With respect, and not meaning to sound offensive, but did you have the cables connected to the Audio outputs left and right connectors (often white and red), or to some other connectors?
globalweb said:
What kind of volume control is it? Is it part of the CD player and is it software or hardware controlled? Give us some more information. We don't know your system!
Gordy said:
.... or some kind of grounding issue.
Tell us more Globalweb. 🙂
Hi
The CD-player is the Njoe Tjoeb 4000 http://www.hifi-planet.com/hpah1.htm
Th amplifier is the AMP 6 from http://www.41hz.com/
When I come I’ll look for the volume control. I'm of to Milan now.
The CD-player is the Njoe Tjoeb 4000 http://www.hifi-planet.com/hpah1.htm
Th amplifier is the AMP 6 from http://www.41hz.com/
When I come I’ll look for the volume control. I'm of to Milan now.
actually, if the preamp is well designed, that figure should be that the signal is corrupted .01% or less (this is called distortion). other than the fact that you can add tone controls, etc... to a preamp, the two main reasons for having a preamp are 1> signal switching and routing, and 2> volume control.
reason 1 exists because people like to be able to re-record music, listen to various audio sources, and don't like replacing worn-out cables every month or so.
reason 2 exists, because people like to sometimes listen to their music loud, and sometimes not so loud. there are vast differences in the signal levels of different sources, and even between various recordings on the same source. there are also amps made with no volume controls. there are also vast differences in people's tastes of how loud they want to listen.
tone controls and other signal processing are a convenience that people happen to like. and a preamp is a convenient central location to put these functions into. at one time, music recording and playback offered no control whatsoever over source and playback levels. edison's phonograph offered only one recording level and only one playback level. whatever was present in the studio is what went onto the cylinder, and whatever was on the cylinder was what was played back. the technology for recording, then mixing and re-recording a master, did not exist.
reason 1 exists because people like to be able to re-record music, listen to various audio sources, and don't like replacing worn-out cables every month or so.
reason 2 exists, because people like to sometimes listen to their music loud, and sometimes not so loud. there are vast differences in the signal levels of different sources, and even between various recordings on the same source. there are also amps made with no volume controls. there are also vast differences in people's tastes of how loud they want to listen.
tone controls and other signal processing are a convenience that people happen to like. and a preamp is a convenient central location to put these functions into. at one time, music recording and playback offered no control whatsoever over source and playback levels. edison's phonograph offered only one recording level and only one playback level. whatever was present in the studio is what went onto the cylinder, and whatever was on the cylinder was what was played back. the technology for recording, then mixing and re-recording a master, did not exist.
globalweb said:
Have you tried using different interconnects?
Is the buzzing sound a low 50/60Hz? Does the buzzing sound change when you touch the metal of the CD or amp? This would indicate a grounding issue.
Does it sound OK with a preamp between CD and amplifier?
What happens to the buzz when you turn up the volume?
What happens when you play music?
Sorry for all the questions! 😀
If you have a MP3 player you can easily drive an amplifier directly from the player. That is the way i drive my amp, and when i want to connect the computer I just swap it.
Sonusthree
So far I haven’t tried different connects. I’ll do it as soon as I can
The buzzing sound is much higher than 50 – 60 Hz about 1000 Hz or so.
There is no change when I touch the metal.
It sounds ok when there is a preamp.
The buzzing doesn’t change when I change the volume.
I can play music but the buzzing is still there.
Also I tried something interesting. I put the probes of my multimeters between the connection of CD-output/power amp input and ground. There where definitely a change in the buzzing. It didn’t stop but the sound changed.
Any ideas?
IrishboyM4
MP3? Perhaps in the future. No plans so far.
So far I haven’t tried different connects. I’ll do it as soon as I can
The buzzing sound is much higher than 50 – 60 Hz about 1000 Hz or so.
There is no change when I touch the metal.
It sounds ok when there is a preamp.
The buzzing doesn’t change when I change the volume.
I can play music but the buzzing is still there.
Also I tried something interesting. I put the probes of my multimeters between the connection of CD-output/power amp input and ground. There where definitely a change in the buzzing. It didn’t stop but the sound changed.
Any ideas?
IrishboyM4
MP3? Perhaps in the future. No plans so far.
Here’s some FAQ taken from the CDP homepage:
“Can it be run without a pre-amp?
Yes. It has a volume control on the remote, and a very high quality analogue section (that is a big part of what you are paying for) with low output impedance, so even running 25 ft cables is no problem. Click here for info. The volume control is defeatable by pushing a button.”
And
“The Ah! Njoe Tjoeb 4000 has a volume control which is digital. Nice convenience if you have no pre-amp, or your pre-amp has no remote. Some notes on operation
• The volume control can be defeated by holding down the edit button for two seconds on the front of the machine.
• The volume performed in the digital arena, so the control should be as high as possible for the best sound during typical listening. At lower level you may lose some resolution...though people don't seem to notice as it is low for background listening.
• If you have an amp that needs little voltage, you can adjust the maximum voltage of the Njoe Tjoeb. It is set at the factory at 2.5v, but can be adjusted up to 5v, or down to 1.25v or .7v to fit a variety of systems. To change the voltage requires soldering and is quite easy. We can do it for you too now or later no charge for labor to the original owner.
• The control will lower the volume, but not all the way. It does not turn down to a whisper. With that, we have customers using the Tjoeb with no preamp and sing its praises. It may still be good to have a preamp if you need big volume swings on the fly.
The output section is robust, and has a low output impedance. So you have the option of using no pre-amp if that is your preference, or if you are in-between or waiting for your next pre-amp.”
Maybe it gives the answer.
“Can it be run without a pre-amp?
Yes. It has a volume control on the remote, and a very high quality analogue section (that is a big part of what you are paying for) with low output impedance, so even running 25 ft cables is no problem. Click here for info. The volume control is defeatable by pushing a button.”
And
“The Ah! Njoe Tjoeb 4000 has a volume control which is digital. Nice convenience if you have no pre-amp, or your pre-amp has no remote. Some notes on operation
• The volume control can be defeated by holding down the edit button for two seconds on the front of the machine.
• The volume performed in the digital arena, so the control should be as high as possible for the best sound during typical listening. At lower level you may lose some resolution...though people don't seem to notice as it is low for background listening.
• If you have an amp that needs little voltage, you can adjust the maximum voltage of the Njoe Tjoeb. It is set at the factory at 2.5v, but can be adjusted up to 5v, or down to 1.25v or .7v to fit a variety of systems. To change the voltage requires soldering and is quite easy. We can do it for you too now or later no charge for labor to the original owner.
• The control will lower the volume, but not all the way. It does not turn down to a whisper. With that, we have customers using the Tjoeb with no preamp and sing its praises. It may still be good to have a preamp if you need big volume swings on the fly.
The output section is robust, and has a low output impedance. So you have the option of using no pre-amp if that is your preference, or if you are in-between or waiting for your next pre-amp.”
Maybe it gives the answer.
globalweb said:
I'm afraid I'm lost!! The frequency that you mention doesn't make any sense to me. I would have assumed some kind of ground loop and it is still a very slight (???) possibilty that the 250Hz buzz is a harmonic of the mains frequency? Are you sure that there is no lower frequency content ,50/100Hz, in the 'buzz'.
Have you tried plugging the CD into a different mains circuit than the amp? This can help sometimes.
Come on folks, someone must have some better ideas.
Why do you need a preamplifier.
Yesterday I heard the best sound that I have ever heard, when a friend brought over his Oppo DV981HD universal player.(this player has improved , both in Audio, and even video via HDMI (!) since the switch mode bridge diodes were replaced by BYV26C
diodes, a parallel 100nF 630V fitted across the main PSU electro, and some sound deadening material fitted)
We fed the Oppo into a highly modified Musical Fidelity X-DAC V3, and then directly into my Class A 15W Ch. amplifier. The Oppo has the ability to control volume in the digital domain via SPDIF.
After this revelation, I have ordered an Oppo player.There doesn't appear to be too many other DVD players with SACD and DVD-A capability with this option.I will soon be adding an extra relay switched input to the Class A amplifier and using my very high quality Class A preamplifier for sources like DVB audio etc.
It appears that even the best preamplifiers, whether active or passive, degrade to some extent the ultimate audio quality.Why put 2 lots of electronics in tandem, UNLESS you need all the other facilities as mentioned in a previous reply ?
SandyK
Yesterday I heard the best sound that I have ever heard, when a friend brought over his Oppo DV981HD universal player.(this player has improved , both in Audio, and even video via HDMI (!) since the switch mode bridge diodes were replaced by BYV26C
diodes, a parallel 100nF 630V fitted across the main PSU electro, and some sound deadening material fitted)
We fed the Oppo into a highly modified Musical Fidelity X-DAC V3, and then directly into my Class A 15W Ch. amplifier. The Oppo has the ability to control volume in the digital domain via SPDIF.
After this revelation, I have ordered an Oppo player.There doesn't appear to be too many other DVD players with SACD and DVD-A capability with this option.I will soon be adding an extra relay switched input to the Class A amplifier and using my very high quality Class A preamplifier for sources like DVB audio etc.
It appears that even the best preamplifiers, whether active or passive, degrade to some extent the ultimate audio quality.Why put 2 lots of electronics in tandem, UNLESS you need all the other facilities as mentioned in a previous reply ?
SandyK
globalweb, I think you may have to try substitution to trace your problems. Try and borrow another amplifier, substitute it into your system, and using the same CD player, see if the problem is still there.
If the problem is still there then the problem is inside the CD player.
You say the problem is 250Hz? How strange. I am guessing, but the power supply may be the best place to start looking. As SY said, you are likely to need a 'scope.
If the problem is still there then the problem is inside the CD player.
You say the problem is 250Hz? How strange. I am guessing, but the power supply may be the best place to start looking. As SY said, you are likely to need a 'scope.
Thank you all for your interest.
About the frequency. All I have is a PC tone generator. And its speaker can’t produce any lower tone then about 105 Hz. So maybe I have frequency’s of 100 and 50 but I can not tell. Sorry.
Trying different mains I will definitely do. I just need to buy longer power cords. Hopefully this weekend.
Sticking a scope on the power supply rails.
I’m a bit of a dummy when it comes to electronics so if anyone could give me some guidelines would be much appreciated.
Exactly where do I measure? What should I look for? After the power supply capacitor?
Substitution solution, will absolutely do. As soon as I can get hold of another CD player.
Anybody have any ideas why the buzz changed when I put the probes between earth and output?
About the frequency. All I have is a PC tone generator. And its speaker can’t produce any lower tone then about 105 Hz. So maybe I have frequency’s of 100 and 50 but I can not tell. Sorry.
Trying different mains I will definitely do. I just need to buy longer power cords. Hopefully this weekend.
Sticking a scope on the power supply rails.
I’m a bit of a dummy when it comes to electronics so if anyone could give me some guidelines would be much appreciated.
Exactly where do I measure? What should I look for? After the power supply capacitor?
Substitution solution, will absolutely do. As soon as I can get hold of another CD player.
Anybody have any ideas why the buzz changed when I put the probes between earth and output?
On the original question of why do you need a pre-amplifier.
I think some of the confusion on this topic may revolve around the fact that discussions of specific pre-amplifiers tend to revolve around the gain stage.
Reading these discussions, one can easily come to the conclusion that the whole reason to have a pre-amp is just for the gain stage.
I think some of the confusion on this topic may revolve around the fact that discussions of specific pre-amplifiers tend to revolve around the gain stage.
Reading these discussions, one can easily come to the conclusion that the whole reason to have a pre-amp is just for the gain stage.
slightly off topic / Oppo player
sandyK: " ... the best sound that I have ever heard, when a friend brought over his Oppo DV981HD universal player. ..."
Besides volume control via the remote, it also has several EQ options ... in case you don't have a sub woofer, try the "Live" setting ... This player also has a "secret" code that will allow playing of all Zone1 and PAL Zone2 DVDs ... plus as you now know, DVD-audio or SACD discs = much more "universal" than most = 😀
" ... the switch mode bridge diodes were replaced by BYV26C diodes, a parallel 100nF 630V fitted across the main PSU electro, and some sound deadening material fitted) ..."
Is this some sort of Mod to the Oppo player or to a pre-amp ?? If to the Oppo, please start another topic, say over in "Digital" or somewhere besides this thread = Thanks ...
FYI: I play my Oppo '981 through a BottleHead tube pre-amp then through a DIY MOSFET amp through two mains only = ordinary old fashioned stereo ... 🙂
sandyK: " ... the best sound that I have ever heard, when a friend brought over his Oppo DV981HD universal player. ..."
Besides volume control via the remote, it also has several EQ options ... in case you don't have a sub woofer, try the "Live" setting ... This player also has a "secret" code that will allow playing of all Zone1 and PAL Zone2 DVDs ... plus as you now know, DVD-audio or SACD discs = much more "universal" than most = 😀
" ... the switch mode bridge diodes were replaced by BYV26C diodes, a parallel 100nF 630V fitted across the main PSU electro, and some sound deadening material fitted) ..."
Is this some sort of Mod to the Oppo player or to a pre-amp ?? If to the Oppo, please start another topic, say over in "Digital" or somewhere besides this thread = Thanks ...
FYI: I play my Oppo '981 through a BottleHead tube pre-amp then through a DIY MOSFET amp through two mains only = ordinary old fashioned stereo ... 🙂
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