Harley Benton GPA-100

Was searching for a discreetly-sized, emergency back-up power amp in case my live rig died on the road. It can (and does) happen and can be a gateway to a realm of nightmares.

The price initially made made laugh, but when something is that cheap you really have nothing to lose so I took a gamble. Believe me, I won.

A solid unit with metal chassis, incredibly simple to use, and thankfully NO WALL-WART.

The sound is transparent enough in a serious live situation for no-one, not even you, to notice you're essentially playing by the grace of a glossy, black brick...unless you want to mess with the provided low-mid-treble dials which can certainly add some character. I leave them at 12 and dial on my pre-amp though.

Anyone who says this runs "quiet" is using it wrong, or needs a hearing aid: it easily keeps up with my Mesa Boogie Roadster. Read the instructions.

As it stands, I am considering ditching my over-priced, over-weight valve amps to use this exclusively on the road. I could carry an extra 3 in a tote bag and keep my back, wallet and pride intact when the "real" thing fails.

Beyond impressed. I'm going to buy a couple more eventually.

I have practiced 3 musical instruments for 30 years....owned tons of gear.

PROS:

1. The value is incredible. This is a 190 watts power amp that fits in your hand. This is a similar design to the Seymour Duncan Powerstage, at a fraction of the price! I have other Harley Benton gear, one isolated power supply and one attenuator. All this Harley Benton gear exceeded my expectations, this is THE best lower cost, professional gear you can buy.

2. This is PERFECT for tube preamps or hardware amp sims. As oppose as other designs such as tube power amp, which colours the sound, which now I do NOT like anymore, the GPA is a class D power amp. Basically, this is a HI-FI power amp for your preamps. You do NOT want class A or class AB power amp for your Pod, if you want the power amp to reproduce EXACTLY the tone you hear in your Pod when you use it with headphones.

In the past I swore by tube power amps....now I do not! I STILL use ONLY tube preamps (not Pod or amp sims) but I am definitely a class D power amp convert. I do NOT want the power amp to colour my preamp. This is an old debate with tube amp guitarists. What happens with a tube power amp is that as you increase the volume, the bass and treble will roll off, and the mids will increase. But today I do NOT want this anymore. Today I want BASS, a modern metal tone. I don't want the bass to roll off! I want the power amp to reproduce EXACTLY the same tone, at ANY volume. THIS is what Class D power amps such as the Harley Benton will do. Also, a tube power amp will distort sooner. Why? Because tube power amps are more expensive, therefore it means less power for the money. But class D doesn't have this problem: Class D watts are far cheaper, which means you get more power, which means more HEADROOM, and so the power amp stays clean. Plus, it is a FAR MORE efficient form of amplification. Almost 200 watts in your hand! With class A or class AB whether tube OR transistor, this would result in much bigger and heavier gear (you need bigger components than class D), etc etc, and this adds to the WEIGHT and the COST. This is why class D power amps cost less. But 75 euros for 190 watts rms? Incredible.

3. The GPA has a powerful ACTIVE eq. So you can add as much bass, mids or treble as you want, AND you can also CUT these frequencies, which you cannot do with PASSIVE tone controls, found on MANY power amps that are a LOT more expensive than the GPA. So basically the GPA is the PERFECT power amp. Some people lamented the fact that the GPA doesn't have resonance control. But ALL power amps have resonance, in the GPA it is just fixed. BUT there's ACTIVE bass control, which is BETTER than resonance control, which is PASSIVE and thus weaker. The bass in the GPA can take your head off, but it doesn't get boomy. Also the treble doesn't get harsh. This works PERFECTLY with my tube preamps.

The GPA will NOT sound inferior to the Seymour Duncan. And it's made solidly, of metal. This is not some cheap Chinese rubbish. The GPA is perfect for pros too....you don't always have to buy famous brands. Frankly you'd have to be dumb to prefer the Seymour Duncan Powerstage to the Harley Benton GPA 100! They both do the same things!

4. the GPA will tell you if the preamp output is too loud and distorting the input of the GPA. It also has a protection circuit in case of impedance mismatches at very high volume. But if you use correct impedances, it will probably last a long time, like any quality gear.

5. With my Blackstar HT Metal tube preamp my setup is pretty much NOISELESS, even with Ultra gain! I usually use noise gates, but I don't need it now. Just incredible! And the tone is amazing!

CONS: Absolutely NONE. A tube power amp does NOT sound better to me, only a tube PREAMP sounds better than non-tube preamps. I have made extensive tests in the past, for example I tested my tube preamp into a tube power amp and a solid state power amp, and the tube power amp did NOT sound better. But both tube power amp and solid state power amps WILL colour the tone and compress it at HIGHER volume. Because they are all class A or AB. But Class D, as used by the GPA , is MUCH more transparent than class A or AB. Like I said, basically a HI-FI power amp for guitarists. In my case, this is EXACTLY what I want. But the other advantages, such as ridiculous price and size and weight, are huge bonuses of course. Class D power amps are the BEST! (If you have a great preamp!).

So be smart and BUY the GPA!



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update: after getting an old hughes kettner ats60, and comparing class D such as the Harley Benton, with the 'current feedback' solid state class AB of Hughes & Kettner, and plugging same preamps used with the Harley Benton, into the Hughes Kettner power amp through the Return, I must say I am shocked.! The HK adds a sort of meatiness and character that class D does not have. In short, if you want a hi fi power amp, low cost and low weight, get the Harley Benton. If you want the power amp to add tone and character, you need class AB solid state or tube.

This is my single review covering 2 specific Harley Benton bits of gear:
: the GPA-100 (~100W class D power amp)
: the G112 (1x12 Cab)
.. plus I have a whole bunch of HB guitars .. my current fave is an ST-25TH Firemist ‘Strat’ (another fantastic HB product from Thomann!)

So I’ve mainly been a valve amp plus pedals guy since forever (i.e. since 1978 with several Marshalls & Peaveys over that time); then, relatively recently, I went ‘digital’ by changing my amp to a very nice Blackstar ID:260 TVP 2x12 modelling combo .. but .. the price I’ve always paid during any gig for having this typical Amp+pedals set-up is :
A) time (setting up & breaking down all my pedals during a gig either with or without the use of a pedalboard or MIDI)
B) my poor old aching back (due to the weight of such amps; and they only get heavier as you get older!)

So, for Christmas, I treated myself one of these new-fangled floor ‘multi-FX’ units everyone talks about these days … in my case, a NU-X Trident (due to it being the right price = cheap; and having plenty of foot-switches for use live with my band). The Trident certainly helped with replacing all my pedals & I was pleasantly surprised with how good it sounds when running in 4-cable method through my old Marshall 25th Anniversary 25/50 1x12 combo … but that amp is still quite heavy to lug around (never mind the fact that it is now worth a few bob so somewhat risky to take out on the road!).

Hence, I’ve been looking for an alternative amp set-up to use live with the Trident, that meets my needs & budget. After looking into the many possible (& expensive!!) amp solutions out there, I came across Harly Benton’s GPA-100 & G112 listed on Thomann … for just .. How Much!!!!!! … a total of £145!! … so, at that price, certainly worth a punt!!
I was a little concerned if the GPA-100 would be loud enough for my band’s typical gig level as several players in-the-know have reported it to be perhaps somewhat lacking in volume. However, when tested at home though the G112 up against my Marshall, in 25W mode, the GA-100 showed itself to be very capable (at least in my back room).

I had my 1st gig (at a medium size club) with this new set-up last Saturday => ST-25TH Firemist -> NU-X Trident -> GPA-100 -> G112 (yes, I know, I’ve become a bit of a HB fan-boy 😊 ).
It was just BRILLIANT!!
I am very pleased with the sound I got from this set-up. I was like a kid a Christmas & could not stop smiling though the whole gig. Plus setting up & breaking down my gear was a total doddle …in fact, it was the 1st time I’ve ever beaten the bass player when packing up our gear after the gig.

The amp weighs literally nothing & the cab not much more than that .. my old back said thank very much you all the way home after the gig!!
Ok, I might tweak some of the sound patches that I’ve set-up on my Trident a touch but with regard to the GPA-100/G112 I’m 100% happy.
And yes, the GPA-100/G112 ‘combo’ was plenty loud enough even with the G112 sat right next to our drummer; it certainly coped very well in the mix with the Drums & back-line Bass/Keyboard amps (note: only our vocals go through our PA)

So I heartily recommend both the GPA-100 amp and/or G112 cab for anyone looking for a bargain but perfect solution for making some noise with their, otherwise silent, guitar multi-effects unit that they also might have got for Christmas 😉
This is also a great solution for home use as the output of the GPA-100 stays consistent throughout its full range from a whisper to a roar.
I say, forget those other more expensive bits of gear that are appearing on the market these days for use with multi-FX such as FRFR combos & the like … the GPA-100/G112 ‘combo’ is IMHO a perfect & terrific bargain solution.
OK, yes, it’s early days for my use of both items so I can’t talk to their reliability but from the hardware reviews I’ve seen there is nothing but good reports in that regard.

PROs:
GPA-100: light-weigh; Clean, powerful sound output with no colouration & includes a peak level indicator for peace of mind & during set-up; handy & effective EQ (if needed); crazily inexpensive!
G112: light-weight; open back for wide sound distribution, Nice sound IMO (might even sound better once ‘broken in’ as folks talk about); looks attractive & really quite nicely finished; crazily inexpensive too!

CONs:
GPA-100: none that I can think of .. apart from not containing any valves … if that counts for you.
G112: none that I can think of … apart from not containing a well know brand/type of speaker .. if that counts for you.

At first I wasn't convinced to the idea. Just wanted to test and see what the hype is all about.

My concern was about bass+mid+treble EQ - instead of traditional depth/resonance + presence that power amp suppose to have

So treble is acting 100% like the presence in my Randall RM100, it works in frequencies of presence, not treble.
Bass isn't a traditional depth/resonance or it's waay more sensitive. You can completely shake your cab or remove the low-end. It's super cool.
Mid can almost turn your G12T75 speakers into V30's or you can scoop your amp to that early Scott Burns death metal sound.

Turn up mids in preamp and cut them in GPA-100 or vice versa, cut in preamp and crank up in GPA-100. It's another cool feature and extra tonal possibility.

I'm going to buy second GPA-100 to make dual amp rig!

I have no idea if it's loud or not - tested it only in bedroom volumes, read other opinions.

I pre-ordered this one and I was waiting about 3 months to receive it.
Luckily I got it before Christmas :-). Paid 79 pounds delivered. Now I see Thoman sells it for 58 !!!!!!!!!!!!!!!
I use it with MOOER GE300 LITE and two fully packed with analog and digital toys pedalboards.
As soon as I received it I looked inside the unit. Pretty good components you can find inside but cheap pots.
Everything works amazingly well. I use 20dB Spark mini booster between Mooer and GPA-100 to get maximum of it. Mooer sends low volume signal so Spark works with full boost when Mooer's volume is reduced. Everything is very loud and almost no unwanted noise that way. This is cheap stuff I know but f... hell it works great and has 3 years warranty :-). I do not think about Seymour Duncan power amps anymore which are totally overpriced.