[KonstantinT]

Hello,
being a Vinyl Enthusiast I prefer older amps with well sounding phono Inputs. Currently I own and enjoy an Arcam Delta 60 with 2x55W form the late 1980ies.
My Sennheiser HD580 sounds very well out of the Arcam´s phones jack. But the AKG K500 sounds thin and bloodless. I know, like many AKG types the K500 is difficult to drive. But in the past it sounded much better connected to a Yamaha C60 preamplifier.
In the Arcam owners Manual there is no Information about the Output impedance of the headphones jack. Does anyone know about it? If it's high, I would try to replace some resistors by lower ohm rated ones, hoping it would increase the phones output power and make it more suitable for low-z headphones.
Is there a way to measure this value?
Thank you in advance for your help!
Konstantin

 

[KonstantinT]

Hi,
I found a schematic of the circuit. It seems there are 330 ohms resistors in line with the phones output. I will replace them with 100 or less.
Konstantin

 

[Baxide]

As long as you realize that the voltage across the headphones will increase. My bet is that if you change it to 100 Ohms or less the voice coils on your headphones will fry before dawn.