Is it OK to bypass the Selenium like this on my MK3s? As opposed to removing it? It seems easier for me to do this than terminal strip thing. Any pro or con?
THX
THX
3 posters
Is it OK to bypass the Selenium like this?
bubbasweet- Posts : 95
Join date : 2016-03-14
peterh
peterh- Posts : 1833
Join date : 2012-12-25
Location : gothenburg, sweden
The cap seems old.
Using the Se as tiepoint may be ok, but i would recommend a kit with caps solder tag and diode. dynakitparts.com has it. You can continue to use the amp until the parts arrives.
Using the Se as tiepoint may be ok, but i would recommend a kit with caps solder tag and diode. dynakitparts.com has it. You can continue to use the amp until the parts arrives.
bubbasweet- Posts : 95
Join date : 2016-03-14
I did the cap was just asking about bypassing the selenium.. I read where when they fail they go high resistance so the diode bypassing is OK.
That is my question. Is there a reason electronically why not to do this? Cap has been replaced THX..
That is my question. Is there a reason electronically why not to do this? Cap has been replaced THX..
peterh- Posts : 1833
Join date : 2012-12-25
Location : gothenburg, sweden
Yes there is. A short in the Se, although very rare, will kill your bias. Eliminating a possible source of failure reduces risk of problems .bubbasweet wrote:I did the cap was just asking about bypassing the selenium.. I read where when they fail they go high resistance so the diode bypassing is OK.
That is my question. Is there a reason electronically why not to do this? Cap has been replaced THX..
In addition to adding the diode you most likely need to adjust the resistors to compensate for the reduced voltage loss. This to make the bias adjustment pot have a reasonable adjustment range.
bubbasweet- Posts : 95
Join date : 2016-03-14
Pots and achieving Proper 1.56V range seemed not a problem with room to move even with the original 1K Resistor. I think I have a few Terminal strips and remove the selenium rectifiers.
danielrhall- Posts : 4
Join date : 2021-05-27
Location : Raymond, NH USA
[Repeating my reply from the AK forum...]
If you want to leave the selenium rectifier in place for nostalgic purposes, I'd have no qualms about using one of its tabs for a tie point (I did the same with my Dynaco ST-70) but I wouldn't use both tabs, especially the way that diode and SR are electrically in parallel.
If you want to leave the selenium rectifier in place for nostalgic purposes, I'd have no qualms about using one of its tabs for a tie point (I did the same with my Dynaco ST-70) but I wouldn't use both tabs, especially the way that diode and SR are electrically in parallel.