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Hey Parke, ive recently purchased a Pioneer amplifier and Cd player/recorder to include in my home Dj set-up.
After connecting my Pioneer stereo amplifier to my mixing controller speakers, Cd player... I switched the amp on and noticed the speakers were making a humming noise.
When re-checking the wiring i discovered it was distortion and wondered that the amp might be too powerful for the speakers?
Ive only a couple of tiny 100Watt, 4-8db Wharfdale speakers ---> http://www.amazon.co.uk/Wharfedale-XR1000-Hifi-Speaker/dp/B000BO10CC/sr=1-3/qid=
for my Pioneer A-209R ---> http://www.amazon.co.uk/Pioneer-45w-din-Stereo-Amplifier/dp/B00005OOJG/ref=sr_11
I now know from reading comments on this site that this is quite harmful to the speakers and more importantly the amplifier itself.
I was hoping you could give me some advice on whats the minimum power output i need, or what type would be the best for sound quality at a reasonable price?
Hope you can help
Thanks, Chris
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Hi Chris,
I'm a little fuzzy on your terminology here... "You discovered it was distortion"...? Can yoou describe that a little more? Was this distortion when something was playing (so everything sounds like a Hendrix solo); was it an occasional "crackle" or "pop" either during silence, during music, or both; or was it just a slight but pervasive "hiss" or water-fall sound that is always in the back-ground?
-It's important that you get back to me on this so we can figure out where the problem is.
And what do you mean by home DJ set-up - are we talking about Karaoke or scratching vinyl?
I'm very familiar with Wharfdale, but not familiar with your description of them as 4-8dB.
Using an amp that is a higher rating than the speakers usually ends up in blown speakers if someone doesn't know what they are doing or can't restrain themselves, but it is possible to manage "gain" on the amp and do just fine (so long as you don't "rock-out" and forget when you try and crank the volume too high).
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Hello, the distortion occures once the amplifier is turned on at low volume (no music being transmitted through). Its a constant humming sound ---> hmmmmmmmmmmmmmmmmmmm like a hiss/waterfall sound yes, which continues if i was to play music.
My Dj set-up consists of 2 Vestax PDX2000 turntables and a Stanton SA3 Channel Mixer (basic mixer) for vinyl/records. Soz i meant the Wharfdale speakers are 4-8'ohms' and 88db.
How do i manage the gain on the amp, for the time being till i purchase some improved speakers?
Tx Chris
Answer -
Hmm... well, again you're using mixed terminaology here.
If the noise is more like a hum, you've probably got a 50-cycle (I'm guessing your on British AC power where you live) hum being picked up, mostly likely either by induction (your power and audio wires are close enough together that one is interfering with the other) or from a ground (a.k.a. "earthing") loop/fault.
The first problem is going to take some vigilence, since you're using all unbalanced audio (which is very prone to picking up unwanted noise).
Start at the turntables and work your way to the speakers, keeping tabs on each of the three categories of cablling: AC Power, Audio interconnect (hook-up) cable (RCA's), and amplified speaker cable.
-each type should be seperated by at least 2 feet from the other types.
-Where cables of two different types have to cross or be close together, they should do so perpendicular to one another (90-degrees like a cross).
-keep cable lengths as short as possible, ESPECIALLY the hook-up cables going to the amp.
-if noise continues you should consider using shielded, twisted conductor RCA cables, like those from Lightning Audio.
-It's also a good idea to not have different audio interconnect signals (turntable to mixer, mixer to amp, etc.) run parrallel to and touching each-other for more than 30cm, but it doesn't sound like this is a problem for you.
The second problem MAY be fixed with some good AC power supply discipline:
-ALL AUDIO EQUIPMENT involved with this system should be on the same circuit... in your case (see second recommendation, below) distributed off the same outlet.
-Get a really good power conditioner with EMI/RFI filtering, like these (make sure they are compatible with your AC standards):
http://www.surgex.com/products/sx1115.html
http://www.sweetwater.com/store/detail/PD11LVP/
NOTE that a computer UPS may or may not have EMI/RFI filtering or the current draw you need, and a surge supressor doesn't have anything useful to you at all.
-Check for ground loops: Are your turntables metal? Are they touching your mixer? Is there any way in which two pieces of gear might be bolted together that might conduct electrically or magnetically? You may want to find a way to isolate all of your equipment from one another.
Be forwarned, if you insist on using consumer grade parts to "DJ", you may never be fully rid of it. In the professional world, all of that should be shuttled over as soon as possible to "Balanced Audio". Without going too far into it, blanced equipment is doubly insured against noise and offers way more sound fidelity.
If I'm way off the mark here, let me know and I will happily help you address the actual problem, especially if it is indeed more of a "static/waterfall" sound than a hum.
Oh, and I forgot to mention - If you don't want to make a major investment, the best way to "Manage Gain" in your case would be to keep the volume down to below the point where you hear the speakers "clipping". This may limit you to a "volume" that is definately not "rocking out", but it may also be the difference between "Upgrading" and "Replacing".
Otherwise, I can recommend some step-down transformers for you from Electrovoice, but unless you know what a :Constant-voltage transmission line" is or have had some training in electronics this is probably not your best option.
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My mistake Parke the amplifier has got a hissing/fuzzing sound once power is on by itself. Then when connecting the stylus(needle) to the record it begins to hum at a high pitch?
Anyway, yes good old British power here in England dude. So would the power leads from the electrical equipment going into an extension lead matter much? One of the plugs off the turntable has its earth pin missing, could that be the fault? Because saying that now ive only tried the new amplifier out on that turntable or would it be the same?
Whilst the music begins to play it sounds clear(because the distortion is hidden). Although when the bass comes in on the along the drive track its a heavy noise which is unpleasant as there is an incorrection somewhere.
The cables are quite parted from one another---> the phonos from mixer to turntables, the phonos from mixer to amp and the earthed wires connected from turntable to mixer. I have some photos of my set-up if you'd like to view it for yourself?
The 2 seperate cables going from mixer to amp are high quality coaxial phono leads. They are 1.5 metres long, which i know you say needs to be short for quality, although it really needs to be that length from how the set-up is layed out(see pic). I can't see myself how this would cause much for concern, but i suppose your the 1 with the technical knowledge on electronics.
Answer -
Well the hissing sound is one thing...
Usually that's a sign of incorrect gain structure - if you have your amp turned all the way up and your mixer is down low for instance. Google "Gain Structure" and your should fine a zillion articles on the topic, here's one I like:
http://www.community.chester.pa.us/files/technote/gainbasc.pdf?PHPSESSID=34d641e
Essentially, you need to send the cleanest possible signal to your amp (not too low so that the signal is so "quiet" that you have to crank the amp - thereby amplifying both the audio and the background noise - but not so high that it's boosted or distorted). Then and only then do you adjust the volume on the amp to your liking.
-You might also find Gary Davis's Sound Reinforcement Handbook (distributed by Yamaha) informative.
The buzzing - the #1 suspect would be chassis earthing ... use ony plugs with earthing pins and buffer them as I mentioned before - ESPECIALLY your record player without the ground plug. YOu'll likely have to fix that by making a new plug - cut off the old one (at the far end, not near the player), strip back the wires a few cm and wire in a new three-prong plug.
The motor on that turntable is pretty small, but is the most likely source of a high-pitched whine.
Using a few extension cords shouldn't matter much, so long as they're all plugged into the SAME CIRCUIT and you find a way to condition the power as I described before. It sounds like the rest of the system is interconnected optimally.
I will be over here hoping all this helps. If it doesn't, feel free to get back to me - even if it is months later.
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Hello again, sorry to keep bothering you but i have now found when i connect the phono leads from the mixer into either tuner or cd connection points the problem is solved!? The music flows through these points like water and finally theres no distortion atall.
The connection circuits(on the rear of the amp) should serve the same purpose as one another shouldn't they?
The amplifier is brand new and im now thinking that after all this time the phono connection point could be faulty? If this is right i will have to replace the amp with a new one.
I havn't yet tried the pioneer amp on my friends set-up to see if the same proble occurs, but im sure i will find the answer to this inconvience shortly.
AnswerI'm a little confused by what you mean here... can you explain a little more?
Do you mean that if you plug the turntable into something else the noise goes away, or if you plug something else into the amp the noise goes away?
If you can be explicit but precise it might help - read off the lables on the connectors and give me the exact terminology of what output is going to what input.
