Anyone knows this amplifier?
I need information about transistors used for Outputstage.
It is called SAE601.
Replacement info needed
Regards,
ManUtd
I need information about transistors used for Outputstage.
It is called SAE601.
Replacement info needed
Regards,
ManUtd
djk said:
So SAE601 is a bipolar NPN?
Do You have also datasheet for this transistor or do
you have the experience?
I do trust you but i want to be sure.
ManUtd. (hope they beat Chelsea tomorrow!!)
it is not a bipolar npn. the transistor is a NPN BJT.
the amp operates on both npn and pnp BJTs... all you have to do now is to look for the complimentary pair....
the amp operates on both npn and pnp BJTs... all you have to do now is to look for the complimentary pair....
hacknet said:
Why complementary when all are marked with SAE601?
Complementary will be like MJ15024 and 25?
ManUtd.
"the amp operates on both npn and pnp BJTs... all you have to do now is to look for the complimentary pair...."
Thanks, I needed a good laugh!
The MKIII and MKIIIA were 120W/8R amplifiers with quasi-complementary output stages. They used epitaxial 2N3773.
The MJ15022 or 24 is the correct part for these.
Starting with the MKIIIC the power was raised to 200W/8R and series connected complimentary darlingtons were used.
The MJ11015 and 16 are the correct parts for these.
Thanks, I needed a good laugh!
The MKIII and MKIIIA were 120W/8R amplifiers with quasi-complementary output stages. They used epitaxial 2N3773.
The MJ15022 or 24 is the correct part for these.
Starting with the MKIIIC the power was raised to 200W/8R and series connected complimentary darlingtons were used.
The MJ11015 and 16 are the correct parts for these.
Bias adjustment
So after innstalled new Transistors all are Mj15024 i need to know the bias voltage?
there is only one potmeter on PCB and i think this is for the bias?
Anyone got scematic?
ManUtd.
So after innstalled new Transistors all are Mj15024 i need to know the bias voltage?
there is only one potmeter on PCB and i think this is for the bias?
Anyone got scematic?
ManUtd.
MKIII
I have the MKIII version with 6 transistors on each channel.
Is this version without any sort of loadspeaker protection?
ManUtd.
I have the MKIII version with 6 transistors on each channel.
Is this version without any sort of loadspeaker protection?
ManUtd.
Mk III
You will see 6 pcs of TO3 metal cans in the output section. Of these, only 4 are power outputs (ie. SAE601). The other two are actually drivers - MJ802 & MJ4502. As djk stated earlier, the output configuration is indeed Quasi-Complementary.
Biasing for the output is non-adjustable. Two diodes and a resistor set the output bias.
The pot you mentioned is for adjustment of VU meter.
Cheers
You will see 6 pcs of TO3 metal cans in the output section. Of these, only 4 are power outputs (ie. SAE601). The other two are actually drivers - MJ802 & MJ4502. As djk stated earlier, the output configuration is indeed Quasi-Complementary.
Biasing for the output is non-adjustable. Two diodes and a resistor set the output bias.
The pot you mentioned is for adjustment of VU meter.
Cheers
Re: Mk III
Thanks for Your answer,but in my amp there ia 6 x SAE601 on each outputstage.So two of these is actually used as drivers?
They are all TO3 case in my amp.
ManUtd.
mcp said:
Thanks for Your answer,but in my amp there ia 6 x SAE601 on each outputstage.So two of these is actually used as drivers?
They are all TO3 case in my amp.
ManUtd.
Yes, there are #6 pcs of T03 metal cans per channel. There should be only 4 pcs that are marked SAE601. The other two are MJ802 and MJ4502. These are the drivers.
One way to help identify the SAE601 is to look for their "emitter" resistors. There should be only 4 pcs of 0.2 ohms/5 Watts - 2 pcs connected to emitters and 2 pcs to collectors.
For the MJ802/MJ4502 drivers, they use 12 ohms/2Watts resistors.
Cheers
One way to help identify the SAE601 is to look for their "emitter" resistors. There should be only 4 pcs of 0.2 ohms/5 Watts - 2 pcs connected to emitters and 2 pcs to collectors.
For the MJ802/MJ4502 drivers, they use 12 ohms/2Watts resistors.
Cheers
mcp said:
Thanks Again,
I think i will find out now.
Btw. As i can see there is no Loadspeaker protect on this Amp?
Suitable must be to build an DC protect for it?
Reg,
ManUtd
There is VI Limiting, but NO DC protect for loudspeakers. You may want to consider some forms of speaker protection in case the amp fails.
I see at Ampslab.com they have a DC protect for Loadspeakers.
Will thisone be good for MKIII amp?
Will thisone be good for MKIII amp?
Yes, it's suitable for MK III or any power amps. Output of amp into DC Protect, then out to speakers. Any DC above 1.2V, the relay will disconnect the speakers. You can have it installed in a separate case so that in future, you can also use it for other amps.
Bias diodes
In this amp there is used some diodes called 1N3754.
I can not find any replacement for thisone.
What diodes can be used instead of this "Hard to find" diodes?
Could it be used ordinary 1N400* ?
Regards,
ManUtd
In this amp there is used some diodes called 1N3754.
I can not find any replacement for thisone.
What diodes can be used instead of this "Hard to find" diodes?
Could it be used ordinary 1N400* ?
Regards,
ManUtd
Re: Bias diodes
Hello ManUtd,
My book says 100V; 0.125 A replacenent type: BA157...158; BY204/4; BY206..207etc.
But my schematic for the SAEMkIIICM states that it are simply 1N4004's. I see MkIII is an earlier version...
😱
ManUtd said:
Hello ManUtd,
My book says 100V; 0.125 A replacenent type: BA157...158; BY204/4; BY206..207etc.
But my schematic for the SAEMkIIICM states that it are simply 1N4004's. I see MkIII is an earlier version...
😱
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