Marantz 1150 rebuild
sucks2beme
Posts: 5,601
in Electronics
I finally got a chance to get to this project.
It's a mid-70's Marantz integrated amp. 75WPC.
I paid too much for it a couple of years ago. It was missing
the balance slider pot. Being hard to find, I ran it with the slider pot
jumpered out. Not having the original (had already been removed)
finding a matching one was tough. I finally got a pot that seemed close.
Not perfect, but it worked. My wife was out of town all week, so I pulled it apart
and made a list of all the electrolytic caps and made an order of Nichicon
audio grade caps. I spend a couple of evenings cleaning up the nasty chassis
and boards. All controls took a good shot of deoxit.
I got the caps on Thursday and stayed up late replacing them.
On Friday I fired it up and made adjustments. I was getting some
right channel crackling on power up until I turned up the volume.
I pulled the cover off the protection relay and sprayed in cleaner. Still there.
I tried the cleaner soaked paper trick, passing through the contacts. Still there.
I went down to the auto parts store and got some 1500 grit sandpaper. I cut off
strip and passed it though the contacts one pass. Success!
It playing right now. Big change. Before the highs were rolled off and
low bass was a bit muddy. Now bass is tight and sounds pretty good.
Highs are there now! Very clean and balanced. The highs are far better than
they were when the amp was new ( I had a 1150d model back in the 70's).
If you are a fan of the old Marantz sound, you might want to use different caps.
The highs aren't harsh, just more of it than I would expect from a Marantz.
Next up, the Sansui!
It's a mid-70's Marantz integrated amp. 75WPC.
I paid too much for it a couple of years ago. It was missing
the balance slider pot. Being hard to find, I ran it with the slider pot
jumpered out. Not having the original (had already been removed)
finding a matching one was tough. I finally got a pot that seemed close.
Not perfect, but it worked. My wife was out of town all week, so I pulled it apart
and made a list of all the electrolytic caps and made an order of Nichicon
audio grade caps. I spend a couple of evenings cleaning up the nasty chassis
and boards. All controls took a good shot of deoxit.
I got the caps on Thursday and stayed up late replacing them.
On Friday I fired it up and made adjustments. I was getting some
right channel crackling on power up until I turned up the volume.
I pulled the cover off the protection relay and sprayed in cleaner. Still there.
I tried the cleaner soaked paper trick, passing through the contacts. Still there.
I went down to the auto parts store and got some 1500 grit sandpaper. I cut off
strip and passed it though the contacts one pass. Success!
It playing right now. Big change. Before the highs were rolled off and
low bass was a bit muddy. Now bass is tight and sounds pretty good.
Highs are there now! Very clean and balanced. The highs are far better than
they were when the amp was new ( I had a 1150d model back in the 70's).
If you are a fan of the old Marantz sound, you might want to use different caps.
The highs aren't harsh, just more of it than I would expect from a Marantz.
Next up, the Sansui!
"The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson
Comments
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Cool man, you can ship that puppy to me anytime for confirmation.
Love the old Marantz's and Sansui's HT SYSTEM-
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's -
Nice project!
What are your plans for using it?Family Room, Innuos Statement streamer (Roon Core) with Morrow Audio USB cable to McIntosh MC 2700 pre with DC2 Digital Audio Module; AQ Sky XLRs to CAT 600.2 dualmono amp, Morrow Elite Speaker Cables to NOLA Baby Grand Reference Gold 3 speakers. Power source for all components: Silver Circle Audio Pure Power One with dedicated 20 amp circuit to main panel.
Exercise Room, Innuos Streamer via Cat 6 cable connection to PS Audio PerfectWave MkII DAC w/Bridge II, AQ King Cobra RCAs to Perreaux PMF3150 amp (fully restored and upgraded by Jeffrey Jackson, Precision Audio Labs), Supra Rondo 4x2.5 Speaker Cables to SDA 1Cs (Vr3 Mods Xovers and other mods.), Dreadnaught with Supra Rondo 4x2.5 interconnect cables by Vr3 Mods. Power for each component from dedicated 20 amp circuit to main panel, except Innuos Statement powered from Silver Circle Audio Pure Power One. -
I don't know what to do with it. I've had the Sansui in the rack for months.
I've run the Sansui on and off for speakers, and have been running my Stax adapter off it for headphone use. The unrestored Marantz had an issue with low bass.
I ran it with the low filter on. I remember when that was pretty normal due to turntable rumble. Highs were rolled off. Now the low bass sounds the way it should.
I may keep this in the rack for a while while I rebuild the Sansui. Back in the 70's
I had the 1150d and a Sansui 8080.
The Sansui au-999 sounds very good as is. I did do a mod from Audio Karma
involving changing some resistor values for the preamp boards. Without that mod
it was very rolled off and lifeless. It will be interesting to hear what happens after that one gets gone through. 45 years does some bad things to old caps.
Reality is I really don't need either. It's tough being a gear wh*re."The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson -
Totally identify with that. I have any number of vintage pieces I don't really need. A Sansui AU-517 has been sitting around under my basement desk for a couple of years. A fine integrated but it NEEDS attention, something wrong on one channel of the phono-section. I have a guy who I will have do a nearly complete restore on this since it really is a nice piece. One I'd like to keep?
Currently orbiting Bowie's Blackstar.!
Polk Lsi-7s, Def Tech 8" sub, HK 3490, HK HD 990 (CDP/DAC), AKG Q701s
[sig. changed on a monthly basis as I rotate in and out of my stash] -
I just ordered another round of caps for the au-999.
My wife gave me a hard time about it. She asked why, so
I showed her a swollen cap. Her response, "why don't you just
throw it out then?". Pretty much sums up her view on stereo gear
in general."The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson -
Totally identify with that. I have any number of vintage pieces I don't really need...
funny... I find that I have almost enough vintage pieces that I don't really need ;- )
That said, I don't have an AU-517, working or otherwise... kinda wish I did (although, truth be told, the one I'd like to have is an AU-717). These were nice amplifiers.
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The AU-999 with the preamp mods sound close to the au-717.
The AU-717 of course has more power.
I just got my caps and soldered them all in.
I changed everything but the two main power caps.
I may do those later. No transistor changes done.
I kept the cost down with shipping under $30 bucks.
I'm letting it cook in hooked up via speaker terminals to the stax adapter
and sr-80's. So far so good. IT sounds good.
Believe what they say, you really don't know what vintage sounds like until you
recap it and dial it in. The Sansui didn't change as dramaticly as the Marantz did,
but it just started cooking. We'll see what happens after some time."The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson -
"The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson
