My Long List of Amplifiers and My Personal Review of Each!

@whitecamaross - I would definitely welcome discussion on the different processors you have reviewed. I would ask that you start a thread in the "Home Theater" subforum. I would definitely comment as I have been through a number of processors as well.

I see you have very positive review of the Emotiva SA-250. Have you listened to the other XPR/XPA monoblocks? I have not heard the SA-250, but if I remember right, it’s basically a single-ended amp - but has separate power supplies fed from a shared transformer. The XPA/XPR monoblocks are fully balanced/differential with larger power supplies and more output transistors. Just curious. The XPA amps sound somewhat bright/harsh in the highs. The XPR amps sound a bit soft, but a bit cold at the same time (yes, I know it’s weird, but it’s my impressions). The stock fuse is the problem on both amps, as replacing them with Isoclean really helped each amp significantly. I’m running all XPR-1 monoblock just because I can’t find any other "equivalent" amp near the price range that will give me as much.

Just wanted to add here on the topic of Emotiva. As I’ve said before, I have extensive experience with a multitude of Emotiva products. My opinion on the preamp/dac side is that they are decent for the money (especially if you only want to spend a few hundred), but they can sound somewhat closed-in. The amps are actually quite excellent for the money you spend. They can be elevated to a very excellent amp by a fuse upgrade and a very good power cord. That being said, there are definitely amplifiers that are much better, but they do cost 3-5 times as much. I have not put my Emotiva amps side-by-side with something like a Parasound JC-1 or Pass Labs, but I am very happy with them that I don’t feel the need to spend 6 to 10 thousand dollars on a set of monoblocks to replace the Emotivas.

That being said, I have noticed a change in direction from Emotiva in the last few years. I believe they may be slowly transitioning away from China manufacturing. They are also transitioning more towards switching power supplies. That coupled with USA manufacturing means they have to do more with less to stay in their targeted price bracket. The lighter weight of the switching power supply on the new Gen 3 amps mean they spend less on shipping. I have not heard Gen 3, so I cannot comment on that. However, I have owned the XMC processor - and it also has a switching power supply. I would say the XMC is very good for the amount of money you spend on it, but I found the sound somewhat lackluster (I got the feeling that it was muffled/closed-in). It would not compete with the likes of Krell.

One thing to keep in mind with Emotiva is that they are skilled marketing folks. Watching their videos, talking with them, and reading their pages -- it is clear that it’s all about the "Emotiva hype". The emotive forum also has this attitude (Emotiva is the best!!). Not to say this is a bad thing -- it’s the job of any business to try to sell. However, I would just take all this information with the right perspective. In the $500-1500 range of items, I would say that it is very difficult (maybe even impossible) to compete with this and find something better.

Sorry to hijack this thread, but I see we diverted into processors just a bit. I do have several comments (I’m sure this belongs in Home Theater section, but several of you are talking about this here).

Bryston SP2 - (Class A discrete audio) This was my first major processor upgrade from an old Sunfire Theater Grand. The Bryston was an extraordinary upgrade. This SP2 model had a lot of attack and detail, however over time I realized that it didn’t really have much decay or fullness. Also, I always felt that I had to really turn it up to hear stuff or have good impact from movies.

Krell HTS 7.1 - (Class A discrete audio) I switched over to this from the Bryston after reading a long posting from a guy over on AVSForum which had the HTS on his short list. This was back in 2005 and I would probably consider that guy the "whitecamaross" of processors for that time, lol. The Krell was amazing and sounded so much stronger than the Bryston. The entire sound spectrum came across much stronger and had so much more impact. Everything "sang" as well. I loved this processor for 10 years.

Emotiva XMC-1 - (lower cost op amps) after moving over to a set of Emotiva XPA amps (which I loved and were excellent), I gave this processor a shot from all the hype that was coming out of this item. The sound was nice, but it was somewhat closed-in. It also did not have the resolution and "separation of instruments" that the Krell had. I would say that this is an excellent choice for someone who is under budget constraints. I have no idea how this compares with the likes of Marantz or Anthem.

Theta Casablanca IV - (discrete/opamp) My brief experience with this processor did not work out for me. I really loved the configuration of the processor and the idea that HDMI is a pure passthrough. Engineering design approach looked very good. However, I just could not get the processor to sound good in my system. The audio output stages are all solid-state and are not Class A circuits. The Extreme card appears to use some sort of resistor-ladder or resistor-switching circuits in the I/V and output stages. The Supreme II card uses a fully differential op amp for I/V and output. The sound was extremely clean, but it just did not "sing" like my Krell HTS 7.1 did. Knowing what I know now (after about 2-3 years of R&D and experimentation with different types of opamp/discrete analog circuits), I think the Theta processor would mate well with a warmer amplifier that has a high bias into Class A (i.e Pass Labs, Parasound JC1, Aragon 8008/Palladium/Iridium, etc.). I had very strong/fast Class AB amps and they just did not work well with the harsh solid-state sound of the Theta.

Bryston SP3 - (discrete Class A audio) I took a shot at this. Like the Theta, it also had a passthrough HDMI (no video processing). I tried a lot with this processor. However, in the end it was just too laid back for me. This coincides with Whitecommaross experiences that Bryston has changed it’s SP3/Cubed product generation to be more laid back. The bass response of this processor was just outstanding. There was so much low frequency energy in the room that it was shaking ceiling joists and my projector frame. However, all the action, voices and music just did not cut through. There was not enough of an impact for me. Everything seemed too far away or laid back. I also felt that it seemed that I could never turn it up enough for impact (just like the older SP2). Bell sounds came across excellent and natural, however. I think part of the root cause is the Bryston approach to circuit design. The Bryston has a very large main power supply. However, after the +/-24V and +/-15V voltage regulators, there is hardly any capacitance (only a 10uf post regulator). There are no power capacitors surrounding the analog circuits so the Bryston circuits do not have enough "immediate" voltage to respond to the very fast transients of the mids/highs. In comparison, looking at the Krell Class A discrete circuits, you can see that each analog circuit (equivalent of a single-channel opamp) has about six 47uf capacitors mounted right there. This give the Krell the extra muscle to respond to the fast mids/highs.

Krell S1200U-3D - (Class A discrete audio). This is the processor that I have finally ended up with and that I love dearly. I probably should have kept to Krell because I loved my HTS 7.1, but I wanted to see if I could get something better. This carries the same sonic signature of the HTS 7.1, but now I can support the hi-res bluray audio (TruHD/ DTS-MA HD). I will say that the Krell processor (and their low-end preamp) have an undersize power supply. I ended up soldering a additional 15,000uf into to each of the +17V and -17V power supplies, and an addition 10,000uf to the 5V digital DAC ref power supply. This completely fixed the lean bass and upper mid shoutiness/forwardness of the Krell. The bluray audio is amazing now. So much that standard DVD dolby digital sounds dirty/grainy to me and satellite DirecTV dolby digital is just horrible in comparison, lol..

I did not try McIntosh processor, but I did really look into it (I may have tried the MX121). The overall McIntosh architecture design is excellent and they make a very good power supply. However, it is still op amp based circuit and I was also scared from the many reports of firmware bugs that McIntosh never fixes

In comparison, I found a firmware bug in my Krell S1200 earlier this year where it was incorrectly applying Dynamic Compression to DTS-MA movie soundtracks. Krell had this firmware fixed and emailed to me within a week!! (which was totally surprising from Krell and even for a discontinued product!!).

I did not try the Classe SSP-800 because it also had op amp architecture, but it was on my short list if the others did not work out. I do not care about 4K, dolby atmos, DTS:X, or room correction.

@thezaks - I have Emotiva XPR-1 monoblocks for my left/center/right/sub. Emotiva XPA-1L monoblocks for left/right surrounds. At the time I had the Theta Casablanca IV, I believe I was using Hi-Fi Tuning Gold fuses in the amps. Using B&W Diamond D2 speakers for fronts.

The Emotiva’s are very strong and fast amps. Very high resolution. The stock XPR-1 was actually soft sounding and a bit cold (weird for being soft, but true). A fuse replacement fixed this. I am running Furutech rhodium fuses in all pieces of equipment now (including the Krell). I also, replaced / soldered in new fuse clips on the XPR-1 power board because the stock ones were really weak. The new ones have rock hard grip/contact on the fuses. These were the larger 6x32 spring metal fuse clips.

When I upgraded to B&W speakers, I didn’t have a good amp from my selection that worked well with this. I used Crown CTS600, Crown CTS2000, and Channel Island 200W Class D monos. The Channel Island were actually the best sounding with the B&Ws. Then I tried an Emotiva XPA-1 monoblock and found that this beat out all the other three. The Emotiva had enough current to handle the B&Ws and the resolution and impact was just so much higher!

Historically, I have used B&K 7 channel (too warm!) and Sunfire Cinema Grand (dull sounding).

I don’t have as deep of pockets as whitecamaross, so I can’t justisfy higher end amps such as Pass Labs, etc. If I ever thought about upgrading, it might be to try out the JC1 monoblocks. However, these are FET devices and I’m not sure that I would like that slant towards warm/FET sound. It’s hard to beat a 1,000 watt differential monoblock with huge power supply, 36 transistor devices. I may look at replacing all electrolytic and film caps on the amp boards and input board.