1950 Magna Electronics (Magnatone) Ray Meany Amp Service & Demo

[@Dan79istheman]

Hi Brad, I forget to comment on all your videos, but they are very awesome and very much appreciated. You and Uncle Doug share the guitar amplifier interests and this makes my you-tube experience A+! I poorly attempted one very rough video like this, and appreciate just how much work goes into edits and prep-ping for upload. Kind Regards, Dan

[@TheGuitologist]

Dan79istheman Thanks Dan. I really appreciate you watching. Yeah, I'm trying to up my editing game a little bit. Still figuring out the new format. I used to just say a few things and play the amp, but now I'm trying to delve more in-depth. I'm no Uncle Doug, that's for sure. He's the man. And Rusty's camera work is second to none. My dog, Buddy,is working on it though.

[@Damaraja]

A have a few old Oliver Sound heads. One of them is my #1 amp for pure tube canvas. They’re in need of servicing. Workin’ on it 🤙

[@TheAndyroid]

I'm sure you've already realised, but pin 8 of the 6V6 is not negative to ground. Pin 5 is negative to pin 8, that's the only 'magic' negativity going on. Pin 8 is used as a centre tap termination because it provides DC elevation to the heaters, thus reducing background hum. Love these kind of videos, I could watch 'em all day (and do!). Keep 'em coming. Cheers.

[@TheAndyroid]

Also, adding a cathode resistor to the 6SJ7 would also require the 10M grid leak resistor to be replaced with 1M or lower.

[@TheGuitologist]

Thanks for the comments. You're right on the negative voltage on the 6V6 cathode, of course. I have not watched this vid back to see what I said, but the reason for using the cathode as a place to "ground" center tap is to elevate the CT above ground and prevent ground loops. At least that's been my rough understanding of the reason for doing it. There's a good discussion of that stuff here for those wishing to read more about it: www.aikenamps.com/index.php/grounding

[@TheGuitologist]

As for the grid leak resistors and rebiasing... If you experiment with this, you'll see you can actually bypass a cathode resistor even when not changing the original high grid leak bias resistor and affect some change in the bass response of the stage. I think you're right that it won't be as pronounced as it otherwise would be. I think I know what you're saying though, in theory this isn't the way things should be done. Thanks for the great comments, and thanks for watching!

[@TheAndyroid]

Yes you 'can' use a cathode resistor and keep the original large grid leak resistor but you can expect it to shorten the life of the valve. Gas in the valve can lead to thermal runaway. If you have a cathode resistor it is a no-brainer to use a typical 1M grid leak, you will not loose any gain from this. You can also remove the input cap when cathode biased. The original 10M grid leak develops a bias voltage from stray electrons hitting the grid and creating grid current resulting in a voltage drop across the resistor (the cap is there to keep the dc bias voltage where it is). I believe this should achieve max gain from the valve. Old valves don't manage so well and you'll get more gain from cathode biasing. Cathode biasing is also more 'compatible' with guitars! There is plenty of good info about 'Grid Leak Biasing' on the web. BTW, elevating the heater CT doesn't prevent ground loops, it prevents hum getting into the cathode through 'diode action'. It's a deceptively simple amp with lots going on!

[@martinskanal]

It sounds glorious!

[@cobberdig]

These simple schematic amps sound great! This one one is also similar to the supro 510-8 you did a video on aye? Great stuff and great playing at the end. Thanks for sharing.

[@TheGuitologist]

+Chris Kennedy Thanks Chris. You are right. I think, contrary to all the 'bells and whistles' and focus on ultra high gain sometimes pursued by modern amp makers, these old, almost dinosaurs of audio engineering represent the true way guitar should be heard. They provide dynamics and expression that gets totally lost when you introduce too much gain and compression into your tone. I was just commenting on this phenomena on an Orianthi video here on KZbin. In the video, she's playing to probably 20,000 people in a stadium, jamming on some Hendrix, but her tone is terrible, completely wrong for the song. There is so much gain and distortion, even before she steps on the wah pedal and kills it even further, as a listener, you just get ear fatigue. Notes have to be able to bloom into and out of an auditory space to produce a pleasing tone. These older amps, more consistently seem to do that. Thanks for taking the time to watch and comment!

[@cobberdig]

Thats quite a comment i could choose my own adventure on where to take that one! I reckon the folky kids have got it sussed. The ones you see in the sessions every year at the festivals. Learn one or 2 instruments until they totally lord it over people twice their age. Quite a few guitarists including myself could benefit from that ethic. But thats it- lots of people don't know how to use what they got. I spent a few years thinking I either needed a distortion pedal or a 2 channel amp, knew nothing about gain staging and valves despite owning a huge OR120. The nice thing with an old amp is you set it so you can manipulate everything by virtue of how you play your instrument. I like it just where the clean starts to break up. I guess the more you push towards outboard gear you start to take the human element of playing your instrument out of the equation. I never really thought of it in terms of tone though it's related. You ever try recording drums onto a computer then in the daw going over the waveforms etc shifting lines around to make the beats line up? Its kinda counter intuitive but sometimes correcting the mistakes can make a nice groove rather dull. I dunno some people definately harness the power of technology better than others but yeah maybe its where it starts and ends that makes the difference "Notes have to be able to bloom into and out of an auditory space to produce a pleasing tone." - thats a great quote!

[@stephenquail3168]

Nice work.love that little amp.

[@kirkglarson]

Hello Brad, I just bought a Dickerson/Fators amp. There is no model number. It has the slanted front and is covered in blue MOTS. There is also a HULA dancer and an island with palm trees on the grill. It is in amazing condition. Looks as if some of the electronics have been changed. The down side is that the speaker is missing. It is one of those that has a transformer attached to it. There is also 5 wires that I guess are for the speaker. I have powered it up and the tubes come on but without a speaker it is hard to tell if it works or not. I also can't find a schematic for it. Can you steer me to some place that might have a speaker for it? I'd love to get it back in service. I have pictures that I could send. Thanks Kirk

[@jerrytimmons7941]

I just picked up a Model 199-35, Serial #15271 Magnatone amp at a yard sale can you tell me anything about it?

[@chriscunningham6362]

On a small amp such as this, what mods would you recommend for harmonica use? Not so much changing the tone but rather modifying for use with a dynamic mic as input source rather than guitar pickups?

[@Arithryka]

My dog really enjoyed the guitar playing at the end of this :P (so did I)

[@charleshultquist9233]

Tasty chops!

[@nationalduo4945]

How many watts would this amp be…I. Thinking 5 ?

[@EarlofBaltimore]

Pretty good "nick" ... Hmmm... Wonder where you picked that up?

[@SlightlyTechnical]

i miss my early 60s magnatone m 5

[@liamazael]

Would you say it's worth 450 in working condition?

[@TheGuitologist]

Yes. It’s a collectible amp.

[@liamazael]

@@TheGuitologist This guy is selling one and has done some repairs to it. Replaced the speaker and used Fender Brown tolex and nickle hardware. He did a decent job on it. I like the sound the one you played has. It would really be worth it if it too had that same sound. Would you buy it knowing these things have been done to it?

[@WvHomestead]

Please tell me why you don't eso Sprague Atom caps?

[@TheGuitologist]

wvhomestead They are not worth the added expense.

[@jonnybeck6723]

Hey, its a hard tail... cool Sounds great

[@jonnybeck6723]

As the late great Jimmy Durante would say: "Stop the music, Stop the music!"... Is that, in fact, a factory Stratocaster 'hard-tail'??? ...and another great video from the master blues-blowin' builder, restorer and all around cool guy: Brad the Guitologist (!) Thanx man BTW, where can one go to complete one's training and then, possibly obtain a degree in guitology? (I know, I know... that venerable college, our cherished alma mater, the one and only "School of Hard Knocks")

[@TheGuitologist]

Guitology is considered a dark art and must be learned through long UNPAID apprenticeship. I'm currently taking applications. :D

[@jonnybeck6723]

Apprenticeships... Yeah, I'm down for a Los Angeles chapter... We have scads of art devoid of light around here... You've got me email but no pressure... (really) So is the Strat a hard tail?

[@nikkihendrix1234]

That would be awesome if you were actually serious. I do kinda the same thing except only do it for myself and have only done a few repairs for other people. I’m currently building a fender 6k6 6g15 reverb as well as restoring an early 1960’s Magnavox el84 stereo console, these videos help pass the time and keep me in the spirit when I’m in between projects or waiting for parts in the mail like styli, project specific parts and or anything besides the normal tech stocked supplies

[@thomasbaker4657]

seems the G is out of its tree.