Hello,
I've done a lot of digging here and elsewhere but my flavor on this common question remains unclear.
Based on the Adcom 5802 Service Manual I have adjusted the voltage across R88 on both left and right channels to 33 mV.
Do I stop there? I do not 'think' so.
I want to confirm I have step 4 right ... setting R88 to 33mV raises the voltage on some of the other source resistors (R96-R114) to as much as 45mV.
Because the correction states that no source resistor should be above 33mV, once R88 is set to 33mV do I then find the highest reading on the others and readjust R61 so the high source resistor is 33mV even if that drops R88 to as low as 20mV.
Is this ok that R88 is so low?
Thank you
I've done a lot of digging here and elsewhere but my flavor on this common question remains unclear.
Based on the Adcom 5802 Service Manual I have adjusted the voltage across R88 on both left and right channels to 33 mV.
Do I stop there? I do not 'think' so.
I want to confirm I have step 4 right ... setting R88 to 33mV raises the voltage on some of the other source resistors (R96-R114) to as much as 45mV.
Because the correction states that no source resistor should be above 33mV, once R88 is set to 33mV do I then find the highest reading on the others and readjust R61 so the high source resistor is 33mV even if that drops R88 to as low as 20mV.
Is this ok that R88 is so low?
Thank you
45mV is just barely over spec. It says 23mV to 43mV is OK.
If I understand you, you have been trimming for 33mV maximum. I think if you follow the 43mV max, then your coldest legs will be above 23mV, which is what it says is OK. They would like the "average" to be 33mV, but that requires absurd device matching. In my opinion, if none are burning and none are stone cold (under 3mV), it will play well. If the average is anything like 33mV then it will amplify as intended.
If I understand you, you have been trimming for 33mV maximum. I think if you follow the 43mV max, then your coldest legs will be above 23mV, which is what it says is OK. They would like the "average" to be 33mV, but that requires absurd device matching. In my opinion, if none are burning and none are stone cold (under 3mV), it will play well. If the average is anything like 33mV then it will amplify as intended.
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PRR's advice is solid, but there was a correction in the service manual on this topic. If you adjust for 33mV average, the amp will run SCORCHING hot.
You can use a clamp-on ammeter to get the channels balanced left-to-right.
The 5802 runs super super hot. IMO, there's not enough heatsink, and these amps cook themselves to death. Make sure you have good airflow, and nothing above the amp. Raising the amp up on feet makes a big improvement in airflow.
You can use a clamp-on ammeter to get the channels balanced left-to-right.
The 5802 runs super super hot. IMO, there's not enough heatsink, and these amps cook themselves to death. Make sure you have good airflow, and nothing above the amp. Raising the amp up on feet makes a big improvement in airflow.
Thank you PRR and Phloodpants !!
Along with your responses and one from PYRAMID AUDIO in AUSTIN, TX I think I have it.
Based on the correction in the Adcom service manual I have set the source resistor with highest input (R96) to 33mV. All others are now between 22 and 30mV.
Big shout out to PYRAMID AUDIO for answering an email. I wrote to them after my attempt to reach Adcom got kicked back. Sad to see that Adcom seems to be a thing of the past. :-(
Along with your responses and one from PYRAMID AUDIO in AUSTIN, TX I think I have it.
Based on the correction in the Adcom service manual I have set the source resistor with highest input (R96) to 33mV. All others are now between 22 and 30mV.
Big shout out to PYRAMID AUDIO for answering an email. I wrote to them after my attempt to reach Adcom got kicked back. Sad to see that Adcom seems to be a thing of the past. :-(