[Harp-L] amp sweet spot



Bruce K Ritter asks:

I've read several mentions of an amps sweet spot-what do I listen for the
find it, is there a process of dialing in settings and testing?


Bruce,

A good tube amp is almost like a living, breathing creature. The response to tone and volume settings is not necessarily linear, and will also be different depending on how hot the tubes get during performance. Most tube amps sound and respond best when pushed--you get the volume at a certain point (with appropriate tone control settings) and the degree and quality of the resulting overdrive, tube compression and distortion gives you the particular sound and response you are after. The real challenge is to get that level of tone and response without feeding back. This is why many of us swap tubes for lower gain preamp tubes and unbalanced phase inverter tubes, keeping in mind that tubing down too much may rob the amp of tone, Also, if the amp has tilt back legs, like many Fender amps do, using them may open up, and therefore change, the tonal characteristics, sometimes dramatically.

Now, the "sweet spot" is an entirely subjective determination and has a lot to do with playing style. You use your ears and different amp and mic settings to find it. The "sweet spot" may be different for different mics into the same amp, and will be different for different players using the same mic into the same amp. Personally, i like a somewhat cleaner sound, so what i consider the sweet spot on, for example, my Super Reverb Reissue, will be different than what some other player may prefer who is after more "crunch." But depending on the amp settings and the particular mic used, the amp will respond to playing technique somewhat differently. Personally, I think too much "crunch" deprives me of articulation and i don't use a bullet mic. Other players may prefer a bunch of low end distortion to fatten tone and will play through a bullet and use mic handling and breath technique to vary the resulting crunchy sound--each of us will find a different "sweet spot" on the same amp for what we are trying to do, or may prefer to play through amps with different gain characteristics and speaker configurations.

Personally, I'm not fond of amps with a master volume control. but such amps are supposed to allow one to set the sweet spot using the volume knob and then set performance volume using the master, which may work for guitars, but which I think works better in theory than in practice for playing harp. But YMMV. Anyway, don't be afraid of extreme tone control settings. like, for example, turning the treble all the way off. On my SRRI, I find I need just a touch of treble (between 1 and 2, and closer to 1 than 2) for cut. Be careful about the conventional wisdom that you should always turn the bass all the way up--bass frequencies can feed back, too, and may muddy your sound. Personally I find a mid range control very useful . Others may like to use an outboard equalizer to boost the freqs around 240, or use an EQ or an outboard preamp or compressor to attenuate (or boost) input gain. There are no set rules--if it gives you the sound you are after, it's the right thing to do. But, in general, the more gear you have, the more problems you have, so, all things being equal, the simpler the set up, the better.

Also, --(and this is extremely important)-- keep in mind that what sounds good in your living room may not sound right on stage at the venue.

Lately, i've just been using the volume control on my 545 Ultimate to attenuate input gain, allowing me to set the volume on my Supper Reverb Reissue at 7 or 8 (or on my Princeton Reverb Reissue, which is my smaller tube amp, at 6 or 7 ) which is a level where I think the tube response sounds best (the "sweet spot"). The reduced input gain from the mic allows me to turn the amps up that far without feeding back and then I will adjust the VC on the mic a little to control overall performance volume, and I don't use any pedals or outboard devices. I find that attenuating the input from the mic is pretty reliable way to control feedback. But there are other ways to do it, and the tonal qualities of some mics will degrade if they are turned down, so it's a trial and error thing. Some players will use a super clean mic, like an Audix Fireball V (which also has a very high feedback threshold), into a high gain amp, using the clean mic signal to balance what might otherwise be unmanageable heavy distortion from the amp, which can also be pretty effective. But I like the sonic character and proximity response of my 545 Ultimate.

On my PRRI there is no midrange control and i set the treble at 0, bass at 10. This makes the amp sound a little "boxy" but i put a set of 14" Fender tilt back legs on it, and if i tilt it back, the tone opens up nicely and it sounds perfect. But, I've heard other players who use a bullet mic into a PRRI say they like to keep the amp on the floor at all times for better low end response. One man's sweet spot can be another man's sweathog, to borrow a metaphor from the world of romance.

Actually, i usually play through a pedal board into an SWR Baby Baby Blue bass amp which has a solid state power stage, a tube preamp and on board semi parametric EQ for tone shaping, so I'm not a regular full time tube amp user myself. But, depending on the gig, I use what i consider to be the right tool for the job which may be my PRRI or my SRRI if I'm not using my SWR. There are a lot players on here that have much more extensive experience finding the "sweet spot" on tube amps than i do. But. since i recently used that term in a post, I thought I would give you my take on it, FWIW.

Best regards,

JP



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