[beyermann]

The G109-P definitely isn't underpowered for a DT770 600 Ohm. By Far.

But how about the g103-p tho? that's the one im aiming at. Will it have a neutral sound too? like supposedly the g109-p has. Someone said that the g109-p has a neutral sound compared to the Schiitt ones.

Also will the g103-p be underpowered for a DT770 600 ohm in default jumper status? I was worried that if I didn't change the jumper I wouldn't get the best of it.

I have looked at your picture and I don't really get it. I thought it was going to be just a single jumper with 3 low med high settings and high was for 600 ohm+ lol

 

[Fegefeuer]

it follows the same philosophy, it will of course not sound as good as the G109-P but power-wise it has more headroom than your ears could take in a span of a few seconds before you get deaf.

• Max. output level: > 17.8 Veff in 600 ohms = 530 mW > 16.0 Veff in 300 ohms = 850 mW > 13.7 Veff in 200 ohms = 940 mW > 7.5 Veff in 50 ohms = 1130 mW > 3.7 Veff in 16 ohms = 890 mW

Let's see what your DT700 600 needs:

Listening Loudness Voltage Needed Current Needed Power Needed
Safe 85 dB SPL 0.2 Vrms 0.33 mA 0.07 mW
Moderate 100 dB SPL 1.12 Vrms 1.87 mA 2.09 mW
Fairly Loud 110 dB SPL 3.55 Vrms 5.92 mA 21 mW
Very Loud 115 dB SPL 6.31 Vrms 10.52 mA 66.36 mW
Painful 120 dB SPL 11.22 Vrms 18.7 mA 209.81 mW

As you can see: at 209,81mW you are already dead.

 

[beyermann]

it follows the same philosophy, it will of course not sound as good as the G109-P but power-wise it has more headroom than your ears could take in a span of a few seconds before you get deaf.

• Max. output level: > 17.8 Veff in 600 ohms = 530 mW > 16.0 Veff in 300 ohms = 850 mW > 13.7 Veff in 200 ohms = 940 mW > 7.5 Veff in 50 ohms = 1130 mW > 3.7 Veff in 16 ohms = 890 mW

Let's see what your DT700 600 needs:

Listening Loudness Voltage Needed Current Needed Power Needed
Safe 85 dB SPL 0.2 Vrms 0.33 mA 0.07 mW
Moderate 100 dB SPL 1.12 Vrms 1.87 mA 2.09 mW
Fairly Loud 110 dB SPL 3.55 Vrms 5.92 mA 21 mW
Very Loud 115 dB SPL 6.31 Vrms 10.52 mA 66.36 mW
Painful 120 dB SPL 11.22 Vrms 18.7 mA 209.81 mW

As you can see: at 209,81mW you are already dead.

Ah I get it, however don't these values change depending on the position of the jumper? these numbers is with the default setup?

Also have you A/B g103p vs g109p? This guy A/B them and said sound wise he couldn't spot much difference:

Good news - the G109-S arrived today and so I have both amps set up side-by-side now.

My setup is iMac -> USB -> Bel Canto DAC 1.5 -> XLR to G103-P / RCA to G109-S.
Headphones tested are Denon D2000, Hifiman HE-4 and Sennheiser HD800.

The quick summary is that both amps are truly excellent and my previous impressions of the G103 hold true for the G109 - I can't hear an audible difference between them.
The most significant difference, other than the wider form factor of the G109 is the volume knob and ALPS RK 27 pot. The knob on the 103 moves smoothly, feels great and has no obvious low level imbalance. The 109's more expensive pot features a larger dial and moves in small steps, rather than moving smoothly (although it is not a stepped attenuator). This feels even more kinaesthetic and is a real pleasure to use.
I chose to change the gain jumpers from the stock middle setting to the higher gain on the 109. This has resulted in average listening position of 12 o'clock with the HE-4's and just past 11 with the HD800's. For anyone wondering whether these amps can drive orthos, rest assured, they are more than up to the job!

So which to keep? In all honesty, I would be quite happy with either. I suspect that I will probably hang on to the G109, if only for the volume knob and to keep the upgrade OCD at bay.

Also, how can I calculate that it's safe to plug two pars at once? it's safe to say that I shouldn't plug my DT770 600 ohm along with my good ol pk2 earbuds right? pk2 could die?

 

[kvik]

G103-P has 4 gain settings, you'll find the manual here.

It's factory set to +8 dB, so in relative terms the settings are -12/-6/0/+6 dB, and in absolute terms -4/+2/+8/+14 dB.

 

[forestitalia]

Funny review that.

I would recommend reading the manual first and than compare.
So Z would have known that on G109 there are 3 different gain settings,
that the figures for the output power are per channel,
that provisions are made so amp will not explode.

But, if you connect a very sensitive headphone to one socket and a very hard to drive headphone to the other ...
than listen to the hard to drive headphone with high levels ... it may be that you will cook the high sensitive headphone meanwhile ...

Sorry, our gear is not dummy-proof under any circumstances.
Remembers me of the cat in the microwave, the Starbucks labeling on the coffee mug: hot beverage,
and, best of all: Objects in the rear view mirror may be closer than they appear.
There is always a gaggle of attorneys hunting you when you are a manufacturer.

Well, to come back to the point again:
We´ve employed high efficient current limiters and other measures to avoid "explosions" or "flames".
Everything on the "life" side of our gear, power socket, cables, fuse, transformer, power switch, PCB, is made to UL specifications.
Like every responsible manufacturer will do. https://www.ul.com/

With heavy improper use it may be that something will break inside - but for those cases we have a fuse to cut mains.

Best regards, Fried Reim

Funny explanation rather..