I am in the middle of completing the service bulletin for the potential resistor failure on the driver boards of the 1801. I have completed one of the boards no problems. The second board was worked on at some point it looks like many years ago with crappy soldering and two of the original bose 102433 output transistors were replaced with nec 2sd555 transistors.I have tested all the other output tranistors on the board and they are fine. I would like to find 2 replacement bose 102433 transistors for the driver board . Does anybody where to source them ?
Bose 1801 ,1800 output transistors
- Thread starter scottyv06
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petehall347
the brandy coffee man
http://www.manualslib.com/manual/796915/Bose-1801.html?page=29
Subject: Output Transistors
Remarks:
Due to supply demands, Bose
and the 1800 amplifier boards currently being produced. The transistors have been change
from Bose P/N 102433 (2N5840) to P/N 117579 ( Motorola MJ15011). The new output transis-
tors are not compatible with the original 102433 transistors. If you service an 1800 power
amplifier or PM-2 mixer, check the serial numbers on the printed circuit board and the P/N on
the output transistors to see which output device is being used. Below is a list of the approxi-
mate serial number break for the newer P/N 117579 transistors.
PM-2 Boards:
1800 Boards:
PM-1 Boards:
1801 Boards:
When replacing output transistors, you must use the correct replacement device. Older units
with P/N 102433 on the output transistors must be replaced with 102433 (2N5840) transistors.
Units with output transistors with P/N 117579 must be replaced with 117579 (MJ15011) transis-
tors.
SERVICE BULLETIN
®
Corporation has changed the output transistors on the PM-2
Approximately 30800 and above
Approximately 30800 and above
All have P/N 102433
All have P/N 102433
28
Date: 10/13/1980
Bulletin # Pro-81-001
Subject: Output Transistors
Remarks:
Due to supply demands, Bose
and the 1800 amplifier boards currently being produced. The transistors have been change
from Bose P/N 102433 (2N5840) to P/N 117579 ( Motorola MJ15011). The new output transis-
tors are not compatible with the original 102433 transistors. If you service an 1800 power
amplifier or PM-2 mixer, check the serial numbers on the printed circuit board and the P/N on
the output transistors to see which output device is being used. Below is a list of the approxi-
mate serial number break for the newer P/N 117579 transistors.
PM-2 Boards:
1800 Boards:
PM-1 Boards:
1801 Boards:
When replacing output transistors, you must use the correct replacement device. Older units
with P/N 102433 on the output transistors must be replaced with 102433 (2N5840) transistors.
Units with output transistors with P/N 117579 must be replaced with 117579 (MJ15011) transis-
tors.
SERVICE BULLETIN
®
Corporation has changed the output transistors on the PM-2
Approximately 30800 and above
Approximately 30800 and above
All have P/N 102433
All have P/N 102433
28
Date: 10/13/1980
Bulletin # Pro-81-001
Yes, I have them.
P M
P M
Some info.
You basically build the protection kit and find a place to install it.
I used a kit from China, very nice. I had to find a transformer to supply the right power voltage.
The kit from Parts-Express just need the 120V line feed. Nice. (never used it but it looks "standard")
I was working on an 1800 with a "pancake" transformer so I had a lot of room.
The 1801 with the "big boy" transformer leave very little room to add in anything!
http://audiokarma.org/forums/index.php?threads/bose-1801-repair-and-upgrade.695969/page-2
http://www.parts-express.com/velleman-k4700u-2-channel-loudspeaker-protection-kit--320-264
You basically build the protection kit and find a place to install it.
I used a kit from China, very nice. I had to find a transformer to supply the right power voltage.
The kit from Parts-Express just need the 120V line feed. Nice. (never used it but it looks "standard")
I was working on an 1800 with a "pancake" transformer so I had a lot of room.
The 1801 with the "big boy" transformer leave very little room to add in anything!
http://audiokarma.org/forums/index.php?threads/bose-1801-repair-and-upgrade.695969/page-2
http://www.parts-express.com/velleman-k4700u-2-channel-loudspeaker-protection-kit--320-264
Lesterbest
Super Member
Worked in audio in mid to late 70s. We carried this amp. Seldom sold one. Struck me as bright in a nasty way. However, it was meant to drive 901 spkr which was hardly a resolving speaker.
What speakers did you test/demo?
Makes all the difference.
First timer I heard one, it was on JBL L100 (or some such). It was impressive.
Selling 80 pounds of sharp heatsinks with meters could have been a challenge.
Lesterbest
Super Member
JBL 15" studio monitors, Heil AMT, Heil tower, Infinity, SAE, AR LST, Ohm F & several others that I forget. I spared my ears by eliminating the Servo Static. In those days, prior to the "Purist Era", switching was not verboten. I often think that a return to switching would eliminate 1/2 the gear on the used mkt. Sales are easier when there are products to sell against. Times have changed. We are in a "Birth with Ear Buds" era. Even the midwives wear ear buds today.
What was the competitive brand(s) that bested the 1800/1801 on those speakers?
Lesterbest
Super Member
SAE, Crown, BGW, Phase Linear
I only played the 901 when requested by head bangers who "rock out." Thankfully very few darkened the doorstep. Besides, we used them only for the ill fated Quadrphonic demo setup.