Gallien Kruger MB150S Headphone HISS.

[bobmartin]

Anybody out there using this model find an excessive hiss on the headphone out? It's the same level at at all volumes even with all controls set to zero. This is the second one from [url="http://Thomann.de"]Thomann.de[/url], their tech guys say that there is nothing wrong but have sent a replacement as goodwill, this has the same issue. The GK techs say take to a service centre...

Bob M.

[BassBod]

My 150E did the same, and also hissed when you switched the limiter on? I think its a "characteristic" of the design, rather than a fault. Mine was a mid 90's version, not recent one btw.

[bobmartin]

I had one in the late 80's, but I don't remember it remember it having this problem, I though "hiss" was a thing of the past..

[BassBod]

Actually, I've now got a '91 200MB. I've not used the headphone output, so I'll try it later and see if there is any hiss.

[bobmartin]

The speaker on the 200MB blew out in bits a few years ago, and I tried to fit the spare that I had bought at the same time. Big mistake, the speaker was rear mounted and it was a hell of of a job to take the cab apart to fit the new one, which promptly blew as well.. Happy Days!

Edited May 10, 2012 by bobmartin

[BassBod]

[attachment=107511:IMG_0105.JPG]

Oh yes...I got my current 200MB a few months ago...and the speaker surround fell apart after about a month of gigging. Speaker itself was fine, just the foam around the edge was rotted and perished. Got a new speaker from Thomann, had someone good put it in for me (too fiddly!) and give the amp section a health check at the same time. The original speaker is going to be re-edged and I'll keep it as a spare.

I'm really pleased with the sound - nicer than the two MB150E's I've had before (and stupidly sold). It will rattle a bit when pushed, but I've never heard it on a gig.

Now I'll go find those headphones.....

[bobmartin]

Just got the old 200MB out, and there is some hiss in the headphones but nothing like on the new MB150..

[BassBod]

Sorry..life got in the way yesterday - I guess you've made your own comparison by now!

The only "silent" headphone send I've experienced is the PJB CUB...but thats a very limited amp (with a weird high pitch whistle thru the speakers!?). I've also got a great Cafe Walter headphone amp, and even that has some background hiss..but nothing that gets in the way.

Have you considered re-furbing the old 200MB? I liked the MB150's I had, but really do prefer the warmer sound of the 200MB - much more musical to my old ears.

[bobmartin]

[quote name='BassBod' timestamp='1336736290' post='1650174']
Have you considered re-furbing the old 200MB? I liked the MB150's I had, but really do prefer the warmer sound of the 200MB - much more musical to my old ears.
[/quote]

It's in such a poor condition, it got used pretty much 6 nights a week throughout it's life. Don't forget that the 200MB has a limiter permanently engaged which might explain the different response. I've got a few gigs this weekend and will experiment with the adjustable one on the 150.

I had a PJB Bass briefcase, the best sound for the size but not practical for me, and the controls where way too small for [u]my[/u] old eyes..

[bobmartin]

Bump anyone?

Have found that high impedance 'phones (400 ohms) don't hiss, all low impedance do. But Thomann tested with low impedance (75 ohms) and all was ok.

Duh..

Bob.

[30507090]

Yeah, mine was like that.

[ThomBassmonkey]

I wish I could help but the only times I've used headphones with GK amps was at a trade show and sadly some other stalls weren't paying attention to the "quiet period" rules so I wouldn't have been able to hear.

Have you tried popping an email to Polar Audio? The link's in my sig, they're the UK dist for GK so they should be able to help.

[bobmartin]

I got it from Thomann in Germany, a big mistake, cheaper at GAK and I don't think that Polar would have any interest because of this.
The techs at Thomann can't find a fault and I've contacted GK who are looking into it at the moment.

400 ohms good, 64 ohms bad..

[ThomBassmonkey]

[quote name='bobmartin' timestamp='1337598809' post='1662425']
I got it from Thomann in Germany, a big mistake, cheaper at GAK and I don't think that Polar would have any interest because of this.
The techs at Thomann can't find a fault and I've contacted GK who are looking into it at the moment.

400 ohms good, 64 ohms bad..
[/quote]

You could still try Polar, they're really nice guys. They're not big fans of Thomann though, admittedly, but they're good people so I expect they'd try and help you anyway. If you're directly in contact with GK though I doubt Polar would be able to do anything that GK couldn't.

[camp6578]

Did anybody find an answer to the hissing problem with the Gallien Krueger 150s, I bought a 150E in November 2012. and it hisses real bad through the headphones, I took it back to the store and they sent it to the warranty distributor for Canada in Ontario, they returned it saying that the hiss was normal and they could not find anything wrong with the amp. The store here in BC said the same. I took the amp in yesterday to a repair shop the guy there said it was not normal and he would try and repair it. Has anybody had any luck getting the hissing to stop, do different headphones work?