Impedance Question?

toddverrone554 posts09-29-2017 11:50amQuick and dirty answer: you want the amp to have an input impedance at least 10x the output impedance of the pre.

This is a good simple answer.

Cheers George

Others have had issues regarding impedance. If the amplifier input impedance is 10k, it is really only suitable to match to a solid-state preamp. With a tube preamp, it can work, but you may start to see weak bass/midbass (among other issues). Look for a higher impedance amplifier. For example, the Parasound A21 has input impedance of 33k for RCA and 66k for balanced. I have seen other amps with input impedance of even 100k or 200k.

So I had this 10k (Symphonic Line RG1) hooked to a Cary (SLP-03) 500ohm and yea I lost some bass/midbass for sure and couldn’t figure it out. However I’ve heard the SL hooked to a SLP-98 (800ohm) and it sounded way better, So I’m trying to match a pre with this amp and need all the help I can get.

Would a pre that has 600ohm -<1Kohm be safe to match?

And right now I'm using a pre that has 100-300ohm and can't figure out which is sounding better.....LOL  This damn hobby can drive me nuts at times but I still love it!

Thank you all for your help BTW!

Ben

Not all preamps that have equal output impedance specs, say 600 ohms, have the same impedance across the frequency band, and often much higher at the lower (bass) frequencies. The result would be a loss of mid/low bass with those having this condition when paired with an amp having low input impedance. 

To mate a preamp with a 10K input impedance amp one would need to know the output impedance of the preamp across the frequency range. 

OK so I got an email back from Rolf at SL and he suggest staying 100-300ohm.

Cary says that on the SLP-98 in the manual 800 but on the item page it says 440. LOL