Starting the st120 up without speakers

by Guest Sun Jul 24, 2022 2:03 pm

Guest: Guest

Post n°1

Starting the st120 up without speakers

by Guest Sun Jul 24, 2022 2:03 pm

Hi,

I want to start my amp up to make sure all the tubes are in good order but I no longer have speakers. Is there a safe way to fire up the amp without speakers (like terminating the speaker terminals with resistors).

Thanks in advance.

by peterh Sun Jul 24, 2022 3:54 pm

peterh

peterh: Posts : 1869
Join date : 2012-12-25
Location : gothenburg, sweden

Post n°2

Re: Starting the st120 up without speakers

by peterh Sun Jul 24, 2022 3:54 pm

jsl1234 wrote:Hi,

I want to start my amp up to make sure all the tubes are in good order but I no longer have speakers. Is there a safe way to fire up the amp without speakers (like terminating the speaker terminals with resistors).

Thanks in advance.

Don't power on without load !!!

Or connect 8 ohm resistors of enough power on the output terminals before
powerin on. ( 10w should do if you are observant on their temp)

by **Bob Latino** Sun Jul 24, 2022 3:57 pm

Bob Latino

Bob Latino: Admin; Posts : 3277
Join date : 2008-11-26
Location : Massachusetts

Post n°3

Re: Starting the st120 up without speakers

by Bob Latino Sun Jul 24, 2022 3:57 pm

jsl1234 wrote:Hi,

I want to start my amp up to make sure all the tubes are in good order but I no longer have speakers. Is there a safe way to fire up the amp without speakers (like terminating the speaker terminals with resistors).

Thanks in advance.

Yes - you need some type of "dummy load" on both output transformers. Check out the link below for a relatively inexpensive solution. You will need two of these > one for each channel. These are from China. If you look on Parts Express in the USA, they also have them but they are more expensive.

Dummy load 8 ohm 100 watt resistors

Bob