Harman Kardon - AVR20 or AVR25II?

25II has more power, dedicated subwoofer out, a few extra features like additional video switching and binding posts for all speakers. Google them and you will find the manuals at H/K support website.

I would prefer the 25II just because it has the sub outs, but I think you have to go by the quality of the used item here. These are older units now, beware the ones that have been abused/overheated.

Both have good amplifier sections and will drive almost any speaker you can throw at them.

I have a 25II I bought new back in the day. The center channel amp died last year, first problem it ever had. I bought a secondhand model for parts from local seller and replaced the amp myself.

Mine still sounds great! We have it driving a set of old Energy E:XL speakers for home theater use. We used to drive a pair of Advent Heritage speakers with it (difficult for some receivers to drive due to low impedance), it never had a problem with those.

Of course, these have no HDMI so you only get pro-logic from them...

Good luck with your purchase.

The 325 is about 8-9 years old IIRC. Thats the newest of the ones you are asking about I think - not quite sure but the other two look quite old by comparison. If the 325 in good shape it should be fine for what you want to do. Its amp is very similar in specs to the AVR 520 I owned for many years. Great sounding AVR but antiquated video switching - no HDMI. Sound was very good. It should be able to drive any speaker you want short of planars.

I agree with Knucklehead90 - in the used market, a newer unit with potentially less hours on it could be a better deal.

I'm assuming you are finding these on local lists where the pictures are really poor to look at - don't be afraid to ask for better pictures by email. Usually if a unit looks well cared for it means it was "adult driven" as opposed to "college dorm life".

Also ask if it was used in a smoking environment - if you don't smoke, items from smoking environments get a funky smell thats really hard to get rid of.

I have a HK AVR-325 and I love it. Definitely a little long in the tooth but very stable and powerful. This baby weighs 40lbs with a large power supply! Should have no problem driving most speakers. I use mine every day in my office.

The only nitpicks are that it takes a second or two to lock onto a digital audio signal (optical or coax). The remote is just okay, nothing special. And you have to connect a composite or s-video cable to setup the On Screen Display and speaker/input configs.

I love the flexiblity of the inputs, crossovers settings, etc. One of the only brand receivers where you setup the DVD input for 7.1 but have the tuner or video input only setup for 5.1. Each input can have its own channel level adjustments too. Its very configurable but can get confusing if you don't know what you're doing. I'd advise a newbie to go with global settings.

I would definitely take the 325 over those much older HK receivers.

I have my DirecTV HD receiver plugged in via optical and my PC just using the stereo analog inputs. Both work very well. I plug in my Droid every once in a while using the mini plug to stereo RCA cable.

The AVR20 & 25 II were made by Inkel (Sherwood) for Harman/Kardon and are about 15 years old... Good in their day but dated..
The mentioned AVR 325 is later and has many more features and upgraded DSP including 7 channels of amplification, bass manager, Logic 7 and later Codecs than the 20/25 II including DTS..

Just my $0.02...