I have just bought a pair of Aragon Palladium’s- the original version from the early ‘90s
Would just like to give them a small service with an adjustment of the bias current an a change or cleaning of the speaker relays.
I can’t seem to find any info anywhere about the alignment procedure - so I would be very happy if any of you could tip me on where to find the service manual ? 🙂
If I decide to change to caps in the power supply or maybe a full recap - what would be a good brand to buy and would it be safe to go 20-30% up in capacity?
Would just like to give them a small service with an adjustment of the bias current an a change or cleaning of the speaker relays.
I can’t seem to find any info anywhere about the alignment procedure - so I would be very happy if any of you could tip me on where to find the service manual ? 🙂
If I decide to change to caps in the power supply or maybe a full recap - what would be a good brand to buy and would it be safe to go 20-30% up in capacity?
What model (year of manufacture)? From the Internet:
ARAGON PALLADIUM II USER MANUAL Pdf Download | ManualsLib
ARAGON PALLADIUM II USER MANUAL Pdf Download | ManualsLib
If they work fine now I would just measure the current. They look like class A amps, so current will be high and not that critical. Link OldDIY provided states 125W at class A into 8 ohms, if they mean resistive 8 ohm load then that is.... why can't i find the square root button on windows 10 calculator in scientific mode.... Should be nearly 4A of continuous current 
With capacitors, supply capacitors (both the main ones and any smaller ones on the amps) should be close for capacitance, but don't go too much higher as it will strain the bridge rectifier diodes. Other capacitors, especially input and feedback parts, should be replaced like for like for capacitance, voltage can be higher.
With capacitors, supply capacitors (both the main ones and any smaller ones on the amps) should be close for capacitance, but don't go too much higher as it will strain the bridge rectifier diodes. Other capacitors, especially input and feedback parts, should be replaced like for like for capacitance, voltage can be higher.
Thanks for your reply’s
They are the mk I versions with 100W class A and 300 AB in 8 Omhs
Would it make sense to change the receiver diodes to something better/newer, that could then maybe handle a bit more - if I change let’s say 30% larger caps in the power supply?
Shouldn’t the bias current be close to the same on the two amps and aren’t there 2 test points per amp when they are fully symmetrically build?
They are the mk I versions with 100W class A and 300 AB in 8 Omhs
Would it make sense to change the receiver diodes to something better/newer, that could then maybe handle a bit more - if I change let’s say 30% larger caps in the power supply?
Shouldn’t the bias current be close to the same on the two amps and aren’t there 2 test points per amp when they are fully symmetrically build?
The specs for the later Palladium II bias was 25mV Vre. The earlier Palladium I will not be able to get that high due to the much smaller heatsinks that the first gen had. You'll be lucky to get maybe 15mV and you'll need to check the heatsinks after an hour of idling with the cover on to see if you can keep your hand on it.
The 100w of Class A output that Mondial claimed on these early amps was ridiculous. They were a Class AB amp with minimal Class A output. It was all marketing BS. If you try to bias this amp up with that much quiescent current you'll destroy it. Some years back I calculated the Class A power and it was a few watts into 8 ohms. I saw some speculation many years ago on this forum that Mondial cheated and used a 16 ohm load to perform this Class A calculation and some of the numbers they posted made sense for a 16 ohm load.
The 100w of Class A output that Mondial claimed on these early amps was ridiculous. They were a Class AB amp with minimal Class A output. It was all marketing BS. If you try to bias this amp up with that much quiescent current you'll destroy it. Some years back I calculated the Class A power and it was a few watts into 8 ohms. I saw some speculation many years ago on this forum that Mondial cheated and used a 16 ohm load to perform this Class A calculation and some of the numbers they posted made sense for a 16 ohm load.
Hi Chamberman
Thanks for your reply
Actually I don’t care to much for class A power. I would rather adjust the bias a bit lower as long as the sound doesn’t suffer.
The main reason that I would like to adjust them, is to make sure that they are both close to the same and that the bias isn’t totally off after all those years.
The power supply should be quite big and the Palladium’s should be able to drive my old B&W 801s3 or JBL XPL200 with ease
Would it make sense to try with lets say 10mV and listen?
Thanks for your reply
Actually I don’t care to much for class A power. I would rather adjust the bias a bit lower as long as the sound doesn’t suffer.
The main reason that I would like to adjust them, is to make sure that they are both close to the same and that the bias isn’t totally off after all those years.
The power supply should be quite big and the Palladium’s should be able to drive my old B&W 801s3 or JBL XPL200 with ease
Would it make sense to try with lets say 10mV and listen?
Sure there's nothing wrong with adjusting the bias a bit lower. Output power will be the same but the downside is that there will usually be a very slight rise in distortion. I wouldn't drop below around 3mV though as distortion may go up much much more if you do so. The positive thing with doing this is that the amp will operate cooler with demanding speakers.
Because these are differential monoblocks you need to adjust both halves of each mono amp. So there will be two bias adjustments per amp.
Because these are differential monoblocks you need to adjust both halves of each mono amp. So there will be two bias adjustments per amp.
Yes, there is a long way from 3mV to 10mV? I will try to measure where they are today and then align them around 10mV 🙂