The SAE 2200 amp is a real sleeper. It comes over as a smallish amp with it's compact size, but it sure has the capability to deliver some very large sound. The 2200 was designed to be 100w per channel with very low distortion, operating without current limiting at 4 ohms loads and greater. While a good number of amplifiers have since come and gone, the 2200 seems to be enduring and still has it's place. I think there's a little mystery to this model too since not a lot has been said about it, but the popularity is apparent since there's a gazillion of them around and they always seem to sell well. But, the amp had it's weakness and many ended up in repair shops along with other amps of that period. This would have been due to the usage of parts that simply did not hold up, as well as engineering technique that didn't either. Well, parts were what they were and manufacturers used what was available. I think SAE in general tried using what was best, but unfortunately some of the parts still came up short when pushed hard. The 2200 seems to exemplify this borderline condition.

Some history:

The main weakness of this amp was the limiter circuit and output devices, on which SAE did issue a service bulletin. The stock circuit let the output devices work too hard, which in turn were not designed for the large amp that people wanted it to be by overdriving. These devices were not of the same capability that today's output devices have, so the two factors kind of worked together in allowing the amp to break down and end up in a repair shop, or left to gather dust. Sadly, this was occuring about the time that service shops in general were in decline and disappearing. People were no longer willing to spend the money it took for a fix. If that wasn't enough, it would be a few more years until better semiconductors appeared. The 2200 amp did not see this and production ceased.

Now, its' main strengths seem to outweigh any weakness, which is why it sounded pretty good for the time and enjoyed a period of popularity that gave us so many that are available today. First, the amp is unique with it's truly symmetrical design, complete with matched parts. This symmetry was built-in for a reason that SAE had in mind, and that was to achieve a more natural and organic low distortion circuit. However, they took the approach a step further and used this symmetry to full advantage knowing that it would promote a vastly reduced output DC offset level. They followed up the overall design with a symmetric and even slightly advanced feedback network that would finish the approach and yield a vanishly low DC offset null. No custom tweaking or special attention needed. Sounds minor, but it's an issue with all audio amplifiers and one I deal with all the time. It's to be appreciated.

Another strength that presents itself to me is the PCB layout and grounding. I fight this like a screaming banshee in other amps with all the rewiring that I have to do, but not so with the 2200. It's already built in and there's not much to be done except for a couple tweaks to make things perfect. I like this too, as it's a byproduct of the symmtrical approach.

Yet another strength the 2200 has is plenty of heatsinking. This is not apparent without first looking closely seeing how the amp is assembled. The heatsink on which each transistor is mounted is not bad at all. Not gigantic, not skimpy, but sizeable. The heatsink assembly is in turn mated to the chassis top and bottom cover, also made of aluminum, turning the amp into one big heatsink. One doesn't see this in many amps at all, but the 2200's fabrication provides a neat fit and pulls it off. I think it's impressive. These main strengths are why I think this amp is pretty cool, smart, and can sound better than it has any business sounding. I don't know why more amps don't follow some of the leads the 2200 has set.

Rebuild:

My rebuild corrects and improves the weak point and enhances the rest of what's already there. The amp gets cleaned up with better parts and some advanced power wiring, along with circuit board tweaks that lift the sound up several notches.

Here's what's included:

- All upgrades and adjustments as per the latest SAE service bulletins. This includes upgrading the limiter circuit. This circuit will usually be blown along with the output section in a damaged amp.

- New Onsemi (Motorola) MJxxx series output transistors are used, which are more powerful than the stock devices and just an all-around better device, at least from a spec standpoint. They will also be better able to take advantage of the sizeable heatsinking the older devices were never able to take advantage of.

- New driver transistors (also by Onsemi), which are also superior to stock both in power handling and performance. The drivers are often blown along with the output devices in damaged amps, so will need replacing anyway.

- All transistors heatsunk with costlier silicone-free compound and new mica insulator pads. Silicone-free compound should be appreciated here because it won't dry out like conventional paste and creep all over the circuit years down the road, thus adding to the dust collecting problem. It is possible to damage a circuit given time from a dirty environment - (dust is everywhere). These more expensive compounds usually contain more oxide particles too for more effective heat transfer, and are just a better overall grade.

- The output emitter resistors are upgraded from the cheap wirewound sandcasted units to new, noninductive power ones. This is significant because all the current going to the load must go through these, so accuracy is a must. These are as important as the cabling one uses.

- New power supply caps - I use what I believe to be the best performers available for the main p.s. caps. I can say they are not any hyped audiophile brand, or advertised as such, but are a current industry standard by an industry leader. You just have to know what to look for. The rest of the caps on the p.s. board have to do with the output relay's delayed turnon and DC offset protection. These are swapped out as well.

- Soft, but fast recovery power supply diodes. These are a much improved version over the stock units. The other diodes on the p.s. board are upgraded as well.

- 100% PCB electrolytic recapping, also much better than stock. All caps are of the same brand and type, so as to achieve a more coherent sound with less "cap confusion". These caps are clean sounding and among the best I know of.

- The PCB compensating caps are upgraded, and will help clean up the sound. The stock units are a cheaper ceramic and polyester combination, replaced with NPO/COG ceramics and polystryrene. The higher frequencies are affected here and smoothed out, getting rid of that harshness and irritating fatigue often found in higher resolution systems. This makes the amp enjoyable by injecting some life into the music.

- The bias tracking circuit is overhauled with a new potentiometer of much better quality. The stock unit deteriorates over time because it's an open frame type, and the wiper and resistive element are exposed and tarnish over time. I have no data or proof how the unit performs during this deteriorating process, but I suspect that it will influence bias tracking and idle level to some degree. I also suspect this can't be good. Should a pot actually fail, it could be responsible for blowing an output section. The stock pot is still commercially available, but I elect to replace it with a hermetically sealed pot just like the big boys use. It should stand up to time much better and hold a tighter tolerance too.

- The LED circuitry caps are replaced with the same type of caps used on the PCB. This can vary depending on the version of LED board, but an attempt is made to keep it as clean as possible. A word of warning here: LEDS that are burnt out are rather difficult to replace. The LED circuit was put together with the approach of never having to be worked on, which of course, we know is not good. I guess you could say that this would be a weak point. If work is needed and wanted on this circuit, an overhaul is available for a $50 charge.

- The output coil (inductor) that was standard in amps of this era is removed, opening up the sound. This is actually a rather noticeable improvement and can be heard on just about any amp this procedure is done to. It's an older protection scheme whose day has passed and no longer needed.

- As mentioned above, the PCB layout is pretty solid to start with. However, there are a couple of circuit tweaks that I feel make the performance more accurate. The power wiring is also brought up to code using modern layout and star technique. SAE took a shortcut here and impacted the quality of the ground system, which was normal for many amps of the time. Unfortunately, it's also normal for many modern amps, but it is directly responsible for making the amp function properly and can be heard.

- In conjunction with the wiring, I also install a 3-prong power cord that utilizes real earth grounding. This is something that was basically unheard of way back when. Even when it was used it was not really fully understood, even by the manufacturers themselves. It's been a source of study for me throughout the years and takes care of a number of hum and groundlooping problems that seem to pervade a lot of systems. Your amp will run quieter and provide a blacker background.

- Last but not least, and not by a long shot unimportant, the amp will also benefit from a new RCA jack assembly and wiring arrangement. The stock setup muddies the signal due to insufficient wiring and cannot be corrected, so a new assembly must be installed to eliminate this problem. I have to fabricate one especially for this application.

- All replacement parts are a direct fit with no sloppy overhang or nonfitting sizes. You have to look at the amp closely and know what the stock circuit looks like to actually tell that it's been modded. The effort has been made to keep workmanship tight and neat, while staying away from the rather popular and sloppy "this amp has been modded" look.

Results:

The 2200 can run just about anything. That's right, I said anything. The new parts and upgraded wiring are so good the amp can deliver into any load. Perhaps not at a sound deafening level, but a respectable one. During the reengineering process, I noticed the circuit was compensated to work into electrostatic loads. At first, I found this sort of amusing given the reliability history. As I progressed and the end result became more apparent, an electrostatic load wasn't such a far out idea. I hooked it up to some Martin Logan electrostatics, and I have to say without reservation that it can play well. It uncovers nuance, instrument sustain, and is exceptionally quiet. It also has some rather impressive imaging and clarity. My experience has been if an amp achieves that, then it's attempting to be accurate and things are more right than wrong. Those characteristics don't just happen on their own. You won't get these results with a stock unit either, there's simply too many substandard parts and inadequate circuit technique in the signal path.

Conclusion:

This modded amp would go great in the garage, workshop, or even a simple hometheater setup. It could also be used in a modest main system. This amp is ideal for those on a budget, but want something that's much more than what a cheap price can normally get elsewhere. The mods take it to a new level and it will clean the clock of many brand new amps in the sub $1000 range, and possibly even greater. The level of realism attained here is very interesting.

The 2200 is commonly available, so anyone who wants one can get one. However, the resale price with all quality vintage gear seems to only increase with time, and so goes the 2200. What was selling for roughly $200 a short while ago can now fetch prices of over $300. Just realize that market forces of supply and demand are at work here, with a word of caution to those interested in a purchase: Just because a seller says the amp has performed flawlessly, never been serviced, and has good cosmetics does not mean the aging process has not been at work on the amp. To the contrary. Somewhere there's a capacitor not feeling brand new anymore, and where there's one there are probably others. Don't expect to repeat a long service life on an amp this old because odds are it simply isn't there. It could use some attention. The rebuild objective is to not only extract all the amp has to offer, but to make it more reliable and last longer yet. There's also a good chance that it will make you want to upgrade the rest of your system when you hear what it can do.

Pricing:

The rebuild price is $300 and is comprehensive. All bugs and shortcomings are removed, and everything is done to get the amp to where it needs to be and still be affordable. I'd label this a best buy without hesitation.