Double Bass AMT S25 Bass Mic

[Robert]

There isn't a lot of information above 10KHz in a bass, and few of us over 40 hear much above 12KHz (or even lower), so I wouldn't think the response limits it, but you never know. There are probably all sorts of clicks and other cues with harmonmic content well into the 10-20KHz range and beyond that we pick up on. People regularly use mics like the U87 (which has a noticible boost in the 10-20KHz range) for bass and I assume they know what they're doing.

No there is not much information above a couple of hundred hertz in a bass note. But in the attack, the frequency information is spread all over the spectrum, and that is why the attacks sound duller with the AMT. String rattles and finger board noises also sound a bit unnatural.

But if I were to choose, unnatural highs or unnatural lows, I would of course choose unnatural highs.

 

[Hampton]

Interesting discussion. I’m using a new AMT this week for a big band program. My previous pickup was an Underwood and before that a Polytone from the 70’s. With the Underwood, I was never happy with the soft articulation. I think that’s because the wings of the bridge are involved and when you damp them with that pickup the instrument loses punch. If you use one, compare the sound of your instrument, unamplified, with the pickups in place vs. without them.

The AMT, by comparison, delivers good dynamic edge and the sound has throw; It shoots out into the hall. So for me now, the question is how to get greater complexity of sound and I’m afraid I partly know the answer. Last time I bought an amplifier (when the Polytone MiniBrute threw a tantrum) I had about 6 hours so I settled on the then new Eden Nemesis – a 200W combo with 4 x 10” drivers. Lots of power and fairly quick, good bottom end, but somewhat underdamped even considering the 10” cones.

Well, that’s a bit of a digression. But the way to get that punch and throw from the microphone seems to be to place it about 1/8 inch from the top. I’m still working with suggestions from you guys in setting it 4 or 5 inches above the bridge on the center line.

I’m interested to try Ray’s suggestion to place it a couple of inches below the f hole. I don’t think I’ll get to that this go round. We’re out of rehearsal and the performance is not the time to second guess your equipment.

 

[mchildree]

After all this raving, I had to jump on the bandwagon. I bought Adrian's AMT and got it yesterday. Pretty dang startling how good this thing sounds. As everyone else says...sounds just like my bass. Gonna be interesting to see how it fits on the gig....I'd love to ditch the pickup entirely.

 

[Adrian Cho]

In general, any mic should sound good but what makes the AMT great is that it's actually very usable for gigs. I keep my pickup (Dyn-B) as a backup because I never know when I might be forced to fall back on it. It's rare but it happens - sometimes I mix both or sometimes the setup is really bad for a number of reasons so I'll use just the pickup.

 

[Chris Fitzgerald]

Gonna be interesting to see how it fits on the gig....I'd love to ditch the pickup entirely.

That's what I was hoping, but it never really happened. I wanted to be a macho "mic only" kinda guy, but I found that I preferred the blended sound 10 times out of 10. Also, be warned: there are some rooms that the AMT or any mic will sound god awful in, and there won't be a damn thing you can do about it - usually square rooms with lots of hard reflective surfaces and few (if any) absorbent ones. In rooms like this, any mic will pick up a lot of reflected "chatter", causing your amp to produce a sound reminiscent of any B movie soundtrack involving an insane asylum in hell. On gigs like this, You'll be glad you still have the pickup.

Congrats on your new toy!

 

[Adrian Cho]

I agree with Chris. I also wanted to be macho "mic only" guy. Well actually I originally wanted to be a "no amp" guy but I certainly can't do that all the time. Rufus was the one who told me that the Dyn-B and AMT blend was better than either alone and I'd have to say he is right. For me, mixing the Dyn-B just gives it a bit more punch. The other thing is you have the option to use just the pickup or a blend on stage and send just the mic to the house.

 

[Chris Fitzgerald]

Quick ressurection of the thread for a question: I've lost my AMT manual, and can't remember what the little switch on the back of the regular preamp is for. Last night on the gig, I was getting a nasty sound and some distortion when I played the open A string. Just for yuks, I flipped the switch and the distortion went away. A phase switch, maybe?

Also just to confirm - there's no way to power the mic with the phantom provided by the Focus, right?

 

[mje]

Ground lift?

 

[Marcus Johnson]

I'm having some AMT issues right now.... someone came up to the bandstand and got tangled up in the cable, pulling on it enough to create a big, loud, short in the signal...enough so that I can't use it at the moment. I guess I should get some yellow crime scene tape to wrap around the bandstand.

So, I'm really interested in converting this thing to a detachable cable setup. Didn't you do this, DURRL? I like Marty Paglione a lot, but I don't want to have to keep shipping it back to him every time the fixed cable derails an otherwise high-end mic. I was even picturing a setup where the mic head (minus all the mounting hardware and gooseneck) just sits happily shock-mounted between the bridge legs, with a short lead down to the afterlength of the strings, and then into a cable to the box. Ideas, anyone?

 

[Uncletoad]

Me too. I just busted mine last week. Sent it out Friday to get fixed. I'm sure it's a cable thing. That cable sucks. To whimpy, to short and to proprietary.

There needs to be another way to make these things be more studly.

My super pre doesn't have any switch.

 

[Bob Gollihur]

Quick ressurection of the thread for a question: I've lost my AMT manual, and can't remember what the little switch on the back of the regular preamp is for. Last night on the gig, I was getting a nasty sound and some distortion when I played the open A string. Just for yuks, I flipped the switch and the distortion went away. A phase switch, maybe?

Also just to confirm - there's no way to power the mic with the phantom provided by the Focus, right?

Yes, the phantom power from the Focus will power the AMT SP preamp. I just ran out of the SP25B mics, they are coming in next week, or I would look at the manual to confirm the switch use. Memory fails.

 

[Adrian Cho]

If I remember correctly, Marty recommends not using phantom power but that if you have to, use what I believe on the standard preamp is the ground lift switch. The super preamp doesn't have a switch because the red output is ground-lifted.

 

[Chris Fitzgerald]

I'm having some AMT issues right now.... someone came up to the bandstand and got tangled up in the cable, pulling on it enough to create a big, loud, short in the signal...enough so that I can't use it at the moment. I guess I should get some yellow crime scene tape to wrap around the bandstand.

Deja vous all over again. That sucks.

So, I'm really interested in converting this thing to a detachable cable setup. Didn't you do this, DURRL? I like Marty Paglione a lot, but I don't want to have to keep shipping it back to him every time the fixed cable derails an otherwise high-end mic. I was even picturing a setup where the mic head (minus all the mounting hardware and gooseneck) just sits happily shock-mounted between the bridge legs, with a short lead down to the afterlength of the strings, and then into a cable to the box. Ideas, anyone?

Exactly what I ended up doing, although it cost a pretty penny. First, Nnick did a pretty McGyverish mounting job of the mic onto the tailpiece, and I used some old shockmount elastic to secure the capsule so that it floats between the bridge feet. Then, I hired Gary Falk (an electronics whiz) to replace the dinky little connector with a heavy duty Neutrik connector - basically looks like an XLR cable end, but with 4 pins instead of three. In order for that to work, Gary had to install another Neutric connection into the preamp box. Like I said, it was kinda expensive, but I've had no problems at all since then, and have gigged with it probably 150 times or so. Considering I broke the cheesy little connector on the original afeter about 2 weeks, I think that's actually pretty good.

So now, the mic stays on the bass, and I just plug in two cables (one for mic, one for p/u) instead of one when it's time to set up. Booya!

 

[Marcus Johnson]

So lettsee...the cost of some shock mounts, a coupla Neutrik connectors, and roundtrip tickets for Nnick and Gary Falk to Maui....hmmmm

Chris, I might bug you for some pics of your rig in the near future.

 

[Chris Fitzgerald]

Feel free. I don't have any pics yet, but that could change. Mr. STANDBETTER designed a much better mounting design for the AMT and has even been so kind as to send me one...and I haven't been able to get up to see Nnick yet with it (sorry, Bob). On the bright side, mounting the mic to the tailpiece is the easy part - just required some nylon straps and some foam. The part that Gary did could be done by just about any competent electronics repair guy...except for the part where he had to cut a new hole in the faceplate of the AMT preamp to mount the Neutrik connector. Seriously, if you've got a good repair guy around and let him be creative, I bet he could hook you up. I was just really lucky to have someone as resourceful and creative as Gary.

 

[phlybass]

Hi Chris and List-mates,

I've also rigged up a mounting method for my AMT to the tailpiece using some cosmetic sponge material as padding and spacers and a couple of 15" velcro cable ties from Home Depot. I just closed down the screw adjustment as far as it would go and using the sponge, velcroed it under the tail piece. This setup is very stable, doesn't rattle, and allows for the mic placement I want.

I would like to replace the regular long and fragile cord, though, so Chris, when you get a chance some pics and part numbers from your tech guy would really be appreciated.

The velcro and sponge idea was originally a test setup, but it's so stable and works so well, coming up with a more permanent mount might just be one of these "rountuit" things.

I'll try to post some pics of my setup when able.

Warm regards to all,

Alex, aka phlybass

 

[bolo]

Quick ressurection of the thread for a question: I've lost my AMT manual, and can't remember what the little switch on the back of the regular preamp is for. Last night on the gig, I was getting a nasty sound and some distortion when I played the open A string. Just for yuks, I flipped the switch and the distortion went away. A phase switch, maybe?

Chris, I'm not exactly sure if you got your answer yet or not -

The little switch on the back of the regular AMT pre is the ground lift, like mje and Adrian mentioned.

Mine has little letters L and G stamped in the metal above and below the switch.

 

[Chris Fitzgerald]

I figured that was the most likely scenario...but then why would a ground lift affect distortion in any way???

 

[mje]

Ground loops can result in modulation of the signal, which causes it to clip- even if you can't hear any of the 60Hz modulation.

 

[Robert]

The ground lift is very fishy on those preamps. Mine acted just like a low pass filter when using a regular XLR->instrument jack cable. I sent it back to Marty because of this, but this was considered "normal". My mic only works with a XLR->XLR cable, otherwise pops are heard in the sound output. According to Marty, he can't reproduce it.. Fishy.