Hi,
I recently purchases a Marantz 2245 reciever for a day, i found them sound warmer and a lot more to my liking. However, on the second day, after I have tried to losen up the potentiometer of the front controls, the amp starter to crackle and pop on the left and channel. The right channel is perfectly ok. The crackle and pop is not affected by the volume adjustment. I told it in to a local tech for service as the lamps were all out too. He cleaned the unit up pretty good, but just cannot figure out the component responsible for the noise. He said it most likely to abe a transistor on the tone board. He returned the unit back to me with a in-line lamp fuse to prevent blowing my speakers. After it happened twice, I call him and he said, he will just replace all the transistors on the tone board and it will run approx. $60, but can't guarantee it will fix the problem. As I have already speed $70 + cost of amp, I would rather try fixing the unit myself. I have tried cleaning the tone pots with a contact cleaners and they turn really smooth and the in-line fuse has not blown the fuse for almost two days of continous use. today it just blown the fuse again as it started to crack and pop again. Can anyone tell me is if the tone board is the most likely problem. I have check the service manual and the transistor required are the 2SC1000 GR OR b1 AND 2SC493 Y OR GR. I cannot find them anywhere, i think they are discontinued. I have found some NTE 290A and NTE 199. Are these the right replacement or can someone suggest something more suitable.
Mike
I recently purchases a Marantz 2245 reciever for a day, i found them sound warmer and a lot more to my liking. However, on the second day, after I have tried to losen up the potentiometer of the front controls, the amp starter to crackle and pop on the left and channel. The right channel is perfectly ok. The crackle and pop is not affected by the volume adjustment. I told it in to a local tech for service as the lamps were all out too. He cleaned the unit up pretty good, but just cannot figure out the component responsible for the noise. He said it most likely to abe a transistor on the tone board. He returned the unit back to me with a in-line lamp fuse to prevent blowing my speakers. After it happened twice, I call him and he said, he will just replace all the transistors on the tone board and it will run approx. $60, but can't guarantee it will fix the problem. As I have already speed $70 + cost of amp, I would rather try fixing the unit myself. I have tried cleaning the tone pots with a contact cleaners and they turn really smooth and the in-line fuse has not blown the fuse for almost two days of continous use. today it just blown the fuse again as it started to crack and pop again. Can anyone tell me is if the tone board is the most likely problem. I have check the service manual and the transistor required are the 2SC1000 GR OR b1 AND 2SC493 Y OR GR. I cannot find them anywhere, i think they are discontinued. I have found some NTE 290A and NTE 199. Are these the right replacement or can someone suggest something more suitable.
Mike
Here is a link for the schematic and the service manual
Marantz 2245 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine
Mike
Marantz 2245 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine
Mike
its a total fact that every small electrolytic inside this amplifier needs to be replaced
there is no question if this one or that one its simply one word ALL !!!!!!
otherwise you will never manage to make it operate properly
the particular amplifier has plenty coloured grey and coloured orange ...the orange ones should be elna sealed type and these and only these caps might still be ok after 30 years
this amplifier beyond the amplifier power supply has also a seconadary power supply that feeds preamplifier and other auxiliary circuits this particular circuit needs a total replacement of caps if not other issues
in the amplifier boards there is also not only filters and decoupling elctrolytics but also some that are related to signal issues that need a replacement
then again the same goes for all prealifier boards
Tuner sufers from the exact same problem and you will see frequency shifting on tuner section also .....
doing this is not the only thing you need to do you need to clean very very carefully all pots and switches
the strange thing is that this will probably cost you between 10-20 usd in parts timewise though is a very time consuming job to do
here is some extra help http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
there is no question if this one or that one its simply one word ALL !!!!!!
otherwise you will never manage to make it operate properly
the particular amplifier has plenty coloured grey and coloured orange ...the orange ones should be elna sealed type and these and only these caps might still be ok after 30 years
this amplifier beyond the amplifier power supply has also a seconadary power supply that feeds preamplifier and other auxiliary circuits this particular circuit needs a total replacement of caps if not other issues
in the amplifier boards there is also not only filters and decoupling elctrolytics but also some that are related to signal issues that need a replacement
then again the same goes for all prealifier boards
Tuner sufers from the exact same problem and you will see frequency shifting on tuner section also .....
doing this is not the only thing you need to do you need to clean very very carefully all pots and switches
the strange thing is that this will probably cost you between 10-20 usd in parts timewise though is a very time consuming job to do
here is some extra help http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
Last edited:
Thank you for the reply. I have tried to com firm where the problem is. In the last few days, I have used the Marantz 2245 as a pre-amp and as a power amp. In the pre-amp mode, the unit still pop and blow the 1 amp fuse on the left speaker. As a power amp, it has no problem at all. I therefore have decided to start with the tone board (P400). If this eliminates the problem, I will then continue to upgrade the parts on the other board.
On the Tone board (p400) I decided to change all the transistors and the capacitors. I have located most of the parts. However I do have a concern with the tolerance of the following:
C405-C406 Elect., 10μF, 35V, +100%, -0%
C409 Elect., 100μF, 35V, +100%, -0%
I presume I can use
Elect., 15μF, 50V, +/-20% (giving 13.50μF to 18μF)
Elect., 150μF, 50V, +/-20%(giving 135μF to 180μF)
These are all NTE brand and they are the closest values my local electronic store stock. Should I go ahead and use them or should I get something more suitable from Mouser (perhaps you can suggest more suitable capacitor if the above is not suitable). Until I find the problem, I am trying to keep cost low. I don't mind using these first and them switch them out later with better and suitable one.
Michael
On the Tone board (p400) I decided to change all the transistors and the capacitors. I have located most of the parts. However I do have a concern with the tolerance of the following:
C405-C406 Elect., 10μF, 35V, +100%, -0%
C409 Elect., 100μF, 35V, +100%, -0%
I presume I can use
Elect., 15μF, 50V, +/-20% (giving 13.50μF to 18μF)
Elect., 150μF, 50V, +/-20%(giving 135μF to 180μF)
These are all NTE brand and they are the closest values my local electronic store stock. Should I go ahead and use them or should I get something more suitable from Mouser (perhaps you can suggest more suitable capacitor if the above is not suitable). Until I find the problem, I am trying to keep cost low. I don't mind using these first and them switch them out later with better and suitable one.
Michael
i have no trouble answering e mails also if i can help in this field that i have a lot of expirience i am more than happy to
on the other hand the manual i have composed is simple enough for any one to understand
also if you look at my previous answer you will notice that i say that you need to replace all small electoryltics inside ...no if ....no why ....just replace them all
for a machine like that there is no question ... what is the point to replave the tone control caps when secondary psu caps are all history and belive me you need more that psu caps than the tone control caps
yet again ther is no way that you will ever manage to operate this amplifier if you replace any tranistor with NTE ..... you will destroy a classic amplifier and make it a ticking bomb ....
kind regards sakis
on the other hand the manual i have composed is simple enough for any one to understand
also if you look at my previous answer you will notice that i say that you need to replace all small electoryltics inside ...no if ....no why ....just replace them all
for a machine like that there is no question ... what is the point to replave the tone control caps when secondary psu caps are all history and belive me you need more that psu caps than the tone control caps
yet again ther is no way that you will ever manage to operate this amplifier if you replace any tranistor with NTE ..... you will destroy a classic amplifier and make it a ticking bomb ....
kind regards sakis
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