Magnavox Concert Grand — I must be crazy

D

Diverted

Active Member
So, I've been looking for a Magnavox Concert Grand for three or four years now. Beasts — twin amps, each with 8x6V6GTs driving a 15" woofer and horn tweeter. Forty-two tubes total, the high end of the console market in the late 1950s and 1960s. Most of these get gutted, but I've always wanted one to add to my console collection (I once owned one before I got into consoles, sold it and have regretted it ever since).
Anyway, I live in Rhode Island and a friend who lives in Seattle emailed me yesterday to tell me there was one for sale near him for $100. Did I want it? Hell yes I replied! And he went and got it. It is now sitting in his garage, waiting for me to arrange for shipping. A freighting company has quoted me just shy of $600 to get it here, and I may try uship as well. Regardless, I'm springing for shipping. Small price to pay for such a beast.

It looks to be in great shape. One thing that concerns me a bit is the right channel amp. Power transformer is a replacement, but I cannot figure out what whoever did it was thinking: The amp uses a pair of 5U4s, so the xfmrs 5V winding should be 6A. Looking at a closeup of hte replacemnt transformer, it looks small, and a paper label on it says the 5V winding is 3A. Also, I hope the HV winding can handle all these tubes, but as I said the xfmr looks small. Having not looked at the schematic yet I'm not sure what they might have done, but I'm wondering if they took one of the rectifiers out of service and also cut out half of the output tubes on the amp to accommodate the smaller xfmr. Not really sure what's up, but I'll get to it!

Coincidentally, does anyone have schematics/ service manuals for this set?

Thanks,

Ted
 

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It certainly looks like all the tubes are in both amps (I see eight 6V6s in both amps).

If you can, measure the height of the lamination stack on the original (left) power transformer. I know where there's one that might work... just want to make sure it's heavy enough.

Regards,
Gordon.
 
Thank you! I will. The amp is currently a few thousand miles away so it may take some time. But I will definitely get back in touch with you. Thank you so much.
 
Diverted said:
Thank you! I will. The amp is currently a few thousand miles away so it may take some time. But I will definitely get back in touch with you. Thank you so much.
Click to expand...

I sent you a conversation message with a question about the transformer- I think I identified the CG power transformer part number correctly, but wanted to verify what's on your original amp.

Regards,
Gordon.
 
I have seen those amps on sale on epay now and again. If you have trouble finding the correct PT.
 
GordonW said:
It certainly looks like all the tubes are in both amps (I see eight 6V6s in both amps).

If you can, measure the height of the lamination stack on the original (left) power transformer. I know where there's one that might work... just want to make sure it's heavy enough.

Regards,
Gordon.
Click to expand...

Diverted said:
So, I've been looking for a Magnavox Concert Grand for three or four years now. Beasts — twin amps, each with 8x6V6GTs driving a 15" woofer and horn tweeter. Forty-two tubes total, the high end of the console market in the late 1950s and 1960s. Most of these get gutted, but I've always wanted one to add to my console collection (I once owned one before I got into consoles, sold it and have regretted it ever since).
Anyway, I live in Rhode Island and a friend who lives in Seattle emailed me yesterday to tell me there was one for sale near him for $100. Did I want it? Hell yes I replied! And he went and got it. It is now sitting in his garage, waiting for me to arrange for shipping. A freighting company has quoted me just shy of $600 to get it here, and I may try uship as well. Regardless, I'm springing for shipping. Small price to pay for such a beast.

It looks to be in great shape. One thing that concerns me a bit is the right channel amp. Power transformer is a replacement, but I cannot figure out what whoever did it was thinking: The amp uses a pair of 5U4s, so the xfmrs 5V winding should be 6A. Looking at a closeup of hte replacemnt transformer, it looks small, and a paper label on it says the 5V winding is 3A. Also, I hope the HV winding can handle all these tubes, but as I said the xfmr looks small. Having not looked at the schematic yet I'm not sure what they might have done, but I'm wondering if they took one of the rectifiers out of service and also cut out half of the output tubes on the amp to accommodate the smaller xfmr. Not really sure what's up, but I'll get to it!

Coincidentally, does anyone have schematics/ service manuals for this set?

Thanks,

Ted
Click to expand...


Ted, before you spring for motor freight, you may want to get a quote from Plycon, transport group. They have a service called blanket wrap, where they will set your console off to the side on the trailer, blanket wrap it and tie it off to the wall. All their trailers are air ride. Have used them several times for shipping larger studio equipment, with always very good results.
https://www.plycongroup.com/freequote.html

best
 
Magnavox service info is filed by chassis number - I think the tuner and amps are covered in different Sams folders. Will likely be easier to find than original Magnavox documents - I probably have 'em.
 
Thanks for the tip on plycongroup. I have tried a few freight companies and the cheapest I've found so far is $782. Yikes!
 
racfan9 said:
Congrats Tom, Why not make it a road trip? The Pacific Northwest is beautiful country.

racfan9
Click to expand...
Ha! I'd love to go out west; never been west of Louisville KY. But finding the time is the issue. But if I had a spare month on my hand I'd definitely do it and have fun along the way and back.
 
Diesel ain't cheap. Maybe get a couple of friends to take a week off and split the driving. (drive straight thru in 4 hour shifts). If you have a large SUV or quad cab truck and can feather the throttle fairly well @ 65 you could probably get 20 to the gallon. Better than 6 to 9 on a 18 wheeler. Do the math. Figure 2500 one way and divide that by your mpg and multiply by your cost per gallon at home. Average in RI is $2.59 per gallon. $647.5 round trip just for gas. As you get out of Penn. gas prices get cheaper (avg about 50 cent lower than Pa.) and if you stay on I-70 and push toward I-80 out of Indy toward Des Moines you won't have any tolls past pa. Veer off at Laramie and go thru Montana into Wa state. Just don't eat on the trip and it will be cheaper.:D When you get back give the wife a couple hundred to buy a pair or two of shoes for her closet. And the obligatory DINNER!!! :naughty:
 
Update on shipping: plycongroup quoted me $438.50 for shipping, insured and delivery in 10-14 days. Sold! Thanks for the tip on that.
I'll post more once they pick it up and ship; 2-3 weeks from now. Can't wait!
 
That's one beautiful console!

I can't imagine why they used so many 6V6 tubes and not a pair of 6550 or something but I want one!
 
Magnavox tended to keep things simple. Use the same tubes across many lines as possible, etc. Maximize power with what ya got. So it takes eight 6v6 tubes per amp. No problem, they're cheap as hell, and we got tons of them.
 
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