This may be an extremely basic question but would appreciate some help. Just got an A400 off ebay and it works great connected to my arcam dv79 and Kef IQ5SE's but if I try to connect it to any other source via the other inputs there is a very noticeable speaker hum. What am I doing wrong?
Speaker Hum with Pioneer A400
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A WDTV via RCA and even trying to connect the CD player to the tuner or tape inputs produces the hum. all the other inputs seem to have a metal ring protruding from them which seems to be missing from the CD input. Does this make a difference? or have I been sold a dud? If I connect the WDTV to the CD input I get no hum either.
not sure .... I have owned 2 A-400's but have only ever connected speakers and cd players to the amps (with no problems whatsoever)
dim_span:not sure .... I have owned 2 A-400's but have only ever connected speakers and cd players to the amps (with no problems whatsoever)
Thanks for trying to help anyway.
Thanks for trying to help anyway.
amarocknrollstar:Silly question but you DID turn the amp off before connecting?Might solve the problem...
Yes I did but hum started once amp was switched on again.
Yes I did but hum started once amp was switched on again.
Checked that it's connected properly....i.e positive to positive and vice versa?
Checked that your interconnects are working properly?
Checked that your interconnects are working properly?
matthewpiano
Well-known member
- Nov 23, 2007
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All the inputs on a Pioneer A400 should look the same. The fact that they don't sounds a little suspicious to me.
Both A400s I've had have had slightly noisy transformers, but then so have quite a few newer amps I've owned including Cambridge and NAD ones. If its noticeable through the speakers then I'd say it could be faulty.
Both A400s I've had have had slightly noisy transformers, but then so have quite a few newer amps I've owned including Cambridge and NAD ones. If its noticeable through the speakers then I'd say it could be faulty.
Oooooh, that's interesting - I expect to receive a Fleabay A-400 next week, as recommended by Dim_Span. The first one I won fell through...literally, the poor seller dropped it as he was preparing it for P&P. At least he was honest enough to immediately cancel the transaction and apologise for the inconvenience. I just hope the back-up arrives in good working order and knows the words!
Have you got a relatively tidy cable arrangement, rather than a nest of snakes? Any chance of interference from other cable runs?
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Have you got a relatively tidy cable arrangement, rather than a nest of snakes? Any chance of interference from other cable runs?
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
ESP2009:
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD.
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD.
dont own any A400 amps at the moment, however, my son has an A300R Precision ... don't want to switch on the bedroom light now, as he is sleeping and has college tommorow ....
will have a look at the connectors in the morning and post (think that they are the same as the A400)
will have a look at the connectors in the morning and post (think that they are the same as the A400)
ESP2009:ESP2009:
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD
The CD input (which is the one that is different from the others) is the only one that doesn't produce a hum. I want to use the other inputs for my WDTV and also to connect the preouts from my Yamaha RXV 3900.
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD
The CD input (which is the one that is different from the others) is the only one that doesn't produce a hum. I want to use the other inputs for my WDTV and also to connect the preouts from my Yamaha RXV 3900.
DrEye:ESP2009:ESP2009:
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD
The CD input (which is the one that is different from the others) is the only one that doesn't produce a hum. I want to use the other inputs for my WDTV and also to connect the preouts from my Yamaha RXV 3900.
My reply was an object lesson in what happens when you read a thread and respond while being distracted by the other half telling you all about the wonderful Virgin Vie party she's just attended! Sorry. Anyway, take a look at these...
[/b]
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD
The CD input (which is the one that is different from the others) is the only one that doesn't produce a hum. I want to use the other inputs for my WDTV and also to connect the preouts from my Yamaha RXV 3900.
My reply was an object lesson in what happens when you read a thread and respond while being distracted by the other half telling you all about the wonderful Virgin Vie party she's just attended! Sorry. Anyway, take a look at these...
Can I just say I worked for a HiFi dealer in the 90's. We sold literally tens of Pioneer A400's and indeed bought one myself. I had mine only untill a month ago when my Father-in-law bought it off me. However, every A400 I tried had a slight hum from the speakers even if nothing is connected to the inputs and the volume control turned right down, some A400's showed this up more than others.
Our workshop Technicians tried hooking a few of these up to an Oscilloscope and identified a slight ripple in the power supply which caused the hum, but be assured it really isn't anything to worry about.
You will usually only hear it if the room is quiet and you put your ear close to the speakers.
Our workshop Technicians tried hooking a few of these up to an Oscilloscope and identified a slight ripple in the power supply which caused the hum, but be assured it really isn't anything to worry about.
You will usually only hear it if the room is quiet and you put your ear close to the speakers.
Tesler:Can I just say I worked for a HiFi dealer in the 90's. We sold literally tens of Pioneer A400's and indeed bought one myself. I had mine only untill a month ago when my Father-in-law bought it off me. However, every A400 I tried had a slight hum from the speakers even if nothing is connected to the inputs and the volume control turned right down, some A400's showed this up more than others. Our workshop Technicians tried hooking a few of these up to an Oscilloscope and identified a slight ripple in the power supply which caused the hum, but be assured it really isn't anything to worry about. You will usually only hear it if the room is quiet and you put your ear close to the speakers.
I disagree with you on this issue ... I have personally owned 2- A400's and can say I never had a problem with humming or sound from the speakers, when the volume was turned right down, or max volume ... (I always check especially when buying 2nd hand)
I have also set up several systems for my son's college mates last year, and several systems included the A400 amp .... tested them all and only one had a crackling sound when the volume control was turned .... we got a full refund from ebay as we specifically asked if there was any crackling etc before bidding
My son's Pioneer A-300R precision also has no issues with humming whatsoever
I disagree with you on this issue ... I have personally owned 2- A400's and can say I never had a problem with humming or sound from the speakers, when the volume was turned right down, or max volume ... (I always check especially when buying 2nd hand)
I have also set up several systems for my son's college mates last year, and several systems included the A400 amp .... tested them all and only one had a crackling sound when the volume control was turned .... we got a full refund from ebay as we specifically asked if there was any crackling etc before bidding
My son's Pioneer A-300R precision also has no issues with humming whatsoever
There is another thread that I started about speaker hum, it could be a ground loop problem and tacima are developing a product to solve it if you look for the thread in hifi section?
ESP2009:DrEye:ESP2009:ESP2009:
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD
The CD input (which is the one that is different from the others) is the only one that doesn't produce a hum. I want to use the other inputs for my WDTV and also to connect the preouts from my Yamaha RXV 3900.
My reply was an object lesson in what happens when you read a thread and respond while being distracted by the other half telling you all about the wonderful Virgin Vie party she's just attended! Sorry. Anyway, take a look at these...
[/b]
[/b][/b]
Yes mine definitely looks different. the CD input that is. The seller has offered to take it back now after I explained the problem. Thanks for the photo its a great help!
Actually, I will check the photos of my impending arrival - may give a clue about your CD input...
Hmmm, the photos from the listing seem to indicate that all inputs are the same - the CD input looks no different from the rest.
Theoretically, and I stand to be corrected, if you have a spare input you can use that for the CDP and leave the input marked as CD unused. I am not completely sure of my ground, but I don't think it really matters much which non-phono input you use, although some models may be different. My 8000S actually states that the 6 line inputs may be used for any line level source, inc CD
The CD input (which is the one that is different from the others) is the only one that doesn't produce a hum. I want to use the other inputs for my WDTV and also to connect the preouts from my Yamaha RXV 3900.
My reply was an object lesson in what happens when you read a thread and respond while being distracted by the other half telling you all about the wonderful Virgin Vie party she's just attended! Sorry. Anyway, take a look at these...
[/b][/b]
Yes mine definitely looks different. the CD input that is. The seller has offered to take it back now after I explained the problem. Thanks for the photo its a great help!
Tesler:Can I just say I worked for a HiFi dealer in the 90's. We sold literally tens of Pioneer A400's and indeed bought one myself. I had mine only untill a month ago when my Father-in-law bought it off me. However, every A400 I tried had a slight hum from the speakers even if nothing is connected to the inputs and the volume control turned right down, some A400's showed this up more than others.Our workshop Technicians tried hooking a few of these up to an Oscilloscope and identified a slight ripple in the power supply which caused the hum, but be assured it really isn't anything to worry about.You will usually only hear it if the room is quiet and you put your ear close to the speakers.
The hum is very loud. Not just a low background noise but really quite noticeable.
The hum is very loud. Not just a low background noise but really quite noticeable.
DrEye:
Yes mine definitely looks different. the CD input that is. The seller has offered to take it back now after I explained the problem. Thanks for the photo its a great help!
Glad I was able to help despite starting off on the wrong track.
I wonder whether it was one that I also bid on? The one I actually won is described as in 'fair condition' but in 'good working order', so fingers crossed.
Yes mine definitely looks different. the CD input that is. The seller has offered to take it back now after I explained the problem. Thanks for the photo its a great help!
Glad I was able to help despite starting off on the wrong track.
ESP2009:DrEye:
Yes mine definitely looks different. the CD input that is. The seller has offered to take it back now after I explained the problem. Thanks for the photo its a great help!
Glad I was able to help despite starting off on the wrong track.
I wonder whether it was one that I also bid on? The one I actually won is described as in 'fair condition' but in 'good working order', so fingers crossed.
Yes. Thanks alot for your help. I'm sure yours is fine. It sounded great though!
Yes mine definitely looks different. the CD input that is. The seller has offered to take it back now after I explained the problem. Thanks for the photo its a great help!
Glad I was able to help despite starting off on the wrong track.
Yes. Thanks alot for your help. I'm sure yours is fine. It sounded great though!
I believe I found the A400's 'Achilles Heel' based on the foregoing. The Fleabay A400 I won arrived (a different one, I might add) and I have straight away come across a very similar problem.
The CD input is not reliable - I had to fiddle with the interconnects at the amp end until I got a decent connection, and even then a slight movement caused noise on the speakers. As it is second-hand and relatively cheap, I opened the box up having noticed a degree of 'give' at the input.
Once open, it becomes clear that pressure has caused the CD input block to come away slightly from the casing, compromising the ability to get a clean connection. The root cause? All the other sections of the input assembly have a screw holding them in place; the CD is the exception. It must rely on the integrity of the rest of the assembly and whatever glue that may or may not be applied.
I have applied some superglue to the area in question and will try it again in due course.
For want of a screw...
The CD input is not reliable - I had to fiddle with the interconnects at the amp end until I got a decent connection, and even then a slight movement caused noise on the speakers. As it is second-hand and relatively cheap, I opened the box up having noticed a degree of 'give' at the input.
Once open, it becomes clear that pressure has caused the CD input block to come away slightly from the casing, compromising the ability to get a clean connection. The root cause? All the other sections of the input assembly have a screw holding them in place; the CD is the exception. It must rely on the integrity of the rest of the assembly and whatever glue that may or may not be applied.
I have applied some superglue to the area in question and will try it again in due course.
For want of a screw...
I actually just unpacked my A-400 after 2 years of living in a storage,only to find Id lost a channel and had slight humming from the other,I took it apart and found that some if not all inputs had dry solder joints,not tested yet but should hopefully have cured problem after a few minutes with a soldering iron 😀
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