Originally Posted by Roscoeiii
I see that you have both the Protector and the PB1. How would you compare the sound of the two? I'm particularly interested in their balanced outputs and how well each pairs with the HE-5LE (which I also have).
I have listened to both in balanced mode with a variety of music. Both of these amps are very capable performers and can easily drive the HE-5LE.
The differences are are fewer than one would expect considering the large difference in price. When comparing the two, I tried to balance the volume by ear as closely as possible, and swapped inputs from my H120 after listening to each for about 15 or 20 seconds of the same music selection.
I also tried both using Low gain on the PB1 and Mid gain on the Protector. While both could provide a reasonable listening level at this gain setting, it was obvious that high gain on each would be more appropriate, as the at lower gain settings, the Protector was running at about 4PM on the volume setting vs 2PM on the PB1. At the highest gain setting on both, my listening levels were about 10PM on PB1 vs 1PM on the Protector.
Subjectively, both are tonally correct, and present the instrument harmonics and overtones quite accurately. The differences when playing music that does not have a great deal of dynamic range are not great. For background music or casual listening where one is not devoting much attention to the music, both sound rather similar. Differences between the two amplifiers become more apparent when listening at higher volume levels, and when listening to recordings which incorporate a wide dynamic range with many transients, especially low frequency transients such as kick drums, tympani, etc.
It is here that the 10 volt greater voltage swing of the PB1 compared to the Protector makes itself apparent. Bass transients are sharper and overall bass seem to me to be better controlled than in the Protector. In busy selections with many different instruments playing at differing volume levels, the PB1 is better able to put space around each instrument and render better individual musical details and nuances. Soundstage is wider in the PB while imaging is very good with both.
It is difficult to assess the accuracy of the imaging as so much depends upon the studio mix when recorded. I did listen to a couple binaural recordings and both amps portrayed accurate instrument placement. It is in the areas of soundstaging and accurate stable imaging that the benefits of the balanced outputs are most readily apparent when compared to listening to the SE outputs of both amps.
Overall, I like the detail and sense of space that the PB1 delivers. The PB1 will reveal shortcomings in the recording such as sibilance to a greater extent than the Protector.
I much prefer the all-metal Hirose connector used in the PB1 balanced output. They are much easier to solder than the plastic ones used in the Protector and are considerably easier to attach and remove.
Some final comments that summarize my impressions are as follows:
Ease of gain changing: Protector
Ease of volume changing: PB1
Depth of bass: PB1
Control of bass: PB1
Transient response: PB1
Susceptible to sibilance:
Can use both BAL and SE simultaneously:
Balanced + SE inputs:
Choice of case color:
Warranty: Protector (lifetime)
Ability to drive HE-5LE: Both
My personal preference happens to be the PB1 due to its increased headroom and dynamic range for the type of music to which I most frequently listen. Others may well prefer the more compact size of the Protector.
Regardless of ones personal preferences, much credit should be given to both RSA and iBasso for bringing to market these well-designed balanced portables that can equal or exceed the performance of many desktop amplifiers!
Edited by HiFlight - 8/28/10 at 2:22pm