Transformer load question

baddog · 12-31-2008, 10:37 PM

Is it safe to run a 8 ohm load on my bassman that has a 4 transformer?

Thanks
baddog

Chuck H · 01-01-2009, 09:38 AM

It should be. You will lose power. Most amps will accept a 1/2 or 2x load without failure. I do it all the time. Some players do it because they prefere the tone. But...

There are alot of different "Bassman" amps. Some may be more finiky than others. I don't know enough about all the different Bassmans to be 100% sure.

Chuck

dhuber · 01-01-2009, 06:44 PM

I've done it and I would say yes. Putting a higher resistance on a amp should not hurt it. Putting a lower resistance on an amp would increase the load on the amp and I would think that could cause stress on the output transformer and output tubes.

Chuck H · 01-01-2009, 07:51 PM

Actually it's the other way around. Running an amp into too high an impedance or an open load can cause arcing in the OT. Too low an impedance or a short will be harder on the tubes but won't generally harm the OT. Most PA failures caused by impedance mismatch are due to too high an impedance or an open load, not too low an impedance or a short. In fact, many MFGs use a shorting jack on the speaker output so that if you try to run the amp with no speaker plugged in the amp will be running into a dead short rather than an open load.

Chuck

Albert Kreuzer · 01-01-2009, 08:05 PM

What he said.
Remember, this is for tube amps. On SS amps, usually there is a minimum load - you can go higher and even open (no load) without damage.

HTH
Albert

Chuck H · 01-02-2009, 08:31 AM

Yea, what Albert said too

Chuck

baddog · 01-02-2009, 11:15 PM

Thanks to all who replied

BAddog

dhuber · 01-06-2009, 01:54 AM

Chuck,

I stand corrected, Thanks for the clarification!

12-31-2008, 10:37 PM	#1
baddog Senior Member Join Date: Feb 2008 Location: Appleton,Wisconsin Posts: 214	Transformer load question Is it safe to run a 8 ohm load on my bassman that has a 4 transformer? Thanks baddog

01-01-2009, 06:44 PM	#3
dhuber Junior Member Join Date: Nov 2008 Posts: 11	I've done it and I would say yes. Putting a higher resistance on a amp should not hurt it. Putting a lower resistance on an amp would increase the load on the amp and I would think that could cause stress on the output transformer and output tubes. __________________ Crate V33h, Peavey Classic 30h & 100h, Traynor YCV20WR

01-06-2009, 01:54 AM	#8
dhuber Junior Member Join Date: Nov 2008 Posts: 11	Chuck, I stand corrected, Thanks for the clarification! __________________ Crate V33h, Peavey Classic 30h & 100h, Traynor YCV20WR

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01-01-2009, 09:38 AM	#2
Chuck H Old Timer Join Date: May 2007 Location: pacific north west Posts: 1,482	It should be. You will lose power. Most amps will accept a 1/2 or 2x load without failure. I do it all the time. Some players do it because they prefere the tone. But... There are alot of different "Bassman" amps. Some may be more finiky than others. I don't know enough about all the different Bassmans to be 100% sure. Chuck

01-01-2009, 07:51 PM	#4
Chuck H Old Timer Join Date: May 2007 Location: pacific north west Posts: 1,482	Actually it's the other way around. Running an amp into too high an impedance or an open load can cause arcing in the OT. Too low an impedance or a short will be harder on the tubes but won't generally harm the OT. Most PA failures caused by impedance mismatch are due to too high an impedance or an open load, not too low an impedance or a short. In fact, many MFGs use a shorting jack on the speaker output so that if you try to run the amp with no speaker plugged in the amp will be running into a dead short rather than an open load. Chuck

01-01-2009, 08:05 PM	#5
Albert Kreuzer Senior Member Join Date: May 2006 Posts: 287	What he said. Remember, this is for tube amps. On SS amps, usually there is a minimum load - you can go higher and even open (no load) without damage. HTH Albert

01-02-2009, 08:31 AM	#6
Chuck H Old Timer Join Date: May 2007 Location: pacific north west Posts: 1,482	Yea, what Albert said too Chuck

01-02-2009, 11:15 PM	#7
baddog Senior Member Join Date: Feb 2008 Location: Appleton,Wisconsin Posts: 214	Thanks to all who replied BAddog

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