Help Needed - Marantz 1060 dead channel

Status
Not open for further replies.
Jump to Latest
Wharf_Creek

Wharf_Creek

Member
Joined 2007
#1
I just purchased an old Marantz 1060 off ebay. Was supposed to be in good shape....working fine when last used, etc. Well.....after blowing out the cobwebs and cleaning the controls and switches....I fired it up w/ a set of test speakers and a CD player for an input source....and found that while the right channel seemed to work fine...the left channel is dead as a doornail. As I could do a de-couple of the pre-amp/power-amp connection....I find that the output section is dead on the left side. So...my questions are: Does anyone know just what output transistors are used in this beast? and, Does anyone have any recommendations for an up-graded replacement? and, Does anyone have any suggestions for any other component replacement that might be necessary or advisable? and finally, Can anyone supply me with an email version of a schematic? My name is Tom and my email address is Wharf_Creek@Hotmail.com Any help or additional words of wisdom would be greatly appreciated!! Many thanks, TSD
 
#3
Hello Peter,

I so much appreciate the manual. It's printing as I write.

Question: The MJ15001 transistor.....Mouser shows it as being sub'ed with the MJ15001G. I'm a complete idiot with semi-conductors....but if this were a tube, I'd want to make sure it would be the best choice to be a sub for the OE 2SC897. Can you please advise? Also, I note that the left channel has been repaired previously and is now out again. A bad sign!! I'm now suspect of the driver board or any other components. Again, any comments? Thanks Peter....I truly appreciate the help. PS: Manual still printing!!.....lol. Regards, Tom
 
#8
Hola Y'all...

The manual Saved as a pdf File, I did not open but i viewed the first page ...

You will need several things . Disconect the speakers and check with zero input(NO preamp or other source) for DC @ speaker out terminals...

Report back as we want a blow by blow. Then on to the next step(s)...

Regards, Elwood
 
#10
I have to laugh......I almost started this reply with "Gents......" but I stopped myself as I realized I was NOT being politically correct....or possibly even literally correct. I found myself in a very involved exchange on Tube Amplifiers once with a very technically competent EE woman in the Boston Mass area who helped me through a difficult issue I was having in working with some 8417 output tubes. The woman sent me some pictures of some wonderful old Bogan amps that she had restored and modified! Very impressive! Anyway...it taught me a lesson......

So....with that....I'll simply express my appreciation to all for their help, words of advice, and the sharing of resources. I hope to give this amp some attention in the next week or so....but I clearly need to source some OTs before I go any further. I've been given several recommendations for alternates...but the one common thread is that I should buy from ONLY a recognized source such as Mouser or Digikey. SO...I'll do that! I just wish I could figure out just which recommended replacement is best. Seems the MJ15003 is good....but I've also received info that a MJ15022 or MJ21194 might be even better choices. Honestly...just how does one pick?

Anyway.....without any semi-conductors to even begin to make some trial & error repairs with....I'm just going to set the amp aside for now and place the orders. And, when the replacements arrive I'll begin some step-by-step diagnosis.......or, I'll just slap in a new set of OTs and see what happens. If they're only a few dollars each....that may be a quick and cheap way to at least know if I've got to go further 'in' to the amp, or maybe I'll get lucky and it will simply be fixed! Not that I have that kind of luck!!

Again....many thanks! I'll check out all the resources....and try to enroll in AudioKarma.

My best to all.......

Tom D.
 
#11
Not quite sure what's going on here....but I just received an email notice that 'd to the g' has responded in this thread. However, I don't see his response here! Don't know what gives with that...but I believe he asked me to de-couple the amp and see if the problem shows up in just the power amp section....which, for the record...it does! No output from the left power amp section...right is fine. I also note that the left side has a different set of OT in it as opposed to the right which still has the OE 2SC897s in it. Thanks for the suggestion D2theG....but, sadly I'm still right where I've been!! TSD
 
#12
The crowd here at DIY Audio is quite capable of assisting you in resurrecting this amp , but since that's not the main focus here, I had suggested getting the attention of a few of the vintage techs at AK. If you're happy with the assistance you get here, there's no reason to run away. 😎
 
#13
Hey EchoWars,

I most certainly appreciate all the help from the members of this forum. And, I am trying to heed the advice of each as I go along the path of trying to fix this amp. I don't plan to go anywhere.....at least not until I've resolved my issue. But....right now it's off to work.......but....to quote Arnold S. ..... "I'll be back!!" TSD
 
#14
Hey everyone, I have the same exact problem... a Marantz 1060 with a dead left channel, isolated to the output stage. I have tried to measure the DC offset but the voltage on the meter is jumping around all over the place, even after letting the amp settle in a bit. It is going between say -5mV and all the way above 40mV sometimes. I am measuring it with no input the the amp and no speakers connected.

Also I measured the bias on the left channel and it was around 6.5mV, which is not TOO far off spec.

Any ideas on what to check next?
Thanks in advance!
Josh
 
Status
Not open for further replies.
Top Bottom