Alternative source for cheap functional Bose speaker amplifiers

[Starman]

Originally Posted by RHanselman

Very good to know... I've 4 vettes and all but 1 have speaker issues... $21 per car is much better than $80 per speaker amp...

Ron - I agree and being cheap actually spent about $35 for all the consumable electronics on the amps in Class A grade. That anti-vibration sticky goo was much more prevalent on my amps and near impossible to remove - maybe there is some trick? Even with union Electricians to help, we were afraid of destroying them, so I chickened out and sent them to Bose - a good option for the non technically inclined, with good results.

Anyway the parts did come in handy when the power supply in the HVAC head unit went bad.

[Starman]

The Bose Solution is not so cheap anymore. $140 refurbishes a speaker/amp unit with a 1 year warranty. The contact info is 508-766-9522 (Patty).

[scottfab]

What a GREAT TIP !!
I was keeping my eyes open for one of these and as luck would have it. A friend is donating her car to charity. I noticed it was a 98 Maxima... asked if I could have my way with the sound system and I RIPPED out the amps. Cost? $0
Free is a very good price.

Originally Posted by mike100

As requested, I put together some pictures and part numbers for 95-99 Nissan Maxima and Infiniti I30 cars that use the same type of Bose amps as the C4 does. They are functionally swappable, but the exact speaker tuning may be slightly different. I found that they sound great in the C4 as they have a similar small/large front to rear (respectively) speaker arrangement.

History- At first I set off to buy a replacement amp for one in the rear that squealed. Once I got that working with a good used Corvette unit (that I parted with $50 for), I realized other amps were weak and another completely dead- I think I had one good one in the whole car. You just couldn't tell because the squealing one was very loud. After reading up on the how-to to replace the capacitors, I redid mine (with used caps from some junkers I procured). Not using new caps was a mistake, but I got 2 out of the 3 working again. One of them failed three weeks later, but I did realize that some would be serviceable. For awhile I was trying to keep it proper using exact oem parts like an NCRS collector would do, but after having taken apart the enclosures a couple times too many, and having spent money for little gain, I considered the information I had found on the Nissans that used this same amplifier.


Nissan front amp- marked 'Sigma 975':


front amp opened:


rear amp:


rear amp side-by-side with oem C4 amp:


note on the last picture that some of the electrolytic caps appear missing on the Nissan part, but they are still there, just in different locations as the board had a layout revision. They work and I was hard pressed to hear a difference. You can tell bass/treble tuning if you swap a front to the rear and visa-versa so it is important to get that straight, but they are a good match for the vettes IMO.

I have been able to get mine from a local pull-it-yourself dismantler for $7 each. They are newer than the ones in our cars, and few people care to restore maximas, so this is the prime age for finding tons of these cars in the scrap yard. I have been able to find at least 4 amps each time I visit my local spot. (No, I have not been buying more).

[Vetman]

Who is Dr. Don I have seen in other forum discussions. Can I sent my bose system in. Where is he located. Is it best to take the car to him?

[Dynomite]

Originally Posted by Vetman

Who is Dr. Don I have seen in other forum discussions. Can I sent my bose system in. Where is he located. Is it best to take the car to him?

Doc Don's (Radio)

Huntsville, Texas 77320

He has a shipping form on his web site.

That is just some great information right there Mike

My 91' ZR-1 had rebuilt Speaker Amps which were directly soldered to the connector wires with the connector removed.

I replaced those modified Pigtails with Stock Pigtails having the six pin connectors in tact and used 975 Amps Front and Rear.
The Pigtails are available from Doc Don's Radio for $5 each plus shipping.

WOW....what volume and a super sound

And ALL those 975s and 075s that were junk at Pull UR Parts worked perfectly....I tested them ALL.

Bose Speaker Amp Options TIPS

Originally Posted by mike100

As requested, I put together some pictures and part numbers for 95-99 Nissan Maxima and Infiniti I30 cars that use the same type of Bose amps as the C4 does. They are functionally swappable, but the exact speaker tuning may be slightly different. I found that they sound great in the C4 as they have a similar small/large front to rear (respectively) speaker arrangement.

History- At first I set off to buy a replacement amp for one in the rear that squealed. Once I got that working with a good used Corvette unit (that I parted with $50 for), I realized other amps were weak and another completely dead- I think I had one good one in the whole car. You just couldn't tell because the squealing one was very loud. After reading up on the how-to to replace the capacitors, I redid mine (with used caps from some junkers I procured). Not using new caps was a mistake, but I got 2 out of the 3 working again. One of them failed three weeks later, but I did realize that some would be serviceable. For awhile I was trying to keep it proper using exact oem parts like an NCRS collector would do, but after having taken apart the enclosures a couple times too many, and having spent money for little gain, I considered the information I had found on the Nissans that used this same amplifier.


Nissan front amp- marked 'Sigma 975':


front amp opened:


rear amp:


rear amp side-by-side with oem C4 amp:


note on the last picture that some of the electrolytic caps appear missing on the Nissan part, but they are still there, just in different locations as the board had a layout revision. They work and I was hard pressed to hear a difference. You can tell bass/treble tuning if you swap a front to the rear and visa-versa so it is important to get that straight, but they are a good match for the vettes IMO.

I have been able to get mine from a local pull-it-yourself dismantler for $7 each. They are newer than the ones in our cars, and few people care to restore maximas, so this is the prime age for finding tons of these cars in the scrap yard. I have been able to find at least 4 amps each time I visit my local spot. (No, I have not been buying more).

[FU]

Cough cough. Hey buddy have a spare ?

[mike100]

!!!!!... and I only found 3 today. BTW, the 6 pin amp fits all 91-up C4 speakers (see my pic comparison of my oem 6-pin 91 amps). I will have to dig back into some links at the other forum to see what the deal was with the wiring to see if you can adapt those to 90-earlier.
Looks like the Bose option was standard on Infiniti and an option on Maximas. It would seem Infiniti stands for unlimited supply of parts in the wrecking yard. I did find that older maximas and Q45 flagship cars also have the Bose speakers- maybe those amps are compatible, but most are 20 years old and I did not bother to break down the speaker enclosures to see what they looked like.

[mike100]

This time my rear amp was marked 'Sigma 975 Rear' similar p/n, but not quite (176059-3321)... I may have to open up my vette enclosure, plug these in and try these new ones out. They look the same as the ones i have pictured above.

I suppose one could make an audio test bench if you had a head unit, the speakers amps, and speakers, but I'm not really trying to go there at the moment.

[mike100]

Do you have a very early 90 car? a brief look into it lists 90-96 speaker amps all the same for the later c4's. 89's are supposed to be different.

[mike100]

Be sure to keep track of front/rear installation because the bass/treble tuning IS important. I could hear the difference when you plug a front into the larger rear speaker enclosure.

The vette wiring harness attaches directly to the 6-pin white connector on the amplifier.

Going to the u-pick-it wrecking yards is a treasure hunt for mechanics. I might go back because I found something for my truck I didn't have the tools for yesterday. My Infiniti find yesterday was a cleaner car that had air-bag deployment. Other cars were completely neglected. I treat my laundry set about the same way tho.. haha.