CD player - power amplifier direct connection


Hi,

I connect my old Sennheiser HD 530 II headphones (nominal impedance: 300 Ω, sensitivity at 1kHz: 94 db, power handling capacity: 200 mW) directly to the output RCAs of my CD/DVD/Blu-ray players via an adapter, as these players have not the headphones output. I cannot change the volume, but I find that it is always very good with both CDs and DVDs/BDs. By this minimal setting, I find that the headphones performance is very good.

I would like to try the direct connection between my Proceed PCD3 CD player and my Jeff Rowland Model One power amplifier by the use of balanced cables, so as to avoid the preamplifier device and - I imagine - to obtain higher performance from my ML Aerius. My Proceed CD player has not a volume control (I know that CD-player integrated volume controls commonly show very poor quality), but I presumed that, as for headphones, it would always be quite optimal (I have not audio volume problems in my house).

Some audio experts, however, have told me that this test would be very dangerous for the security of my system, but they have not clarified why...

May someone help me to understand the problem?

Thank you very much.

Luca
luca58
Don't do it!

Based on a quick look at the specs, it appears that on high volume musical peaks the voltage sent into the amplifier by the PCD3 would be approximately twice as much as the voltage that is required to drive the amplifier to its maximum power capability. In other words, the amplifier's output would be severely clipped and distorted on those peaks, not to mention that the volume level would undoubtedly be extremely excessive. The results could include damage to the speakers (clipped waveforms tend to destroy tweeters, because they have much greater high frequency content than the original signal), as well as damage to the amplifier and your ears.

The relevant specs (CD player output voltage and amplifier input sensitivity), btw, are in the same general ballpark for most other players and amplifiers as well.

Regards,
-- Al
Listen to Al.
but if you re determined to try this out, you could consider the Bolero approach. As most any American male of a certain age knows, Bolero starts at a very low level and gradually builds, so you can shut it down before it destroys your tweeters or your ears. But...listen to Al.
This is where the quality of a very good preamplifier comes into play. While auditioning different models, select a few very minimal models (with as few "features" as possible) to test. Insert each one between your current CD/DVD player and Sennheiser headphones first to hear how much, if any, difference you hear when you adjust volume. The one that changes the sound the least is the one you want. Use that one between the PCD3 and amp to manage the volume. This is going to take a bit of trial and error, but should help you find a very good model for your system.