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Solid State Amplifiers => Guitar News => Topic started by: joecool85 on September 29, 2020, 08:46:45 PM

Title: More class D love - GPA-100 from Harley Benton
Post by: joecool85 on September 29, 2020, 08:46:45 PM
Harley Benton has just released the GPA-100, a 210w (at 4 ohm) class D amp that can fit in your pocket.  For $77 you get a three band eq and a master volume.  While I don't have any experience with the brand, for the money, I'd honestly give it a try!

https://www.gearnews.com/harley-benton-gpa-100-a-100-watt-power-amp-in-a-pedal-sized-enclosure/

https://harleybenton.com/product/gpa-100/
Title: Re: More class D love - GPA-100 from Harley Benton
Post by: tonyharker on September 30, 2020, 03:39:53 PM
Something odd about this amp. The blurb here https://www.thomann.de/gb/harley_benton_gpa_100.htm says '130 watts into 8 ohms or 210 watts into 4 ohms,' however the rear of the amp shows the power consumption - 230 v ~50Hz 0.6A which equals 138w . So how can you get 210 watts from a 138w supply >>100% efficiency. Even 130w from 138w is 94% just about achievable for Class D amplification.
Title: Re: More class D love - GPA-100 from Harley Benton
Post by: joecool85 on October 01, 2020, 03:22:45 PM
Something odd about this amp. The blurb here https://www.thomann.de/gb/harley_benton_gpa_100.htm says '130 watts into 8 ohms or 210 watts into 4 ohms,' however the rear of the amp shows the power consumption - 230 v ~50Hz 0.6A which equals 138w . So how can you get 210 watts from a 138w supply >>100% efficiency. Even 130w from 138w is 94% just about achievable for Class D amplification.

My guess is that because the 210 watts at 4 ohms is only a peak rating, the PSU can supply it for a few ms, maybe even a few hundred ms.  Nominal RMS wattage will be roughly half that most likely, settling in at around 100 watts.  Assuming that is the case, that would be well within the limits of Class D amps.

That said, it would probably benefit from a larger PSU...or simply not driving it to the max.
Title: Re: More class D love - GPA-100 from Harley Benton
Post by: g1 on October 02, 2020, 12:05:41 PM
I'm not sure what the rules are regarding the power consumption labelling.
I'm not sure that 240V .6A marking is necessarily maximum.  Could be average or nominal etc.
I bet it's fused at something bigger than .6A ?
And further to the confusion, the spec sheet says 100W into 8, 190W into 4 ohms. 
 ???
Title: Re: More class D love - GPA-100 from Harley Benton
Post by: flester on October 18, 2020, 02:41:28 PM
its a bit like '0-60 mph in 4 seconds'. But either way, even let's say 100W from a little brick would make this very useful. A few pedals in front and Robert is the sibling of your parent,

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