[solved] Need help with diode replacement

[RayRay]

Hey guys.
I need to replace a few fried diodes on an old amp (30DF2 ones) and I don't have an exact match in my stock, but do have a couple that could potentially suffice (MUR460 & UF5408) and this is what I need your help with.

Here are the datasheets:

Original (30DF2):
https://html.alldatasheet.com/html-pdf/86434/NIEC/30DF2/79/1/30DF2.html

Potential replacement #1 (MUR460):
https://www.onsemi.com/pdf/datasheet/mur420-d.pdf

Potential replacement #2 (UF5408):
https://www.vishay.com/docs/88756/uf5400.pdf

They seem to be compatible for the most part (with some small quirks). Is it okay to replace a fast diode (200NS) with a faster one (50/75NS)? Also, does it matter if the replacement is rated for a slightly higher "Maximum Instantaneous Forward Voltage" than the original? Looking at the datasheets, do you think these replacement optiosns are adquate? Thanks!

[bob91343]

A circuit diagram would help.

[fzabkar]

I would use either as a substitute.

[floobydust]

For the speed issue, need to see where they are used to know if it will affect things. Likely not at audio frequencies.
Higher voltage diodes can have higher forward voltage i.e. MUR320 (200PIV) 0.89V vs MUR330-360 (300-600PIV) 1.28V at 3A.
UF5402 is 200PIV 3A fast recovery 50nsec, Vf=0.9V 3A for the UF5400-5404, Vf=1.4V 3A for the UF5405-5408.
30DF2 is 200PIV 3A fast recovery 200nsec, C-16 case Vf=1.05V 3A

[RayRay]

Update: Ended up using a slightly lower UF diode (UF5404) and the amp works perfectly now!
Thanks guys.