Thats bad@$$.
So is the inductor is in series with the grounds of the speaker drivers in each speaker, then you just connect the positive ends of the inductors together?
BTW good job on fixing the amp. Glad the parallel resistors is working fine on the soft start. Also I see you got some good transistors. AS you see big bunches of them don't very so much in gain, because they were made together at the same time, probably from the same silicon.
Awesome system.
So is the inductor is in series with the grounds of the speaker drivers in each speaker, then you just connect the positive ends of the inductors together?
BTW good job on fixing the amp. Glad the parallel resistors is working fine on the soft start. Also I see you got some good transistors. AS you see big bunches of them don't very so much in gain, because they were made together at the same time, probably from the same silicon.
Awesome system.
Hi Ben,
The impact from a snare must be awesome!
The amp is not rated for that low an impedance, so try not to drive it too hard. You are living outside the envelope here.
With regard to board cleaning, the ultrasound is required. You can clean your boards 'till the cows come home and they may never become clean. You must use an ultrasound. I typically do two runs of 6 min each for tough boards. You may need to bring the concentration up to 5:1, or as hi as you can go without foaming. I am not happy to tell you this, because I know you have tried, but it's not enough. You really have to get those things cleaned properly.
One test you can try. Pull the op amp and clean the PCB. If the stuff is still there, you can smell it when you hit it with a soldering iron. Test closest the worst damage. You may need to remove every component in that area and clean one by one (or replace the part(s) ). My goal is to see you succeed here. Generally speaking, things never get better with time (except tuning caps with fluid in them).
-Chris
The impact from a snare must be awesome!
The amp is not rated for that low an impedance, so try not to drive it too hard. You are living outside the envelope here.
With regard to board cleaning, the ultrasound is required. You can clean your boards 'till the cows come home and they may never become clean. You must use an ultrasound. I typically do two runs of 6 min each for tough boards. You may need to bring the concentration up to 5:1, or as hi as you can go without foaming. I am not happy to tell you this, because I know you have tried, but it's not enough. You really have to get those things cleaned properly.
One test you can try. Pull the op amp and clean the PCB. If the stuff is still there, you can smell it when you hit it with a soldering iron. Test closest the worst damage. You may need to remove every component in that area and clean one by one (or replace the part(s) ). My goal is to see you succeed here. Generally speaking, things never get better with time (except tuning caps with fluid in them).
-Chris
I think you are on the right pageEWorkshop1708 said:Thats bad@$$.
So is the inductor is in series with the grounds of the speaker drivers in each speaker, then you just connect the positive ends of the inductors together?
anatech said:Hi Ben,
The impact from a snare must be awesome!
The amp is not rated for that low an impedance, so try not to drive it too hard. You are living outside the envelope here.
With regard to board cleaning, the ultrasound is required. You can clean your boards 'till the cows come home and they may never become clean. You must use an ultrasound. I typically do two runs of 6 min each for tough boards. You may need to bring the concentration up to 5:1, or as hi as you can go without foaming. I am not happy to tell you this, because I know you have tried, but it's not enough. You really have to get those things cleaned properly.
One test you can try. Pull the op amp and clean the PCB. If the stuff is still there, you can smell it when you hit it with a soldering iron. Test closest the worst damage. You may need to remove every component in that area and clean one by one (or replace the part(s) ). My goal is to see you succeed here. Generally speaking, things never get better with time (except tuning caps with fluid in them).
-Chris
Thanks Chris. I guess it s time to buy an ultra sonic cleaner next.
Hi Ben,
Is there anyone you know with a large one you can use? All you need to do is bring the boards, simple green and your soldering iron (to test). Too bad I'm in Canada, there would be no problem.
-Chris
Yes. Sorry about that.I guess it s time to buy an ultra sonic cleaner next.
Is there anyone you know with a large one you can use? All you need to do is bring the boards, simple green and your soldering iron (to test). Too bad I'm in Canada, there would be no problem.
-Chris
Hi djk,
Cool.
The one I use looks exactly like the CD-4800 (second link). It seems to do a good job, but a larger one would be handy. I bought some tea / spice infusers to control small parts while cleaning them. Lift out and rinse.
The ad says it's quiet. No, not a chance! That thing buzzes loudly.
-Chris
Cool.
The one I use looks exactly like the CD-4800 (second link). It seems to do a good job, but a larger one would be handy. I bought some tea / spice infusers to control small parts while cleaning them. Lift out and rinse.
The ad says it's quiet. No, not a chance! That thing buzzes loudly.
-Chris
Hi Ben,
If your preamp is plugged in, then you are shorted at the source end.
-Chris
No, I didn't. That seems odd if there was nothing plugged in. I think (from memory) that you ought to be reading around 200 ohms between the RCA grounds (channel to channel). Each has a resistor to ground of 100 ohms, so they should be in series.Did you see where I posted that I am getting zero resistance from the ground to ground on my RCA's?
If your preamp is plugged in, then you are shorted at the source end.
-Chris
anatech said:Hi Ben,
No, I didn't. That seems odd if there was nothing plugged in. I think (from memory) that you ought to be reading around 200 ohms between the RCA grounds (channel to channel). Each has a resistor to ground of 100 ohms, so they should be in series.
If your preamp is plugged in, then you are shorted at the source end.
-Chris
I disconnected a bad diode, and I am now getting 20ohms. There is a 10ohm between ground, and input ground on both sides. The service manual calls for 10ohms R136, and R186. Well its 5:30 here time to check in, and get a little sleep.
Hi Ben,
1N4148 signal diodes, not rectifier diodes. Here is a link to the actual data sheet (or close enough).
1SS178 Data Sheet link
These will be fast enough and should have lower reverse leakage. It's interesting that these are blown. I'd check the others closely and also consider replacing Q107 and Q108. At least check them for reverse leakage and gain.
-Chris
1N4148 signal diodes, not rectifier diodes. Here is a link to the actual data sheet (or close enough).
1SS178 Data Sheet link
These will be fast enough and should have lower reverse leakage. It's interesting that these are blown. I'd check the others closely and also consider replacing Q107 and Q108. At least check them for reverse leakage and gain.
-Chris
anatech said:Hi Ben,
1N4148 signal diodes, not rectifier diodes. Here is a link to the actual data sheet (or close enough).
1SS178 Data Sheet link
These will be fast enough and should have lower reverse leakage. It's interesting that these are blown. I'd check the others closely and also consider replacing Q107 and Q108. At least check them for reverse leakage and gain.
-Chris
I found IN4148's at rat shack 10 for $2. I bought 20, and I am going to replace all of them.
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