Help diagnosing Marantz SR 1000

[saabracer23]

Hello all, I have a beautiful Marantz SR 1000 that is on the fritz. Left channel plays perfectly, but the right has very low output and is extremely distorted. I bought some of the Radio Shack brand contact cleaner (they were out of Deoxit, but assured me it was just as good) and cleaned all of the pots very well, but nothing. I have found though that if I turn the treble potentiometer all the way down that the amp seems to "unload". There is a pop and no audio for about 5-6 seconds then it will start playing quietly and build back up. Also if I turn the receiver off and my source is still playing, it will still play through the speaker for another 5-6 seconds and die off. All of these symptoms I mentioned occur through the right channel only.

Unfortunately I cannot find a schematic anywhere to show you all. Any help would be greatly appreciated!

Thanks,
Dan

[eric10]

I have one with a similar problem only the left channel was dead unless you turned it up about half way then it would make horrible distorted sound.
I replaced the SKT463 amp module and now it sounds great.
I got a new one on line for $5.99 from electronix corp.
Let me know if you need more help or info.
Eric

[sakis]

there is absolutelly no chance that inside this machines exists even one propely working electrolytic ....

most of capacitors twill get leacky or all shorts of corosion down under ...

now even if the big caps are still working up to some point there is going to be a million other small problems like bad soldering, and small electrolytics in the protection area, amplifier boards, secondary psu,tuner and vu meter board

this is an amplifier worth fixing and really deserves to be fixed ...

yet again this is not an easy job to do it is time consuming but at least it will not cost a fortune ...

if you can follow procedure ....here is some instruction vintage amplifier repair/upgrade manual

[CoolbeaN]

Hello. I picked up one of these for about $35. All appeared to be in working order, but now that I have used it for a while I have noticed a slight issue.
The right channel will get static and loose some of its response in part of the range. I found that if I play with the trebble knob by either turning it or putting some slight downward pressure on it, the issue goes away.
I'm sure it may just need cleaned or a new switch, but I was wondering if it was possible just to bypass the whole bass/trebble board completely?

Looks to be just a quick snip of a wire here, solder in a resister there and it would be good, but I'm not sure which wires to connect and what value of resistors/capacitors to use.

[ostripper]

Marantz SR 1000 = 1979 = 32 years = EVERY CAP IS BAD (or damn close to it). Even if it is new in the box (never used) , the water based paste in the capacitors is way past the point of no return - expired.
Some computer grade/industrial caps are good out to 25 years - but an OEM usually does not use them.

When I ebay a unit this old (my 82 altec lansing) , I just reuse the case , transformer , heatsinks. Most if not all of the electronics and all of the caps go to the landfill. The ones I do fix , the 90's sampsons , alesis's , adcom's - have at least the larger , more "abused" caps going bad already.
21'st century amps just have the usual blown output stages.

OS

[CoolbeaN]

I knew someone was going to say that....
So.. the question is, rebuild or steal parts and DIY? Possibly a little of both (i.e. Rebuild the power supply, reuse case, switches, pots, and DIY an amplifier)

[ostripper]

So.. the question is, rebuild or steal parts and DIY?

For the marantz , it would be restored for it's antique/classic hi-fi value. being low power and nice looking , some would pay $200-900 !! for a totally restored one ! marantz receivers | eBay

If you just want to DIY for nearly nothing , just find the right "victim". Any of the adcom's , hafler's , altec- lansings, yamaha home amps can be used. Pro- amp's mileage will vary , it is best to do a google image search to find an amp that has possibilities. Center trafo - caps , side mounted heatsinks , heavy chassis , these are what I look for.

OS

[CoolbeaN]

Well.. this one isn't so nice looking.
Someone set something heavy on it for a long time. The wooden vents on the top are bowed in and there are several scuffs on the front.
The "real power" meters for both channels do not work either.. but I honestly don't care about that.
I played with the bass and treble switches, (and by that I mean I turned them vigorously each way several times) and now it seems to be functioning correctly. Yeah I know... redneck fix that will not hold. At this point I am just happy to have something that functions for $35. If it starts acting funny again I will probably just use what parts I can and make a simple single input, no audio adjustment, stereo amplifier out of it.

[farjon]

Originally Posted by saabracer23

Unfortunately I cannot find a schematic anywhere to show you all. Any help would be greatly appreciated!

Anywhere? Why not here?

MARANTZ SR 1000 SCHEMATICS

[CoolbeaN]

Thank you for the schematics. However I don't see any tone control switches?? I see a tone PF00 TONE COMPONENT, but it doesn't have any switches. Could this have been a slightly different model without controls?