I have a vintage Pioneer SSX-1000 receiver. This does just fine driving my speakers, and was OK with Sennheiser PX-100s. Just got a pair of HD-555s, and discover there is an annoying level of noise, which is not affected by the volume control.

I'd be grateful for advice on a cost-effective solution. I can think of three broad categories:

1. Shouldn't happen -- the receiver needs servicing (which may be expensive?)

2. Old amps vary in the noise level of the phones socket -- worth listening to some others

3. Better to get a CMoy

4. Unknown unknown.


TIA for advice at a distance.

no surprise. You need to get an amp. Cmoy should be OK if you are not too picky. It may not eliminate the noise floor. Maybe try to find one with a low gain.

If you like the receiver, have it checked out. Most diagnostics and cleanings are about $20. You can always check out the fees beforehand and then decide if it's worth it to you. Depends on the receiver quality imho.

If the noise is a hum or buzz,you may have a leaking capacitor in the power supply or pre-amp.If you are inclined at all,you can get a chill spray from an electronics repair store and isolate the offending component by chilling them one at a time.

If it just a noisy contact type of noise, try spraying the internal headphone jack contacts with a contact cleaner/solvent. Touching up the solder points may also solve the problem.

If the noise is not heard through the speakers or altered by the volume control,it is likely the jack connection.

If the noise was acceptable with the old headphones but not with the new (presumably more sensitive) ones then a simple solution might just be to attenuate the output of the amplifier. Since the noise is independent of the volume setting, raising the volume to compensate for the added attenuation will leave the noise at a lower value.

yes, simply connect a resistor in series with each channel.

If this person is truly "technically ignorant" I doubt they will put resistors in series anywhere. They may not even have a soldering iron. Imagine that.

I do have a soldering iron *somewhere*, but I wouldn't dream of bringing it anywhere near electronics, or of futzing with anything involving mains voltages (which might, in any case, be illegal in New Zealand).

My ignorance is exceeded only by my manual ineptitude

Thank you for all the help so far -- it looks like a trip to a repairer might be the first step.

Michael

Why?! And of what value?! It will alterate the channel's impedance. I don't think it is a good solution.

Before you arrange for a repair, try this: while listening to music, slowly rotate the plug inside the receiver's socket. Does the noise become intermittent? If so, purchase a good quality electrical contact cleaner.

I use Caig, but there are others which are probably just as good. I also invested in some reusable brushes which fit perfectly into headphone sockets and female RCA connectors. I usually put a couple of drops on the brush and clean the socket first, then I use a lint free cloth to use the cleaner on the plug. There will always be a little cleaner residue left in the socket, which is no big deal. Just insert the plug, wipe, repeat until it comes out dry.

Since the noise only occurs with one of your headphones, I'm guessing that the culprit is the plug of your newer headphones. You could also try plugging each into another device to troubleshoot.

Good luck,

John

Thank you all for your help. You have stimulated me to investigate a bit further, and as it's now too late here to get it in for service before next week, I'll impose a bit more on your patience.

The Sennheiser HD 555s are OK: nice inky black silence when connected to my puter or iRiver. They have a 1/4" plug, which goes naked into the Pioneer phone socket, so it's not adapter trouble. Rotating the plug in the socket produces no effect (except for making the woodpecker say "Lord bless my soul!", but that's in a very old song ).


The troublesome sound I now think sounds like AC hum. The interconnect was routed through a rat's nest of wires, but I've dragged it clear of all power cords, and the noise is still the same. It's also unaffected by the volume control, as I said, so I guess it's not something picked up through the input. (There's also a high pitched hiss that appears when the volume is turned up to about 7, but that's not what I'm bothered with, and I normally only have the knob halfway round the dial, anyway.) Even when I've cranked the volume up really high, I don't hear any of the noise coming from my speakers (which are KEF C Series bookshelf jobbies, in case it makes a difference).

My totally ignorant guess is that this is pointing to a leaking capacitor type of problem, which means it needs a trip to the hospital but should be fixable, yes? Or, no?

I'm going on a bit because there aren't too many audio repairers here, and the minimum charge is likely to be pretty close to the cost of a cmoy, so I'd like to have some sort of clue before I commit money.

With many thanks again

Michael

I can guarantee you that the repair shop won't "fix" it because nothing is broken.

High efficiency headphones like the PX100 were not what Pioneer had in mind when your receiver was built. You are most likely hearing ordinary amplifier noise that is really part of the design, not a defective component. Yes, a power supply rebuild might reduce some hum, but in all likelihood it was always there and you just couldn't hear it.

Simplest, cheapest solution: go to Radio Shack and get an in-line headphone attenuator cable for about $8. It is a short interconnect with an in-line volume control. Knock that down about half way and turn the Pioneer up, it will work. I use that all the time as an easy fix for noisy laptop headphone outputs, too.

http://www.radioshack.com/product/index.js...rentPage=search

Simple, not so cheap solution: get/build a headphone amp and don't use the receiver. More "tweaky" than the solution above, may or may not yield better results for you.

The hum, if it is 60hz, is from your power supply,most likely a leaking capacitor.

Reversing the power plug into the wall may reduce the problem.

Cooling the capacitors with the spray I mentioned earlier will isolate the leaking component.

I'm keeping this going, just in case it will ever be of any use to anyone else.

I tried an attenuator (which I take it is functionally equivalent to adding resistors, if not technically the same), but alas once I'd attenuated enough to lose the hum, I then lost the ability to get adequate music volume. I couldn't use a Radio Shack part since, although New Zealand is supposedly part of the advanced industrial world, Radio Shack doesn't operate here. Got one from a chain that is about one step below RS in quality (true).

Doubtless the old receiver would benefit from an overhaul, but I'm moving towards the headphone amp idea. Is there anything that will give perceptible improvement in SQ over a well-made cmoy for a modest increment in price? My ears, BTW, are 62 years old and don't hear anything much above 11 kHz.

Once more, thanks for all your help.

Michael