Hi All,
I have a Cyrus 2 amp and while servicing it (recap) I've found that the rectifier diodes have been replaced in the past so now there is 2 GI852 (fast recovery 3A diode) and 2 8827 diodes (can't find any info about it).
according to the service manual there should be 4 PFR852 (3A rectifier diode).
I have few HER508 MIC diodes which are 5A ultra fast diodes with much higher voltage ratings, can I replaced the 4 (2 GI852 and 2 8827) with the HER508 diodes?
Or should I just buy the same PFR852 diodes (or equivalent replacement) as in the service manual?
Thanks
Thanks
I have a Cyrus 2 amp and while servicing it (recap) I've found that the rectifier diodes have been replaced in the past so now there is 2 GI852 (fast recovery 3A diode) and 2 8827 diodes (can't find any info about it).
according to the service manual there should be 4 PFR852 (3A rectifier diode).
I have few HER508 MIC diodes which are 5A ultra fast diodes with much higher voltage ratings, can I replaced the 4 (2 GI852 and 2 8827) with the HER508 diodes?
Or should I just buy the same PFR852 diodes (or equivalent replacement) as in the service manual?
Thanks
Thanks
There is an article in Linear Audio Soft Recovery Diodes Lower Transformer Ringing by 10-20X that will help you.
No need for ultra fast diodes as we are not speaking HF here just mains speed.
D5 - 8 should be the same type and HER508 will work.
D5 - 8 should be the same type and HER508 will work.
Thanks.
The HER508 ultra fast 5A diode is what I have in hand.
I've looked at the HER508 datasheet and noticed that it's Vrrm is 1KV which in the PFR852 is 200V and it's average forward current is 5A (HER508) vs 3A(PFR852), to be honest I don't really know what should I look for in the datasheet when choosing a suitable replacement.
I just want to make sure that the HER508 that I have can replace the 2 GI852 and the 2 other unknown diodes.
The HER508 ultra fast 5A diode is what I have in hand.
I've looked at the HER508 datasheet and noticed that it's Vrrm is 1KV which in the PFR852 is 200V and it's average forward current is 5A (HER508) vs 3A(PFR852), to be honest I don't really know what should I look for in the datasheet when choosing a suitable replacement.
I just want to make sure that the HER508 that I have can replace the 2 GI852 and the 2 other unknown diodes.
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Yes, use your HER508.
Several years ago, an American engineer published in Audio Amateur (now audioXpress) an article in which he measured the noise generated by the most commonly used diodes. The usual 1N4002, for example, generates noise that reaches 4MHz, this engineer concluded that they are unsuitable for use in Audio.
The 'normal' diodes are frightening devices and should be avoided in Hi-Fi, better fast or super fast diodes, more important than the speed is that they are soft recovery, between a fast soft recovery and an ultrafast no soft recovery you have to choose the first one. And the best ones are the Schottky ones, they generate less noise, if they are available for our application they are the preferable option.
Several years ago, an American engineer published in Audio Amateur (now audioXpress) an article in which he measured the noise generated by the most commonly used diodes. The usual 1N4002, for example, generates noise that reaches 4MHz, this engineer concluded that they are unsuitable for use in Audio.
The 'normal' diodes are frightening devices and should be avoided in Hi-Fi, better fast or super fast diodes, more important than the speed is that they are soft recovery, between a fast soft recovery and an ultrafast no soft recovery you have to choose the first one. And the best ones are the Schottky ones, they generate less noise, if they are available for our application they are the preferable option.
The HER508 you have can replace the currently installed oddballs. But the important keyword for rectifiers in audio is soft recovery. Fast, ultrafast speed is the keyword you need for switching application. Just a note for your next diode purchase.
Thanks all.
I couldn't find any mentioning for soft recovery in the datasheets, HER508 or the PFR852.
I'll buy new ones if needed, any suggestions for a specific diode?
I couldn't find any mentioning for soft recovery in the datasheets, HER508 or the PFR852.
I'll buy new ones if needed, any suggestions for a specific diode?
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I've found an ultrafast soft recovery diode, a Vishay UF5402 to replace the GI852 rectifier diodes in my Cyrus 2 amplifier.
looking at the datasheet of the UF5402 and found that there is one difference between the 2, I would like to know please how important the marked parameter in the attached datasheets?
Can the UF5402 diode can be safely replace the GI582 diode?
Thanks
looking at the datasheet of the UF5402 and found that there is one difference between the 2, I would like to know please how important the marked parameter in the attached datasheets?
Can the UF5402 diode can be safely replace the GI582 diode?
Thanks
