Bose/GM Delco Radio

[J. B. Wood]

Hello, all, and I realize the difficulty in diagnosing a problem via
e-mail alone. Does anyone have repair experience with OEM Bose radios
that go by the name of "Silver Series" that were/are installed in GM
autos? My radio/cassette player in my '91 Chev Lumina Z-34 had been
developing distorted sound in both the L and R channels for some time and
has finally failed. During that time you could still listen to the radio
if you cranked the volume control to max. However, the radio would
periodically break into an extremely loud whine for which the volume
control had no effect. Ditto when in cassette player mode. I think the
problem is in the audio power amplifier section. Your time and comment is
greatly appreciated. Sincerely,

John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

 

[Daniel K. Rasmussen]

Hello, all, and I realize the difficulty in diagnosing a problem via
e-mail alone. Does anyone have repair experience with OEM Bose radios
that go by the name of "Silver Series" that were/are installed in GM
autos? My radio/cassette player in my '91 Chev Lumina Z-34 had been
developing distorted sound in both the L and R channels for some time and
has finally failed. During that time you could still listen to the radio
if you cranked the volume control to max. However, the radio would
periodically break into an extremely loud whine for which the volume
control had no effect. Ditto when in cassette player mode. I think the
problem is in the audio power amplifier section. Your time and comment is
greatly appreciated. Sincerely,

If this unit is anything like a Bose unit I had in an early 90's
Honda, the head unit is just a pre-amp. The amps are in the
speakers. I wound up adding new speakers with small single channel
amps in-line but was never really happy with the results. I wound
up replaceing the head unit with another non-Bose Honda head unit
from a junk yard.

Dan Rasmussen

 

[JR3611]

If you do have the amps at the speakers then you will need to replace ALL OF
THE SURFACE MOUNT CAPS on the amps. They all leak and cause allot of
problems. This will fix 90% of them. In the 1990s about 80% of all of this
type of capacitor used a defective material. It was a big story in Taiwan
over the last few years as to who was at fault for this problem, but in the
end it the consumer who paid for this error.

If you use www.google.com and search for Bose repair, you will find some
more info.

Jerry



"J. B. Wood" <wood@itd.nrl.navy.mil> wrote in message
news:wood-1211030705570001@jbw-mac.itd.nrl.navy.mil...

Hello, all, and I realize the difficulty in diagnosing a problem via
e-mail alone. Does anyone have repair experience with OEM Bose radios
that go by the name of "Silver Series" that were/are installed in GM
autos? My radio/cassette player in my '91 Chev Lumina Z-34 had been
developing distorted sound in both the L and R channels for some time and
has finally failed. During that time you could still listen to the radio
if you cranked the volume control to max. However, the radio would
periodically break into an extremely loud whine for which the volume
control had no effect. Ditto when in cassette player mode. I think the
problem is in the audio power amplifier section. Your time and comment is
greatly appreciated. Sincerely,

John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

 

[TCS]

On 12 Nov 2003 10:18:31 -0500, Daniel K. Rasmussen <rasmusd@L71020846.msd.ray.com> wrote:

Hello, all, and I realize the difficulty in diagnosing a problem via
e-mail alone. Does anyone have repair experience with OEM Bose radios
that go by the name of "Silver Series" that were/are installed in GM
autos? My radio/cassette player in my '91 Chev Lumina Z-34 had been
developing distorted sound in both the L and R channels for some time and
has finally failed. During that time you could still listen to the radio
if you cranked the volume control to max. However, the radio would
periodically break into an extremely loud whine for which the volume
control had no effect. Ditto when in cassette player mode. I think the
problem is in the audio power amplifier section. Your time and comment is
greatly appreciated. Sincerely,

If this unit is anything like a Bose unit I had in an early 90's
Honda, the head unit is just a pre-amp. The amps are in the
speakers. I wound up adding new speakers with small single channel
amps in-line but was never really happy with the results. I wound
up replaceing the head unit with another non-Bose Honda head unit
from a junk yard.

That would have been pretty horrible; bose tries to compensate for mediocre
drivers with equalization and it was probably done in the head unit.

Sounded tinny as hell, right? Like it had 18db@20khz instead of a tweeter?

 

[Jeff]

Most likely amp/s however tuner/preamp and head unit
are possiable problems, model numbers would help.
I think you tried calling me, sorry I was out.
The LOUD whine is usually the amp 99% in any OEM
Bose system, check with a chevy dealer for the location/s
of the amp/s in that system.... If the antenna plugs into the
radio then its what drives the amp/s, if not then you have
a third part, a tuner/preamp modual that drives the amp/s
Good luck finding a surface mount capacitor in any of
the above units as another poster wrote, as there are none in there to find,
well electrolytic anyway.
Jeff
..
"J. B. Wood" <wood@itd.nrl.navy.mil> wrote in message
news:wood-1211030705570001@jbw-mac.itd.nrl.navy.mil...

Hello, all, and I realize the difficulty in diagnosing a problem via
e-mail alone. Does anyone have repair experience with OEM Bose radios
that go by the name of "Silver Series" that were/are installed in GM
autos? My radio/cassette player in my '91 Chev Lumina Z-34 had been
developing distorted sound in both the L and R channels for some time and
has finally failed. During that time you could still listen to the radio
if you cranked the volume control to max. However, the radio would
periodically break into an extremely loud whine for which the volume
control had no effect. Ditto when in cassette player mode. I think the
problem is in the audio power amplifier section. Your time and comment is
greatly appreciated. Sincerely,

John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

 

[Jeff]

"TCS" <The-Central-Scrutinizer@p.o.b.o.x.com> wrote in message
news:slrnbr5jut.2hg.The-Central-Scrutinizer@linux.adamf625.kaosol.net...

On 12 Nov 2003 10:18:31 -0500, Daniel K. Rasmussen
rasmusd@L71020846.msd.ray.com> wrote:

Hello, all, and I realize the difficulty in diagnosing a problem via
e-mail alone. Does anyone have repair experience with OEM Bose radios
that go by the name of "Silver Series" that were/are installed in GM
autos? My radio/cassette player in my '91 Chev Lumina Z-34 had been
developing distorted sound in both the L and R channels for some time
and
has finally failed. During that time you could still listen to the
radio
if you cranked the volume control to max. However, the radio would
periodically break into an extremely loud whine for which the volume
control had no effect. Ditto when in cassette player mode. I think
the
problem is in the audio power amplifier section. Your time and comment
is
greatly appreciated. Sincerely,

If this unit is anything like a Bose unit I had in an early 90's
Honda, the head unit is just a pre-amp. The amps are in the
speakers. I wound up adding new speakers with small single channel
amps in-line but was never really happy with the results. I wound
up replaceing the head unit with another non-Bose Honda head unit
from a junk yard.

That would have been pretty horrible; bose tries to compensate for
mediocre
drivers with equalization and it was probably done in the head unit.

Sounded tinny as hell, right? Like it had 18db@20khz instead of a
tweeter?

He said he changed speakers and head unit.
Early 90s Honda.......? ~1 ohm speakers!
If the amps were with the speakers then the EQ
could not be done in the head unit as the 2 years that
that was done in Honda the amp was the head unit and
it had an EQ box mounted to it.
The EQ is done in the amp most of the time.
There is a Bose circuit in the head unit but its not EQ.
Jeff

 

[TCS]

On Thu, 13 Nov 2003 02:39:33 GMT, Jeff <frontline_electronics@NSatt.net> wrote:

There is a Bose circuit in the head unit but its not EQ.

Sure. What, pray tell, do you suppose it is?

 

[Daniel K. Rasmussen]

He said he changed speakers and head unit.
Early 90s Honda.......? ~1 ohm speakers!
If the amps were with the speakers then the EQ
could not be done in the head unit as the 2 years that
that was done in Honda the amp was the head unit and
it had an EQ box mounted to it.
The EQ is done in the amp most of the time.
There is a Bose circuit in the head unit but its not EQ.

Well, I simplified the story to save typing. Here's the details:

Original head unit died in my 94 Accord (standard honda head unit).
Unaware that I needed amplified speakers, I blindly bought a Bose
head unit off Ebay (had bass, treble controls). Installed easy but
was real quiet . Figured out I needed amps for the speakers and
tried a pair of cheapo 10W mono kit amps. As I reall, the setup
actaully sounded OK, not great, when the engine wasn't running that
is. I had a big noise problem otherwise.

I was getting ready to chase down the noise when I found an original
equipment standard head unit at a yard sale. I bought it for $5 and
gave up on the Bose.

Dan

 

[Jeff]

"TCS" <The-Central-Scrutinizer@p.o.b.o.x.com> wrote in message
news:slrnbr74of.2gr.The-Central-Scrutinizer@linux.adamf625.kaosol.net...

On Thu, 13 Nov 2003 02:39:33 GMT, Jeff <frontline_electronics@NSatt.net
wrote:
There is a Bose circuit in the head unit but its not EQ.

Sure. What, pray tell, do you suppose it is?

Depends on model, and what you would call EQ.
I would call it signal level/impedance conditioning to feed their amp from
someone elses design.
The amp is where they do the EQ with the exceptions I
wrote and maybe some I have not seen yet.
Jeff

 

[Jeff]

"Daniel K. Rasmussen" <rasmusd@L71020846.msd.ray.com> wrote in message
news:m3n0b01gg4.fsf@L71027515-udp3444539uds.msd.ray.com...

He said he changed speakers and head unit.
Early 90s Honda.......? ~1 ohm speakers!
If the amps were with the speakers then the EQ
could not be done in the head unit as the 2 years that
that was done in Honda the amp was the head unit and
it had an EQ box mounted to it.
The EQ is done in the amp most of the time.
There is a Bose circuit in the head unit but its not EQ.

Well, I simplified the story to save typing. Here's the details:

Original head unit died in my 94 Accord (standard honda head unit).
Unaware that I needed amplified speakers, I blindly bought a Bose
head unit off Ebay (had bass, treble controls). Installed easy but
was real quiet . Figured out I needed amps for the speakers and
tried a pair of cheapo 10W mono kit amps. As I reall, the setup
actaully sounded OK, not great, when the engine wasn't running that
is. I had a big noise problem otherwise.

I was getting ready to chase down the noise when I found an original
equipment standard head unit at a yard sale. I bought it for $5 and
gave up on the Bose.

Dan

Well thats totally different, high level output direct to
the speakers replaced with a unit that requires an amp
to drive a speaker.
The $5 choice was a good one, you could have got the
lgnition noise out but it would have cost more and had
less power. Then again if the vehicle had an electric fuel
pump near an amp you might have been there a while..
I am not a fast typer so my responces are usually short
and may lack some of what I would say.
Jeff