[Todd R]

Even though there have been a couple previous reviews of this amp already, I thought I'd post some of my impressions.
 
I had been using another one of Ray's amps, the Protector, with the TAG balanced cable attached to my JH Audio 16 pro custom monitors. I was able to compare the Protector to the prototype SR-71B at the last Chicago meet. RSA house sound for sure, but the SR-71B is warmer in the midrange and has a feeling of more power & drive.
Couple months later I had my very own SR-71B and I am very happy with it.
 
Build quality is top shelf as usual, but we all knew that didn't we? 

Even as most of Ray's new amps seem to keep shrinking (I think they will be implantable soon) I actually appreciated the larger size of this one. It's about the same width as an iPod Classic and only a little shorter. That makes it easier for me to stack one on top of the other & carry them around. I also like the longer volume knob which is easier for me to get hold of with my fat fingers.
 
I made up a cable to come from the balanced outputs of my Modwright modded Logitech Transporter to the special 4 pin balanced connector that is required for a fully balanced signal. 
Is there a difference between a balanced input & single ended?
Yes, there is a wider soundstage and a sense of "ease & clarity" that is missing with a single ended input. Not night & day different but if you have the option on your source it's well worth doing.
 
So far so good, but can it drive the big cans?

Replaced the 1/4" plug on a stock Sennheiser cable with the 4 pin plug so that I could use the balanced output on the SR-71B to power my HD-650's. These headphones I've had since they came out and have been the longest lasting component in my system. The balanced outputs fed the SR-71B while the single ended outputs of the Transporter fed the Bottlehead Crack amp (With Speedball update).
 
The Crack has been one of the best amps I've owned to drive the 650's. Could the SR-71B keep up?
Keep up?
Yes & then some. It's almost the equal of the Crack!
With the 650's the SR-71B is quieter than the Crack as you might expect and sounds very clean & detailed. I was also pleasantly surprised that the SR-71B drives the 650's almost as well as the Crack. It does not quite have the "richness & tube sound" of the Crack but it comes very close. In fact, you'd never notice the difference if you weren't comparing them side by side.
 
This might be the only amp you'll ever need.

 

[ben201]

Great review. Its just sad that I cannot afford SR-71B,
 
But i am getting protector

 

[caracara08]

great review. i have the protector but tihnk i might stay away from the 71b because of the increased size. for me, portable means smaller.  i might end up selling my protector to go smaller.

 

[wolfen68]

Thanks for your thoughts.  I am enjoying my "b" as well.

 

[blitz-dice]

Quote:

Great review. Its just sad that I cannot afford SR-71B,
 
But i am getting protector

i have the same sentiments! no moolah! lol

 

[fusionramjet]

I recently got the SR-71B, as well as the DHC Symbiote cable with a balanced connector, which I use with my Future Sonics mg6pro.  I use an iPod nano with Sendstation's Pocketdock line out adapter [i ordered the Cypher Labs Algorhythm Solo to eliminate this weak point in my rig].
 
I first used the SR-71B with my IEM stock cable in single-ended mode and then switched to balanced with my DHC Symbiote.
 
The difference from single-ended to balanced is huge.  In balanced mode, the sound is incredibly dynamic, bold, with enormous impact.  In particular, the bass is mind-blowing in detail, punch, power, quantity - everything about it is spectacular.
 
I read that a potential downside of using balanced mode is a decrease in coherency.  I didn't notice this, but I imagine that this is because I'm using the Future Sonics mg6pro IEM, which uses a single 13mm dynamic driver and has excellent coherency.
 
Now, i'm eager to get my CLAS and see what the whole thing sounds like.
 

 

[Matter]

Guys,
 
SR71B or 2Stepdance?
I'm currently awaiting the arrival of my Heir Audio 8A and I simply cant make up my mind if the SR71B is really worth the money.
In a dillema because with the amount I spend on the 71B, I can easily purchase both the 2Stepdance as well as the TWag cable.
Obviously, if I were to purchase the SR71B I will be spending more on reterminating my cables.
 
Hope you guys can help.
 
 
Thank you!

 

[fusionramjet]

i'm not at all an authority in this matter, but it might help a bit to know that I have the RSA SR-71B --> DHC Symbiote balanced --> Future Sonics mg6pro.  The balanced output of the SR-71B BLOWS AWAY single-ended.
 

 ​