SA-9100 vs 8100

[KeithD]

I know there was a thread on this several years ago, but the basic question I have was not covered. Other than the obvious differences between these two classic amps (output power, controls on the front, connections on the back, etc.), is one better than the other in terms of the internals? I know the design of these two is different as I have looked at the circuit diagrams, but what I can not tell, is one a better design than the other and/or did one use better components than the other? By better I mean better sound quality and/or less problems/less likely to fail/easier to maintain. I've heard both amps played through the same set of speakers and did not hear a noticeable difference. I don't want to assume that just because the 9100 was TOTL in its day, that means it is a "better" amp.

For reference I have an 8100 that I've been repairing and I think the sound is wonderful. I picked up a 9100, but it has issues (protection, constant low level background hum and hiss), and I don't hear a difference in the sound quality (other than the hum/hiss issue). I'm wondering if it is worth keeping the 9100 or returning since the price was on the high end of what they seem to go for.

Thanks for any opinions.

 

[KeithD]

Forgot to mention, I do notice that the 9100 gets noticeably warmer than the 8100 when played for the same amount of time. Since I don't need the higher wattage of the 9100, I consider that a negative.

 

[KeithD]

the 9100 is just a better design,

OK, but how does the owner experience that? What makes it a better design? I know it is different, but why is it better?

 

[QSilver]

I've worked on both and listened to both - I also have an SA-7100 with original box, packaging and original slip form the factory with each channels THD and power outputs specs on it!

If I was keeping one, I'd probably would not keep the SA-9100. That power supply in the front is just not a good idea in my opinion. It runs too hot, and has poor to no ventilation. I'd be tempted to migrate the regulator transistors to large heatsinks somewhere... I think the only real benefit is the phono pre-amp is a better design but not to the point you will really hear a big difference. The SA-8100 has most of the nice features on the front that the SA-9100 has. Only thing I might miss is the Speaker B attenuation control on the back.

The SA-9100 has its amplifiers mounted on separate heatsinks either side of the amp but.... its jam packed in there and that overheating power supply... I'd gravitate to the SA-8100. Sounds just as nice a little less power but a lot less hassle.

 

[KeithD]

I've worked on both and listened to both - I also have an SA-7100 with original box, packaging and original slip form the factory with each channels THD and power outputs specs on it!

If I was keeping one, I'd probably would not keep the SA-9100. That power supply in the front is just not a good idea in my opinion. It runs too hot, and has poor to no ventilation. I'd be tempted to migrate the regulator transistors to large heatsinks somewhere... I think the only real benefit is the phono pre-amp is a better design but not to the point you will really hear a big difference. The SA-8100 has most of the nice features on the front that the SA-9100 has. Only thing I might miss is the Speaker B attenuation control on the back.

The SA-9100 has its amplifiers mounted on separate heatsinks either side of the amp but.... its jam packed in there and that overheating power supply... I'd gravitate to the SA-8100. Sounds just as nice a little less power but a lot less hassle.

Agree with all your points on the 9100. I was thinking the B speaker control was a nice feature until I discovered that it only works when the selector is set to B speakers only, NOT A+B, so I would still need the separate Niles speaker volume control box I use for the rear speakers in my setup. Looking inside the 9100 is daunting, as you say things are tight in there - much tighter than the 8100. It's not clear to me how you can work on the power amp boards without disconnecting the output transistors mounted on the heatsinks?

As I mentioned, for me, I can't tell any difference in the sound quality on my system between the 8100 and 9100. I've also got so much time in refurbishing my 8100 that I couldn't let that one go anyway. Had I paid much less for the 9100 I'd keep it just for the learning experience of refurbing it, but I paid too much to have to be rebuilding boards. The seller had said the amp was serviced and was working perfectly, but I found out otherwise.