amp info bose 1801

[greyhound]

currently im using a denon pma qs10 amp. its an intigrated amp thst gives 50 watts at 8 ohm but doubles it at 4 ohm. it still sounds a bit to nice (too audiophile) so im looking to improve.
im in the fortunate position of buying the bose 1801 power amp. theres not much info on it here and certenly no first hand experience with it.
any one over there who knows this amp. i know its big and powerfull but is it suitable as a home amp?
it will have to drive the century gold speakers who can coop with 800 watts in peak.
am i a fool for this change:( or should i go for it.:applaud:

[SEAWOLF97]

This is the Bose 1801 power amplifier. Probably the biggest home audio amplifier ever made in size and weight. It is rated at 400 watts per channel in a 4 ohms load. The heat sink goes all around the side and back, which makes it awkward to move. Take a look at the size of the transformer, sign of huge power delivery. Each channel has 14 TO-3 cased transistors, all of the same type. It is a quasi complementary output circuit. You can replace the originals with SD555.

This unit had one channel defective. A hot resistor melted the solder and two output transistors blew. A common problem for these amps is a zener diode which shorts and causes a resistor to flare up therefore damaging the printed circuit board, making the amp unusable. Bose does not sell these proprietary parts anymore which makes' it difficult to fix. It is a monster well worth keeping
http://www3.sympatico.ca/sireno/vintage_audio.htm


http://www.diyaudio.com/forums/showthread/t-20439.html

[greyhound]

This is the Bose 1801 power amplifier. Probably the biggest home audio amplifier ever made in size and weight. It is rated at 400 watts per channel in a 4 ohms load. The heat sink goes all around the side and back, which makes it awkward to move. Take a look at the size of the transformer, sign of huge power delivery. Each channel has 14 TO-3 cased transistors, all of the same type. It is a quasi complementary output circuit. You can replace the originals with SD555.

This unit had one channel defective. A hot resistor melted the solder and two output transistors blew. A common problem for these amps is a zener diode which shorts and causes a resistor to flare up therefore damaging the printed circuit board, making the amp unusable. Bose does not sell these proprietary parts anymore which makes' it difficult to fix. It is a monster well worth keeping
http://www3.sympatico.ca/sireno/vintage_audio.htm


http://www.diyaudio.com/forums/showthread/t-20439.html

the owner has changed some components like elco's en transistors and its been done by a well known company. it looks pretty mint and he's asking 500 euro thats less than 500 dollar. im realy tempted to buy it. espacially since i like the vintage stuff so much. im playing guitar music mostly so it doesnt have to be to sutble you know. guitars should sound like a V8 engine if you know what i mean.

[alskinner]

I have two Bose 1801s and a Bose 1800. I have found them to work well with JBL speakers. I run an 1801 on my 4344 clones and find it one of the best matches so far. Besides the zener diode mentioned ealier there are also some of the caps on the driver board that it really pays to change. The main thing to watch out for is like the Phase linear 400 if the 1801 blows output transistors it will take the speakers with it. This was especially true in the lower serial numbered units. Bose did a modification that tiook care of this in the later units. I keep mine on 24 hours a day and have not had a problem with it over the last 3 years. If you are interested in the 1801 it would pay to buy a service manual for it. They can usually be found on e-bay for about $12.00. Also at about 90 pounds it's a chore to move around.

Regards
AL

[greyhound]

I have two Bose 1801s and a Bose 1800. I have found them to work well with JBL speakers. I run an 1801 on my 4344 clones and find it one of the best matches so far. Besides the zener diode mentioned ealier there are also some of the caps on the driver board that it really pays to change. The main thing to watch out for is like the Phase linear 400 if the 1801 blows output transistors it will take the speakers with it. This was especially true in the lower serial numbered units. Bose did a modification that tiook care of this in the later units. I keep mine on 24 hours a day and have not had a problem with it over the last 3 years. If you are interested in the 1801 it would pay to buy a service manual for it. They can usually be found on e-bay for about $12.00. Also at about 90 pounds it's a chore to move around.

Regards
AL

i never switch off my amp so it will be glowing for 24/7
i wont play it very loud but what kind of behaviour causes the trans to blow?
the 90 pounds are no problem (im a powerlifter for a hobby)its more the way you hold it because of the cooling ribs.

what do you mean with "watch out for the phase lineair"

[hmolwitz]

I phoned up the folks @ Bose and they mailed me a schematic No Charge.
I bought it with one side blown been working beautifully for years, nice amp.
Harry

[greyhound]

I phoned up the folks @ Bose and they mailed me a schematic No Charge.
I bought it with one side blown been working beautifully for years, nice amp.
Harry

thats good to hear. im rwaly getting exited because my amp (thats for sale) is quite popular so it seems.

[doodlebug]

I do remember those amps when I worked in a Bose dealership in the mid-70s. We went through 2 Barzilay shelves before we found one strong enough to support it.

Yes, one of them also had the instability problem that led to both amps going bad at the same time and it took out a set of 901s - all 18 drivers!, too.

I think we sold one of the 1801s but sold many, many Crown DC300s mainly due to our loss of confidence in the amp.

Still, it was fun to watch those big meters bounce along with the music.

Cheers,

David

[pentictonklaus]

Yes, one of them also had the instability problem that led to both amps going bad at the same time and it took out a set of 901s - all 18 drivers!, too.

I think we sold one of the 1801s but sold many, many Crown DC300s mainly due to our loss of confidence in the amp.


I had that Bose about 20 years ago. It took out all drivers in a Dynaudio 5000 one morning at startup. Very expensive 1/4 of a second.
DC prevention curcuit is a must on these amps.I run DC 300 after, but
the crown does also benefitt from DC prevention curcuits.

Klaus

[greyhound]

the bose deal didnt get trough. instead i have now a pre and power combination from bryston. this is a big improvement over the denon. i was looking for a american amp but levinson and krell were just to expensive.
the controll over my century's have improved a lot and they sound like a happy marriage. im getting closer to my ideal sound thats a bit like PA but also capable of playing mozarts requim.
of course there is a humming sound in the back so i might have to replace the tranformator and the condensators. the importeur here in holland is giving me a hard time with the warranty so if they dont fix it ill have to do it myself. they are build rather simple so i can pull it of i think.
anyway thnx for the bose input.
i still love the look of Vu meters.

[greyhound]

i finally got it.
its in gtreat shape and sounds even better. lost of control especially in the loweer regions. we replaced the zener diode wich was in bad shape and took out 2 transistors. it kept on playing though. after have seen it opened its a real nice handmade beast. the frase "they dont make em like they used too "comes to mind when you browse through it. thick printplates, large powersupply. realy beautifull.
why on earth didnt bose continue this course in stead of the crap they make today i will never understand.
well anyway im a happy owner now.

[ray134]

I'm using a Bose 1800 (same amp, different package) to power a pair of Altec Lansing 816 cabinets for the fronts on my Ht. I bought the 1800 because I have an 1801 that I bought new in 1973. It was in a house fire and still worked. It has failed twice since then but it gets fixed and I still like it. These amps are happy delivering large amounts of current. I'm a big fan of speaker fuses and I keep 4 amp fuses on the outputs. Playing music wil lnever take an amp near its rated output unless you really like distortion.

[lenajonathan]

I am a big fan Bose 1800 as I have been using it for such long time, I agree with you about the large amounts of current this one can deliver which makes it really astonishing!



I'm using a Bose 1800 (same amp, different package) to power a pair of Altec Lansing 816 cabinets for the fronts on my Ht. I bought the 1800 because I have an 1801 that I bought new in 1973. It was in a house fire and still worked. It has failed twice since then but it gets fixed and I still like it. These amps are happy delivering large amounts of current. I'm a big fan of speaker fuses and I keep 4 amp fuses on the outputs. Playing music wil lnever take an amp near its rated output unless you really like distortion.

[Audiobeer]

Thier speakers are absolutely incredible. :banghead: Just having fun folks. I wonder what if the Wave had Preouts and Ins to use with the 1801?