# Review: Soundstream Rubicon 555



## Chaos (Oct 27, 2005)

Since this forum seems to appreaciate active crossovers and multiple channel amps, I thought I would post this FYI in the event that anybody happens to see one of these amps and is curious about what it can do.

Sadly, these amps are no longer in production and are not very easy to find. This is a product of the original US-made Soundstream company, and it is probably one the most capable 5 channel amps ever made from that era. Not to be confused with the post-sellout Rubicon II series. If you happen to be lucky enough to discover one, here is some information to consider:

Link To Manual 

Highlights include:

4Ω / 12.5v (conservatively) = 40x4 + 150x1


Fully variable 3-way operation:

Highpass: 500-5000Hz @ 12db/octave
Bandpass: 50-500 (highpass) up to HP cutoff (lowpass) 12 db/octave 
Sub: 55-220hz @ 24db/octave (includes subsonic filter & hawkins eq circuit) 

Also, the processing features can be independently defeated or engaged on all 3 sets of inputs and/or configured as full range pass through for another amp. You also have independent level (gain) control for each set of inputs that makes level matching between the channels possible. This is where the true versatility stands out with this amp - once you look at some of the possible configuration diagrams in the manual it becomes clear just how many different options it gives you. 

It can also be run in mixed-mono or bridged for 3 channel operation, again with independent processing depending on the number of inputs. Perhaps the only downside is the fact that the high frequency crosovers are only 12db/octave and it's difficult to determine exact corner frequencies with the pots. Other than than that, this amp can easily run an entire system with as little as 1 set of inputs. There is more, but it's all in the manual.


As far as SQ is concerned, this amp sounds fantastic - especially for it's modest power ratings. Whether you believe that an amp has an effect on SQ or not, the power supply in this one is very sophisticated and robust enough to deliver adequate headroom for a simple daily driver. 
Although these Rubicon amps may not be quite as well known for the pure power of the SS Reference amps, the extra features & flexibiltiy of the Rubicon series actually make them the better overall amp IMHO. 
If you ever get a chance to hear one of these, I would highly suggest taking the time to listen. If you are looking for a very high quality, extremely versatile amp to run your system, one of these may be worth hunting for.


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## rizznits (Nov 11, 2006)

I have one of these BNIB that I can't wait to power up. Hopefully I can build a good system around her to do it justice. Have you added any eq-ing to your setup from the Clarion (not sure what that is capable of)?


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## GlasSman (Nov 14, 2006)

Oh yeah, the Rubicon amps are great. THey'll go heads up against any of todays high end amps. ANY of them. I've known this for years thats why I've been hoarding them. Whenever I see a nice one on Ebay I snatch it up. I have 4 Rubicon 702's and a Rubicon 604 in addition to 2 Reference 500's. The thing with the older Soundstream amps is if you find one that works and it's installed properly or furthermore not strained to within an inch of it's life it'll work for years and years.


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## legend94 (Mar 15, 2006)

very nice amp, i would love to hear your system


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## chuyler1 (Apr 10, 2006)

Nice amp. I considered this before I bought my PPI 5440 several years ago. The PPI put out 200w to the sub channel so that was deciding factor. They pop up on eBay occasionally also and have a great pass-through crossover system which allows you to run fully active off a single pair of RCAs.

I went looking for another one when I started my Dad's truck but I couldn't find one. I ended up going with a NeXT 5-ch amp and a PPI crossover (since the NeXT crossover wasn't sufficient for running active). I wish I had remembered this amp.


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