Double Bass iamp200 and infrasonics

[bolo]

Yesterday and today I was able to check out my new Gigpro preamp.

Unfortunately, I don’t think I care for the effect that the Gigpro creates with my iAMP-200 Wizzy combo. I tried the Gigpro through the Wizzy three different ways:

1) into the effects return
2) into the preamp
3) through a DTAR Solstice and then into the preamp

To my ears, the Gigpro took away almost all of the natural sounding “edge” that I find characteristic of the Wizzy. And I found that after the Gigpro took that edge away, I wanted it back!

I much preferred the snap and the initial hit of the Rev SOLO pickup straight into the Wizzy’s preamp to any of the three combinations I tried using the Gigpro.

I could tell the high pass filter was working because of the way it changed shape of the sound. But I didn’t really like the resulting shapes through the Wizzy with the Gigpro’s high pass filter engaged at any setting.

So, to my ears and my tastes, the whole Gigpro thing was kind of a bust at this point, infrasonics or not.

Just my opinion, personal tastes, and my limited experiences, of course, FWIW.

For my experiences with the Gigpro and a Series I Contra, read on:

I can definitely understand pano's comments about the Gigpro helping to reduce the piezo thonk effect. In my opinion, this effect isn't quite as pronounced with the RS as it is with some other pickups, but to a small degree it's still present. And the Gigpro did seem to curb or even eliminate it. I noticed this in particular when I ran it through an AI Series I Contra.

The Gigpro also pleasantly got rid of that somewhat subtle "boxiness" that I have always found present in the Contra (perhaps it comes mostly from their 5" driver?). Finally, I found something that gets rid of that slight styrofoam like flavor in the Contra's mids!

However, the Gigpro fattened up the sound so much that I found it unusable with the Contra. To my ears the Contra can get kinda blurry sometimes, especially in the upper register. The Gigpro just turned this blurriness into a dense fog, even with the high pass filter set to about 10:30 or 11:00. With the Contra in its traditional down-firing position, it was pretty muddy, and I much preferred the sound of the SOLO pickup straight into the Contra, without the Gigpro.

The highlight of this little Gigpro experiment was when I flipped the Contra on its side (10" front facing, 5" pointing up at the ceiling). I don't know yet if it's usable in a live setting, but good gracious ... I was very surprised how deep and natural it sounded. With this setup, the Gigpro did exactly what I bought it for - namely, eliminate the super low end freqs with the high pass filter. This really opened up the sound without taking away any of the meat in the lows and low-mids. I hope this will work for me in some settings w/ low to modest volumes ... we'll see...

 

[winston]

I have similar equipment (Rev Solo, iAmp 800, Wizzy) but I haven't gigged with the Rev yet. No problems at all with infrasonics using and Underwood-->iAmp 800-->Wizzy or Bergantino HT-112. After a while of using a BassMax or Stat-B I've been trying (and enjoying) the Underwood. I plan on trying out the Rev Solo for the next couple gigs; some low-volume ones this weekend where I'll use my GK 200MB, and a party next week where I think I'll bust out the big EA rig.

I haven't used the GigPro but I did have a Baggs Para-Coustic DI for a bit. I found it very transparent and liked the versatile EQ, overall it had a musical sound that didn't mess with the Wizzy's midrange magic. I wish it had an adjustible low-cut filter (has a fixed one) and a ground-lift switch.

If you want a transparent pre with adjustable low-cut filter I'd recommend the Fishman Pro Platinum Bass EQ/DI. Very clean/non-colored; between the filter, phase switch, EQ and compression I've been able to get excellent DB tone at loud volumes in some problematic venues with minimal feedback.

 

[Adrian Cho]

I have the impression (just only impression) that the trim filter of Gigpro is better than the high pass filters of Focus, or at least more friendly.

In theory, the specs on the high-pass filter on the GigPro and the Focus are the same. That's what I recall anyway.

Using the Gigpro (with my RS, also tested and verified with my older Bassmax), i'm getting the mid frequences significantly more warm and pleasent, without the piezo thonk. This allows me not to cut down the midrange as i did in the past. I heared from someone that the class A electronics amplify the even harmonics of sound, eliminating so the unnatural harmonics of piezo pickups. Maybe DRURB could comment about this.

There's more science in this thread than there needs to be so I won't try to add any. Simply put thought, the GigPro really does sound good throughout the range. All the LR Baggs stuff sounds great and it's very reasonably priced and the packages are compact. I use the GigPro into the AI preamp because I wasn't getting a hot enough signal from the Vektor. I think of it more as a signal pre-processor (and pre-preamp) much as the AMT preamp is. I have it setup so that the sound coming into the Focus is to my taste, with flat EQ on the Focus. That's nice to because it means that flat EQ on the Focus for both channels means that I am dealing with a neutral (or close to) sound. If for whatever reason I have to futz with the EQ then I will make the adjustments on the Focus.

The MixPro is also great as a blender.

 

[Adrian Cho]

If you want a transparent pre with adjustable low-cut filter I'd recommend the Fishman Pro Platinum Bass EQ/DI. Very clean/non-colored; between the filter, phase switch, EQ and compression I've been able to get excellent DB tone at loud volumes in some problematic venues with minimal feedback.

I had heard the opposite - that it colours the sound a fair bit. Also heard that it adds noise.

 

[bolo]

winston, thanks for your remarks. I guess I shouldn't be surprised that the line of Fishman DI's and blenders has been so popular with so many players over the years. Thanks for suggesting it as another way for me to try out a low pass filter. And I hope you enjoy your Rev SOLO!

Adrian, yes, I can see how the Gigpro might work really well for some folks, and I have always heard good things about all the L.R. Baggs stuff. And it did have a nice musical quality to it, like winston said. But I just did not care for the way it "messed with the Wizzy's mid-range magic," like winston said so well. It just made things too gooey through my rigs, to my ears, et al.

I did have the preamp on the Gigpro set at about one-third. Do you think perhaps I had it set too high, and was overloading the input to the next stage? I thought one third would be a clean setting. It certainly was capable of going higher and louder ...

I too strive for a natural sound using neutral EQ settings. I run everything on my EA and Solstice flat EQ-wise. I bump the mids slightly on the Contra, but otherwise it's set flat too.

I did try the bass & treble EQ controls on the Gigpro a little, but I kept coming back to their neutral settings.

I guess I just prefer the sound of my pickup straight into the EA and AI preamps, or into the Solstice and then the EA.

Thanks again.

 

[Adrian Cho]

Bolo, regarding gain (as opposed to volume), all you can do is use your ear to determine how much you should use. The GigPro does have a lot of gain so even one third is a fair bit. All of this mucking around with gear is a matter of coming up with a combination of equipment that does what we want. Good luck.

 

[bolo]

All of this mucking around with gear is a matter of coming up with a combination of equipment that does what we want. Good luck.

Roger that, and thanks. I'm gonna keep the Gigpro for the time being.

Sometimes it does seem like a lot of mucking around. I don't know how much time I've spent just trying to get the "optimal" settings between (a) gain on the Solstice, (b) master volume on the Solstice, (c) gain on the EA preamp, and (d) master volume on the EA. You can set all four at a multitude of different levels and still produce the same overall volume, ya know - so which settings "sound" best to produce that volume? Geez, how many combinations have I tried ???

Many, to be sure. And enough to know that each part a-d has an impact on the tone and shape of the sound, not just overall volume. And (for now at least) I have a set of baseline settings with that gear that I am reasonably comfortable with.

And on it goes ...

 

[Adrian Cho]

You should set your gain as high as you can and still get the tone you desire which usually means acceptable levels of distortion and noise. The less you can drive the power amp section the better.

 

[winston]

I had heard the opposite - that it colours the sound a fair bit. Also heard that it adds noise.

IME it's pretty transparent compared to other preamp units in its price range I've tried: the Paracoustic and the SansAmp BDDI. I had a Raven Labs PMB-1 for a little while (though not at the same time); both it and the Fishman pass the signal faithfully when set flat. I don't know how they compare to units in say, the Avalon, Pendulum or Millenia price range but I don't hear a lot of extra junk added to the sound. I consider its preamp more transparent than the preamps on my Eden and GK amps, and comparable to my EA. The Paracoustic is more colored, but in a way that works well with piezos.

With my Pedulla Rapture 5 BG (with Bartolini J-J pickups + preamp) I can hardly hear a difference between the sound of the bass straight into an amp (Eden WT-400 into Bergantino HT-112) and going through the Fishman set flat and adjusted for similar output, into the amp. The Fishman adds a little more top end clarity but I would attribute that to its 10Meg input impedance vs. the Eden's 1 Meg. Similar results into EA iAmp800/Wizzy.

Using the Fishman as a tone control for my Schertler Stat-B; this pickup has its own preamp box, and adding the Fishman (set flat/comparable gain) to the chain doesn't change the sound or add noise. Of course with piezos (BassMax, Underwood, Rev Solo) there's an appreciable change in the signal with/without preamp but that's to be expected.

The Fishman doesn't put out a true line level signal so it can get kind of noisy if you use it as a preamp directly into a power amp or an effects return jack, because turning up the power amp master to compensate for the lower level introduces noise. For use between a bass and amp, and in both live gig and recording situations I (and the engineers to whom I sent the XLR signal) haven't had any problems with noise. It's not a perfect box (it would need a higher output level, a couple parametric bands, and a mute switch) but it's a very useful tool for $170.

 

[drurb]

You should set your gain as high as you can and still get the tone you desire which usually means acceptable levels of distortion and noise. The less you can drive the power amp section the better.

Okay, except for the last sentence. When you have achieved a given output power, the power-amp section is being "driven" at the same level regardless of the settings of the stages that precede it. The optimal settings of multiple stages that precede the final power-amp stage are those yielding the best tradeoff between signal-to-noise ratio and the potential that the particular stage may overdrive the one that follows. Overdriving a stage produces distortion.

 

[Adrian Cho]

Maybe not the best choice of words but what I'm saying is that if you want to be turning knobs, the preamp should be the first choice and not the master volume.

 

[bolo]

Maybe not the best choice of words but what I'm saying is that if you want to be turning knobs, the preamp should be the first choice and not the master volume.

Hey Adrian, sorry, but I guess I thought it was the other way around, and was more like what DRURB outlined. Maybe I'm all wet, but in general ... in general, after you've optimized all your preamp stages and signals, wouldn't the master volume be your first choice to control your overall volume?

The optimal settings of multiple stages that precede the final power-amp stage are those yielding the best tradeoff between signal-to-noise ratio and the potential that the particular stage may overdrive the one that follows.

For example, in my case, I send my pickup into a Solstice. I adjust the input gain on the Solstice for maximum signal to noise from the pickup without distorting. Then I leave that setting on my preamp alone. I don't turn it up when I need to get louder.

Same goes for the master output volume on the Solstice, which feeds an input on my Wizzy combo. I adjust those two levels for the nicest sound, and highest SNR before distortion. Then I leave those two preamp settings alone. They're optimized in relation to each other, so I don't reach for them either when I need to go louder.

So ... if I need to go louder, the only knob left is the master volume on the amp, right? Sorry if I misunderstood your last post.

 

[Freddels]

Well, last night was the first time I had my new iamp200 and Wizzy out with "the band."

But . . . how did it sound?

 

[drurb]

Hey Adrian, sorry, but I guess I thought it was the other way around, and was more like what DRURB outlined. Maybe I'm all wet, but in general ... in general, after you've optimized all your preamp stages and signals, wouldn't the master volume be your first choice to control your overall volume?

For example, in my case, I send my pickup into a Solstice. I adjust the input gain on the Solstice for maximum signal to noise from the pickup without distorting. Then I leave that setting on my preamp alone. I don't turn it up when I need to get louder.

Same goes for the master output volume on the Solstice, which feeds an input on my Wizzy combo. I adjust those two levels for the nicest sound, and highest SNR before distortion. Then I leave those two preamp settings alone. They're optimized in relation to each other, so I don't reach for them either when I need to go louder.

So ... if I need to go louder, the only knob left is the master volume on the amp, right? Sorry if I misunderstood your last post.

I really should sit down and write a detailed post on these issues. I have done that to some extent elsewhere. In an earlier post, I wrote:

"When setting the gains, you are likely to have the most success by setting the "master" on your amp reasonably high and bringing up the individual channel control to the desired level. This configuration is preferred because it minimizes the potential for distortion that could arise in the inter-stages of the amplifier. When you cut back on the master, you limit the gain across the power amp stage. In contrast, keeping the master high allows for the full gain across the power amp. The downside of running the power amp section "wide open" like this is increased amplifier noise (hiss, hum, etc.) all of which are usually very well masked once you and your band-mates
begin to play. In a hi-fi setting the pre-amp/power-amp gains are tweaked for optimization of distortion and signal-to-noise ratio but that's another world (and web site) entirely!"


Not meaning to confuse things further, one must distinguish between level controls on pre-amps that affect true amplifier GAIN and those that are simple attenuators. Here's what I mean. Many pre-amps have settings that affect the actual amplifier gain followed by pots (simple resistive circuits). With such designs, the amplifier gain should be adjusted until the inputs of greatest intensity (your hardest hit notes) just produce distortion and then the gain should be backed off a bit. From then on, the level pots (simple resistive attenuators) should be used.

The situation one wants to avoid is the one in which the master is turned down and then the level on the previous stage (pre-amp on the same chassis, outboard pre-amp) is turned up when more level is desired. This can end up overdriving the previous stage depending on the particular amplifier configuration.

Here's the bottom line. In bolo's case, he's doing what makes perfect sense. The gains of the stages are optimized for low distortion, good SNR. Then he adjusts the master. The master control is an attenuator at the input of the power-amp stage. When he turns it down, he actually gets better SNR. What he would not want to do, and apparently what he does not do, is boost one of the previous stages once the master has been turned down. That could actually increase distortion.

So why did I suggest in a previous post that you leave the master up high? Because it is a simple rule that produces success across many configurations. It avoids distortion from overdriving "front-end" stages while giving up some SNR by running the power-amp section (nearly) wide open. So you get a little more hum/hiss etc., which will be masked by the music.

In other words, if you have to be non-optimal, it is far better to have the master too high and the pre-amp too low than the other way around.

I apologize if I've now confused more folks than I've helped.

 

[drurb]

But . . . how did it sound?

I promised a detailed report and I will keep that promise. I also will be writing a full account of the solution to the infrasonics problem with the iAmp. Because you asked, here's a preview.

The folks at EA were fantastic. Gary Gibilisco, tha amp's designer, took my analysis very seriously and is modifying my amp to rid it of the problem. He even sent me a loaner amp with the mod completed so that I could test it. It was very successful.

How does the Wizzy sound? Keep in mind that I'm still playing around with it. In a small combo situation, it is very impressive. It really does sound like the bass. The other day, my sax player was remarking on how much like the bass it sounded at moderate levels. He asked me to turn the amp on so he could compare. I pointed out that IT WAS ON! When I turned it off, he realized that he had been hearing what, to him, sounded like my bass, just bigger!

It does a fine job at higher levels as well. It is not as pleasing but I don't think that's really the fault of the rig. At quite high levels, all kinds of room resonances, etc. are excited and I don't know that any rig would sound to me "just like my bass." The fact that the Wizzy rig does at lower levels is quite a tribute.

More to come in separate posts... please wait.

 

[Adrian Cho]

Sigh. I believe we're all saying the same thing. I'm not saying that you use the preamp control when you want more volume. By adding gain you are changing the tone and you certainly don't want that. I'm just saying that you should initially set the preamp as high as you can (while getting the tone and distortion that works for you) so that you use the level control (the attenuator) to give you the full volume potential. The reason I started my posts on this is because I thought that earlier in the thread you were talking about setting the gain very low and the master volume a lot higher. I was surprised at how low the gain was but if it's optimal for you then that's exactly what you want.

 

[drurb]

Please see:

http://www.talkbass.com/forum/showthread.php?t=212228

 

[bolo]

DRURB, when you first detected this infrasonic problem, did you have the Rev SOLO p/u with the brand down (toward the table) or brand up (toward the strings)?

Just curious if the infrasonic effect was present with both pickup orientations, or more pronounced w/ one vs. the other.

And if I may ask, which way do you have your RS "permanently" mounted?

Thanks.

 

[drurb]

DRURB, when you first detected this infrasonic problem, did you have the Rev SOLO p/u with the brand down (toward the table) or brand up (toward the strings)?

Just curious if the infrasonic effect was present with both pickup orientations, or more pronounced w/ one vs. the other.

And if I may ask, which way do you have your RS "permanently" mounted?

Thanks.

It's permanently mounted with the "R" facing up. That is, away from the body of the bass. I did not assess the infrasonic response with both orientations but I will. If I boost the low end on the iAmp, I can still produce the effect, which is fine because it has been tamed sufficiently. I'll see what happens in the different orientations the next time I have the rig plugged in.