SVT-7 Pro treble hiss

greggster59 · #1 02-09-2011, 07:34 PM

I just switched from a Fender combo to an Ampeg SVT-7 rig with a 610HLF cab. I generally love the sound but if I set the treble past 9 o'clock I can hear hiss through the cab. The louder the master the more obvious the hiss. Below that setting fairly quiet.
I keep the cab horn off and generally like a lower tone anyway but given some of the quality control issues I've read about concerning this head I'm wondering if this is typical or a possible problem. Any ideas?

BassBob1 · #2 02-09-2011, 07:39 PM

I have the same head with a 410HLF. I never noticed a hiss and have my treble set between noon and 2 usually (i use flats). I even have the horn on a little too. Do you have the ultra high on? Where is your gain, comp, and master set?

greggster59 · #3 02-09-2011, 08:03 PM

Compression around 9:30,
Gain: 10 o 'clock
Bass: Flat
Mid @ position 3 is 2 o' clock
Treble: 9 o' clock
No to Ultrahigh and tone knobs towards the low side on both basses.

Thanks.

BassBob1 · #4 02-09-2011, 08:09 PM

I just tried to see if i got the his with your settings and i couldn't reproduce it. Wish I could be more help.

greggster59 · #5 02-10-2011, 05:29 AM

I'm taking the cab back for an exchange. It came out of the box with a mangled coaster and a hole in the grill cloth. I guess I'll bring the head with me and try to compare it to another unit.

Growly Lytes · #6 02-10-2011, 05:48 AM

Could be other factors matey dont exchange anything just yet.
Try a few things first.Try plugging in another room or friends place even.Try different basses if posible.Lights can cause hiss.Where you are standing can cause it too.Poor electrical wiring in the house. You have to try a few things first dont just diss your brand new stuff unless your totally sure its faulty.

greggster59 · #7 02-10-2011, 06:01 AM

I hear you, Growly. I have tried all of those things you mention. My old rig was parked by the same a/c outlet and had no issues. I have a Birdsong Cortobass and a Fender AS Jazz and get the treble hiss with both. The only other thing I can think of is that for the moment I am using a speakon to 1/4 inch cable from my old rig to connect the head and cab. I'm waiting on a short speakon to speakon cable which should be here very soon and I'll see how that goes.

Thanks.

Growly Lytes · #8 02-10-2011, 06:19 AM

I found that speakon cables are great & help in the area of blocking crazy hiss !!
I cant stand high-end myself.I made some cabinets lately & chucked some Legend BP102.These speakers dont have much top-end which i love.The hiss factor doesnt even come in to play.
I hope you can work it out.
G.L

jlt5x · #9 02-10-2011, 06:39 AM

I just picked up this head and I have noticed the same thing. In fact, while comparing it to my Shuttle 9, I did some recording straight from fx send. No cabinet.

The SVT-7 definitely had some hiss to it. It seemed to be mainly from the treble. It was more the higher I turned it. I was listening through headphones, where it can really be picked up. I think in a live setting, this wouldn't be too big of an issue, but again, you would want to keep the treble down ( I think I have it around 12 or 1 o'clock). Also, maybe rolling off some tone on your guitar.

I think this is how the head is - but let us know if you get a replacement and it is different.

greggster59 · #10 02-12-2011, 12:42 PM

I went back today to exchange the cab. As I mentioned the 610HLF came out of the box with a mangled coaster and a hole in the grill cloth. I brought the head with me and told them about the hissing issue. We plugged the head into the replacement 610 and the hiss was gone. I had to set the treble above 3 o'clock with the horn on to hear any hiss at all.

It looks like the problem was with the cab. From the look of it, it took a pretty big hit or fall. Must've messed up something inside as well I hooked everything up when I got home and tested it and it still sounding good.

Thanks for the help, folks.