Pauly22
22 posts
Aug 10, 2013
10:09 AM
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Guys,
I play through one of Greg's custom wood mics and a silverface Fender Princeton reverb. Been working on my tongue blocking and getting much better crunch.
Still looking for the crunch on the straight-ahead, lip-blocked 2 draw, with and without bend, and I think that's where the amp kicks in.
My amp won't distort with the volume at 3, but it distorts nicely with the volume at 9. Problem is, I haven't found a room yet that will allow me to turn the volume to 9 without feedback. 3 to 5 is pretty much the feedback limit for the rooms I'm playing. Yes, I've changed out the tubes in the amp to cut the gain, going with 12U7, I think. I can't remember, but I've made those modes.
I'm wondering if anyone has played through a parametric notch filter. This claims to find the frequency that is feeding back and eliminate it from the sound profile.
http://www.sweetwater.com/store/detail/FBQ1000/
Another option, if the layout will allow, is to put the amp in another room, turn it up to 9, and mic it through the PA. This offers the benefit of putting my playing into my in-the-ear PA monitor, which I like.
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TheATL
54 posts
Aug 10, 2013
1:08 PM
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In short, yes - auto parametric notches work. I guess the reason you do not see them more is that they are pricy. Another reason is that a lot of guys alter their (tube) amps to change the gain profile so the feedback is not so severe. Plus, the amp changes allow players to get more crunch without high gain.
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SuperBee
1351 posts
Aug 10, 2013
3:13 PM
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Interesting. My silver face PR is unmodified, no tube swaps. I can't turn it up to 3, but I don't need to. The maximum pre-feedback volume is too dirty, if I need max volume I get cranky because I dislike what it does to my sound. The nicest sound is just a couple of hairs anticlockwise from feedback town.
Actually, I forgot, I suppose the amp is not quite stock. I'm running a weber 10 A 125 O speaker, and added a bias adjustment pot.
I always run treble off and bass max, and I don't use the reverb or trem. Unless there's an emergency.
My favourite amp but maybe too loud for my duo and outdoors band, not loud enough with the full kit
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garry
422 posts
Aug 10, 2013
5:49 PM
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i experimented for a while with the behringer shark, which has similar anti-feedback features. never got it to work worth much.
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arnenym
174 posts
Aug 10, 2013
6:23 PM
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I had one of those for a while. It works very well for song. But it steal tone from hi-z microphones.
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garry
423 posts
Aug 10, 2013
6:28 PM
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There is an earlier thread on the shark here. not a whole lot there, but may be helpful.
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Greg Heumann
2307 posts
Aug 11, 2013
10:00 AM
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@SuperBee re: "Interesting. My silver face PR is unmodified, no tube swaps. I can't turn it up to 3, but I don't need to."
You say you don't need to - but that suggests to me you haven't had to play up near the feedback threshold very much. I've used this analogy many times but I think it is a good one. Gain is like the travel on your car's throttle pedal. In fact, to make this more vivid, imagine your car is a Mazda Miata with a 500Hp V8. When you can only get your volume knob to 3, it is like having only 1" of pedal travel. Idle is idle, full throttle is full throttle, but in between it is very hard to feather the throttle in the turns. You're almost always getting too little or too much. Decreasing the gain of your amp so you can get the volume to 7 or 8 is exactly like increasing the travel of that gas pedal to 5 inches. Idle is still idle, full throttle is still full throttle, but it is much easier to control the car in the corners. On the amp, this means that feedback no longer LEAPS out of the amp, it SWELLS. You can actually play much closer to the feedback threshold and easily manage it with technique and a volume control at the mic. SO - you may not have "needed to" yet - but you might enjoy your amp a lot more if you did.
Many guys try this but don't go far enough. A single 12AX-->12AY swap in a typical Fender 3-12AX7 preamp is usually not enough reduction. I recommend 12AX-12AU-12AU. You will STILL be able to get enough volume to feed back - it just won't happen until the knob is a lot further up.
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Last Edited by Greg Heumann on Aug 11, 2013 10:02 AM
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Kingley
3017 posts
Aug 11, 2013
10:06 AM
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SuperBee - If you run with a 12AY7 in V1 you'll get the volume up around 7 on a Princeton Reverb. Princeton Reverb's make killer harp amps!
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The Iceman
1081 posts
Aug 11, 2013
10:29 AM
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Not a gear head...
do you really have to push an amp to its feedback limit in order to get a great sound? (I've never had to).
One amp I used had an aftermarket volume control put in between the amp and the speaker so you could turn the amp up to 10 and keep the speaker volume at a low level. Sounded pretty good to me.
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The Iceman
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Rick Davis
2213 posts
Aug 11, 2013
12:24 PM
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I've tried several anti-feedback devices, including the Sabine adaptive parametric filter. It sucks big chunks of tone out of your sound by greatly reducing the level of the notes that are causing feedback. It's like there are big gaps in your harp. It didn't work for me.
All anti-feedback devices will impact your tone. With our current technology they have to. The only one I've found that does it in an acceptable way is the Kinder AFB+. It does not leave gaps in your tone, but it makes it a little raspier and depending on your settings it may make it very nasal and annoying. When set up correctly it sounds very good, but it is still something of a trade-off.
I have not tried the Behringer device but I doubt it will be a a good solution. If you get one I'd be interested to hear how it works for you.
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SuperBee
1353 posts
Aug 11, 2013
2:16 PM
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All I was trying to say is that I get plenty of distortion pre feedback. I understand I could get more sweep on the volume knob. But the thing sounds better before it gets to that point anyway. I was remarking on Pauly's observation that his feedback limit is 3 - 5 depending on the room, but his amp still sounds clean at that point. Mine feeds back around 3 but I rarely want to push it that far because the amp sounds better prior to that. If I have to squeeze that extra volume I'm getting a less attractive sound before I get to feedback. I wasn't complaining about my amp, just surprised Pauly22 has a clean sound at feedback.
I haven't tested it with a SPL meter, so I don't know how loud it is. Must do that.
I understand I could get more sweep on the volume control, but as I said, I'm not looking for more sweep. Not from a feedback avoidance angle anyway.
I suspect it's a bias issue.
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capnj
147 posts
Aug 11, 2013
8:29 PM
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Very much considering a tube change in at least V1 of my princeton reverb to 12ay7 via kingley suggestion.Get some great cut with the ax'es though.Used pedals with this amp,harp attack,lw octave,lw delay,and carbon copy,yes somedays sounds good,but others not.Very leary of going with Gregs AU theory on this amp,but ponder the thought just crank it up.The lw octave pedal does help with feedback,but the tradeoff is some raspiness,not a tone destroyer.
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walterharp
1154 posts
Aug 12, 2013
7:54 AM
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you might also want to try a weber min mass attenuator. It put an extra speaker load on so you can crank the amp to distortion but get whatever final volume you want, from pretty quiet to just shaving a few db off of your total volume. This also allows you to cut gain (e.g. increase the volume sweep so you can get right to the edge of feedback.
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Rillo
1 post
Aug 13, 2013
4:24 PM
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The auto-feedback detecting devices will notch out feedback but you must understand how they work. They are very good at detecting a continuous frequency and notching it. If it hears that frequency again, it notches it deeper. Some of these devices will notch up to a dozen frequencies. The problem is that the sound produced by a harp is detected as feedback. So the more you play, the more it cuts the good stuff. The good news is there is a way to work with feedback eliminators. With my Sabine, I cup the mic and harp to my mouth without playing, then I turn up the volumes until 3 frequencies have been notched. Then, I lock the device so that it is no longer auto-detecting. Voila, I have increased my potential volume by a wee little bit. Yea, that's really all it will do. I don't bother trying to kill a bunch of frequencies. There are other ways (probably more effective) to get that done.
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