Rolls PM351

[donchampo]

I just bought a Rolls PM351 and I get heavy instrument distortion with my Sennheiser HD380’s and HD280’s. Every other pair of headphones I tried work fine but none are as comfortable. What’s really weird is the Sennheisers work fine with a Rolls PM350 that I borrowed to try out. I called Rolls and the person I talked to had no solution. He said it must be a impedance mismatch. Any thoughts?

 

[frankie5string]

What are you using to power it?
I have it's brother the pm55p (version with the limiter) and you can drive it with as little as a 9v battery, but it works best with a little extra voltage - yours will take up to 16 volts DC. It could be that those Sennheisers just need more power to be driven at a volume you like.

 

[donchampo]

What are you using to power it?
I have it's brother the pm55p (version with the limiter) and you can drive it with as little as a 9v battery, but it works best with a little extra voltage - yours will take up to 16 volts DC. It could be that those Sennheisers just need more power to be driven at a volume you like.

I’m using the power supply that came with it. 15V. I tried a 9V supply and had the same results.

 

[lildrgn]

Assuming you're not overdriving it with too hot an input from the bass? Have you tried another bass? I bought one of these a few years ago but stopped using it as I have a focusrite that does the same thing. However, just started bringing it to band practice (we are using headphones all the way around) and have found it semi-useful. All 5 band members share the same headphone mix, so the Rolls sort of helps, but I have never had distortion.