muted low end hurricane Amp

[illenema123]

I have a pair of Antique Sound lad Hurricane amplifiers.
I have a test one CD and was going thru the tones And on 1 amplifier I have about 6DB of low output from 20-200hz only.
Have replaced the tubes, swapped cords ect

 

[TheGimp]

Post some links to the amp schematics please.

Without design details it is difficult to help.

 

[illenema123]

Will do. Thanks

 

[illenema123]

I cannot find a copy on the web I have one I could email please.

 

[illenema123]

HERE IS THE HURRICANE SCHEMATIC

http://4tubes.com/2-SCHEMATICS/BY-BRAND/Antique-Sound-Lab/Catalogue/antique/Circuit/C_Hurrican.jpg

Any help greatly appreciated

 

[rayma]

Not at all likely to be the amplifier, more the speakers and/or room acoustics.
Have you checked that your speakers are in phase? Try a different impedance tap just in case.

 

[TonyTecson]

a dummy load of 8 ohm 250 watt at least, and a 1khz test signals to both amps, and then measuring the output ac on both channels will confirm.....you can also do it at 100hz and 5khz...

 

[illenema123]

No I ran a test tone cd into the amps, I have 4 monmoblocks 1 is about 6 db low at 20,40,50,120,160 all other frequencies fine I have very accurate power level external power level meters, changing tubes no differences maybe preamp.

 

[illenema123]

a dummy load of 8 ohm 250 watt at least, and a 1khz test signals to both amps, and then measuring the output ac on both channels will confirm.....you can also do it at 100hz and 5khz...

I did this with test tones from a cd confirms

 

[illenema123]

Ended up being the Input driver/splitter tubes....

 

[as_audio]

This can hardly explain effect on lf only.