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Technics SA-310 Intermittent Weak Left Channel

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William R. Walsh
Guest

Thu Aug 19, 2010 2:00 am   



Hi!

Quote:
Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out above the
rest, whether free or not?

William

William R. Walsh
Guest

Thu Aug 19, 2010 2:23 am   



Hi!

Quote:
The ones I've seen with the notoriously bad solder connections are much
later models using the SVI series outputs - not STK.

The solder on this unit looked bombproof. I could only find one joint--and
this was only if I squinted at it the right way--that looked bad in any way.
So I redid it, made it look "perfect" and found no improvement. I guess I'll
get to practice sixteen times when my new module arrives.

I've found plenty of other bad solder connections (but I think I mentioned
that already)...some of the panel indicators on my SA-560 and an equalizer
of some kind (don't recall the model #) needed to be redone before they'd
work. The EQ was easy, the SA-560 not so much.

Was there any difference to speak of between an STK and the SVI modules? The
"SVI" designation struck me as nothing more than a house numbering scheme
from Matsushita Electric, and some of my service manuals show an SVI
numbered part when the actual receiver had an STK-XXXX II of some type in
it. I also saw similar numbering with the tuning microcontroller...SVIxxxxx
in the book, and the actual part number/manufacturer name in the receiver.

William

Meat Plow
Guest

Thu Aug 19, 2010 2:30 am   



On Wed, 18 Aug 2010 19:59:37 -0500, William R. Walsh wrote:

Quote:
Hi!

You could always swap the caps since each channel has its own pair. Or
just shotgun them all and cross your fingers.

I swapped the caps at the kitchen table and held my breath. There was no
improvement in the unit's behavior at all.

Thinking that I'd rather not smell burnt speaker coils, I put a speaker
protection device between the receiver and the crappy speakers. All of a
sudden, the protection device kicked in and muted the left channel. I
haven't checked to be sure, but my guess is that the hybrid module's
left channel finally went completely bad. (At the moment, I can't find
my multimeter.) Interestingly, the headphone output still seems to be
OK. I'm not sure where its signal comes from.

I found some replacement modules on eBay and ordered two of them.
They're said to be generic replacements, so I hope they come close to
meeting the specifications of the original. I also intend to find a
suitable power source in the unit for a small fan that I will mount to
the heatsink. And I sure won't crank it up that high ever again!

Replacing the amplifier module doesn't seem to be so bad (16 pins) but I
am wondering about what work might be required to finish the job. Would
there be any need for bias or other adjustments? I have the service
manual but it does not mention anything about this. Only removing the
module and its heatsink are discussed.

William

I don't think you need to worry about biasing a hybrid module. Those
things are STK-something right?



--
Live Fast, Die Young and Leave a Pretty Corpse

Meat Plow
Guest

Thu Aug 19, 2010 2:30 am   



On Wed, 18 Aug 2010 20:00:45 -0500, William R. Walsh wrote:

Quote:
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out above
the rest, whether free or not?

William

I gotta get me one of those. Still listening (and watching) my 30 gig
Ipod. Looked for the new 64 gig I Touch, pricey! But not out of my price
range even with the 3G option.



--
Live Fast, Die Young and Leave a Pretty Corpse

William R. Walsh
Guest

Thu Aug 19, 2010 2:35 am   



Hi!

Quote:
I don't think you need to worry about biasing a hybrid module. Those
things are STK-something right?

In this case, it's an STK-2038 II module that is used.

This receiver has something called "Computer Drive". It's not clear what the
"Computer" in use (a 4-bit Matsushita microcontroller) actually *does*, but
I really think it is only watching the input signal level, temperature (via
a tripping-type sensor set to 60C! Ouch!) and triggering the "preheat"
operation, operating some LEDs and generally looking pretty. (My only other
"Computer Drive" receiver, an SA-560, doesn't seem to *have* the "Computer
Drive" IC. It has only a small circuit that switches on for a time at
startup to "preheat" the power transistors.) I smell marketing and maybe
some "audiophoolery" here...?

There's also "New Class A Synchro Bias" which I take to mean (after having
done some reading) that the transistors in the amplifier are prevented from
ever switching off completely when the unit is in operation. If I'm not
mistaken, wouldn't that result in a lot of needless heat dissipation and a
stressful operating environment for the STK-2038 module?

There are what appear to be bias adjustment pots on the main board in what
little outboard supporting circuitry the amplifier uses. So far as I know,
they're not mentioned in the service manual, so my guess is "no adjustments
intended".

William

William R. Walsh
Guest

Thu Aug 19, 2010 8:35 am   



Hi!

Quote:
I gotta get me one of those. Still listening (and watching) my 30 gig
Ipod. Looked for the new 64 gig I Touch, pricey! But not out of my
price range even with the 3G option.

I bought a first-gen unit at a severe discount when the second generation
ones came out. It doesn't really matter to me if I'm "one step behind".

Even as nice of a piece of equipment as it is, there's nothing about it that
screams "killer app". I've only ever used it very occasionally to browse the
web at home when a computer wasn't convenient or to play video. I don't care
much that it will never see iOS 4.

I found a well received and free audio frequency generation app, but the
iTMS is somehow dorked up at the moment and convinced that my credit card
will be expiring soon (in 2013?). Not quite.

William

Mark Zacharias
Guest

Thu Aug 19, 2010 12:05 pm   



"William R. Walsh" <newsgroups1_at_idontwantjunqueemail.walshcomptech.com>
wrote in message news:xbWdnVB1kd3AGvHRnZ2dnUVZ_gSdnZ2d_at_mchsi.com...
Quote:
Hi!

The ones I've seen with the notoriously bad solder connections are much
later models using the SVI series outputs - not STK.

The solder on this unit looked bombproof. I could only find one joint--and
this was only if I squinted at it the right way--that looked bad in any
way.
So I redid it, made it look "perfect" and found no improvement. I guess
I'll
get to practice sixteen times when my new module arrives.

I've found plenty of other bad solder connections (but I think I mentioned
that already)...some of the panel indicators on my SA-560 and an equalizer
of some kind (don't recall the model #) needed to be redone before they'd
work. The EQ was easy, the SA-560 not so much.

Was there any difference to speak of between an STK and the SVI modules?
The
"SVI" designation struck me as nothing more than a house numbering scheme
from Matsushita Electric, and some of my service manuals show an SVI
numbered part when the actual receiver had an STK-XXXX II of some type in
it. I also saw similar numbering with the tuning
microcontroller...SVIxxxxx
in the book, and the actual part number/manufacturer name in the receiver.

William



You are correct that Panasonic added an SVI prefix to the STK modules' part
numbers - I had forgotten that!
The later models from approximately the 1990's used Panasonic (Matsushita)
built outputs with original SVI numbering on the modules themselves.

The chips were very different and not at all interchangeable. Also, the SVI
modules were very expensive, often leading to repair work being declined by
the customer.

The STK's almost never had any external biasing - I might have seen that
once in 35 years. Occasionally there could be an external resistor burned.
Normally you just replace the module and fuse if necessary and enjoy!


Mark Z.

Meat Plow
Guest

Thu Aug 19, 2010 4:52 pm   



On Wed, 18 Aug 2010 20:35:45 -0500, William R. Walsh wrote:

Quote:
Hi!

I don't think you need to worry about biasing a hybrid module. Those
things are STK-something right?

In this case, it's an STK-2038 II module that is used.

This receiver has something called "Computer Drive". It's not clear what
the "Computer" in use (a 4-bit Matsushita microcontroller) actually
*does*, but I really think it is only watching the input signal level,
temperature (via a tripping-type sensor set to 60C! Ouch!) and
triggering the "preheat" operation, operating some LEDs and generally
looking pretty. (My only other "Computer Drive" receiver, an SA-560,
doesn't seem to *have* the "Computer Drive" IC. It has only a small
circuit that switches on for a time at startup to "preheat" the power
transistors.) I smell marketing and maybe some "audiophoolery" here...?

There's also "New Class A Synchro Bias" which I take to mean (after
having done some reading) that the transistors in the amplifier are
prevented from ever switching off completely when the unit is in
operation. If I'm not mistaken, wouldn't that result in a lot of
needless heat dissipation and a stressful operating environment for the
STK-2038 module?

There are what appear to be bias adjustment pots on the main board in
what little outboard supporting circuitry the amplifier uses. So far as
I know, they're not mentioned in the service manual, so my guess is "no
adjustments intended".

William

I don't know why you would need to pre-heat a hybrid module. Must be a
sales gimmick. If I still worked for a Matsu authorized repair center I'd
be better able to answer. Having not been active in warranty repair for
them in over 27 years I don't recall exactly the verifications after
repair procedure we had to do. I would almost bet the farm that they
won't need adjustment.



--
Live Fast, Die Young and Leave a Pretty Corpse

Meat Plow
Guest

Thu Aug 19, 2010 5:08 pm   



On Thu, 19 Aug 2010 02:35:43 -0500, William R. Walsh wrote:

Quote:
Hi!

I gotta get me one of those. Still listening (and watching) my 30 gig
Ipod. Looked for the new 64 gig I Touch, pricey! But not out of my
price range even with the 3G option.

I bought a first-gen unit at a severe discount when the second
generation ones came out. It doesn't really matter to me if I'm "one
step behind".

Even as nice of a piece of equipment as it is, there's nothing about it
that screams "killer app". I've only ever used it very occasionally to
browse the web at home when a computer wasn't convenient or to play
video. I don't care much that it will never see iOS 4.

I found a well received and free audio frequency generation app, but the
iTMS is somehow dorked up at the moment and convinced that my credit
card will be expiring soon (in 2013?). Not quite.

William

I currently have a 30gb video Ipod. And an Ipod Shuffle. I'm pretty sure
that 32 gigs will serve me fine. My video Ipod has some dark lines in the
screen going from right to left. Not much of a deal unless you want to
watch a video. Funny thing is the lines are in the back light. They don't
show when looking at the display with the back light off. My music and
video library is over 100 gb. I frequently change the music and videos.
Currently have 10 gigs of music on the 30 and 10 gigs of video. Made a TV-
out cable so I can watch video on TV. And the picture is pretty damn
good. I've read some pros and cons for the 64 gb model. Don't care for
some of the cons so I will probably buy a 32. One app I like is called
Scanner911. It gets its audio from radioreference.com. People donate
scanner streaming to the site. You can listen on the PC. Around here all
of the departments except our local public safety switch to APCO-25/EDACS
800mhz trunked encrypted so I can no longer listen in on the sheriff/
state patrol. Someone in this area feeds Radioreference with a Uniden 996
scanner capable of receiving that traffic. I can pick it up on the PC or
on my netbook also. Being a Ham for 20 years now it's always been a hobby
of listening to police and fire along with SW.



--
Live Fast, Die Young and Leave a Pretty Corpse

Arfa Daily
Guest

Fri Aug 20, 2010 2:33 am   



"William R. Walsh" <newsgroups1_at_idontwantjunqueemail.walshcomptech.com>
wrote in message news:bIadnVM7xZ5rHPHRnZ2dnUVZ_vidnZ2d_at_mchsi.com...
Quote:
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out above
the
rest, whether free or not?

William



I have two on there. One is called "FreqGen" and the other is called
"Oscillatr Free" actually spelt like that. Both are much the same in
functionality, but I think that FreqGen is a bit nicer to use.

Arfa

Meat Plow
Guest

Fri Aug 20, 2010 5:19 pm   



On Fri, 20 Aug 2010 02:33:32 +0100, Arfa Daily wrote:

Quote:
"William R. Walsh" <newsgroups1_at_idontwantjunqueemail.walshcomptech.com
wrote in message news:bIadnVM7xZ5rHPHRnZ2dnUVZ_vidnZ2d_at_mchsi.com...
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out
above the
rest, whether free or not?

William



I have two on there. One is called "FreqGen" and the other is called
"Oscillatr Free" actually spelt like that. Both are much the same in
functionality, but I think that FreqGen is a bit nicer to use.

Arfa

I still use my old Leader from the 80s. It's coupled to my freq counter
if I need to be precise.



--
Live Fast, Die Young and Leave a Pretty Corpse

Arfa Daily
Guest

Sat Aug 21, 2010 2:55 am   



"Meat Plow" <mhywatt_at_yahoo.com> wrote in message
news:pan.2010.08.20.14.18.33_at_hahahahahahahah.nutz.I.am...
Quote:
On Fri, 20 Aug 2010 02:33:32 +0100, Arfa Daily wrote:

"William R. Walsh" <newsgroups1_at_idontwantjunqueemail.walshcomptech.com
wrote in message news:bIadnVM7xZ5rHPHRnZ2dnUVZ_vidnZ2d_at_mchsi.com...
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out
above the
rest, whether free or not?

William



I have two on there. One is called "FreqGen" and the other is called
"Oscillatr Free" actually spelt like that. Both are much the same in
functionality, but I think that FreqGen is a bit nicer to use.

Arfa

I still use my old Leader from the 80s. It's coupled to my freq counter
if I need to be precise.




For most bench work, I use a Ferrograph Pro Recorder Test Set that has a
rather nice frequency and amplitude stabilised multi decade oscillator in
it, but I also have an old and cherished Marconi Instruments "R-C
Oscillator" which uses tubes as I recall, although it's been a long time
since I've been inside it. Looks like it probably dates from the 60s.

Arfa

Meat Plow
Guest

Sat Aug 21, 2010 9:32 pm   



On Sat, 21 Aug 2010 02:55:20 +0100, Arfa Daily wrote:

Quote:
"Meat Plow" <mhywatt_at_yahoo.com> wrote in message
news:pan.2010.08.20.14.18.33_at_hahahahahahahah.nutz.I.am...
On Fri, 20 Aug 2010 02:33:32 +0100, Arfa Daily wrote:

"William R. Walsh"
newsgroups1_at_idontwantjunqueemail.walshcomptech.com> wrote in message
news:bIadnVM7xZ5rHPHRnZ2dnUVZ_vidnZ2d_at_mchsi.com...
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out
above the
rest, whether free or not?

William



I have two on there. One is called "FreqGen" and the other is called
"Oscillatr Free" actually spelt like that. Both are much the same in
functionality, but I think that FreqGen is a bit nicer to use.

Arfa

I still use my old Leader from the 80s. It's coupled to my freq counter
if I need to be precise.




For most bench work, I use a Ferrograph Pro Recorder Test Set that has a
rather nice frequency and amplitude stabilised multi decade oscillator
in it, but I also have an old and cherished Marconi Instruments "R-C
Oscillator" which uses tubes as I recall, although it's been a long time
since I've been inside it. Looks like it probably dates from the 60s.

Arfa

Since I don't have my I Touch yet I recorded some test tones on my Sharp
MD, transferred to PC and uploaded to my video IPod Smile How's that for
ingenuity?



--
Live Fast, Die Young and Leave a Pretty Corpse

Arfa Daily
Guest

Sat Aug 21, 2010 11:26 pm   



"Meat Plow" <mhywatt_at_yahoo.com> wrote in message
news:pan.2010.08.21.18.32.17_at_hahahahahahahah.nutz.I.am...
Quote:
On Sat, 21 Aug 2010 02:55:20 +0100, Arfa Daily wrote:

"Meat Plow" <mhywatt_at_yahoo.com> wrote in message
news:pan.2010.08.20.14.18.33_at_hahahahahahahah.nutz.I.am...
On Fri, 20 Aug 2010 02:33:32 +0100, Arfa Daily wrote:

"William R. Walsh"
newsgroups1_at_idontwantjunqueemail.walshcomptech.com> wrote in message
news:bIadnVM7xZ5rHPHRnZ2dnUVZ_vidnZ2d_at_mchsi.com...
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out
above the
rest, whether free or not?

William



I have two on there. One is called "FreqGen" and the other is called
"Oscillatr Free" actually spelt like that. Both are much the same in
functionality, but I think that FreqGen is a bit nicer to use.

Arfa

I still use my old Leader from the 80s. It's coupled to my freq counter
if I need to be precise.




For most bench work, I use a Ferrograph Pro Recorder Test Set that has a
rather nice frequency and amplitude stabilised multi decade oscillator
in it, but I also have an old and cherished Marconi Instruments "R-C
Oscillator" which uses tubes as I recall, although it's been a long time
since I've been inside it. Looks like it probably dates from the 60s.

Arfa

Since I don't have my I Touch yet I recorded some test tones on my Sharp
MD, transferred to PC and uploaded to my video IPod Smile How's that for
ingenuity?




Nothing more or less than I would have expected from you, Meat ! It's
lateral thinking like this that sets us old timers apart from today's 'black
box' kids ... d;~}

Arfa

Arfa Daily
Guest

Sat Aug 21, 2010 11:39 pm   



"Arfa Daily" <arfa.daily_at_ntlworld.com> wrote in message
news:koYbo.106547$KP3.4319_at_hurricane...
Quote:


"Meat Plow" <mhywatt_at_yahoo.com> wrote in message
news:pan.2010.08.21.18.32.17_at_hahahahahahahah.nutz.I.am...
On Sat, 21 Aug 2010 02:55:20 +0100, Arfa Daily wrote:

"Meat Plow" <mhywatt_at_yahoo.com> wrote in message
news:pan.2010.08.20.14.18.33_at_hahahahahahahah.nutz.I.am...
On Fri, 20 Aug 2010 02:33:32 +0100, Arfa Daily wrote:

"William R. Walsh"
newsgroups1_at_idontwantjunqueemail.walshcomptech.com> wrote in message
news:bIadnVM7xZ5rHPHRnZ2dnUVZ_vidnZ2d_at_mchsi.com...
Hi!

Do you have any kind of iPod Touch or iPhone?

Yes, I have a first generation iPod Touch. I should have thought of
that..."there's an app for that" too I guess.

Out of the applications you have, is there any one that stands out
above the
rest, whether free or not?

William



I have two on there. One is called "FreqGen" and the other is called
"Oscillatr Free" actually spelt like that. Both are much the same in
functionality, but I think that FreqGen is a bit nicer to use.

Arfa

I still use my old Leader from the 80s. It's coupled to my freq counter
if I need to be precise.




For most bench work, I use a Ferrograph Pro Recorder Test Set that has a
rather nice frequency and amplitude stabilised multi decade oscillator
in it, but I also have an old and cherished Marconi Instruments "R-C
Oscillator" which uses tubes as I recall, although it's been a long time
since I've been inside it. Looks like it probably dates from the 60s.

Arfa

Since I don't have my I Touch yet I recorded some test tones on my Sharp
MD, transferred to PC and uploaded to my video IPod Smile How's that for
ingenuity?




Nothing more or less than I would have expected from you, Meat ! It's
lateral thinking like this that sets us old timers apart from today's
'black box' kids ... d;~}

Arfa

Hey Meat, just saw your response to the 'car windshield fitter story' whilst
I was cruisin' on uk.rec.cars.maintenance. Which of the many cross-posted
groups were you responding from ? Didn't see any in the list that looked
like the sort of place I'd find you lurking ... !

Just as a matter of interest, I'm sure I remember having a windshield
replaced in one of our cars a few years back, and the fitter actually had to
take the vehicle away to a facility to do the job, as it was an aerodynamic
screen glued in rather than being just 'traditionally' fitted in a rubber
seal. I feel that I can recall the fitter saying that the replacement glue
had to be 'baked' under IR lamps for something like 2 hours, and the vehicle
could not, as a result of this, be moved for at least that amount of time.

Arfa

Goto page Previous  1, 2, 3  Next

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