Here goes nothing. I want you to remember that this is a comparative evaluation. Meaning the best amp sound/construction I hear is given the 10. The lower marks are somewhat arbitrary.... I feel that giving the poorest one a 1 would turn this into a more difficult analysis and downplay the quality of the amp. There was no doubt that the cosmic was my 10 rated amp in this entire review and thus is my primary basis of comparison.
This is how I would rate the Porta Corda:
Construction - 8/10
This awesome amp is extremely solid. Not as solid as the bulletproof cosmic, but I have no doubt that it could survive a 6-7 ft fall. I'm pretty sure both the JMT altoid amp and the RA-1 can't make the same claim. It's extremely professional... I expected the board inside the amp to be exposed when you open it up (to replace batteries) as it is on the JMT, but its not. It's just like any other battery driven device as the insides are covered up. The squeeze test on the unit did not yield anything... it is very well protected. My only complaint is that the faceplate controls are far too small. The volume control knob is also not too easy to turn due to both its size, location (its squeezed between the crossfeed switch and the output jack) and the necessary amount of pressure. Its definately bigger than the JMT, but still easy to fit in the pocket. I'm also very glad that the belt clip can be taken off easily as I won't ever need it.
I gave the Porta Corda an 8 on construction. I rate the cosmic a 10, the JMT a 5, and the RA-1 a 4 (the wood gives me the creeps... probably much better than my rating in reality).
Sound - 7/10
I really enjoyed the sound of this amp. When I think of amps and sound, I think of the sound as a tunnel with water flowing through it. The higher I turn the knob on the amp, the tunnel and the water proportionally increase. However, for different amps there seems to be a volume point where it seems like the tunnel stops growing and only the water is increasing.... it starts to sound "stuffy". With the JMT, I'd say that this occurred around the halfway point with my Etys. With the RA-1 it was right before the very top, but the amp never got too loud for me and my Grado SR-80s ( I think I must be deaf...
). The Cosmic never seems to suffer from this phenomenon but didn't seem to go up as high as the JMT or the Porta Corda (it is VERY possible that this was due to it never getting "stuffy"). The Porta Corda is great and seemed clear till the 3/4 max for my Etys. I did notice both stuffiness and a blurring of details and vocal separation at higher volumes though (loses sharpness). All in all, I gave it a 7. The RA-1 deserves an 8, and the JMT a 5. The cosmic is a 10.
Crossfeed Impressions
As only the Porta Corda and the Cosmic have this feature, here are my views. The cosmic's cross feed is so subtle... it does seem to provide more depth and most often feels great. I usually keep this on all the time... I didn't for the sound review above. The Porta Corda is very noticeable with the Etys... it seems to absolutely collapse the sound stage. As the manual also describes, the bass impact almost disappears in some recordings. I did not like it at all, but I do enjoy having that option. When I used my V6s for either amp with crossfeed turned on, I did not notice any substancial differences than with it turned off.
Portability 10/10
I love the size of the porta corda... the belt clip is a nice option as well (though I will never use it). I lied about the cosmic being the 10 on everything... in this situation, with its damned battery pack, I can't give it more than a 4. The RA-1 was only slightly better at a 5... hate using 2 9V batteries. The JMT gets a 9, but I wouldn't feel as comfortable taking it out in public. I have enough problems from security now without someone mistaking the JMT amp for a bomb.
Thats all I could think of. I really am impressed with this beautiful amp! I hope this is useful for some of you. Later!
