MotorolaNut
New Member
Love it! Looks like it's in great shape too. I love the Motorolas in the Drexel cabinets. Here's my daily driver - an SK76WA from 1962. It has the Vibrasonic spring reverb just like yours.
Greg
Calling All Motorola Consoles!!!
- Thread starter relaximus
- Start date
Greg
MotorolaNut
New Member
Wow. That one looks like it was babied its whole life
Other than two little white marks that will buff out and a new stylus, yes it has been babied. All tubes offer a comforting glow, the tuning eye is strong and bright. It's a Drexel French model with the specs saying 20 watts per channel, which is more like 12ish per channel but it does thump. Now I just need to find the matching external speaker!!!
Wow, I'm loving this Moto/Drexel unit,,sound is fantastic but I have one tube running hot. I haven't replaced any caps yet (has the good all caps) or checked any resistors. Before I pull the amp I wanted to ask you good folks - where do I start to fix the redplate tube?
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century tek
Addicted Member
WOW yeah, don't turn it on again. Its either going to be a bad tube or bad coupling capacitor or both. If you have been listening to it this way, you might have caused other damage so you need to check it out.
Is that a 3 channel?
Is that a 3 channel?
Caps appeared to be the fix. Didn't have any .02 caps so I used .022 - I changed all four of the goodall caps. That small difference in capacitance should not pose an issue, or will it? And it's only two channel, beefy two channel. Also, I have another HS711 amp that I plan on using as a stand alone. Will I do it any damage by bringing it up on a variac without tubes or speaker load? Just to check voltage(s). Thank You.
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craigtone
Tubehead
This may be sacrilege ... but ... in my defense I received the pieces as pictured!
I did some research and apparently these old consoles sounded pretty good. My plan is to find a mid-century modern end table or night stand and mount the power amp on top with the preamp in the face where the drawer would go. I picked up an OEM Motorola Golden Voice 15" on eBay and will mount that in the bottom of the cabinet firing down.
I put the schematics into TINA and simulated them. If I jumper the dual RC filter on the L&R amp input I can change them to full-range. I also need to change the coupling caps between the phase splitter and output stage to 0.1uF. The idea is to make the amp a full-range L&R stereo amp and keep the reverb/bass channel as-is with a switch similar to the OEM verifier to bring the 15" speaker in and out as desired.
The finished product would be a stereo tube integrated amplifier with an optional bass/reverb speaker included. I'll post pictures along the way as the mods are relevant to anyone restoring one of these beauties as well.
I did some research and apparently these old consoles sounded pretty good. My plan is to find a mid-century modern end table or night stand and mount the power amp on top with the preamp in the face where the drawer would go. I picked up an OEM Motorola Golden Voice 15" on eBay and will mount that in the bottom of the cabinet firing down.
I put the schematics into TINA and simulated them. If I jumper the dual RC filter on the L&R amp input I can change them to full-range. I also need to change the coupling caps between the phase splitter and output stage to 0.1uF. The idea is to make the amp a full-range L&R stereo amp and keep the reverb/bass channel as-is with a switch similar to the OEM verifier to bring the 15" speaker in and out as desired.
The finished product would be a stereo tube integrated amplifier with an optional bass/reverb speaker included. I'll post pictures along the way as the mods are relevant to anyone restoring one of these beauties as well.
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MotorolaNut
New Member
Congrats! That's a real nice console. I have one just like that in my garage - one of my upcoming projects. Surprising how heavy it is even though it is one of the more petite consoles out there. By the way, I do believe it has the HS-839 amplifier.
Greg
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lhomme61
New Member
It has a HS-870 amplifier.
MotorolaNut
New Member
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MotorolaNut
New Member
Don't worry. I thought I had done the same. I looked at my service manual first of all instead of checking out the amp itself. Didn't want to take that snowy walk to my workshop in the garage.Oops! My mistake. I glanced at the schematic not the chassis.
It is a HS-839A date 10/60.
lhomme61
New Member
Interesting thing is that the 870 amp only differs from the 839 in the power supply. Probably because the 870 amp was used with preamp only systems, though, power tubes in the 839 receive higher screen voltages relative to the plates. This would lead me to believe that the power output of the 839 would be slightly higher.
Hello, I just picked up a 1961 SK49 (I know this from reading this thread, thank you!) today for $50. It is in pretty good condition. It has the optional tuner and the vibrasonic system. It all seems to function except I am not getting anything out of the right channel. I am new to tubes so if anyone knows of a thread with diagnosis for this I would appreciate it. I started with my dad's Pioneer SX1000TW, and since have been running a Sansui 5000A with HPM 100s and a 1019 turntable. Any advice for my new beauty appreciated. Thanks.
