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auscab
17th February 2018, 03:05 PM
Hi .
I have a pair of nice Tannoy speakers which I made the boxes for 37 years ago . They still get used and are now set up in their new home in my workshop. Not much point having them in the house because who gets to listen to decent music with the wife and kids around anyway . Not Me .
I'm always getting " Turn it down "

Any way the speakers have been developing a strong thick crackle type distortion especially on start up as they warm up ,but its getting worse. The distortion is now coming back at quieter sections of music and stronger louder bits just push through it and it goes away again.

So Ive been reading up about it online and what I have read is to clean or spray connections with either contact cleaner, or most recommended is a US product called Deoxit . It comes in a rejuvenator kit from Jaycar.
Any experience with this or these products, or is there a better way?
The contact cleaner in spray cans is a lot cheaper will that do it ? or go the $30 plus post or pick up with the Deoxit ?
I don't mind giving them the best treatment I can, they are very special to Me.
I just don't want to pay a lot more if its the same thing.

The speakers also have crossover switches at the rear and I did read this could also be a problem area so I will have to treat that as well .

Also what about where the wires terminate at the speaker ? I think they are soldered on .
Ill have a look but If that is the case should I leave them . Only clean and treat if its a plug ?

Thanks
Rob

DavidG
17th February 2018, 03:22 PM
Sometimes old speakers sag and rub their voice coil on the speaker magnet core.
Try turning the boxes upside down for a while and see if it changes.

Bohdan
17th February 2018, 04:28 PM
Rather than invert the boxes rotate the speakers 180.

Chris Parks
17th February 2018, 05:05 PM
Could it be noisy pots in the amp?

Skew ChiDAMN!!
17th February 2018, 05:30 PM
It does sound like it may be a capacitance issue but have you swapped out the speakers with another, known set to be sure it is the speaker(s) and not elsewhere in your system? (eg. amp, pre-amp, whatever.)

I'd recommend using new speaker wire for this test as well as old cabling can break down from age, even without flexing, and give similar effects.

It's also worth looking at the cross-over PCBs looking for potential dry joints. A quick touch of a soldering iron to each would ensure this isn't a possible cause.

Cleaning the contacts every few years is a good idea anyway, if you're a true audiophile. Even if you have no problems! I like Deoxit for this as other, cheaper cleaners can be a tad harsh. Fine to clean contacts once or twice (eg. for soldering) but I wouldn't base even a decadely cleaning regimen on them.

Personally, in your shoes I'd just use a cheaper cleaner just to see if cleaning makes any difference at all.

Even if it does fix things I'd still recommend checking the other things I've covered. When age becomes involved it's often lots of little things adding up to cause the problem and while fixing one may seem to make the problem go away... it'll only take another little thing becoming worse to seemingly bring the same problem back but not be fixable in the same manner as last time.

My beloved custom DA towers are coming up to 38 years old now and have outlasted many an amp (...and partner. :rolleyes:) I know what you mean by their being special to you. :)

auscab
17th February 2018, 08:39 PM
I turned them upside down and they still did it but it may have been less , Im not sure . Ill try them the right way up again tomorrow and see. sounds like its a good idea to turn them in the boxes any way . Id turn them and not just the boxes if its the main problem . Don't know any thing about pots in the Amp hopefully its not that. I have another set of smaller speakers nearby so Ill try them out . Ive been meaning to get on to fixing this for months . I want to raise the speakers up high so have to get it sorted before I do that .

Ill clip the ends for some fresh wire first and try that . Its looking a bit old on the ends. Try the other speakers and then get some cheap contact spray . The boxes were made for the speakers. I bought the speakers off a shop that dealt in mainly Tannoy speakers and other Hi Fi gear like Amps and the brand new CD with its player that had just come out .
They had a pair with no boxes for some reason . So I worked out the internal dimensions of the English box that they came in and built them to that out of 25mm MDF . Then veneered them in Mahogany . They are braced on the inside and packed out with wadding held in place with Hession . They are heavy .
First had them on a Yamaha 80 W amp that the shop sold as well . loved that amp but it started having problems years later and I gave it to the wrong guy to fix , it got worse from there . He fitted a new transformer that was to big for it and buggered it right up . I used a Rega Planner 2 turntable for the records . And had some crazy Hi Fi nights with the mates over in the days we were all apprentices :).
Crystal clear perfection it was . Or as close as I could afford to get a great sound.

Rob

DavidG
17th February 2018, 08:48 PM
Inverting the boxes or speakers will take weeks for any results to become obvious. It has taken years for the sag to develop

derekcohen
17th February 2018, 09:01 PM
Rob, I'd swap out the amp and see if a different one duplicates the crackle. In my experience with ageing amps (like their owner), the joints begin to go. I've have to twice deal with a crackling volume control. This responded to cleaning (compressed air).

Regards from Perth

Derek

auscab
17th February 2018, 10:09 PM
Rob, I'd swap out the amp and see if a different one duplicates the crackle.

I could try that if I had another amp Derek but I don't have a second one . I hope I don't have to go amp shopping .

Rob

derekcohen
17th February 2018, 10:32 PM
Rob, those old Tannoys are very efficient speakers. This means that you could connect a low power source to one, such as a bedside radio. Perhaps that may be enough to get sound sound from them. Alternately, try the amp with headphones - I assume the output is from the same control? What amp do you have, and how old is it?

Regards from Perth

Derek

auscab
17th February 2018, 11:04 PM
The Amp is an Onkyo integra Derek . The speakers are a dual concentric from around 1981.

Rob

derekcohen
18th February 2018, 01:41 AM
The amp has a headphone socket. Try it with headphones - you do have headphones? Do you still get the crackle when the volume control is adjusted?

Regards from Perth

Derek

auscab
18th February 2018, 11:16 AM
I have headphones for use at the computer but the jack is 3mm roughly . The Amp one is next size up .

I'm going to try freshen the speaker cable ends this morning then I'll swap speakers out . And if its still there I'll start worrying that its the Amp .
If its the speakers then Ill buy some contact spray and see how that goes.
I'm thinking if there was a slight difference in crackle like I though I possibly heard yesterday when I flipped the speaker boxes then it may be the cable end . I haven't actually given them a wiggle while the problem shows itself. I do know the cable ends are oxidized and not fresh .
Rob

FenceFurniture
18th February 2018, 07:27 PM
The Amp is an Onkyo integra Derek . The speakers are a dual concentric from around 1981.What is the age of the Amp Rob, and is it Stereo or 5.1 or similar? I had a 1999 vintage Onkyo 777 (with other letters there too) which was a 5.1 jobbie. About 2 years ago, maybe 3, it started buzzing (a constant buzz) when first turned on. This would more or less disappear once it warmed up - depending upon winter or summer it would be 3-8 or so minutes (we're a cold climate here). This was clearly a heating issue, in that a bit of heat was required to get rid of the buzz. We got into the habit of turning it on enough minutes before we needed it, so it wasn't a huge big deal, but annoying enough.

Then, about a year ago, it started turning off and then back on seemingly at random. It could do this a few times in a row, and it seemed to be worse in hot weather. This was not just annoying in the end (and annoying in the "end") it just had to be replaced. So this was due to over-heating, it would seem. Clearly this amp had a very finicky temp range where it would work properly.

I did some research and found a new model Onkyo on runout special for a good price (somewhere around $900) and consulted with a friend who knows about such things. He said he didn't like Onkyo's because of the way they didn't handle heat. "Funny you should mention that....."

So I bought a Denon 7.1 AVR-X2400H and crikey it's a good thing. I only have 5.1 speakers in the main room so I can use the extra two channels stereo cordless speakers in another room if I want. Amps these days are as cheap as chips when you consider what you get. Connected to the net through my modem for Spotify et al, automatic firmware updates - one happened a couple of nights ago. The sound quality from a Direct to Disc Vinyl (San Francisco Ltd) with the amp set to "Pure" (aka Direct) is just beautiful. The sweetest acoustic bass I've ever heard.




I have headphones for use at the computer but the jack is 3mm roughly . You can get an adaptor for that at some sort of electronics shop. Just a few bucks.

auscab
18th February 2018, 09:22 PM
I bought it second hand around 1996 maybe ? So its getting on a bit I suppose .

If your using 5.1 and 7.1, that's for surround sound with a tv isn't it ?
I do have a spare 5.1 from a surround sound for the tv . Its a Yamaha, will that run the stereo OK ? A Tuner , cassette tape, which I rarely use , a CD player and possibly the turntable if I ever plug it back in ?
I could get by on just a tuner , its not digital though and the CD player.

I trimmed both ends of wires today and the Tannoy speakers still had distortion . Swapped speakers with the other set , sounded good at first but then I heard distortion again . It wasn't happening as much but it was there. Ill still get some contact cleaner posted and clean fittings first. The back of the second set is work shop dirty . All this gear was used in my old workshop for the last ten years or so .

Rob

FenceFurniture
18th February 2018, 10:44 PM
I bought it second hand around 1996 maybe ? So its getting on a bit I suppose . So definitely a Stereo amp. 5.1 and so on only started around 1998.

If your using 5.1 and 7.1, that's for surround sound with a tv isn't it ? Yes. The 5 is the old stereo speakers, plus a centre channel (front) plus 2 rear speakers. The ".1" is the feed to a sub-woofer which has its own built in amp (because bass really sucks power). The amp decodes the signal and spreads it around to where it needs to go. There are different ways of decoding it which result in a different soundscape, so you can have Dolby Digital 5.1 (the most common), DTS 5.1 (the best in my opinion), 5 channel stereo, and then a whole bunch that I suspect nobody ever uses. Almost all, if not all movie DVDs default to Dolby Digital, but many of them also have DTS 5.1, and it can be selected from either "Setup", "Sound", or "Languages" on the DVD menu. It's surprising how often it is buried in Language.

I do have a spare 5.1 from a surround sound for the tv . Its a Yamaha, will that run the stereo OK ? Should do, they have multiple formats to choose from. My 2017 model still defaults to stereo if that's all that it receives.

A Tuner , cassette tape, which I rarely use , a CD player and possibly the turntable if I ever plug it back in ?
I could get by on just a tuner , its not digital though and the CD player. Just check the inputs on the back of the amp (or consult the manual). There will definitely be a CD input, and if there is no Tuner i/p then just use Acc 1, or DVD. They are all pretty much the same on older amps, with the exception of Phono which can sometimes go to an internal pre-amp to boost the signal. These days you'll be VERY lucky to get a Phono i/p on a new amp. I had to purchase a separate pre-amp for in between my turntable and the new Denon to boost the signal of my moving coil phono cartridge. It was about $150 or so - but I'm in heaven!

I trimmed both ends of wires today and the Tannoy speakers still had distortion . Swapped speakers with the other set , sounded good at first but then I heard distortion again . It wasn't happening as much but it was there. Ill still get some contact cleaner posted and clean fittings first. The back of the second set is work shop dirty . All this gear was used in my old workshop for the last ten years or so .If you can, see if you can borrow a reasonably new speaker from someone, even a small one - this would obviate having to get a 3mm-6mm converter for the headphones. You can plug it in to either channel in turn and see if you get the crackling. If it's still there then the amp is buggered and frankly not worth repairing unless it's a REALLY high spec amp from the period, with gold contacts and the like, or unless the repair can be done for <$100 :no:. It may just be a case of dry joints, which may or may not cost too much to repair (pretty sure I know what the Tech will say though :D)

If it's not still crackling then it's the speakers which may or may not be worth repairing (new cones can be put into old boxes).

My money says it's the amp.....

Pete57
19th February 2018, 07:45 AM
Sometimes dust can get onto contact inside potentiometers (volume, base, treble etc) and cause clacking. Especially noticeable when trying to adjust them. Dust can also be an issue with switches. With the amplifier off , try adjusting all to knobs and switches through their full range several times to see if that helps.
If only one side that is crackling, try swapping speaker leads over to see if crackling stay with one speaker or swaps to other speaker I.e. narrow down a speaker or one channel of the amp.

bradonj
22nd February 2018, 11:41 AM
As Pete 57 said, it could be the pots. I would turn the amp off and just go to town spinning them back and forwards. When you think you have done it enough, do the same number again. I work with commercial PA amps on a daily basis, you would be surprised how often this cures distortion and crackles.

JohnBB99
23rd February 2018, 02:53 AM
I'd echo Pete57 and bradonj, but then power up again, and turn the volume and other pots up and down, gently at first. And with the volume low until you establish you're not sending loud crackles to your speakers. (Having said that, those Tannoys are pretty robust!) If the problem is with the pots (or switches) you'll hear it diminish as you continue to operate the knob/switch. Don't forget to check all other plugs and sockets, just by unplugging and replugging a few times, BUT with the volume at minimum!!.
My money is on poor contacts [ie those pots and switches] (but possibly a dry solder joint) in the amp. Look for some Contact Cleaner - any brand - intended for use on electronic equipment and spray some on those controls. Online is cheapest [here in UK anyway]! (You could try a little drop of 3-in-one light oil as a quick-and-dirty fix, if you can reach a hole in the noisy pot!)
Follow other advice above to find out where the problem is occurring, changing only one thing at a time.
If it is the speakers, and you've remade the cable connections at the back [eliminating them] I'd check the internal wiring very carefully. Where a wire is connected to terminal, try to make a tight physical connection before soldering, as inevitably there will be vibration in your speaker.
If you're sure it's in the speaker, and you've done all the above, then I would check all the solder joints on the crossover. If you're not familiar with soldering printed circuit boards, I'd take it to someone who is. It could, of course, be a faulty component on the crossover, but if the noise is on both channels, that would be quite a coincidence!
Good luck!
John

auscab
23rd February 2018, 07:50 PM
Thanks for the good advice Gents. I'm going to give them a go . I haven't touched it for a week one reason is I've been busy.
Another reason is, I cant wait to change the position of the cabinet full of gear, amp and all . I'm sick of being down on the ground
on my knees in the back of the cabinet. Never liked it, and always liked the look of technician types where they had all the gear at desk to height.
Whether it be audio or computer stuff.
I cant have it all spread out like I've seen, but I can raise the cabinet where it can be accessed at standing
height and it has to be able to be spun around to get at the back and at the same time be just to the right side of my work bench .

Another thing I went and did was buy another Amp . Ill play with the first one to see if it gets better first.
The new one coming is the same as I first bought with the speakers in 1981 /2 A Yamaha A-560.
Another second hand buy but the Guy sounds like he knows his gear and he says its been checked and is working well .

Rob

daddywoofdawg
24th February 2018, 03:11 AM
Sometimes dust can get into contact inside potentiometers (volume, bass, treble etc) and cause clacking. Especially noticeable when trying to adjust them. Dust can also be an issue with switches. With the amplifier off, try adjusting all to knobs and switches through their full range several times to see if that helps.
If only one side that is crackling, try swapping speaker leads over to see if crackling stay with one speaker or swaps to other speakers I.e. narrow down a speaker or one channel of the amp.Get some canned air open the amp case and vac and blow out any place dust can settle. also, it could be the cone of the speakers are getting old or loose. but I think it's in the volume knob/pot

Yanis
25th February 2018, 10:22 AM
I have seen a couple of instances where the voice coil failed. In one case the cause was running the amp to loud for too long and it "cooked" the voice coil. When I took it apart the insulation had clearly burnt and the voice coil was distorted. In the other case the speakers were stored in a shed for a number of years and moisture got into the speaker and caused corrosion. Although you can get the speakers re-coned it is not worth it in most cases.

In your case you need to isolate the source so put the speakers on another amp (really any audio source will do) or use another speaker on the same amp.

The cause of the crackling can be the following in decreasing order of likleyhood.

1. Switches on the amp. Selection switch, source switch, speaker switch etc. This one is pretty easy to tell. If you wiggle each switch you should see a change in the crackling. Spray contact cleaner on the switches as you move them back and forth.

2. Volume, balance, tone controls. Again easy to diagnose. If the crackling gets worse as you adjust them then this is the cause. If they operate without any additional crackling then they are fine. Remedy is again contact cleaner. They can wear out over time with a LOT of use in which case they will have to be replaced.

3. Loose connections. This is the hardest to diagnose since the loose connection could be anywhere. If it is in both speakers then the loose connection is most likely in the audio cables between the source and the amp or the amp and the speakers. replacing, cleaning or re-terminating the cables will fix this.

4. Speaker voice coils as mentioned above. Remedy is new speakers.