SA-9800 Frys Speakers!
- Thread starter ehc68
- Start date
ehc68
My SX-1050
c2526 (NPN), the first one....
black lead to base, red lead to collector, result = OL = No conduction
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 525mV
red lead to base, black lead to emitter, result = 538mV
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction
c2526 (NPN), the second one....
black lead to base, red lead to collector, result = OL = No conduction
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 540mV
red lead to base, black lead to emitter, result = 548mV
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction
black lead to base, red lead to collector, result = OL = No conduction
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 525mV
red lead to base, black lead to emitter, result = 538mV
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction
c2526 (NPN), the second one....
black lead to base, red lead to collector, result = OL = No conduction
black lead to base, red lead to emitter, result = OL = No conduction
red lead to base, black lead to collector, result = 540mV
red lead to base, black lead to emitter, result = 548mV
black lead to emitter, red lead to collector, result = OL = No conduction
red lead to emitter, black lead to collector, result = OL = No conduction
You're right, I like those readings a LOT better....
Re: stuff, hopefully most of it comes back into the reserves here....
I hope the small package doesn't even have to be unwrapped....
I got lucky that the monday night mouser order arrived in Thursday's mail...
Re: stuff, hopefully most of it comes back into the reserves here....
I hope the small package doesn't even have to be unwrapped....
I got lucky that the monday night mouser order arrived in Thursday's mail...
I KNEW I forgot something........:sigh:
ehc68
My SX-1050
That's ok, I forgot about those myself until I was going through all the parts and getting them ready to be shipped and ran across them.
It looks like one has 4737 on it, but I can't read the other one. It has a crack going right through where the numbers are.
It looks to me like they are C2 and C3 (0.047MFD), is that right?
It looks like one has 4737 on it, but I can't read the other one. It has a crack going right through where the numbers are.
It looks to me like they are C2 and C3 (0.047MFD), is that right?
yes, the voltage is what is unknown....
they are to suppress rf interference pickup.
common enough parts.. cheap too.....
0.047uF 50v AVX - SR21 @ 20% and Z5U tempcomp curve
part # 581-SR215E473MAR @ $0.22 ea
A little more expensive than I thought....
Use the RS ones....
I take it the goodies weren't in the Saturday mail....
part # 581-SR215E473MAR @ $0.22 ea
A little more expensive than I thought....
Use the RS ones....
I take it the goodies weren't in the Saturday mail....
My NEW plumbing is connected, under pressure and not leaking (wheeew, whatta weekend!!) but I've got one he## of a mess to clean up.... and a couple of loads of neglected laundry.... ALL for tonight, but I will be checking back in occasionally...
Yup, although I would compare the voltages on the good channel's Q35 to the new one, looking for about 0.6 volts difference between the emitter and base, to avoid the argghh factor when trying to do the adjustments...
But it's not necessary, although I would check for anything heating up.
Oh, just the plumbing is done, now I need to hang walls on the studs and put in a tub surround. At least the ceiling survived... and there's this big da## WINDOW over the tub at the back of the shower area...
But it's not necessary, although I would check for anything heating up.
Oh, just the plumbing is done, now I need to hang walls on the studs and put in a tub surround. At least the ceiling survived... and there's this big da## WINDOW over the tub at the back of the shower area...
ehc68
My SX-1050
Well I went ahead and adjusted the offsets and they are ALL adjusted to their proper voltages.
Q1,Q2,Q3, Q6, Q8 are all still getting really hot.
Because I shut off the amp after each measurement when I connect the probes to the other pins, I have to wait quite a while to let the voltages climb to as high as they are going to go THEN adjust the pots. Otherwise it will continue to increase after being "set". I think MAYBE as the transistors heat up the voltages go higher, but they do seem to stabilize after a while.
Q1,Q2,Q3, Q6, Q8 are all still getting really hot.
Because I shut off the amp after each measurement when I connect the probes to the other pins, I have to wait quite a while to let the voltages climb to as high as they are going to go THEN adjust the pots. Otherwise it will continue to increase after being "set". I think MAYBE as the transistors heat up the voltages go higher, but they do seem to stabilize after a while.
Re: Offset?? Bias??? the 56 and 70 millivolt readings....??
Have you tried the heatsinks on Q1 and Q2 ?
Plus just because they are hot, doesn't mean they are TOO hot...
that is decided by a voltmeter reading over time as they heat up.
I should have sent TWO Q35 replacements, because (with some lead rearrangement) they CAN replace Q1 and Q2. (like I said they do in the sx-3800).
The driver transistors are good to 150? volts, and the power supply transistors are good to 80 volts...
and at 50 cents apiece, why quibble?
Have you tried the heatsinks on Q1 and Q2 ?
Plus just because they are hot, doesn't mean they are TOO hot...
that is decided by a voltmeter reading over time as they heat up.
I should have sent TWO Q35 replacements, because (with some lead rearrangement) they CAN replace Q1 and Q2. (like I said they do in the sx-3800).
The driver transistors are good to 150? volts, and the power supply transistors are good to 80 volts...
and at 50 cents apiece, why quibble?
ehc68
My SX-1050
Yes, I followed the manual as before step by step and was able to get the DC Balance to zero volts, the idle current for 56mV on VR3 and VR4, and 70mV on VR5 and VR6.
No, not yet. I wanted to see (out of curiousity) if they would heat up without them. I'm getting ready to put them on now.
Ooh, I know....I remember you saying that before but I was just letting you know how things were behaving thus far.
Edit: heatsinks are now on
Looks pretty good, we'll see how it holds, and trust the protection circuit to keep from smoking any speakers, but use speakers that you can afford to risk.
Check the DC offset occasionally, plus after a long listening session. Basically it has to earn back trust...
Looks like this thread is finally tapering off......
Check the DC offset occasionally, plus after a long listening session. Basically it has to earn back trust...
Looks like this thread is finally tapering off......
