Radial Tonebone Pz-Pre noise issue

unclepete · #1 03-08-2016, 12:27 PM

Hello,

I've had a Radial Tonebone PZ-PRE unit for a few weeks and recently I started using it through a PA system. While I love it in general for excellent features and overall sound, I'm concerned about signigicant hiss/white noise it adds to any acoustic amp/PA speakers I use. It is a problem similar to the issue that another forum user (Petty1818) described in July last year in relation to his Radial PZ Deluxe preamp.

So just as in his case, the hiss is always there on both 1/4" and XLR outputs. I also tried playing with the controls but the hiss never goes away. Strangely enough, boosting the volume/level knob doesn't increase the hiss at all, it's constant. It only increases when I boost the high freq eq knob. What's even more surprising, the hiss is there: (a) even when no instrument is plugged into the preamp input; (b) even when I press the mute button on the preamp, which theoretically should cut all signal from coming out of the unit.

Also similar to Petty1818, there is anoother issue. If I touch the pedal enclosure, I generate a slight increase in the intensity of the hiss, to the point of buzzing (especially noticable when the high tone eq knob is turned past noon).

I am wondering if anyone else has had this problem? Any solutions? Petty1818, did you perhaps manage to solve your hiss problem with your Radial preamp?

I will be grateful for any suggestions. When I play through the PA in my church, the hiss is really bothersome during quite moments and I need to find a solution (or perhaps replace Radial with another preamp).

MikeBmusic · #2 03-08-2016, 02:28 PM

Have you tried the Radial plugged into anything besides your church PA mixer? Tried plugging into a different channel on the mixer? Because the noise is still there even when there is no instrument plugged in, and when the mute button is pressed, I suspect its some type of ground-imbalance problem on the input of the mixer.

unclepete · #3 03-08-2016, 03:25 PM

Yes, for example when I plug it into my Ultrasound acoustic amp, the hiss problem is there (as well as the "microphonic" effects when touching the Radial pedal enclosure).

As for our church PA (it's a simple Fender Passport), I also tried plugging the Radial into any of the several channels available and using three or four different XLR cables. The hiss "follows" the XLR output from my Radial Preamp regardless which channel and which cable I use. Using the ground lift function and/or polarity reverse on the Radial XLR doesn't help.

The other channel/cable combinations (with vocalist microphones) on the mixer remain quiet.

Also, when I plug my guitar to the mixer with 1/4" without using the preamp (either directly or via the lineout output of the Ultrasound amp used as a stage monitor), there's no significant hiss.

I thought my Radial might be a defective unit but on the other in some other threads on this forum (e.g. the one I mention in my initial message) I've now found opinions which lead me to think that it may be a more common problem. I'd be curious to hear other Radial PZ PRE or Delux preamp users - have you encountered similar problems? Have you contacted Radial support or sent your units for repair?

jonfields45 · #4 03-08-2016, 04:28 PM

Have you tried a different power supply?

lschwart · #5 03-08-2016, 04:45 PM

Every system has some self-noise. Have you compared the noise to the PA without the PZ-Pre or with other preamp/DI units?

I've been using a PZ-Pre with many systems for several years and I've never experienced any extraordinary noise except when there's a ground loop problem. That doesn't mean yours isn't noisier than it should be, but you need to compare it to other similar set-ups to know for sure. Also make sure your overall gain structure is set to maximize your overall signal to noise ratio. You may just be amplifying the basic self-noise of the system at a particular stage (or at more than one stage).

Louis

Petty1818 · #6 03-08-2016, 06:07 PM

I somewhat fixed the noise issue and it ended up being my error. I was plugging the Radial PZ Deluxe into my K12 speaker to test it but I had the speaker set to "mic level". Once I switched to "line level", the hiss went away. I did a comparison to my Fishman DI boxes and the PZ Deluxe does have a bit more hiss. I too found that increasing the volume did not add to the hiss and oddly enough, when I engage the mute switch, the hiss stays. It seems to just be part of the design. It's definitely low but I was/am a bit disappointed seeing as Radial is known for their DI boxes.

As for the static when touching the enclosure, try placing the PZ Pre on a pedal board so that it's not right on the ground. I have a couple pedals that have that problem and it seems to only happen when I have them directly on the ground.

YamaYairi · #7 03-08-2016, 06:21 PM

I have the PZ Deluxe and I don't get this noise at all. Not when I run it into a board or when I run it into my Fishman Loudbox Mini (to use it as a booster pedal.)

Petty1818 · #8 03-08-2016, 08:08 PM

Quote:

Originally Posted by YamaYairi

I have the PZ Deluxe and I don't get this noise at all. Not when I run it into a board or when I run it into my Fishman Loudbox Mini (to use it as a booster pedal.)

My test for noise, once I fixed the original hiss problem with my speakers, was to plug different DI boxes into my K12 speaker and listen to the noise. I was very close to the speaker so in a normal setting, you most likely would not hear any hiss. I just found that the PZ Deluxe added a bit more hiss than my Fishman boxes but again, that was with me basically right beside the speaker.

MikeBmusic · #9 03-09-2016, 09:06 AM

I have had no noise issue with my PZ-Pre.

Does the noise still happen when you use the 'Pre' XLR output?

Have you checked to see if you pushed in the piezo preamp switch for the input by accident? (Not that should make a difference when the unit is muted).

slimey · #10 03-10-2016, 10:54 AM

Try switching the lift button , you'll need something thin and long to push it in.
I have a pre ze and get no noise at all, used it for quite a few years with no issues.

unclepete · #11 03-10-2016, 12:34 PM

Thank you for all your responses and suggestions so far.

@jonfields45
Yes, I tried both the Radial factory wall wart power supply and my CIOKS DC 10 unit (which is a high quality device). The hiss is the same on both.

@lschwart
Yes, I tried that. There is no hiss in my church PA (even when several mic XLRs are plugged in and the mics are on) until I plug in my Radial.

What kind of gain structure would you recommend in my case? I have a built in guitar preamp (Shadow) with volume, bass and treble knobs. Then I go to my Radial Pz Pre (which has one knob for level - no separate volume/gain controls), then from Radial XLR out straight to the Fender Passport XLR in. The Passport also has a volume knob on my instrument channel and some eq. The hiss starts to be heard even when the volume knob on the Passport in low.

@Petty1818
Thank you for sharing your experience. I understand what you're writing about being a little dissapointed. When buying my Radial unit I also took into consideration the brand's renown in terms of DIs etc. That was one of my reasons for choosing it over LR Baggs Venue DI. Now I think perhaps I should have chosen differently.

@MikeBmusic
Thank you for your tips. I checked the piezo preamp switch and as far as I understand it's in the right position for my active pickup system (i.e. normal, not pushed).

@slimey
Yes, I tried that, but it didn't make any difference.

***

I guess I will have to learn how to tolerate the hiss (at least until I buy another preamp in the future). Thank you all anyway.

MikeBmusic · #12 03-10-2016, 02:49 PM

You should contact the store you bought it at for warranty repair/exchange.

The only problem I had with my PZ was I pushed the A/B switch in one time and the whole thing pushed into the chassis. Luckily it was in the A+B mode at the time, so I could use it for duos at the open mic I was hosting.
I contacted Chicago Music Exchange, where I had purchased it, and they sent me a new one right away, and credited me when I returned the old one.

I will say that those switches that need something thing and small poked into them to change them are the worst design feature on this unit. Don't know why they didn't use standard slide switches.

lschwart · #13 03-10-2016, 06:15 PM

Quote:

Originally Posted by unclepete

@lschwart
Yes, I tried that. There is no hiss in my church PA (even when several mic XLRs are plugged in and the mics are on) until I plug in my Radial.

What kind of gain structure would you recommend in my case? I have a built in guitar preamp (Shadow) with volume, bass and treble knobs. Then I go to my Radial Pz Pre (which has one knob for level - no separate volume/gain controls), then from Radial XLR out straight to the Fender Passport XLR in. The Passport also has a volume knob on my instrument channel and some eq. The hiss starts to be heard even when the volume knob on the Passport in low.

You should have your output on the guitar at around 2:00 as a decent starting point. The "PZ" switch on the Radial's input channel should be disengaged. If you've got more than one guitar on the PZ-Pre, you should use the volume controls to get a decent balance between the two channels. Otherwise, it depends on how strong the pickup's signal is and how sensitive the Passport's input is. For my active guitar, I usually find that I set it around 10:00, and that gives me a good, strong, and clean signal going to my PA channel, but every situation is going to be different. Is there no gain control on the inputs of the Passport?

Louis

MikeBmusic · #14 03-11-2016, 09:37 AM

Gain structure not withstanding, there should be no hiss/noise from the PZ-Pre. Period. Specially if the mute switch is activated!

Petty1818 · #15 03-11-2016, 11:36 AM

Quote:

Originally Posted by MikeBmusic

Gain structure not withstanding, there should be no hiss/noise from the PZ-Pre. Period. Specially if the mute switch is activated!

I am not sure if it's the same for the Pz-Pre but when I engage the mute switch on my PZ-Deluxe, it only seems to mute the input and not the output...if that makes sense. I can still turn the eq controls and hear them impacting the bit of hiss that comes from the Radial DI. For example, a turn of the treble makes more hiss, even with the mute switch engaged.