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greyhound
07-16-2007, 02:14 PM
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
07-16-2007, 02:38 PM
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
07-16-2007, 03:05 PM
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
07-16-2007, 04:12 PM
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
07-17-2007, 12:46 AM
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
07-17-2007, 09:27 AM
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
07-18-2007, 01:34 AM
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
07-27-2007, 08:49 PM
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
07-30-2007, 11:02 AM
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
08-02-2007, 03:01 PM
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
10-12-2007, 01:01 PM
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
01-31-2010, 04:49 PM
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
12-02-2010, 11:33 AM
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
12-17-2010, 06:53 AM
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?

marvinf
12-10-2013, 10:42 AM
[QUOTE=greyhound;177251]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.

"I have owned one of these for over 35 years now. If you want information on this amp, email me at marvinf@comcast.net and I will send you a copy of the owners manual, service manual, and other information that I have. It will be in a pdf format." Whatever you do, if you have one that is in good condition, do not sell it. It is one amp that a lot of people would love to own. I also have the Bose 4401 pre-amp. I also have owned a set of Bose 901's for about the same time period. I now have the Bose 901 Series VI and I would not buy any other speakers but these. I have audition speakers costing $60,000.00 and more and I will say hands down, the 901 is the best. They must be set up correctly in order to get the best out of them, but once you have done that, you will hear why I am saying they are the best." :applaud:

martin2395
12-10-2013, 12:18 PM
The 1801 is a very nice amp with it's own, special 70's sound BUT I've heard from a tech that the circuitry has a few flaws which must be fixed because when the amp breaks down it will fry your speakers with like 90V DC.

I think that the 1801 is sonically similiar to the Phase Linear 400/700.

BMWCCA
12-10-2013, 03:09 PM
I now have the Bose 901 Series VI and I would not buy any other speakers but these. I have audition speakers costing $60,000.00 and more and I will say hands down, the 901 is the best. They must be set up correctly in order to get the best out of them, but once you have done that, you will hear why I am saying they are the best."

Thanks for sharing and welcome to Lansing Heritage.

Now you'd better close your eyes if you're thin-skinned. Remember, this is a JBL group! Not that we're not open-minded but claiming the 901 is "the best" is likely to either get ignored or laughed at here. Can we still be friends?
:seeya:

mikebake
12-10-2013, 04:02 PM
I have one of these Bose 1801's laying around that I got with a pile of JBL gear. I'm told one channel does not work, seemingly from the same problems described above. If someone is interested in purchasing it as is, send me a private message.

cooky1257
12-11-2013, 01:48 AM
I could be wrong(ask the wife) but isn't the 1800 a rebadged BGW750?.

BMWCCA
12-11-2013, 05:58 AM
I could be wrong(ask the wife) but isn't the 1800 a rebadged BGW750?.

There seems to be some disagreement on that: http://www.audiokarma.org/forums/showpost.php?p=3131103&postcount=16

cooky1257
12-11-2013, 06:19 AM
There seems to be some disagreement on that: http://www.audiokarma.org/forums/showpost.php?p=3131103&postcount=16
Not even sure where I originally got the info. The 1801 certainly has plenty of bling with led and VU meters.

Mr. Widget
12-15-2013, 02:35 PM
"I have owned one of these for over 35 years now... I also have owned a set of Bose 901's for about the same time period. I now have the Bose 901 Series VI and I would not buy any other speakers but these. I have audition speakers costing $60,000.00 and more and I will say hands down, the 901 is the best. They must be set up correctly in order to get the best out of them, but once you have done that, you will hear why I am saying they are the best." :applaud:A friend recently asked about the 901s. I told him that when I first heard them in 1974 I was blown away by them. They were in a stereo shop powered by a McIntosh MC2300 and knowing what I know now, were not set up ideally... however with my young and admittedly inexperienced ears, they blew me away.

In any event, Bose sells the current version, the Series VI for the modest cost of $1400 a pair including the equalizer and will let you audition them in your home for 30 days. My friend ordered a pair. I eagerly went over to help him set them up and give them a listen. I was impressed that Bose can sell them at this price point, and with a big amp, they will get very loud without undue strain... however, they do not hold up well overall compared to anything I listen to daily. Admittedly everything I have at home costs several times their cost, but I really missed true bass and treble free of breakup mode harmonics. Now, with a sub and proper super tweeter they would be pretty enjoyable and they do offer a very interesting take on stereo presentation.

If you listened to a male a cappella ensemble, they would likely blow you away and not need any augmentation... ;)


Widget

SEAWOLF97
12-15-2013, 04:36 PM
I could be wrong(ask the wife) but isn't the 1800 a rebadged BGW750?.

well, the quote from one of our members is:

Originally Posted by loach71 http://audiokarma.org/forums/images/buttons/viewpost.gif (http://www.audiokarma.org/forums/showthread.php?p=3125818#post3125818)

The BOSE 1801 was manufactured by BGW and re-badged.


does NOT reference the 750. I had also read somewhere else that it was designed by Bose and produced by BGW.

I've had correspondence with Tim (loach71) and never heard anything that I could question. If you knew his creds , I don't think anyone would doubt his statement. Sure, he can be wrong , but I'd bet against it.

And yes, some other posters contradicted him, but that's the innerweb. :blink:

lightning11.0
03-23-2015, 10:10 AM
does anyone know how to get 4 speakers 901s to play out of an 1801 bose amp? at the same time I get 2 on main and 2 on remote but can't figure how to get all 4 going at the same time

dezmond
02-26-2016, 05:22 AM
Yes use both pairs on one set of binding posts.

rusty jefferson
02-26-2016, 07:37 AM
Yes use both pairs on one set of binding posts.
I didn't read this whole thread, but wiring 2 pairs in parallel as described will cut the (already low?) impedance in half. May be a problem for sound quality, or the amp. Consider wiring them in series. You can Google parallel vs series wiring speakers to see the difference.