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RM Station 550
- Thread starter redlght
- Start date
This reminds me of some of the cars i worked on in the 70's and 80's that the same car had 4 different flywheels 3 different sets of crank pulleys ect was no standardizing between them just what ever left over parts they had to use at the time.
Total to date of parts replaced:
TR10
IC2
IC1
TR7
R29 x 2
F1 F2 and guards
About to be TR9
Total to date of parts replaced:
TR10
IC2
IC1
TR7
R29 x 2
F1 F2 and guards
About to be TR9
Got a schematic laying around for that old version? I have been running using a schematic for a newer style and it is not working well for me.
Any chance on using an nte152 in it's place with lead changes?
In all these years you would think i would learn when to toss in the towel be it as it may. I have not. lol
Any chance on using an nte152 in it's place with lead changes?
In all these years you would think i would learn when to toss in the towel be it as it may. I have not. lol
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TR9 in the newer amp can use a NTE152 the version i have uses a BD179 or NTE182
But they have different current ratings but seems both versions use the same parts as each other all but TR9. maybe remote mount a NTE152 in it's place? Did they find they could use a part with less current handling or did they change something to lower it in the new versions?
But they have different current ratings but seems both versions use the same parts as each other all but TR9. maybe remote mount a NTE152 in it's place? Did they find they could use a part with less current handling or did they change something to lower it in the new versions?
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I probably have the schematic for early versions on my old pc but i can't get to it right now. I moved house & most of my stuff is at the old place.
The later amps use a larger higher
rated pass transistor,
Just about anything comparable to the bd179 or higher rated with a similar hfe will work with the standard parts.
179's are worth 2 dollars max or buy something better.
If you remote the transistor make sure you don't get rf on the wires.
The later amps use a larger higher
rated pass transistor,
Just about anything comparable to the bd179 or higher rated with a similar hfe will work with the standard parts.
179's are worth 2 dollars max or buy something better.
If you remote the transistor make sure you don't get rf on the wires.
I used a nte152 seems to work now but it is not heat sinked yet. I can not find bd179's for under 20 dollars US. Also if you run acrossed The schematic I would like a copy. Thanks
It no longer has that tunneling on the scope trace so that is a plus.
It no longer has that tunneling on the scope trace so that is a plus.
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It needs to be heatsinked. The pass transistor dissipates a fair amount of heat at high drive.
As the transistor gets hot conduction increases & bias voltage increases for the same base emitter voltage.
That's not what we want.
Voltage needs to go down as the amp heats up to maintain the same idle current.
Smoking 1ohm within seconds of powering up sounds like you forgot the mica insulator under the bd179.
As the transistor gets hot conduction increases & bias voltage increases for the same base emitter voltage.
That's not what we want.
Voltage needs to go down as the amp heats up to maintain the same idle current.
Smoking 1ohm within seconds of powering up sounds like you forgot the mica insulator under the bd179.
