Oh Fishman, why do you do this?? (Platinum Pro EQ hiss)

cmac · #1 06-28-2019, 08:35 AM

After my recent exploration of the Behringer ADI21, I have been looking at preamps much more than I have done previously - I currently work with a K&K Pure XLR - and I started to think about how much simpler my life would be if I had a Fishman Platinum Pro EQ. The built-in tuner and the boost would be very useful, and the plentiful tools to shape the tone would help get the best from my guitar.

So I ordered one and it has arrived. I spent a bit of time working through it to get a tone that I liked, and the EQ (not surprisingly) ended up similar to the K&K - cut some bass and mid (the mid frequency is low-ish) and treble is pretty much centred. A touch of brilliance adds some sparkle, because I'm fingerpicking at this stage.

But there's an elephant in the room and it's a constant hiss from the Fishman. I'm testing this via the DI into my FastTrack Ultra 8R audio interface and monitoring on headphones from there, so the signal chain is pretty small. But this hiss is annoying me.

So I decided to A/B with the K&K. Both are set up to produce similar levels, so I recorded a very short piece through each:

The Fishman is first, K&K second. The settings on the audio interface were not touched between recordings, and both were processed identically. Both showed pretty much identical levels in Sonar, so it's not like one had to be cranked up more than the other in processing.

The hiss diminishes if I turn the treble down (not a solution, just an observation) so I guess it's coming from a stage before the EQ is applied. Beyond that, nothing seems to change it.

The guitar has a JJB 330 fitted, so it's not the strongest of signals. I'll try with another guitar that has a K&K pure mini (stronger output) and see if that changes things. Maybe the Fishman just gets noisy if the gain is above a certain threshold.

I notice that I'm not alone in discovering hiss with this unit. Has anyone else experienced this? Am I missing something?

(Edit: I discovered later that the hiss is constant regardless of the gain setting on the preamp. This means the hiss isn't coming from the input stage, which is before the gain is applied. The hiss does get louder when the boost is active, which means it isn't coming from the output stage which is after the boost. All that's left is the EQ stage in the middle as the source of the hiss.)

martingitdave · #2 06-28-2019, 08:48 AM

Deleted. My post was not related to his problem.

Petty1818 · #3 06-28-2019, 08:53 AM

I did a shootout a while back comparing the noise of various preamps. I had everything from the Session DI to the Radial Pz Delue to the Grace Design Felix. The quietest one to my surprise was the aura spectrum di. I also have an older platinum pro and it was just as quiet. Not sure what's going on with yours but that seems to be a unique issue.

cmac · #4 06-28-2019, 09:00 AM

To take the pickup / guitar out of the equation, I unplugged the cable from the guitar and the hiss is still there. Plugging it back into the guitar makes no difference to the level of hiss.

I suspect it's simply that if the gain is high enough then it exposes some inherent noise in the system. This shouldn't really be a surprise, since each of the many EQ controls available is going to be a source of noise to some degree or other. The K&K preamp is a much simpler beast.

ljguitar · #5 06-28-2019, 09:05 AM

hi cmac
I've owned the baby brother to the Platinum Pro (Platinum Stage) for several years and it is extremely quiet... It adds no noticable self-noise. I’ve had hands on both models and never encountered hiss or other artifacts.

If the unit is not defective, I'd investigate other influences.

cmac · #6 06-28-2019, 09:31 AM

Quote:

Originally Posted by ljguitar

hi cmac
I've owned the baby brother to the Platinum Pro (Platinum Stage) for several years and it is extremely quiet... It adds no noticable self-noise. I’ve had hands on both models and never encountered hiss or other artifacts.

If the unit is not defective, I'd investigate other influences.

I was tempted by the Platinum Stage from our conversation on the ADI 21 thread, and decided to go for the Pro because of the tuner and the foot switch boost. Maybe I'll try the Stage after this, and just try to find a way of having the boost button accessible

I just tried a bit more experimentation and the input gain control doesn't affect the hiss at all. I can turn it up full and the hiss level stays the same. The boost pedal, however, boosts the hiss as well as the signal. So it seems clear that the hiss is being introduced in the EQ stage. The only thing that affects it is the treble control.

I have sent a query to Fishman, but I don't expect they will really add any useful information. I have 14 days to return it, so I'll wait to see if Fishman come back in the next few days.

cmac · #7 06-28-2019, 09:43 AM

Definitely not alone on this.

Quote from an Amazon review: "Sounds excellent through my live setup. During recording however, I am getting a "hiss" from bothmthe XLR output and the 1/4" that I cannot get rid of. Have tried multiple settings, new cables, checking for interference, etc. Contacted support and they said to use the 1/4" for recording and the "hiss" is coming from the EQ and is normal. Seriously?"

Might give it a spin through a PA this weekend just to see how it sounds, since that's the purpose of having it in the first place.

martingitdave · #8 06-28-2019, 09:52 AM

Hmmm. Clearly you're not imagining it. I wonder if power supplies or defects are at play? Are you using it on battery? Many of us like the noise free operation of our Fishman products. But, you're not alone in your experience either. Go figure?

cmac · #9 06-28-2019, 10:07 AM

Quote:

Originally Posted by martingitdave

Hmmm. Clearly you're not imagining it. I wonder if power supplies or defects are at play? Are you using it on battery? Many of us like the noise free operation of our Fishman products. But, you're not alone in your experience either. Go figure?

It's on battery, there are no fluorescents in the room, and I don't live under power cables. I would very much like to it to be environmental because I'd like this thing to work, but I just can't see it as anything other than the nature of the unit.

martingitdave · #10 06-28-2019, 10:11 AM

Quote:

Originally Posted by cmac

It's on battery, there are no fluorescents in the room, and I don't live under power cables. I would very much like to it to be environmental because I'd like this thing to work, but I just can't see it as anything other than the nature of the unit.

Hmmmm. Did you buy it new or used?

cmac · #11 06-28-2019, 10:17 AM

Quote:

Originally Posted by martingitdave

Hmmmm. Did you buy it new or used?

Both battery and preamp new out of the box today.

Of course, the preamp could have a history that I don't know about, but I have no reason to believe that it's anything other than brand new.

martingitdave · #12 06-28-2019, 10:17 AM

Quote:

Originally Posted by cmac

Both battery and preamp new out of the box today.

Of course, the preamp could have a history that I don't know about, but I have no reason to believe that it's anything other than brand new.

I’m stumped. :/) Maybe they have a quality control problem?

RockerDuck · #13 06-28-2019, 10:21 AM

I regularly gig with my Taylor 414r and Fishman platinum pro EQ, into different PA systems and acoustic amps and there is no noise whatsoever. There's a faulty culprit in your setup somehow. I have used Martin guitars with UST piezo's that would produce hiss with some DI's and not others.

cmac · #14 06-28-2019, 10:42 AM

Quote:

Originally Posted by martingitdave

I’m stumped. :/) Maybe they have a quality control problem?

Maybe there was a bad batch and I happened to get one of them.

I just tried running it into my guitar amp, in case the audio interface was part of the problem, but the hiss is still there. I've also tried different cables. So basically everything external to the preamp has been eliminated and the hiss is still there.

Fishman might come back and say "no, it's faulty" in which case I'll consider trying another one. But if they say that this is normal then I'll be avoiding their stuff in the future, either because their designs are not good enough or because their customer support has refused to admit to the problem and handle it properly.

James May · #15 06-28-2019, 04:58 PM

This sounds like a gain staging problem, where the preamp is not getting enough signal relative to its own internal noise level, which admittedly will be worse when boosting highs with the EQ. Still, it sounds excessive.

My sense is that either your pickup is putting out a very weak signal causing you to boost the input gain enough to expose the background hiss, or the unit is defective.