The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Reply
 
Thread Tools
  #16  
Old 04-01-2011, 08:27 AM
Doubleneck Doubleneck is offline
Registered User
 
Join Date: Mar 2005
Location: Ohio
Posts: 6,284
Default

I am mainly an acoustic player but got my first tube amp for my hybrid. Got a Mesa Boogie TA15. Very small and switchable wattage down to 5 watts. It is amazing on the electric side. You make me want to try it on the acoustic as well will try this weekend. Tubes are the way to go on electric used pedals and modelers all my life. Wow are the tubes a step up.
__________________
Steve
2005 McKnight SS Dred
2001 Michael Keller Koa Baby
2014 Godin Inuk
2012 Deering B6 Openback Banjo
2012 Emerald Acoustic Doubleneck
2012 Rainsong JM1000 Black Ice
2009 Wechter Pathmaker 9600 LTD
1982 Yairi D-87 Doubleneck
1987 Ovation Collectors
1993 Ovation Collectors
1967 J-45 Gibson
1974 20th Annivers. Les Paul Custom
Reply With Quote
  #17  
Old 04-01-2011, 09:11 AM
acquirephile acquirephile is offline
Registered User
 
Join Date: Feb 2011
Location: Pittsburgh, PA
Posts: 51
Default

The Loudbox 100 is amazing and I had one for like 5-6 years, but i just traded it in for a Bose L1 Compact for it's versatility and sonic capability. If I had to choose an amp (the L1 Compact is technically a PA) for my Taylor, it would definitely be a Fishman Loudbox.

Quote:
Originally Posted by ErikH View Post
No it's not worth trading your loudbox in for. Check out Rivera amps though, they have an acoustic/electric amp that kills
__________________
---
2011 Taylor 716ce
2005 Fender Mexi J-Bass
1980 Yamaha Classical

Find me on YouTube.
Reply With Quote
  #18  
Old 04-01-2011, 09:58 AM
BuleriaChk BuleriaChk is offline
Registered User
 
Join Date: Jan 2005
Location: Santa Barbara, CA
Posts: 1,150
Default

When I jumped back into Flamenco 6 years ago, or so, I re-entered the search for a decent (nylon string) acoustic sound. I went through a very frustrating, time consuming, and expensive process trying to get the right combination - if the pickups were bad, I tried to change the preamp, EQ, and applied extensive modelers, both hardware and software to the sound.

My take on it is that tubes can color the sound (to absurdity), as can modelers or effects, but the most important aspect for plugged in acoustic sound is the pickup (and its installation in the guitar), followed by the preamp, and then the amplifier, which should be as transparent and clear as possible before jumping into tube color (or effects like reverb).

That is, tubes/effects should NOT be used to try to compensate for a unsatisfying basic sound.

My final result was to settle on Takamine (TC-132C, TH-5C) with CTP-2 preamp and palathetic pickup with Fishman SA-220 SoloAmp (LR Baggs A-Ref and SR Jam150 are fine as well). I find that I turn the tube completely off in the CTP-2, though - if I want a tube effect I use software or hardware modeler in the effects loop or DAW...

There are other solutions that may work for others, but the first goal should be to get the basic sound as absolutely pristine as possible from the guitar, pickup, and preamp - find a FLAT PA or acoustic amp, and work from there.

But do NOT use the external devices to try to correct an underwhelming sound - it is not worth the effort. (IMO, even if you don't go the Takamine route, they are a good place to start as points of comparison - but for me, I've never looked back)

YMMV, of course,

Chuck
Reply With Quote
  #19  
Old 04-11-2011, 08:38 PM
ValveMan ValveMan is offline
Registered User
 
Join Date: Oct 2009
Location: NYA, Minnesota
Posts: 54
Default Review in Acoustic Guitar magazine

Worth checking out when you have a couple of minutes

http://www.acousticguitar.com/articl...rticleid=26824
Reply With Quote
  #20  
Old 04-11-2011, 10:42 PM
terrapin terrapin is offline
Registered User
 
Join Date: Aug 2007
Location: Oceanside, Ca
Posts: 4,190
Default

I SO agree about tubes being a way cool thing for acoustics sometimes. Fallacies already posted here are that tubes distort (they can but don't have to, my McIntosh tube driven preamp and power amp will attest to that), tubes wear out often and cause problems (transistors wear out also and can cause as many problems). I would MUCH rather fix or have fixed a PTP or Turret wired component board with vacuum tubes then pay to replace a PCB mother board.


Most acoustic guitar amps these day are solid state and SO many are SOO good.

But, do you think James Taylor or Jackson Browne, Taj Majal (substitute most any of the guys from the early years..) did NOT record through analogue/tube driven preamps......and probably power amps????

Both have GREAT characteristics......and down sides.

Quote:
Originally Posted by olrocker View Post
The previous posters have valid points in that, tubes do, in fact, color tone, but this can be a desirable characteristic, even for acoustic guitar. Tubes create "compression" which is almost universally desirable for elec., but still being investigated for acoustic. Basically, the more juice you send thru a tube, the more compression it creates. That's why Vox put a 12ax7 in the pre section of the 150, because it was successful in creating compression in their line of ADxxVT amps for electric. An additional reason is arguably for marketing reasons. I have the AD50VT. There are a couple of tube amps designed for acoustic, which, coupled with their ability to accept the Taylor TRS signal, yield fantastic tone. As I've said before, "the guitar is what you play, the amp is what you HEAR". If you want truly transparent tone, look at some of the great PA's out there. Amps tend toward colored tone anyway, and usually come with effects, like chorus, reverb, feedback suppression (yes, that colors tone too) I love the clean warm tone of my Rivera amp, which work really well for vocals too (makes me sound better than I am) and much prefer it to the colder, thinner tone of my solid state acoustic amp. Is the Vox worth trading the Loudbox for? Probably not, because in that price range, the Loudbox is alot of amp. But one day, you might consider ADDING the Vox to your collection.
Reply With Quote
  #21  
Old 04-12-2011, 05:38 AM
Rick Jones Rick Jones is offline
Registered User
 
Join Date: Mar 2010
Location: Jersey UK Channel Islands
Posts: 1,468
Default

Old 1970's Sound City guitar/bass heads have HUGE Partridge transformers and often Mullard tubes, and give such a fat, clean full range signal, up to such volumes, that I've had my acoustic sounding pristine at ear slitting volumes.
They are too big/hefty/delicate to schlepp around for gigging though.
__________________
Avalon L32, in these vids;
Me flatpicking.

Me fingerpicking.
Reply With Quote
  #22  
Old 04-12-2011, 05:53 AM
ukejon ukejon is offline
Registered User
 
Join Date: Jan 2008
Location: Milwaukee
Posts: 6,501
Default

Gerry, thanks for the informative post about Humphrey amps. They sure look great and I bet they sound beautiful. Sure would be fun to try one out....
__________________
My YouTube Page:
http://www.youtube.com/user/ukejon



2014 Pono N30 DC EIR/Spruce crossover
2009 Pono koa parlor (NAMM prototype)
2018 Maton EBG808TEC
2014 Hatcher Greta 13 fret cutaway in EIR/cedar
2017 Hatcher Josie fan fret mahogany
1973 Sigma GCR7 (OM model) rosewood and spruce
2014 Rainsong OM1000N2
....and about 5 really nice tenor ukuleles at any given moment
Reply With Quote
  #23  
Old 04-12-2011, 06:48 AM
Herb Hunter Herb Hunter is offline
Registered User
 
Join Date: Nov 2005
Location: Maine
Posts: 18,382
Default

Quote:
Originally Posted by terrapin View Post
...Fallacies already posted here are that tubes distort (they can but don't have to, my McIntosh tube driven preamp and power amp will attest to that), tubes wear out often and cause problems (transistors wear out also and can cause as many problems). I would MUCH rather fix or have fixed a PTP or Turret wired component board with vacuum tubes then pay to replace a PCB mother board. ...
It is not a fallacy that the distortion levels before the onset of clipping in tube amplifiers is higher than that of solid state amps.

McIntosh claims a total harmonic distortion of 0.5 percent for its 300-watt, MC2301, tube amplifier while rating its 300-watt, MC302, solid state amplifier at 0.005 percent. That is an enormous difference. Just how audible the difference is when the program material is a solo acoustic guitar is a different issue. (McIntosh's tube amps have the lowest distortion I've seen - the Conrad Johnson, $7,500, 250-watt, ET250S amplifier's total harmonic distortion is rated at a whopping 2 percent.)

Also, tube performance begins to deteriorate from the moment the equipment is first used at a rate that makes it necessary to make them user replaceable. That is not the case with transistors. While they may eventually fail they are not subject to the steady performance decline of tubes.
Reply With Quote
  #24  
Old 04-12-2011, 12:51 PM
dave251 dave251 is offline
Registered User
 
Join Date: Jan 2003
Location: Kansas City MO
Posts: 196
Default

There is more than ONE type of distortion( harmonic distortion is usually what is listed)....and as such, unless taken with specs of the other distiortions...really doesn't mean much.

Here's a list of a few:

harmonic- the ability of the amp to accurately reproduce the harmonic ratios of a signal; ie, the aligning the 1st, 2nd, and 3rd order harmonic in their respective ratios. Critical for tonal accuracy;

clipping- this is what our ears usually percieve as "distortion", a fuzzy, though harmonically rich sound that occurs when an amp is being driven too hard.

transient- The ability of the amp a reproduce the attack transient, sometimes reffered to as "slew rate".

The trick is to listen to the amp and learn to recognize the "distortions" that each has.

Basically...just learn to trust your ears.
__________________
Dave W.
Reply With Quote
  #25  
Old 04-12-2011, 02:14 PM
Herb Hunter Herb Hunter is offline
Registered User
 
Join Date: Nov 2005
Location: Maine
Posts: 18,382
Default

Quote:
Originally Posted by dave251 View Post
There is more than ONE type of distortion( harmonic distortion is usually what is listed)....and as such, unless taken with specs of the other distiortions...really doesn't mean much.
My point was that tube amps have higher distortion than solid state amps and by distortion most people understand it to mean the harmonic and intermodulation variety. There are other, of course, other forms of nonlinearity. I didn't post intermodulation distortion because I thought that the data I provided made my point well enough.

Nevertheless, the IM distortion rating of the McIntosh MC2301 tube amp I mentioned is "0.5% maximum, if the instantaneous peak power output does not exceed twice the rated power output for any com- bination of frequencies from 20Hz to 20,000Hz." The rated IM distortion of the solid state McIntosh MC302 solid state amp is "0.005% maximum, if the instantaneous peak power output does not exceed twice the rated power output for any combination of frequencies from 20Hz to 20,000Hz".

Amplifiers with a high damping factor will exhibit faster bass transient response and the above tube amp has a damping factor of 15 while the above solid state amp has one of 40. While McIntosh's web site doesn't specify it, typically the slew rate of solid state amps is better than what tube amps can deliver.
Reply With Quote
  #26  
Old 04-12-2011, 04:12 PM
terrapin terrapin is offline
Registered User
 
Join Date: Aug 2007
Location: Oceanside, Ca
Posts: 4,190
Default

I really appreciate the education I am getting from Herb Hunter and Dave 251, I have learned alot.

Can you guys, or someone tell me if I am correct about my assertion that much of the '60's and '70's acoustic guitar recordings that so many of us hold dear come from acoustic guitars into tube equipment? I do NOT hear any distortion on the 1st James Taylor album or Joni Mitchell or...
Reply With Quote
  #27  
Old 04-12-2011, 04:57 PM
Herb Hunter Herb Hunter is offline
Registered User
 
Join Date: Nov 2005
Location: Maine
Posts: 18,382
Default

Quote:
Originally Posted by terrapin View Post
I really appreciate the education I am getting from Herb Hunter and Dave 251, I have learned alot.

Can you guys, or someone tell me if I am correct about my assertion that much of the '60's and '70's acoustic guitar recordings that so many of us hold dear come from acoustic guitars into tube equipment? I do NOT hear any distortion on the 1st James Taylor album or Joni Mitchell or...
I really don't know. If Trident Studios in London was using all solid state equipment by 1968 then tube equipment wasn't a factor in the recording of James Taylor's eponymous album. Trident Studios did have a reputation for having advanced equipment in those days. They were using Dolby noise reduction and 8 track recorders by 1968. It is possible that they had a mix of tube and solid state equipment when James Taylor was there but, again, I really don't know.

Last edited by Herb Hunter; 04-12-2011 at 05:44 PM.
Reply With Quote
  #28  
Old 07-09-2012, 01:37 PM
jbefumo jbefumo is offline
Registered User
 
Join Date: Sep 2010
Posts: 6
Default

Not necessarily the case. Audio aficionados value high-fidelity tube systems for accurate audio reproduction. The same factors apply to the amplification of individual acoustic instruments.


Quote:
Originally Posted by sludgefactory View Post
Tube amps have never been the best choice for acoustic guitars. The idea with an acoustic amp is to reproduce the sound of the guitar as faithfully as possible.
For electric guitars, the tube amp becomes almost an instrument onto itself as it can color the sound significantly. Which is why some electric players have more than one tube amp just to achieve different sounds.
Reply With Quote
  #29  
Old 07-09-2012, 03:42 PM
Herb Hunter Herb Hunter is offline
Registered User
 
Join Date: Nov 2005
Location: Maine
Posts: 18,382
Default

Quote:
Originally Posted by jbefumo View Post
Not necessarily the case. Audio aficionados value high-fidelity tube systems for accurate audio reproduction. The same factors apply to the amplification of individual acoustic instruments.
Tube systems have higher distortion and noise levels than solid-state equipment. Below is a comparison of a solid state and tube power amplifier from the same manufacturer showing that a tube amp has a much higher distortion level:

McIntosh MC302 Solid State Amplifier $5.500

Power Output:.........................300 watts
Total Harmonic Distortion:............0.005
Signal to Noise ratio:................122 dB
Dynamic Headroom:.....................1.8 dB
Frequency Response (+0,-0.25 dB):.....20 Hz to 20 kHz
Frequency Response -3 dB:.............10 Hz to 100 kHz
Damping Factor:.......................> 40 Wideband


McIntosh MC2301 Tube Amplifier $11,000

Power Output:.........................300 watts
Total Harmonic Distortion:............0.5
Signal to Noise ratio:................117 dB
Dynamic Headroom:.....................1.2 dB
Frequency Response (+0,-0.34 dB):.....20 Hz to 20 kHz
Frequency Response (-3 dB):...........10 Hz to 100 kHz
Damping Factor:.......................Greater than 15

Last edited by Herb Hunter; 07-09-2012 at 03:49 PM.
Reply With Quote
  #30  
Old 07-09-2012, 08:50 PM
Joseph Hanna Joseph Hanna is offline
Registered User
 
Join Date: Feb 2005
Location: Topanga Canyon, CA
Posts: 2,585
Default

Quote:
Originally Posted by ValveMan View Post
I know this thread's a couple of months old, and that I might be inviting all kinds of criticism and nay-saying, but regardless, I can't resist throwing in my 2c-worth.

I'm the designer & builder of the Humphrey Amp mentioned above. It took over a year of full-time 7-day weeks to finalize the design & testing (I might be slow, but I'm big
First, I'll point out some obvious negatives, which really isn't good marketing practice - but I'm not marketing here, just explaining why I do what I do, so I guess it's ok.
1* Cost - yup, tube amps are more expensive than solid-state in general, and as mine are hand-built starting from raw lumber, and hand-wired, they are even more expensive - but they're certainly not targeted at the general market.
A typical solid-state amp can be made with a bill-of-materials total cost that is less than the cost of a pair of quality EL84's

Don't get me wrong - there's some fine s.s. amps out there and the fact that they CAN be made at low-cost and in high volume gives a lot of folks access to good gear.

2* Weight - yup, a Humphrey Amp weighs about 37lbs, depending on the wood used. We do need some hefty transformers. Actually more hefty than those used in electric guitar tube amps (don't want to saturate the xformer in an acoustic amp).
Also - we use a very heavy hi-fi class 10" speaker and brick of a horn-tweeter (all for good reasons)

3* Reliability. Depends what you're doing with it really. Tubes do wear out over time, but it depends largely on the voltage supply and how long they're played. My Marshall amp drives the EL84's with more than 420V (they're spec'ed for 300V) and after 5 years I'm thinking it's time for new tubes. I just use it for personal playing though - not gigging every night.
A Humphrey Amp using high quality JJ EL84's, running at much lower voltages, would run for many years before the sound degraded - unless you ride it hard & put it up wet every night of the week, of course.

There's actually fewer components & connections in a well-designed tube amp, so the reliability is inherently 'better' from the get-go.
It depends on a lot of factors though, and I'm not saying S.S. is inherently unreliable.
If I were to play the most important gig of my life & could choose only one amp, it would certainly be a (good) tube amp.

Okay - the positive stuff
1* I think it was Rollie that pointed out that some of the finest hi-fi amps in the world use vacuum tubes, so I'll not repeat what he said already. He's right, but I'd say that MOST of them use tubes. There's reasons for that.

We use a similar design methodology in our acoustic amp - it's all about the signal quality. In an electric guitar tube amp, everything about the design contributes to shaping, coloring and distorting the sound in ways that are pleasing to our ears. Understanding those things means that we can avoid the stuff that would be considered nasty for acoustic guitars, while still benefiting from the acoustic qualities that only tubes can deliver.

As Edward said . . . " . . The "correct" tube amp for the acoustic guitarist has to be designed thusly from the get-go, . . . "
Well said.

Add some secret sauce in the cabinet/speaker design and you have an amp that will cause you to pick up and play your guitar for longer, and more frequently (that's what my customers tell me).

Because it's not cheap to make, we figured it needed to bring as much to the table in aesthetic appeal as it does in sound quality, giving it some 'collectability' value, like one of the fine guitars it would be married to.
Like I said - I know it's not everyone's ideal, so don't knock us for going out on a limb with what we believe is solid product that meets an unmet need (yes, it's a niche market, but we're happy to serve it).

The interest is growing rapidly, I'm happy to say, and we're totally pumped at the reaction we get from folks that try/buy them.
There's a really nice video of Al Petteway doing a demo if you'd like to check it out. http://www.youtube.com/watch?v=k4Wm0nl1tWk

Hopefully, this late night rambling will be received in the spirit in which it was given. I'm just offering a perspective & an explanation for why there's yet another piece of cool gear available for ACOUSTIC guitar enthusiasts. Maybe some of what I said is helpful in some way - I hope so. I don't intend to engage in arguments or respond to slams - but I'd sure welcome any good questions or fair comments.
Thanks!
Gerry Humphrey
I am sooo, sooo totally with you here Gerry. I've been posing similar"how come nobody makes an amp like this" posts here and other forums for some years now.

Here's the thing for me. If we take, as an example, ANY current acoustic guitar pickup system (K&K, LR Baggs, Fishman, PUTW, Highlander and the other 2 thousand entries on the market) each and every one of them represents a dramatic departure from what is actually a true acoustic guitar sound. It's just a fact it's no longer "my guitar only louder". That's an empty mantra. In virtually every case the pickup system departs from the actual sound of the guitar.

As an extension then to that thought, I have never understood the industry mindset that an acoustic amplifier must gravitate towards being deadly accurate clean. Like a mini PA. That somehow a pleasant sonic footprint from an amp (perhaps with tubes) is a no-no for acoustic guitarist. As if an LR Baggs Anthem is so organic that it must be amplified with the utmost accurate response. You can argue ss specs and cleanliness until the cows come home but why would you want a McIntosh amplifier to amplify your Baggs Element pickup? The result would be piezo bad, but loud and clean. Give me some harmonic content, some hair, some roundness. Something to tame the ills and round the edges of acoustic pickup systems. It doesn't mean distortion or at least distortion in the "electric guitar" sense.

I dunno, but for me it's hard to argue all of the current acoustic guitar pickup systems don't need a little (to a lot) of sonic help. I don't want my Fishman piezo to be dead balls accurate and loud.

I can't afford a Humphrey but if I could I'd be all over it. This seems like a tremendous leap in live, pickup equipped, acoustic guitar amplification. It also seems like something that could be mic'd to a larger PA if needed.

I want one!!

Gerry if you ever need someone to run around and demo your amp.......I'm your Huckleberry
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Thread Tools



All times are GMT -6. The time now is 12:38 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright ©2000 - 2018, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=