Inside Yamaha amps

[Jimbob54]

Let's try and stick to the topic please. Search for relevant existing threads to ask.in or create a new one for specific advice . Thanks

 

[GuyIsDamGood]

To continue the unequal warm Heat-sink issue:

Yesterday; I connected (wife's Insignia NS-B4111 CD Boombox) to the Yamaha A-S2200. I was playing music for 5 hours at 110db. The room was 59°-Fahrenheit.

I checked the temperature of the left and right heat-sinks. (they were both 88°)

I played music on the Technics SL-PD8 (compact disc player) connected to the Yamaha A-S2200 (at the same 110db volume) and the heat-sinks reached got warmer (left reached 92° and the right reached 90°).

Anyone know the reason for this?

 

[Willem]

To continue the unequal warm Heat-sink issue:

Yesterday; I connected (wife's Insignia NS-B4111 CD Boombox) to the Yamaha A-S2200. I was playing music for 5 hours at 110db. The room was 59°-Fahrenheit.

I checked the temperature of the left and right heat-sinks. (they were both 88°)

I played music on the Technics SL-PD8 (compact disc player) connected to the Yamaha A-S2200 (at the same 110db volume) and the heat-sinks reached got warmer (left reached 92° and the right reached 90°).

Anyone know the reason for this?

Difference in the source? Measurement error?

 

[Doodski]

To continue the unequal warm Heat-sink issue:

Yesterday; I connected (wife's Insignia NS-B4111 CD Boombox) to the Yamaha A-S2200. I was playing music for 5 hours at 110db. The room was 59°-Fahrenheit.

I checked the temperature of the left and right heat-sinks. (they were both 88°)

I played music on the Technics SL-PD8 (compact disc player) connected to the Yamaha A-S2200 (at the same 110db volume) and the heat-sinks reached got warmer (left reached 92° and the right reached 90°).

Anyone know the reason for this?

Because the temps of 90 and 92 are so close the cause will be small too. It might be more signal on the hotter heatsink channel, variation in metering method, bias calibration variation, venting to each heatsink. I would meter the offset voltage and check the bias if there is a small potentiometer for recalibration then that may be done and the same goes for the offset voltage. What amp is this? I'll see if I can find a service manual.

 

[Audiofire]

What amp is this? I'll see if I can find a service manual.

Only a block diagram (based on what I can find):

https://europe.yamaha.com/files/download/other_assets/5/1323175/web_VCV3040_A-S2200_om_G_EnFrDeSvItEsNlRu_A0.pdf

 

[Doodski]

Only a block diagram (based on what I can find):

https://europe.yamaha.com/files/download/other_assets/5/1323175/web_VCV3040_A-S2200_om_G_EnFrDeSvItEsNlRu_A0.pdf

The A-S1200 seems to be very similar. It does have idling current and DC offset adjustments. I was able to source an A-S1200 service manual. The idling current and DC offset calibration requires probing and attaching meter clips @ the amp PCB(s) and measuring down to millivolts and a single mistake as you probe the circuit PCB will result in a fried amp module. So for the sake of interest I can email you the A-S1200 service manual for your review but I recommend you take it to a authorized Yamaha service depot for calibration. If you want the service manual private me and give me your email address.

 

[GuyIsDamGood]

I have the A-S2200 manual. Can I get the same or similar info from the manual that came with the device?

 

[Doodski]

I have the A-S2200 manual. Can I get the same or similar info from the manual that came with the device?

You need the service manual for the specs and procedure for calibrating it. Not the owners manual.

 

[dualazmak]

By the way, we can find A-S2100 "service manual" in PDF (consists of 115 pages) here.

At least for me, it is also very nice finding A-S3000 "service manual" in PDF (102 pages) here since I have been, will be, using A-S3000 in my audio rig (ref. here for the details).

 

[GuyIsDamGood]

Thank you; to everyone for their help/info.