Oh, so there are such compatibility issues as well? But I have used this amp all along with an older Focal model(bought at around the same time when this Power Amp was released) and there was no problem. Both worked well together. The dealer suggested their pairing(NAD and Focal) because they worked well. Any idea what he got later?This all happened a few years ago for my friend and is second hand, IIRC he was told that some about the architecture/design of Crown was not compatible with the Focals and he got a different amp as a result.
I seem to remember Cambridge? I think Focal would be the best source of advice there. I'm a hoobyest and an electronics expert.Oh, so there are such compatibility issues as well? But I have used this amp all along with an older Focal model(bought at around the same time when this Power Amp was released) and there was no problem. Both worked well together. The dealer suggested their pairing(NAD and Focal) because they worked well. Any idea what he got later?
So you have a multimeter on the way to test DC offset.? Thats a good older NAD amp but could have had something let go.Oh, so there are such compatibility issues as well? But I have used this amp all along with an older Focal model(bought at around the same time when this Power Amp was released) and there was no problem. Both worked well together. The dealer suggested their pairing(NAD and Focal) because they worked well. Any idea what he got later?
I will be doing this again, properly. I ran a test tone track earlier when the speakers sounded distorted. Did not pay close attention to each speaker a single was in a state of panic. I need to determine now if other drivers are damaged as well and this will be first step before I open anything up. I have planned to check the drivers physically after this with a multimeter. I have not used one in my life and am just reading about it usage before putting them to use.A decent non-technical way to test if speakers are damaged is to play tones (not too loud!) and listen for anything odd. As you noticed with the double-bass, it made a distorted sound.
Sweep through the range with this and if you don't hear anything wrong with tones or music you may not have any damage.
You can also record the output with a mic and REW to check this more closely, if you are so inclined.
So you have a multimeter on the way to test DC offset.? Thats a good older NAD amp but could have had something let go.
Speaker repair businesses should have test equipment to measure driver parameters. They can detect voice coil rub and can compare drivers against each other to ensure they are operating identically.The good news is that they have spares! They confirmed it when I wrote to them asking about its availability. I guess it would be a 1-1 switch. My concern now would be if such damage spared the other two, namely, the tweeter and the woofer. How do I even know if those are fine?
Well damn. I am hearing these horror stories of power amps destroying speakers. It is really frustrating to see this happen when you are extra careful. I am not sure what exactly went wrong at my end but this happened after a good month into usage. What is even more annoying is the very fact that the Power Amp was sent to the agent for servicing and given the all-clear to be used.
Clmrt, I am looking to diagnose this from a consumer level. From my readings here and elsewhere, I gathered that it is possible to determine the condition of these drivers through measurements taken with a mic and REW software. I got myself a UMIK mic and will be using the REW software. Is this the setup you are referring to?Speaker repair businesses should have test equipment to measure driver parameters. They can detect voice coil rub and can compare drivers against each other to ensure they are operating identically.
If you can't find such a resource, Parts Express sells speaker evaluation products and software. You get the best value from this if you have access to the drivers' TS parameters from the factory.
I did a quick check with the multimeter for the DC offsets. I took the readings an hour after the power amplifier was powered ON. The readings were identical the next day when I repeated this. The next day, measurements were taken immediately(2-3mins) after it was powered ON to see if there was any difference. They were the same though. Also, the readings on the multimeter took a few seconds to stabilise. But when they did, they remained without fluctuation.So you have a multimeter on the way to test DC offset.? Thats a good older NAD amp but could have had something let go.
This sort of issue is not unheard of. It may indicate that the electrolytic capacitor determining turn-on delay has seen better days and developed excessive leakage current. Some preliminary investigation on the schematic would be advisable. If you want to reproduce the problem, look for suitable probe points for DC offset preceding the protection relay inside the amp that could be accessed quickly, even though I suspect there'll be nothing concerning on either channel and changing the suspect cap itself would rectify the issue. (The capacitance value is generally too large to be easily replaced by a film cap, unless it's <<10 µF. The best choice will be a quality cap of normal ESR and a generous voltage rating up to 50/63 V.)However, I made another observation. When the amplifier was switched ON(after a week), it took about 4 minutes for the relay to click in and emit the green light for usage. The last time this happened was when I got it serviced after storage and put it to use. The next day, it took 10 secs to get ready. I am wondering if this is normal.