SVT - Hiss

Groover · #1 06-28-2010, 10:09 AM

I've been running my SVT through a NV215 Bergantino, and all is well. This weekend, I plugged into a 410HLF just to try out and I noticed a very prominent Hiss... the only way to make it stop was to turn the horn all the way down. I'm assuming I've never noticed this on the Berg because of no horn.

I tried the cab with another amp, and all is well. Then put the SVT into the Berg again, and noticed the hiss was there too, but just very subtle.

What can this be? I tried different cables, etc... just seems like the amp may be hissing somewhere and cabs with horn really highlight it.

I have mostly new tubes in there, and none of them are microphonic.

Gearhead17 · #2 06-28-2010, 03:23 PM

Do you have the ultra high boost switched on? If so, depress it. It's a boost for the highs that go to the tweeter and is really not too helpful. Is everything biased correctly?

Groover · #3 06-28-2010, 03:28 PM

Good tip. I'll have to check the switch once I get home as I left it how it was when I was trying the cabs out.

The BIAS should be set properly, so hopefully the switch is it.

Thanks.

Seans · #4 06-28-2010, 03:35 PM

Dirty contacts?, many times I have had curious noises etc from mine and each time it was a valve base, setting off a pre valve to go microphonic, but a good wiggle cured all.

Groover · #5 06-28-2010, 03:47 PM

I'll try that too. My Stand-By switch also makes a very loud clunk sound through the speakers, I know that's another issue probably, but shouldn't the switching be a little more silent? It's pretty loud, sort of like plugging or unplugging the instrument cable when the amp is on and turned up.

heath_r_91 · #6 06-28-2010, 04:07 PM

My Ampeg SVT-610HLF tweeter makes it hiss like crazy as well.

I think the Ampeg tweeters just suck.

derridiandrift · #7 06-28-2010, 04:34 PM

Quote:

Originally Posted by heath_r_91

I think the Ampeg tweeters just suck.

+1!!!

Turn the tweeter off and forget it's there. Problem solved.

coreyfyfe · #8 06-28-2010, 09:00 PM

Quote:

Originally Posted by derridiandrift

Turn the tweeter off and forget it's there. Problem solved.

Sort of solved. It would probably be better to wire the speakers straight to the jack and remove the crossover. At least this way you're getting all of the signal to the speaker instead of only everything below 5000Hz or whatever the crossover point is.

Groover · #9 06-28-2010, 10:15 PM

User error on my part.. A little embaressed here, but for the sake of the thread.. Here it goes:

I had Channel 2 cranked, and so was the treble, and treble boost was also on.... Lol. Yikes, I know

mind you, I was using channel 1 and nothing plugged in channel 2.

That said, turning the boost off, made a huge difference. Turning highs down on the vacant channel 2 helped even more, and obviously turning channel 2 volume all the way down silenced the whole thing.

Moral of the story here... Turn down the channel your not using

Funny though that all that didn't really matter to the Berg, but the HLF was all fussy and hissy about it.. Lol

JimmyM · #10 06-28-2010, 10:53 PM

Quote:

Originally Posted by Groover

User error on my part.. A little embaressed here, but for the sake of the thread.. Here it goes:

I had Channel 2 cranked, and so was the treble, and treble boost was also on.... Lol. Yikes, I know

mind you, I was using channel 1 and nothing plugged in channel 2.

That said, turning the boost off, made a huge difference. Turning highs down on the vacant channel 2 helped even more, and obviously turning channel 2 volume all the way down silenced the whole thing.

Moral of the story here... Turn down the channel your not using

Funny though that all that didn't really matter to the Berg, but the HLF was all fussy and hissy about it.. Lol

that's because the berg has a mid cone instead of a tweeter, so the most obnoxious highs won't come through it. plus, anything through a piezo tweeter sucks. it ain't just ampeg...they all suck.

btw, the tweeter only amplifies what your amp puts out, so if you have a hissy tweeter problem, it's not the tweeter itself. turning it off does make it quieter but the hiss is still going to be there if you have a hissy amp...it just won't be amplified if it's out of range of the rest of the speakers.

anyway, i was going to say that my svt is dead quiet and it's a 69. but now that i see you figured out the problem, never mind

Seans · #11 06-29-2010, 02:19 AM

If I'm in channel one and I switch the 123 switch to 3 it does click loud, on switching back to 2 and on to 3 again its quiet, could be some surge build up of sorts. But I do use Ultra hi.

Luckydog · #12 06-29-2010, 04:21 AM

mmmmmm. SVT + Berg NV215. My setup exactly. Love it.