Sumo Andromeda II question about shorting connectors

[jdh]

I need help, please. I have a Sumo Andromeda II amp with a constant hum, that I bought a number of years ago (with no manual) and found out it has no shorting plugs. I figure that this is the cause of my hum since I don't use it in balanced mode.. Can some one tell me how they are constructed? straight shorting wire across terminals of RCA plug? or use of a resistor or cap? if so what values?

Appreciate an advise/help or redirection to someone who could.

[llwhtt]

Since the inputs of that amp are capacitor coupled just use a direct short, center pin to ground. Have you always had the hum or did it develop after using it? Do you have or want a schematic? Just about the only place for SUMO info is SAE TALK group. James Bongiorno chimes in occasionally as he was a designer at SAE and started GAS and SUMO. He did NOT design the Andromeda II (not a fan of MOSFETs) only the I, which has a single ended input but balanced output. Join the group and you'll find a schematic for it in the files section. It may or may not be exactly what you have but is close, it does NOT match the version I have. The inputs on the schematic are directly above where it reads "CHANNEL 2".

Craig

[jdh]

Thanks Craig,
After searching around the internet for about and hour, I found the answer to my question (the same as you gave) and so I proceeded to create a pair. I did NOT ever have the shorting plugs as I bought the amp for about 1/2 price from a vendor that was no longer going to carry it. He gave NO mention of the fact that if I didn't use it in balanced mode that I would have to have the shorting plugs (I was given no manual with the amp).... I believe he (vendor) did have it connected to Sumo Pre-amp when I bought it (probably in balanced mode?). I never noticed the hum before (for approx. 5 years), until I moved to my current residence (a newer house). So it all seems so weird that I didn't have a problem before. Now with the new plugs in, the bass is 2x as much and extremely tight, exactly as I remembered at the previous residence. It sounds like a whole new system. I am using the amp as a bass amp in an active xover system. I have the original son of Ampzilla (a pre-release version, non-flat face plate with VU meters) on the mid/high end and it seems to have cleaned up the mid/high end as well. Can I explain that? No, but it's true. What a difference grounding can make. Thanks so much for the info, I truly appreciate the response and the additional info on the where-abouts of James B.

[jdh]

Craig, Does the Sumo/SAE group have any GAS owners? After getting all the equipment working right and doing some extensive listening, the Son (of Ampzilla) amp has started developing a thump (upon turn on) and slight hum on the left channel. I have noticed that the amp is getting particularly warm (to the point of almost hot) during its use. I am not pushing the amp as the VU meters are barely budging (It's only driving the lower midrange/tweeter section). Upon opening the top, I noticed the power cap has a small brown stripe up the side which was never there before. I want to have it looked at but by whom? I understand that GAS WORKS is long gone, but would like someone to check out the amp for me. Do you have any recommendations. I'm in the greater Los Angeles area. Any help or direction would be greatly appreciated.

[llwhtt]

JDH, I PM'd you.

Craig

[jdh]

Craig,
sorry I didn't get any PM's.

[llwhtt]

I sent a second PM did you get that?

Craig