Yamaha G100 III Head

There are a few good feature descriptions for the G100-III combos which are far more accurate that those listed in the accompanying head reviews, so I suggest that you take a look at all the G100-III reviews, since they share all the features of the head.

As one of the combo reviewers stated, this is a jazz guitarist's dream. To use it with a bunch of effects would be a crime. As a jazz hobbiest, the features are more than adequate and the gain and presence controls, as well as the effects loop go unused.

For my purposes, the only missing feature is the inability to toggle the reverb on and off via a foot switch. This is somewhat inexplicable, as the available footswitch does channel switching, activates the parametric equalizer and the effects loop. BTW, the footswitch is proprietary, as it uses a single a single pair of conductors for all three functions.

This is what really matters. The clean on this amp is awesome. It's warm and clear while transmitting every nuance of attack. This amp doesn't hide anything. Changing picks or moving picking position up or down 1/2 inch is easily descerned. For clean, no tube amp I've heard holds anything over this. The gain channel's output just muddies the sound, at best. Consequently, I don't use it. Fortunately, the gain can be turned off to provide two clean, foot-switchable channels with independent volume and tone controls. The tone controls are very sensitive and give a wide range of control. The 12:00 position of the tone controls is flat. The min. position is 100% cut. If all three tone controls are set to their minimum position, there's no output. At max. the controls add considerable boost.

Both channels are very quiet, even the B channel with the gain turned up. By very quiet, I mean that you can barely hear any hiss with your ear to the speaker. With the volume at max and my guitar level turned very low, noise remains barely perceptable. (Raising the guitar volume doesn't add any noise, but after a fews seconds my hollow body's low-frequency feedback is deafening!)

I can't attest to behavior at high volumes, as I can wake the dead at 1/3 volume. Others have written that the clean doesn't break up at high volumes. I wouldn't believe them, simply because frequent use at max. volume would likely render the user close to deaf and unable to be any judge of sound quality.

The reverb was missing from my used purchase, but I was able to procure a new exact replacement Accutronics unit from sepi_group on Ebay for a good price. I couldn't determine where the original unit was mounted, and it took some effort to find a noiseless location and orientation, but the reverb is virtually noiseless at 50%, which is as high as I use it. The reverb is an Accutronics Type 4, same as a Fender Twin Reverb and can be used to add a touch of ambience without overwhelming the sound. In other words, the reverb is as good as a spring reverb can be.

I'm playing a Samick JZ3 (archtop w/2 humbuckers) driving an open cabinet (Lopo Line - good quality/value) with a single 15" Eminence Legend 1518 speaker. Amp tone controls are set flat with the parametric equalizer cutting bass response centered around 500Hz. Typically I use only the neck pickup with the tone rolled off or at 3-4 of 10. This gives a very rich, slightly dark but clear sound without too much bass (and feedback). Without the eq., the walls would be shaking, as I think this amp/cab would be at home with a bass guitar.

My tastes run to Wes Montgomery, Jim Hall, Joe Pass, Kenny Burrell, et. al., who use(d) Polytones, big tube Fenders and some very expensive boutique amps. The G100 can match them all and do it far more quietly.

I'm guessing that my unit is at least 20 years old. It's in pretty good cosmetic shape, but it has seen a fair share of travel. It was also pretty dirty, inside and out, but after cleaning the pots and vacuuming a lot of dust, I don't anticipate any future problems, because this thing is built like a brick sh*thouse! No sign of any cost-cutting shortcuts. It has a heatsink bigger than most amp chassis. Of course the downside of this is that it weighs about 40 lbs., which is OK with me, as it stays in one place. Anyway, 20 years with no problems seems qualify for a 10. Did I mention that it's solid state?

Tried to contact Yamaha twice via email to inquire about the availability of a footswitch. I never received a response, so support is almost totally non-existent. The user's manual is available at Yamaha's web site, which saves them from a rating of 1.

I was able to purchase a copy of an official repair manual on eBay, which is not great, but at least it had the Accutronics part number for the reverb I needed to replace.

Yamaha seems to have drastically reduced their amp offerings, so I suspect that factory authorized service will be hard to find, if I ever need it.

I gave up playing 35 years ago after about 15 years of playing, when I had to sell my stuff to help support my young family, and I've only gotten back to playing within the last year.

I spent a lot of time evaluating guitars, but far too little on amps, remembering that my old '62 Fender Vibro-something-or-another was cheap and more than adequate. I thought a cheap new Fender would be OK for my needs. That was a rude awakening! So was learning that the old Fender was worth about $750 in good condition, and for good reason, because there's little market for amps designed the jazz player. To make matters worse, the noise makers buy the great old jazz tube amps (although I see that they even buy Polytones) to use as overdriven distortion engines. What a waste!

The G100's seem to be the little-known, inexpensive, great performing amps every jazz player would like to find.

I would have preferred to have purchased a combo, because it's less expensive than going the head/cab route, but I kept losing bids. Figure that a 212 combo goes for $100 more than the head. A new cab, including shipping, will cost $200, and used ones are hard to find for less.

If it was stolen, I would certainly look for another.

80's SS head Yamaha stuff always had a good layout easy set up L-R 2 channels pull bright gain knobs Switchable FX and Parametric EQ

Same as the combo's just as a loose head, plenty of juice to annoy any sound tech or keep up with your fac bass players 4X10

Head version has a free rack size space at bottom for FX tuner etc

pretty much dial in any dound you want, I never worry about this thing letting me down in the winter

Solid state so I know the tube guys dont like it already, I have used a G100 and actually on a bass this sounds good too, with the 3 band EQ as opposed to the G versions parmetric It will pass through pretty much any stomp box in either pre head or in the effects loop set up

these things get a 10 from me simple circut design although a few techs told me its difficult to find equivalent transistors if you smoke it (same as any vintage yamaha)look at the reviews for the combo versions you'll see why I agree

Yamaha are good people also the manuals for most stuff are online now look for the Manual Library link in their site

this is the second one I had other was a B100 212 III and I also have a G100 115II reliable solid state

wont win you the tone war but for gigging you'll never have to worry about it especially in the winter just plug it in and go, decent buy for a 1st rig if your kids wanna play rock or if your gettin back into playing like I am , if you see one at a pawn shop or flea market you won't go wrong at < 150

also makes a decent KB amp in a pinch

Made in the 80's I think. It's 100 watts, separate distortion and clean channels with separate EQ, reverb, a special "scoop" parametric EQ, effects loop with send and return level controls, footswitch jack, balanced and unbalanced direct out, and two external speaker jacks. It also has a pass-through AC outlet so you can use the amp as an extension cord for your other amps or effects pedal adapters- that's proven useful quite a few times.

Usually played a Yamaha SG copy with dual humbuckers and a Big Muff Pi. This was for a hardcore/punk trio. It's an EXTREMELY loud amp, and produced very clear clean sounds. It has a parametric EQ that lets you carve out some interesting curves in your tone.

As for the distortion- just use your effects pedal. If you wanted to use the amp's distortion you'd buy a tube amp anyway.

No problems ever. Got bumped tipped and dropped many times at shows with no ill effects.

n/a- never tried. Wish yamaha kept more of their old manuals online though.

I've been playing for over 15 years. This amp was great for me when I needed volume and didn't have a lot of money, and if I was doing primarily clean or heavily saturated metal sounds I'd probably still be using it today.