Hi,

I recently replaced the STK amplifier module in a Genelec speaker. These
STK modules are not easy to find, but I did find one on the net, delivered
from the far east, which was a quarter of the price of the official spares
supplier here in the UK (HHB). I informed the customer prior to order, and
he was happy to take the much cheaper part.

Anyway it lasted 1 day before failing short circuit. Fortunately the
drivers are not damaged.


There are photos he
http://postimage.org/image/1gb2ui0lg/
http://postimage.org/image/2p2rdrs9w/


The new looking part is a new part subsequently ordered from HHB. The old
one with the mangled legs is the cheap failed device.

Is anyone able to tell whether this might or might not be fake?


Cheers,



Gareth.

"Gareth Magennis" wrote in message
...
: Hi,
:
: I recently replaced the STK amplifier module in a Genelec speaker. These
: STK modules are not easy to find, but I did find one on the net, delivered
: from the far east, which was a quarter of the price of the official spares
: supplier here in the UK (HHB). I informed the customer prior to order, and
: he was happy to take the much cheaper part.
:
: Anyway it lasted 1 day before failing short circuit. Fortunately the
: drivers are not damaged.
: There are photos he
: http://postimage.org/image/1gb2ui0lg/
: http://postimage.org/image/2p2rdrs9w/
:
:
: The new looking part is a new part subsequently ordered from HHB. The old
: one with the mangled legs is the cheap failed device.
:
: Is anyone able to tell whether this might or might not be fake?
___________________
Open them up and have a look

Colin

"Colin Horsley" wrote in message
news
"Gareth Magennis" wrote in message
...
: Hi,
:
: I recently replaced the STK amplifier module in a Genelec speaker.
These
: STK modules are not easy to find, but I did find one on the net,
delivered
: from the far east, which was a quarter of the price of the official
spares
: supplier here in the UK (HHB). I informed the customer prior to order,
and
: he was happy to take the much cheaper part.
:
: Anyway it lasted 1 day before failing short circuit. Fortunately the
: drivers are not damaged.
: There are photos he
: http://postimage.org/image/1gb2ui0lg/
: http://postimage.org/image/2p2rdrs9w/
:
:
: The new looking part is a new part subsequently ordered from HHB. The
old
: one with the mangled legs is the cheap failed device.
:
: Is anyone able to tell whether this might or might not be fake?
___________________
Open them up and have a look

Colin





One of them is new and is going to be fitted in the speaker. The customer
does still have the original failed device but I don't have it back yet.

I wanted to take a photo before destroying the casing or I would not have
been able to post this thread for external visual i.d..



Gareth.

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?



Gareth.

On 3/21/2011 5:28 PM, Gareth Magennis wrote:

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?

My guess? A transistor die (unpackaged)
There's 4 of them, each pair shares a 3-legged
SMT.

Jeff

"Gareth the Menace" ...

Here's a hi res picture of the opened module:

http://postimage.org/image/2qgigsn38/

What are those things?

** Here is the datasheet for the similar STK422-90.

http://datasheets.pl/S/STK/STK442-090.pdf

The 4 output devices are Darlington pairs and the SMD devices in the middle
of each pair are the bias stabilisers. The Darlingtons each have twin
emitter leads soldered to the PCB.

Looks an easy enough to copy the thing - just normal SMD board plus four
power chips on metal headers.

Older versions (made by Sanyo) had no SMD - but instead used transistor
chips and printed resistors directly on the board. They were known as
"hybrids" to distinguish them from regular ICs.

My local supplier ( WES Components) has the STK442-130 listed for A$22.50
each.

Littlediode in Surry offer them for 10 UK pounds + VAT.



..... Phil

"Gareth the Menace "

Is anyone able to tell whether this might or might not be fake?


** It is rare for anyone to set out to manufacture a "fake" electronic
device for sale - so the terms "fake" and "counterfeit" are misleading.

What IS done is to remove the labelling from a cheap device and re-label
it as another, more expensive and far more sellable type.

In the case of the STK422 series of modules, the game would be to re-label a
lower spec part as a higher spec one.

FFS - buy from a trusted local supplier.

Is 10 UK pounds plus VAT too much for a 65 watt per channel stereo power amp
??


..... Phil

"Phil Allison" wrote in message
...

"Gareth the Menace "

Is anyone able to tell whether this might or might not be fake?


** It is rare for anyone to set out to manufacture a "fake" electronic
device for sale - so the terms "fake" and "counterfeit" are misleading.

What IS done is to remove the labelling from a cheap device and re-label
it as another, more expensive and far more sellable type.

In the case of the STK422 series of modules, the game would be to re-label
a lower spec part as a higher spec one.

FFS - buy from a trusted local supplier.

Is 10 UK pounds plus VAT too much for a 65 watt per channel stereo power
amp ??


.... Phil






I did buy this at Littlediode, (First time I've used them). I am now
wondering if they are indeed a trusted supplier. It was shipped (according
to them) from the far east, taking a week or so to arrive.

I woudln't normally do this, as if it is too good to be true then usually it
is.
Hence me buying another one from HHB who I trust implicitly and will have
sourced the part from Genelec.

Unfortunately I paid more for postage from HHB than the entire Littlediode
transaction cost!

Ho hum, and there's me trying to do the customer a favour.


Thanks for the info, when I get the other one back from the customer I shall
break it open for comparison.


Gareth.

"Gareth the Menace "
"Phil Allison" "Gareth the Menace "

Is anyone able to tell whether this might or might not be fake?


** It is rare for anyone to set out to manufacture a "fake" electronic
device for sale - so the terms "fake" and "counterfeit" are
misleading.

What IS done is to remove the labelling from a cheap device and
re-label it as another, more expensive and far more sellable type.

In the case of the STK422 series of modules, the game would be to
re-label a lower spec part as a higher spec one.

FFS - buy from a trusted local supplier.

Is 10 UK pounds plus VAT too much for a 65 watt per channel stereo power
amp ??



I did buy this at Littlediode, (First time I've used them).

** Are they " the new kids on the block " ??

Avoid them like the plague if they are.


I am now wondering if they are indeed a trusted supplier. It was shipped
(according to them) from the far east, taking a week or so to arrive.


** Verrrry suspicious.

Straight from eBay - to you.


I woudln't normally do this, as if it is too good to be true then usually
it is.
Hence me buying another one from HHB who I trust implicitly and will have
sourced the part from Genelec.

Unfortunately I paid more for postage from HHB than the entire Littlediode
transaction cost!

Ho hum, and there's me trying to do the customer a favour.


Thanks for the info, when I get the other one back from the customer I
shall break it open for comparison.


** If it is an old example - it will look very different inside.

Probably be no SMD parts used at all.



.... Phil

"Phil Allison" wrote in message
...

"Gareth the Menace "
"Phil Allison" "Gareth the Menace "

Is anyone able to tell whether this might or might not be fake?


** It is rare for anyone to set out to manufacture a "fake" electronic
device for sale - so the terms "fake" and "counterfeit" are
misleading.

What IS done is to remove the labelling from a cheap device and
re-label it as another, more expensive and far more sellable type.

In the case of the STK422 series of modules, the game would be to
re-label a lower spec part as a higher spec one.

FFS - buy from a trusted local supplier.

Is 10 UK pounds plus VAT too much for a 65 watt per channel stereo power
amp ??



I did buy this at Littlediode, (First time I've used them).

** Are they " the new kids on the block " ??

Avoid them like the plague if they are.


I am now wondering if they are indeed a trusted supplier. It was shipped
(according to them) from the far east, taking a week or so to arrive.


** Verrrry suspicious.

Straight from eBay - to you.


I woudln't normally do this, as if it is too good to be true then usually
it is.
Hence me buying another one from HHB who I trust implicitly and will have
sourced the part from Genelec.

Unfortunately I paid more for postage from HHB than the entire
Littlediode transaction cost!

Ho hum, and there's me trying to do the customer a favour.


Thanks for the info, when I get the other one back from the customer I
shall break it open for comparison.


** If it is an old example - it will look very different inside.

Probably be no SMD parts used at all.



... Phil







Funny how not even the OEM or replacement Genelec devices have any
manufacturers ID. Doesn't fill me with great confidence, and the Genelecs
are not cheap speakers.

http://www.dawsons.co.uk/acatalog/info_00058481.html



Gareth.

"Gareth Magennis" wrote in message
...
Hi,

I recently replaced the STK amplifier module in a Genelec speaker. These
STK modules are not easy to find, but I did find one on the net, delivered
from the far east, which was a quarter of the price of the official spares
supplier here in the UK (HHB). I informed the customer prior to order,
and he was happy to take the much cheaper part.

Anyway it lasted 1 day before failing short circuit. Fortunately the
drivers are not damaged.


There are photos he
http://postimage.org/image/1gb2ui0lg/
http://postimage.org/image/2p2rdrs9w/


The new looking part is a new part subsequently ordered from HHB. The old
one with the mangled legs is the cheap failed device.

Is anyone able to tell whether this might or might not be fake?


Cheers,



Gareth.


The one WITHOUT the lot number on the back is the real Sanyo part.

Mark Z.

"Mark Zacharias" wrote in message
eb.com...
"Gareth Magennis" wrote in message
...
Hi,

I recently replaced the STK amplifier module in a Genelec speaker. These
STK modules are not easy to find, but I did find one on the net,
delivered from the far east, which was a quarter of the price of the
official spares supplier here in the UK (HHB). I informed the customer
prior to order, and he was happy to take the much cheaper part.

Anyway it lasted 1 day before failing short circuit. Fortunately the
drivers are not damaged.


There are photos he
http://postimage.org/image/1gb2ui0lg/
http://postimage.org/image/2p2rdrs9w/


The new looking part is a new part subsequently ordered from HHB. The
old one with the mangled legs is the cheap failed device.

Is anyone able to tell whether this might or might not be fake?


Cheers,



Gareth.


The one WITHOUT the lot number on the back is the real Sanyo part.

Mark Z.


Thanks Mark, that's pretty much confirmed my suspicions then.


Gareth.

"Mark Zacharias"


The one WITHOUT the lot number on the back is the real Sanyo part.

** Prove it.


..... Phil

Gareth Magennis wrote in message
...
Hi,

I recently replaced the STK amplifier module in a Genelec speaker. These
STK modules are not easy to find, but I did find one on the net, delivered
from the far east, which was a quarter of the price of the official spares
supplier here in the UK (HHB). I informed the customer prior to order,
and
he was happy to take the much cheaper part.

Anyway it lasted 1 day before failing short circuit. Fortunately the
drivers are not damaged.


There are photos he
http://postimage.org/image/1gb2ui0lg/
http://postimage.org/image/2p2rdrs9w/


The new looking part is a new part subsequently ordered from HHB. The old
one with the mangled legs is the cheap failed device.

Is anyone able to tell whether this might or might not be fake?


Cheers,



Gareth.



I would say the more precise script is on the genuine one. Rougher/less
robust ink is probably on the copies/fakes. At least they did not make sham
logos like the Philips , Fairchild, Linear Technology soics in an MBOX I was
looking in recently

"Nutcase Kook "

I would say ...

** Therein lies the rub....

the more precise script is on the genuine one.

** ROTFL

Both are rough as guts.


At least they did not make sham
logos like the Philips , Fairchild, Linear Technology soics in an MBOX I
was
looking in recently

** Not one scrap of proof exists to back that ****wit assertion up.



.... Phil

On Tue, 22 Mar 2011 11:52:47 +0000, N_Cook wrote:

Gareth Magennis wrote in message
...
Hi,

I recently replaced the STK amplifier module in a Genelec speaker.
These STK modules are not easy to find, but I did find one on the net,
delivered from the far east, which was a quarter of the price of the
official spares supplier here in the UK (HHB). I informed the customer
prior to order,
and
he was happy to take the much cheaper part.

Anyway it lasted 1 day before failing short circuit. Fortunately the
drivers are not damaged.


There are photos he
http://postimage.org/image/1gb2ui0lg/
http://postimage.org/image/2p2rdrs9w/


The new looking part is a new part subsequently ordered from HHB. The
old one with the mangled legs is the cheap failed device.

Is anyone able to tell whether this might or might not be fake?


Cheers,



Gareth.



I would say the more precise script is on the genuine one. Rougher/less
robust ink is probably on the copies/fakes. At least they did not make
sham logos like the Philips , Fairchild, Linear Technology soics in an
MBOX I was looking in recently

They are both genuine. They badge lesser spec'd devices to sell at a
higher amount. I've seen this with projector TV convergence amplifiers.
I try to buy from the manufacturer or a well trusted source.



--
Live Fast Die Young, Leave A Pretty Corpse

On 3/21/2011 5:28 PM, Gareth Magennis wrote:

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?



Gareth.

Interesting.

most of the failed power modules i have opened up show clear arcing on
the power device slugs. They look relatively clear on yours.

It does look like a couple of the SMT transistors are damaged.
Its kind of hard to tell from the picture if that's true or it was
damage from prying the case off.

The epoxied power device slug leads do look a little close together
on a couple of the output devices.

bob

"Gareth Magennis" wrote in message
...

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?



Gareth.



Why would you mount them in a corner rather than the centre of the heatsink?



Gareth.

On Tue, 22 Mar 2011 20:14:50 +0000, Gareth Magennis wrote:

"Gareth Magennis" wrote in message
...

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?



Gareth.



Why would you mount them in a corner rather than the centre of the
heatsink?

The back of the device is not the heat sink. Don't forget it is to be
torqued down to a much larger heat sink where the location of the power
devices within the package is insignificant.



--
Live Fast Die Young, Leave A Pretty Corpse

"Meat Plow" wrote in message
news
On Tue, 22 Mar 2011 20:14:50 +0000, Gareth Magennis wrote:

"Gareth Magennis" wrote in message
...

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?



Gareth.



Why would you mount them in a corner rather than the centre of the
heatsink?

The back of the device is not the heat sink. Don't forget it is to be
torqued down to a much larger heat sink where the location of the power
devices within the package is insignificant.



Oops, I did forget that.


Cheers,


Gareth.

On Tue, 22 Mar 2011 21:59:13 +0000, Gareth Magennis wrote:

"Meat Plow" wrote in message
news
On Tue, 22 Mar 2011 20:14:50 +0000, Gareth Magennis wrote:

"Gareth Magennis" wrote in message
...

Here's a hi res picture of the opened module:


http://postimage.org/image/2qgigsn38/


What are those things?



Gareth.



Why would you mount them in a corner rather than the centre of the
heatsink?

The back of the device is not the heat sink. Don't forget it is to be
torqued down to a much larger heat sink where the location of the power
devices within the package is insignificant.



Oops, I did forget that.


Cheers,


Gareth.

In addition I've seen STK devices similar to these standing alone
without an external sink used to drive large discrete arrays. I think
this was employed in an older Sansui receiver. Formerly doing warranty
service for the Sansui brand I wasn't very fond of any of their equipment
especially higher powered amplifiers.



--
Live Fast Die Young, Leave A Pretty Corpse

In article , Gareth Magennis
writes

What are those things?

If you mean the square silvery things, they look like power transistors
to me.

Since you have had two fail, how sure are you of other parts in the
output stage or the customer's speakers?

--
(\__/)
(='.'=)
(")_(")

In article , bob urz
writes

The epoxied power device slug leads do look a little close together
on a couple of the output devices.

They're both connected to the same solder pad, so no problem.

--
(\__/)
(='.'=)
(")_(")