Has Anyone Got a Bose Amplifier circuit diagram?

[John Biles]

Hello Everyone,
For years I have heard that Bose is top quality.
I assume that its a B class Amplifier by the size of it.
Does anyone have a circuit diagram of any Bose they could put on the forum.

[richie00boy]

Awaits responses lol Have you got your flameproof suit on?

[destroyer X]

There are many revoluctionary guys loving deeply bose, others than use this name referenced to some clown.

This thread will be very hot......ahahahaha

regards,

Carlos

[jackinnj]

When I took a gander at a Bose in their store in Aurora OH it certainly seemed that they were using a National Semi Overture chipamp in the WAVE Radio.

[kevinkr]

Early ones used chips from SGS. Don't ask me how i know.. LOL

Kevin

[Eva]

The expensive factory equipment I've seen from BOSE in very expensive cars is just made of:

- Loudspeakers with tiny voice coils, plain poorly-treated paper cones and fragile plastic frames, placed in plastic enclosures or supports.

- Amplifier modules, made with low-cost ST or Philips 12V stereo ICs (no more than 15W/channel), with built-in crossovers and phase shifters made out of TL074 op-amps (12V sinlge supply operated), SMD resistors and lots of electrolytic capacitors.

This makes me think that BOSE just sells boxes filled up of hype.

[Cal Weldon]

Originally posted by Eva
This makes me think that BOSE just sells boxes filled up of hype.

[Netlist]

We've got plenty of (open) threads about Bose filled with exotic posts. Let's stick to the original posters question in this one.

/Mod head off

Other then that I must say I can't remember I ever encountered a free Bose schematic on the net.

/Hugo

[ChocoHolic]

Originally posted by John Biles
Hello Everyone,
For years I have heard that Bose is top quality.
I assume that its a B class Amplifier by the size of it.
Does anyone have a circuit diagram of any Bose they could put on the forum.

...or class D.
And if not designed properly, then it could sound like jackinnj described....

[PRR]

> For years I have heard that Bose is top quality.

Bose has been spending millions of dollars telling us that for years.

> BOSE just sells boxes filled up of hype.

A significant part of the retail price does go to promotion. Everybody does some of that; Bose does it very well.

> Does anyone have a circuit diagram of any Bose

You can't see "quality" in a schematic.

Amir Bose's real genius is in putting together low-cost pieces so that the result is much more than the sum of the parts. There is a lot of art in those products.

And Bose never sold many standalone amps. Most of their amps were made to work as part of a Complete System. The schematic alone would be less than half the story.

> equipment I've seen from BOSE in very expensive cars is just made of:

The average price of a car-audio speaker is like $1.27.

When car-makers assembled their own audio, they would pick the cheapest speaker in the catalog, demand slightly better specs and a much lower price, and get the lower price. Considering the huge quantity and steady demand, it is possible to get a "good sound" for $1.27/speaker. But not very likely. Random selection of parts does not ensure that the total is worth even $1.27, not when a carb-designer or upholstery specialist is re-assigned to sound system development.

That's where Bose comes in. Aside from getting some pay-back for decades of promoting the Bose name, the company is good (better than some spare auto-engineer) at mixing and matching drivers and electronics to give pleasing sound-for-cost.

I myself, an experienced audio dude, made a mistake as bad as Detroit would have. I replaced stock Honda drivers with some Big-name drivers. Because I could not audition all possible drivers, I ended up with ones with low mid-bass efficiency and a complete lack of upper-mids. This suits the market; it does not suit my music. But it does not make sense for me to buy two of every driver available and try them all. But that's something that Bose could do for a million-car deal.

> fragile plastic frames

Also: Bose has a dedicated speaker factory that is bigger than their other products need. And with total control, they can shape the speaker efficiency so monster amps are not needed, fix the un-flat in the TL074 processors. If you left it to Ford/GM/etc you would not even have the TL074s, just a lowest-price SGS or LG chip-amp.

And EVERYTHING made in lots over 1,000 today is SMT.

> lots of electrolytic capacitors.

That's better than not-enough caps, which would be the normal way to go for car-audio.

And it is a car, and a system for the Masses. 99% of people can't hear an electrolytic cap. The 1% who do, take the base or no-radio option and put in their own favorite boxes. The car makers are not selling collectable wine: they sell basic-beer and good-beer. If you want very-very-good beer, BYOB.