^^ indeed, as my fellow passengers on the bus sometimes will attest
....or is the protest??
....or is the protest??
I do not mean to interfere - but I can testify that the Lisa III can easily drive the HD650 to the stars...
I have communicated with the designer Phil on the RS version, and subsequently had the opportunity for a good, in-depth listen to this amp.
First, some introduction on the RS - according to Phil Larocco :-
Quote / Extract :
Unlike previous LISA III’s, The LISA RS is available in only the Home edition. Therefore the limitations imposed by alternate battery operation are removed because the LISA RS is an AC mains only powered headphone amplifier. The decision to keep the two Box systems of power supply and Amplifier is to allow the upmost in placement either vertically stacked one on top the other or placed side by side. Housing the Amplifier and power supply in separate enclosures also reduces the potential for hum and noise by virtue of shielding provided between the units.
The LISA RS takes the previous LISA XP and LAB POWER supply to the next level with circuitry enhancements that obtains the absolute highest performance obtainable from Phil Larocco's Buffered Op-Amp Topology. Additional circuitry refinements include operating the amplifier from high voltage power supplies. In the RS version The LAB POWER SUPPLY is set to provide 32 volts of Supper Clean regulated DC power to the LISA RS giving slightly over twice the power potential of the previous 24 volts in LISA III XP.
Taking full advantage of this improvement the amplifier circuitry was upgraded in several areas to provide more linear output current allowing operation into load Impedances one quarter the value useable with the previous LISA III’s at the same power and distortion performance. To avoid over-stressing the output transistors originally used in the LISA III’s, so these were replaced with the output transistors utilized in the definitive HEADCODE allowing the full benefit of the other circuitry enhancements to the listener. Large value reservoir capacitors occupy the space previously filled with batteries for substantial dynamic impact completely preserving every nuance and detail of the music.
With all these Improvements in power and output stages, it makes sense the voltage gain circuitry be also improved? How do you improve upon perfection? The original LISA III has utilized many unique and proprietary techniques to extract the utmost from the humble monolithic IC Op-Amp. Indeed a difficult task it is to improve upon this however, there remains one obscure technique described by Walt Jung, which reduces distortion in the Op-Amp by 10dB, and this was put to good use.
I took possession of a RS prototype in mid-October and have, despite a work-disturbed month, a good listen to it. I still have a special version of the original LISA III XP (in wooden case) with me so I was able to capture some obvious difference between the new RS and the battery powered XP. My prototype is still in the same LISA III XP and LLP casing so from the outside there is no markings saying it is a RS. I would expect the final commercial version will be marked as such.
In the car industry, the "R", "S" and "RS" are being prestigious suffixes of something special, and usually more expensive. I believe Phil wants to mean the same thing, though I am not sure about the pricing.
As good as the LISA III XP as a sub-$1K amp, I can almost immediately spot the difference when I listen the LISA RS, which is now probably the cheapest amp I have which have made the HD800 really shine. My first impression is instrument separation and overall imagine is improved. The RS is faster and more meaty - displaying astonishing dynamic response. Bass is more extended and better controlled. Decay and air are superb. It still shares the same DNA as the LISA III, only better in almost every aspect.
I am not sure of the official pricing, but was told it will be priced to be affordable.
Comparing to the other solid state and tube amps that I have owned and listened to, the LISA RS is a step above quite a few of them, including the Corda Symphony, Amphora SE, Woo Audio 6, Headphone Pro (even with the Little Pinkie v3i PSU), Lehmann Black Cube Linear, and the Graham Slee Solo (with PSU1), the Headroom Ultra Desktop (with Desktop Power Supply), the RSA Raptor, Grace M902, Lavry DA10, .... and others.
It is surprisingly close the the Rudistor RPX-100 (according to the notes I kept), which is now evolved to become the RPX-300. If the RS is priced below US$1,200, it can easily be one of the best buy as the last solid state headphone amp one may ever need. Compared to the Rudistor RP010B MKII (in single end output) that I currently own, the LISA RS is still a tad less in resolution and sound staging but that's probably all. I must say this is no shame as the Rudistor RP010B MKII is easily over 3 times more expensive than the LISA RS.
Is it perfect ? Well, almost. Phil does want the LISA RS to be the best achievable from a OP-AMP based topology and I would say he has his mission accomplished. But there are a few things that we should take note. First, the gain setting of my RS prototype is more suited to higher impedance cans. When I hooked the RS to the output of my Chord QBD76 (which provide an single end output of 3.7V), I only need to set the volume to less than 9 o'clock for a good enough volume on my HD800 and HD650. Using the Edition 8, I have very little play at the knob before it becomes just too loud. The situation does improve when I paired the LISA RS to my Nagra CDP ( which as a default output of only 1.2V). I am not sure if the commercial version will have a lower gain setting though. ( The battery powered LISA III has a gain setting to suit portable player like the iPod.)
Second, like the LISA III XP, the LISA RS is a single purpose machine - it has only one pair of inputs and does headphone amping only. So, feature wise, it is a bit lacking compared to others as a home amp ( multiple inputs, pre-amp out, SE and balanced out...etc.). Instead, the RS does the single job so well that one will have to shell out a lot more money to get above its performance as a headphone amp.
And one can certainly put in better a volume control (but that will tilt the price significantly). The one on the RS is good and I have no problem in channel tracking and balance, but I just can't stop imaging what this little gem can do if it comes with a better pot.
In short, for those who are looking for a compact desktop or home headphone amp, the LISA RS should be near the top of your list. I have enjoyed it tremendously.
F.lo, you have basically named every desktop on my wish list (Isabellina a notable omission, but that is more expensive by several orders of magnitude) and said 'This is better'. Is it possible for you to start a new thread dedicated to the RS, please ?
Oops , camera dont work, uh, daa,, Will get help..
Brass on Black sure looks cool.. see soon..
Lisa RS , Desktop/home amp, (we just do not fit into categories neatly)
is now ready!!! & available!! When you get to the Lisa level of Sound Quality
it is hard to best, and improvements are measured in small degrees. To attempt this
Phil has nearly doubled the power, (removing the batteries in the process) now up to
home amp standards, added more capacitors & transistors as only he knows how.
And WALLA, the result is noticeable, slightly, in a word - MORE - just a little more
of what Lisa is already known for.. Of course source, cable, & can changes are
extremely obvious. Phil amazes me.. What can I say? Limited quantities
He hasn't named the Phonitor yet. By the way, do you mean the Isabella? The amp of the Isabellina is the Amphora SE which F. Lo has already mentioned.