Help Identifying a Magnatone amp

[Stevewdewitt]

I am in possession of a Magnatone amp that doesn't have a model number. I am attaching photos. It is low watt single ended with a single 12AX7, 6V6, and 5Y3. Came with a lap steel. I am trying to get a schematic.

Here are some pics. I have done some searching and haven't found the exact amp yet. Thanks in advance.

Steve

[eleventeen]

Really gotta like that front panel motif, and the "static eliminator" switch and "level indicator" lamp. Excellent! This was obviously a small amp carried on early space flights to play blues in the ship's rec room during those long interplanetary periods when there was nothing else to do.

[Stevewdewitt]

So the pot codes are 140836 putting the amp probably 36th week of 1958. I found a pretty good picture of one, at least what the front looks like, but the schematic doesn't seem to match.

Here is a link to the picture http://i.imgur.com/8yupb.png

It seems like it could be a model 108 or 109.

Any suggestions for the type of adhesive to use to stick the MOTS back down. The guy who brought this to me said the handle gave out and it hit the corner and flew apart.

I don't think that this is the original speaker. I think it had an 8 inch speaker.

Thanks,
Steve

[terminalgs]

Looks like a 108, but the panel markings aren't consistent with Magnatone branded amps.   Built by Magna, no doubt, but might have been an OEM.  perhaps for some reseller like Aloha?  Ray Meany? etc..  AFAIK, through the 50's, Magna always put the model number and "Magnatone" somewhere on the metal control panel. on the other hand, if a company contracted with Magna as an OEM, the company often got to customize the control panel, and sometimes make slight circuit changes. 


With a single 12ax7,  I'm guessing the two volume controls feed the same channel in the circuit?  are input 1 & 2 controlled by that first level control? maybe out front of the first 12ax7 stage?  and the second 'master' control and tone in between the two 12ax7 triodes?


It looks like a 108.  The 109 was push-pull, and the later 118 was a 108 with a 12" speaker (more or less). Magna moved from Inglewood to Torrance (fall 1958). Also, Magna stopped making MOTS amps and guitars coincident with the move to Torrance.  They elected not to take the vats of chemicals to the new location. So, pot codes of 1958 make it one of the last MOTS amps produced.  end of MOTS: (1) Demand for amps changed, the Hawaiian motif of the MOTS wasn't in favor like it was a decade before (2) it took a really skilled hand to wrap the amps and guitars correctly and smoothly in the plastic while it was still pliable and (3)  the process really really smelled bad (the chemicals stunk).


Check out the schematic for the 118 and see if its any closer to yours.   It won't be exact (118 has a bright switch),  but it is the successor to the 108. AFAIK, the 108 was the only SE 6v6 amp Magna built in 55-58.


Very cool, I'd love to see more pics..

[Stevewdewitt]

Thank you everyone.

I would like to replace the can cap. It is a 20uf/450VDC, 20uf/450VDC, 20uf/50VDC. Any recommendations about where to get this? Also I could use 3 caps internally and leave the can cap for aesthetic value.

I would also remove the "death cap". Just because I have read that it doesn't do much and could be lethal. I could replace it. I plan to make a schematic for this amp since I cannot locate one.

Thanks,
Steve

[HotBluePlates]

I would like to replace the can cap. It is a 20uf/450VDC, 20uf/450VDC, 20uf/50VDC. Any recommendations about where to get this? ...

If it were my amp, I'd get the F&T 16uf/16uf @ 450v from Hoffman (checking measurements to see the can is compatible with the existing hole). I'd use an individual 22uF @ 50v cap to replace the 3rd section (Hoffman has this, too).

Radio restoration places, mainly Antique Electronic Supply may have the unusual can cap arrangements, but you can count on them being very expensive. Also, the old 10, 15, 20, 25 value series generally doesn't exist in modern parts. You replace a 20uF with either 16uF or 22uF (next value up is 33uF, 47uF, 68uF, etc)

[Stevewdewitt]

Here are some construction and finished pics. Pretty cool amp. After much consideration, I did not replace the can cap. I will tell the customer about it and let them decide. The guy was really happy with the tone it had before it fell apart. The old handle broke and it hit the corner and broke apart. The thing was held together by staples. It is now dowels and screws. So maybe it can make it another 57 years. It got a new handle, 3 wire plug, and I removed the "death cap". I also reconstructed the cabinet. It looks pretty good.

[Willabe]

Very nice job!