Throughly disappointed with my new Yamaha A-3000 Integrated.......

^ I think it's the result of shipping. The bias is adjusted by simple trim pots on the top of each amp channel, near the heatsinks. Yamaha should be using some sort of tamper putty on them, unfortunately they don't and I wouldn't be surprised if repeated transport vibrations is what throws them off.

These amps are great but the packaging is absolutely ridiculous for an item that weighs over 50 lbs. Something that heavy and expensive should be shipped in a wooden crate.

Dear members, the application of microcontrollers in stereo amplifiers has introduced  a lot of problems. The microcontrollers sense and register all kind of paramters such as DC-offset at the speaker output, output current, heatsink temperature ultra high frequency input/output etc.

This technique was first introduced in surround sound receivers. Some even have several types of protection mode. Depending on the maximum current drawn from the power transistors, the period and slew rate of the maximum current decides whether the consumer can return to the normal mode by recycling power or that the unit shuts down forever. That is, until a service technician bypasses this mode by means of a secret (published in the service manual though) key-combination while powering on the unit.

The point is that most of the error-messages are of no use to the consumer because most of the times it is a fault caused by the amplifier itself! You would have to drive your speakers with lots of power for a long time until the protection mode kicks in. If it kicks in at moderate levels, your amplifier is at fault!

Often the DC-offset is exceeding a certain threshold and this is often due to the application of el cheapo Chinese made transistors at the input stage of each channel's power amp. A consumer can not solve this problem!

A-S3000 was delivered to my workshop today with the amp going into protection mode regularly. I already checked the service manual and the Japanese are crazy. They have more than 10 morse code like sequences of the flashing power LED in protection mode.

To run the diagnostic mode and to browse through the items one has to set rotary switches in certain positions....

One important thing to mention: In the service mode one can override the protection mode. This can cause additional damage, especially if the trouble cause is a high current running through the power amps. If this high current runs for a long period (it even runs when no speakers are connected) the power transistors wil be destroyed!!

Since this amp also seems to have bias-issues (heatsinks get too hot to touch), it may very well be that the bias is set so high that the amp will shut down immediately after it is switched on!!!

Bias circuits should be designed to be fail-safe. That means that if the bias trimmer's contacts get poor the bias should go to zero. Unfortunately some designers do not follow this scheme thus causing the bias to go to maximum current. This may destroy the power transistors.

The Japanese have the bad habbit to use bias trimmers that adjust very coarsly!! One just have to move the scredriver a little bit and the current goes through the roof!!

However, I do not believe that the adjustment is changed by vibrations during transport. I think it is just a matter of quality control. Also, bias adjustment takes time. The heatsinks have to warm up until one can set the right current and this may have to be repeated because if the heatsink's temperature drops, the bias current drops as well when we are talking about bipolar power transistors (it is different for power MOSFETs).

I will keep you informed about my reapir experience with the A-S3000 but I am aware the Yamaha uses plenty of SMD-componets. SMD-components, especially the complicated chips increase the failure rate of electronic equipment!    

I owned an A S2100 and had the same issue occur twice within a week so I sold it.. I now have an R N803 and have had zero problems. 

My A-S3000 started shutting down a couple of weeks ago. It went into protection mode a week ago and has remained there. I called Yamaha and they are sending me a box so I can ship it to a repair center in NY. Hopefully it will function properly again. I'd just started using a pre amp with the unit, not sure what caused the problem.

OMG- this thing was $7k!?!?!?!!!  For that you could buy a Raven and a Decware and be set for life! Beautiful to look at too! Instead of this monster of an ugly box - that doesn't even work! And yet people bought them! Who says advertising doesn't pay?

Update on my A-S3000 that went into protection mode: After going through everything the manual suggested the next step was to call customer service per the manual recommendation. I was completely blown away with Yamaha's customer service!!! After discussing what happened, they told me they were sending me a new box and shipping label. My wife threw out my box while I was away on a business trip several months before I noticed it was missing. The repair shop performed a factory reset and tested the unit for 10 days! They were unable to find anything wrong with it after testing all functions. They were great as well, emailing me every couple of days to ask questions and apprise me of their testing. The unit came back to me without a single scratch or mark on it! It has been working flawlessly during the past week. All it needed was a factory reset. It would have been nice to have the instructions on how to perform that in the manual.

The only thing I can think of that might have caused the problem was that I had taken the amp to a high end store a week before the problem occurred. I took it there to compare hearing it with a Prima Luna preamp versus Prima Luna pre/power amp and Audio Research tube power amp. During one of the connection changes the sales person forgot to turn the system off and there was a loud pop. My amp shut off but he reset the power switch and it turned back on and continued to perform.

The Yamaha/Prima Luna preamp combo sounded amazing! Sonically it was close between the PL pre/power but I'd give the nod to the Prima Luna combo, mainly due to triode mode. However the Yamaha had greater power. The Yamaha/PL pre sounded much better than the PL pre/Audio Research tube power amp, it wasn't even close. I forget the model ARC but he said the price of it was 12k. I didn't purchase anything that day. I bought a reconditioned DYNA PAS-3X tube preamp a couple of weeks prior to going to the high end store. After returning home and having the system on for a couple of hours the amp turned off during two separate listening sessions. I reset the power switch and it continued to perform until turning it off several hours later both times. The next time I used the system, the amp turned on and immediately turned off and was in protection mode.

The PAS-3X/Yamaha combo sounds awesome! It is quiet but not as quiet as the Prima Luna. The PAS-3X is a nice interim component as well as extremely affordable. It has two phono inputs which is perfect for my stereo and mono tables. I'm running vintage Great Britain Mullard tubes in the phono stage, German Telefunken in the line stage and a vintage Holland Amperex Bugle Boy for the rectifier tube.

I can't say enough positive things about my experience with Yamaha's customer service, United Radio's service and UPS shipping!