). I tried many power tubes at various primary impedances and the KT66 sounded best, to my ear.

Do you have a plate voltage and primary impedance picked out yet for your Maggie build? Also look for the work Martin Manning did on the varistors some years back, if you don't have that already in your amp literature.
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

280V 2k5. I've read and listened to everything available. I forgot the pic.
20210811_120657.jpg
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Colossal
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Re: MagnaTone? Anyone?

Post by Colossal »

TUBEDUDE wrote: Wed Aug 11, 2021 10:16 pm 280V 2k5. I've read and listened to everything available. I forgot the pic.20210811_120657.jpg
That looks great!

Ok, so you are going classic, deep fried, textbook Class A for the KT66.
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Re: MagnaTone? Anyone?

Post by TUBEDUDE »

At least as a starting point. I wanted to use KT-88's and 2 12" speakers. That quickly became a non-starter. So the compromise is KT-66's and 2 tens. I'm thinking ET-10's at this point as they're so efficient and sound good.
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