Chinese eBay HiFi Scam

Whilst looking for a used CD player on eBay, I found an amazing deal; a stunning and expensive CD player for a ridiculous ‘Buy It Now price’ – a deal too good to be true?  I was immediately sceptical so did the usual scroll down to look at the seller’s feedback and information.  Below that info, eBay shows ‘Similar Listings’ and that’s where I came across a notice from another member highlighting a scam being set by Chinese members.  I copied the listing in order to propagate the information.  I can no longer find the original member who highlighted the scam but many thanks to him for his input!

Chinese HiFi scam on eBay.

Chinese HiFi scam on eBay.

This is a copy & paste of what his listing said:

“Excuse the dramatic headlines but it had to catch peoples attention. This is a warning to all on Ebay UK because people are still buying these things. There are hundreds of under priced items being listed by scammers from China. I have pages of them in my watchlist some of which people have been bought and paid for overnight. An example is a Sonos Play 3 for £23.46 or a pair of Quad Electrostatic speakers for £45.26 with free postage. Most of the scammers (though it could just be one opening hudreds of fake accounts) have a name that consists of random numbers and letters. Some with a – or an underscore _ at the end of their name followed by a number. Also the title of most of their ads have ebayt or Ebayq or a random letter at the end of the item title plus none of them have a feedback score. Don’t buy off these scum thinking it’s a legit ad. I’ve reported over 400 of them but ebay have only removed some of them and they’re still coming. In the time it’s taken me to edit this and re-list this there’s 19 more crooked ads popped up so be careful what you’re buying folks. ”

An good example is shown in these two screen grabs of a listing:

Chinese HiFi scam on eBay example A.

Chinese HiFi scam on eBay example A.

Chinese HiFi scam on eBay example B.

Chinese HiFi scam on eBay example B.

Have you bought some HiFi that turned out to be a scam?
Do you have any ideas on how eBay could stop this happening?
Feel free to make any comments that would help.

Here are messages from other members in response to my listing:

Chris C**********
“Hi Matt – I saw your ‘scam alert’ listing. Thanks for taking the time to put it on. Last year I was scammed for £3,300 for a pair of B&W Nautilus speakers – from China. A mighty tempting price. The guy insisted no paypal – bank transfer only. The guy actually did have the speakers – I asked him to write my name on a piece of paper and put the paper next to the speakers and take a photo. And he did, and it looked real, and probably was. But after transferring the money he said he had big customs fees to pay to export them – believe it or not – and I grew wary. Eventually gave up. His account was closed by ebay as it turned out it was hijacked. So … if you can add this story to your scam alert thing it would be useful to others. If it’s too good to be true, it very probably is.”

Gerry
“hi
i reported this to ebay a month ago on the phono
to no avail

they are list item far to cheap with free post ie speaker 1000 a pair for £33,76

an buyer are paying for them and will never receive items

so easy to see ebaya / ebayb / ebayk and so on

if they pay buy credit card because its under 100 pounds it lost to them

good thinking scam card but ebay do not care”

Cookies
“Hi matt,

Your add is appreciated. I have seen loads and loads of adverts from China, top end stuff marked really low. I mean a B&o system for £24 with free shipping. You have to think really!?

Like you said a lot of ppl are buying these and thinking what a bargain. More of an impulse automatic buy.

I don’t think you will ever beat them, as they will continue doing the same scam. Maybe Ebay needs to do something, verifying an account / a person before they let anyone just open a account.

Ebay is good in terms of money back guarantee but they really need to do something to stop the problem.

Best of luck, and if it’s too good, then it probably is.”

Jza
“I’ve reported lots of these.

Let’s hope eBay don’t take this listing down

Good work”

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Pioneer SX-5580 Broken Pot / Switch Shaft Repair / Fix

The Pioneer SX-5580 I am renovating was not looked after very well at some point, surprising considering how prestigious a piece of equipment it is and how much it would have cost.  One of the problems was some bent volume control shafts and switch shafts.  The 10KHz Treble switch in particular was very bent indeed.  The others were not too much of a problem as it was only a case of bending the two split parts of the aluminium shaft into alignment.  But the 10KHz switch was a whole different game, just looking at it made me feel a little ill as I knew how hard finding a solution was going to be.  The shaft was broken right at the edge of its casing (as you’d expect) so did not protrude at all.

This picture shows the board this switch came from, the switch is already out having been de-soldered – you can see the gap it’s left in the assembly hanging at the bottom (the white card is polystyrene foam from a pizza box and used to insulate and protect the board that’s hanging in the middle):

Pioneer SX-5580 during repair.

Pioneer SX-5580 during repair.

This problem (broken potentiometer / switch shaft) is quite common and is now solved so I am going to put everything down here in case others find it useful.

First of all, I looked at the web forums and the consensus was buy a new potentiometer / switch.  That was not a solution for me as this switch is dedicated to the SX-5580 and finding a different switch to replace it would cost too much (approx. £50).  Plus I am renovating this unit to sell in order to finance Liquiphonics and buyers (understandably) want as much originality as possible.  So onto the fix…

All materials (as far as I’m aware) work harden, thats how a strong piece of metal can be broken, just keep bending it at the same point; eventually it will give and break in two.  I’m no scientist and in some ways understanding what happens to metal crystals when they stretch through work hardening is irrelevant; the fact is, if you keep bending a piece of aluminium rod, it goes hard and will at some point snap instead of bending.  Aluminium does this fairly soon in the number of bends and since this shaft was bent so much, I felt very nervous about forcing it too much and too far.  I used a piece of steel tube with a good fit and put it over the end of the shaft and pulled, I did this in situ so the casing took the load and not the PCB.  It bent a little but not enough so I did it again and looked at the results.  I kept doing this until it was very nearly inline – and then it broke.  There’s no point in me telling you what I called it as you can probably make a pretty good guess.

When taking a switch apart, it’s good practice to put it in a position that will help you put it back together.  That way all the parts will be in correct alignment so say -10dB on the scale gives -10dB and  not +20dB.  I turned the switch so that it was completely clockwise and then took lots of photos of it to show me where the insides were positioned:

The Pioneer 5580 10KHz Treble switch.

The Pioneer 5580 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

Inside the 10KHz Treble switch.

The 10KHz switch disassembled.

The 10KHz switch disassembled.

The 10KHz switch disassembled.

The 10KHz switch disassembled.

The shaft with two beryllium washers.

The shaft with two beryllium washers.

When metal (or any other material) breaks the slight imperfections in its structure cause greater or lesser stretching of the material and this is like a finger-print.  In other words, the two pieces will fit closely together in one position only.  This ‘fingerprint’ is useful as it helps to align the two elements.  Nothing is perfect and there may be subtle differences between the two parts but in my case they were close enough for this to not be a problem.  You can see the shape of the metal in this picture:

The broken ends of the shaft.

The broken ends of the shaft.

Putting the two together showed the join to be very tight fitting and the shaft to be almost straight.  I then superglued it in this position.

The shaft after supergluing.

The shaft after supergluing.

I haven’t measured the angle but looking at it against a right angle it looks some fraction of a degree.

A right-angle showing alignment of shaft after supergluing.

A right-angle showing alignment of shaft after supergluing.

Superglue is nowhere near strong enough for this application and even if it were stronger, I would feel uncomfortable about relying on it.  What I really wanted was the two parts to be mechanically joined and the best way I could think of was to use a split pin rod, the split rod can be seen in a picture further down.

To hold the two parts rigid together while I drilled it, I put three layers of heat-shrink sleeving around the shaft:

The shaft before drilling showing heatshrink tubing.

The shaft before drilling showing heatshrink tubing.

The picture below shows the drill in position.  Actually I took the photo after all the work was done but took it just to be complete – I know how scary this sort of thing can be even for experienced workers in this field so every picture counts.  Plus I’m a bit anal when it comes to this sort of thing.  Down with this sort of thing (that’s an in-joke for lovers of ‘Father Ted’):

Drilling the shaft.

Drilling the shaft.

When holding a hand-drill it must be kept perpendicular to the work, the last thing you want is for the bit to exit out the side of the shaft.  That’s unlikely as it’s not that hard to keep the drill vertical but even a little miss-alignment may mean the shaft has a kink in it at the joint which would totally defeat the whole point of doing this.  Fortunately with this shaft, it has a split down the middle (as many do) and that meant the drill bit was kept in correct alignment in the z axis (away and towards you).  That means only the x axis has to be judged by the person drilling.  So keep the slot running left to right (along the x axis) and it is then easier to see that the drill bit is vertical.

Drilling the hole broke the superglue hold but I had put enough of a hole in the lower section for that to not be a problem.  I simply pulled out the upper section and carried on drilling:

The shaft during drilling showing heatshrink tubing.

The shaft during drilling showing heatshrink tubing.

Once drilled I removed the heat-shrink sleeving.  The hardened steel split pin can be seen to the left of the shaft:

Shaft showing holes and spring pin.

Shaft showing holes and spring pin.

Here is something important to note.  The split pin I used was 2mm in width and 12mm long (the drill bit I used was 2mm though measured 1.96mm with a vernier gauge).  I wanted about 7mm in the lower section of the shaft leaving about 5mm in the upper section.  Since I have a shite memory I totally forgot to watch how far I drilled in, most of my brain cells were watching for alignment (the rest were off napping somewhere).  I could have put a piece of PVC tape around the drill bit to show me when to stop.  The result was I drilled about 2mm too deep into the lower section.  I cut a piece of 14 SWG (2.032mm) tinned copper wire and dropped that into the hole.  In case you don’t know (but you probably will), wire cutters leave a right-angle cut or a sloped cut depending on which end of the cut you look at – I used the cutters to give right-angles at both ends.  This piece of wire stopped the split pin from going in too far when I tapped it into the lower section with a small hammer.

One thing I did note from looking at the forums (a list of which is below), they recommend JB Weld so I bought some and used that to glue the too parts in addition to the pin.  Before glueing, since I would not be able to see the join of the two parts, I put an indelible mark on both sections of the shaft to make it easier to align once the JB Weld was added.  The marks are only for rough alignment as your fingers will feel it drop into place when exactly aligned:

Shaft pinned and glued showing alignment marks.

Shaft pinned and glued showing alignment marks.

Having put the glue on and pushed the upper shaft section onto the split pin using the small hammer and watching the alignment marks, I smeared the glue out and over the join to help reinforce the junction and fill the gap.  I then left the whole thing for the glue to set over night and cut off the excess with a sharp knife (scalpel) leaving a smooth finish.  To clean the shaft I used a fibreglass cleaning stick.  I’m mentioning this here as I find this stick to be incomparably good at cleaning things such as this and especially corroded switch or connector contacts.  This stick is a rod of long glass fibres held together with plastic (presumably heat-shrunk on).  The ends of the fibres do the cleaning and being made of glass they are hard and abrasive but very fine indeed plus the stiffness (and therefore abrasion) can be regulated by the length of the fibres showing by cutting back the plastic – so one end can be long, the other short.  I have had one for decades now, use it all the time and having started out at average pencil length, it is still three inches long.  So well worth any cost involved.

Here is the finished shaft join:

Pioneer SX-5580 Treble 10KHz Shaft finished.

Pioneer SX-5580 Treble 10KHz Shaft finished.

One last thing and my apologies if you already know this but if not it could prove useful.  Drill bits should not be put too far into the drill’s chuck.  Drill bits are hardened at the cutting end but softer at the chuck end.  This is so the bit does not bend (or break) when pushing forces are applied.  If you find your bits are breaking or bending you are putting it in too far.  I generally put them in no further than 1/2″ (1.5cm).

Forums I used, many thanks to those people:

http://www.harmonycentral.com/forum/forum/guitar/acapella-41/1190182-
http://audiokarma.org/forums/index.php?threads/repairing-broken-pot-shaft.377979/
https://www.talkbass.com/threads/how-to-repair-a-partially-broken-pot-shaft.562200/
http://www.mylespaul.com/forums/showthread.php?t=161235
http://www.tdpri.com/threads/broken-pot-shaft-got-any-ideas.79289/
http://homerecording.com/bbs/special-forums/diy-mods-and-homebrew/repairing-broken-pot-amp-266725/
https://www.thegearpage.net/board/index.php?threads/pulled-the-shaft-out.1009977/

http://music-electronics-forum.com/t30639/

Posted in Construction, Finance, pioneer, Receivers, renovation, sx-5580, Vintage HiFi Renovation | Tagged , , , , , , , , , , , , , , , , , , , | Leave a comment

HighResAudio / MQA Wars Continue on HiFiPlus

HighResAudio are to stop offering MQA encoded files. Here is a link to an article on HiFi Plus:

http://hifiplus.us11.list-manage.com/track/click?u=7c2c6adc5d8e2ef6eb0c411f0&id=5a140ac6f2&e=792bccbd1a

Posted in Construction, DACs & File Formats, DACs & File Formats, Gadgets, High Definition Sound, Media, Signal Source | Tagged , , , , , , , , , , , , , | Leave a comment

Dry Solder Joints

Dry solder joint.

Dry solder joint.

Some parts in a power amp stage get very hot.  The output transistors of course but also some of the resistors in the output stage.  After years and decades of getting very hot and then cooling and running through this hot, cold cycle repeatedly, some solder joints can develop a hairline crack.  Especially if there was a weakness in the joint to begin with.  The crack, known as a ‘dry joint’ can give an increased resistance or may be open circuit completely.

Above you can see the track side of a wirewound resistor in the output stage of the power amp of the SX-5580.  To fix this, it simply needs resoldering.  The second picture shows the joint fixed.

Re-soldered joint.

Re-soldered joint.

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Pioneer SX-5580 Power Amp Module

Here are some photos of the power amplifier module.  As you can see, it’s big.  But then it would be at 120 watts per channel RMS.

This is before cleaning and changing of the electrolytic capacitors.  Given heat, electricity (generating electrostatic charge) and 30 or 40 years, there’ll be accumulation of grime and dust and that needs removing.

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Pioneer SX-5580 Receiver Refurb

Here is what I’m working on at the moment, a Pioneer SX-5580 monster receiver (amplifier with built in tuner).  As far as I’m aware, it is identical to the SX-1050 but is in black instead of all aluminium.

Pioneer SX-5580 Monster Receiver in black.

Pioneer SX-5580 Monster Receiver in black.

This photo shows what the front panel should look like if it wasn’t all dirty and a little scratched:

Pioneer SX-5580 Front Panel.

Pioneer SX-5580 Front Panel.

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High Resolution Audio, MQA and Others

Not sure where to start with this post. I suppose I should just ramble on…

CD audio was a little short of musical quality and has been bemoaned ever since its introduction pretty much. By anyone who likes quality above convenience at least. Vinyl has hung around and is now even making a comeback. That is due to the resolution of vinyl which is largely dictated by the size of the plastic molecules as much as the recording medium but may also be due to the artistic nature of the artwork with a pressing and the emotional quality of owning vinyl.

Now that computers are coming into their own, we have the opportunity to increase the resolution of digital audio. But then mp3 has become popular because of its small file size of around 1/10 of an AIFF or WAV (depending on the compression level) and apparently that small file size is bought at the expense of losing the higher frequencies. Everyone loses their ability to hear higher frequencies as we age and the older we are the less up the frequency range our ears can go. But then, there is another argument that although we cannot literally hear the higher frequencies, we can still hear the effects of higher harmonics so they are necessary.

I have a personal theory that the older we are, the better our brains are at filling in the blanks so we may not literally hear a high pitch sound, because the hairs in our ears are not there but our ears do hear the lower frequencies and our brains fill in the gaps (higher frequencies) because from experience, it knows what should be there. But that is a different discussion.

So mp3s have brought greater convenience at the expense of some musicality and that was fine since digits were still expensive when that format was designed, especially for download/streaming. But things have moved on again in computer land and efforts are now being made to increase the resolution to exceed CD quality both in terms of sampling frequency increases (44.1KHz for CD and 96KHz+ for HR) and bit depth (how many bits are used in each sample – e.g. 16 for CD, 24 for HR).

I am not convinced that increasing the bit depth to 24 makes that much difference since many recordings do not reach 16 bits in dynamic range anyway, so increasing to 24 would make no difference. On the other hand, regarding sampling rate, 44.1KHz seems utterly inadequate to me – how can you sample a frequency of 22KHz (within the frequency range of young people) with just 2 samples and expect to recreate the exact wave shape?

None of this affects my boombox or amplifier designs since I decided to leave that side to others – it has taken me nearly seven years to get this far with my design, how could I keep up with developments in digits! My boombox (ghettoblaster) and amp will both be Bluetooth connected but that unit is bought in and so replaceable as digits develop further and there are six inputs in all (including four phono/RCA) with only one for Bluetooth. The other input is two jacks in parallel (one 3.5mm and one 6.5mm) so musicians can play music from their e.g. iPod and play along with it with say a guitar or piano etc.

But here’s the main purpose of this article, to draw your attention to how some companies are taking advantage of us by doing bad things with digits and saying they are doing good things. One example would be how some companies are taking old recordings and converting them to High Res by resampling them at 24bit/96KHz. For me, these files are not high resolution if the original was not high resolution. For example, recordings made in the 60’s may have all sorts of distortions and noise caused by the lack of quality recording equipment. The HR version may simply be a high res recording of a crap original – it will still sound crap, only that crap will be accurately reproduced. In other words; beware the claims of High Res companies.

One person who really does seem to know what he is talking about (he’s an experienced recording engineer with his own studios and also a musician) and is fighting this cause (the reason I follow his blog postings) is Dr. Aix (Mark Waldrep). You can follow his posts here:

http://www.realhd-audio.com/

He is also publishing his own book about Hi Res which can be found here:

http://aixrecords.com/

Mark’s latest post gives a link to an article by Jim Collinson of Linn and I urge anyone interested in HR to give it a read.  The article claims a company called MQA is developing technology that will very much stifle new music and lock us all into their monopoly.  Here is a link to that article:

https://www.linn.co.uk/blog/mqa-is-bad-for-music

Happy listening (and reading),

Matt

Posted in DACs & File Formats, Ghetto Blaster / Portable Music Player, High Definition Sound, Media, Music, Signal Source, Vinyl | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment