Dynaco ss 80 Amp

I have a Dynaco solid state 80 watt power amp made in 1970. It plays well, very clear sound. However, the low end sounds weak. I cannot see any bulging on the large capacitors inside. Is there anything that can be done to this amp to give a little more "oomph" to the low end? I realize these are not poplular amps. Thank You For Your Help.
I've got one too, a Dynaco SCA-80Q -- I've had it for years, and like it. A few questions / suggestions:
1) If you usually play the amp at low volume, have you tried turning the Loudness swith on? It's the rocker switch just under the Volume knob. When activated, it boosts the low bass and high treble contours somewhat, to compensate for the fact that, at low volume, most people don't hear low and high frequencies as well as middle frequencies.
2) Have you tried turning the bass knob up, the treble knob down, and the volume knob up? Maybe using the tone controls will be enough to get the sound the way you want it.
3) Have you had the amp for a long time, and noticed recently that the sound in the bass end is getting weaker than you remember? Sometimes the filter capacitors on older amps dry out and need to be replaced. If this is the problem, you need to find a good repair shop which can handle vintage equipment. Maybe Curcio Audio Engineering could help -- check out www.curcioaudio.com. Or did you buy the amp recently, and just notice after listening for a while that the bass didn't sound as heavy as you expected? If this is the case, maybe you're just not used to the neutral sound of this amp.
4) What speakers are you playing it through, where are they positioned in your room, and are you using a self-powered subwoofer? If you're using small bookshelf speakers (6.5" woofer or smaller), if they're located up off the floor and away from the wall, and if you don't have a subwoofer, you're probably going to get bass-shy sound no matter what amp you use. Before you give up on the amp, try moving your existing speakers lower and closer to the floor; back toward the wall, rather than out in the room; and into the corners of your room, rather than in the middle of the wall. You might also try buying somewhat louder speakers, or tower speakers, or a self-powered subwoofer.
I hope that some of this helps you to figure out how to get the amp and your system to sound the way you want. The Dynaco SCA-80 is a good piece of equipment which should serve you well if it's in good condition and used with an understanding of the various factors which can affect the sound of your system as a whole.
PS -- if you want more info, try this web site: http://home.indy.net/~gregdunn/dynaco/components/SCA80/index
Thanks for the response, Pete. Yes, I have the loudness switch on,on the PAT4 preamp. I haven't had the amp very long so I have noticed no changes in the sound. I am not looking for booming bass, just realistic hifi bass. I am comparing the Dynaco amp to the Technics amp I have. The techics seems to put out the right amount of bass, whereas the Dynaco seems weak. This is under all of the same conditions, speakers, room placement, media, etc. I have been told the 5000uf 80v output caps increase in impedance as they age. They can be replaced by 4700uf 100v snap-in caps. I cannot find these anywhere so far. I am told that these caps will usually clear up the weak bass problem. Maybe someone on the forum has a source for these. Oh, I forgot to mention the Dynaco sounds better on the mid and high end than the Technics does. Thanks Again.