[average_joe]

Hi, I am looking for a good amp for my T1 and have been reading as much as I have time for here and also been asking everyone I know and trust.  I have narrowed it down to four amps below, but am still open for suggestions.  I am leaning toward either the NX03 or M1, but don't want to discount the others.  I have searched, but either the new search capability isn't what it once was, or there just aren't may comparisons of the below amps.
 
RudiStor NX03 - a trusted friend has the NX02 and said it is the best amp he has heard under $23K.
 
CIAudio HPA2 - Small, affordable, and I have read many good things.  A different friend just bought this and from a form factor/looks standpoint (which is important to my wife), this is the best.
 
Decware Zen Select CSP-2 - Rated very high by Skylab in 2008, but how does it compare with the SS amps of today?  I am not fond of the look of this amp, though.
 
Musical Fidelity M1 HPA - Not yet released, but if it is an improvement over the X-CAN V8P, can it be all that bad?
 
Here are my questions:
- What you would choose and why (your experience with the above amps/other amp)
- Any issues with the above amps that I may not know about
- Links to threads that might not have the keywords/titles that would allow me to easily find them
- How often you have to change the tubes, and if the stock tubes are good enough.
- I know there are aftermarket modifications, and if any of the above offer a mod and you know about it, please let me know.
 
Thanks in advance for your answers.

 

[TheWuss]

man, the specs on the m1 hpa look mighty impressive.
also, the line out and pre-out are nice features.  and, form factor is also pretty slick.
 

 

[Ypoknons]

Quote:

RudiStor NX03 - a trusted friend has the NX02 and said it is the best amp he has heard under $23K.

I'm so glad there's a >$23K amp segment! 

 

[hahahigh]

I have not heard any of the amps on your list, but man, the M1 DAC and Amp combo looks absolutely gorgeous... I would buy that without hesitation if I had $1450 to spare.

 

[average_joe]

Thanks for the input?  I didn't think anyone would have heard the first three amps on the list, and I don't think anyone has heard the new CI amp, but any suggestions, recommendations, Can Jam experiences, etc?
 

 

[GuyDebord]

From the list, I vote for the Decware Zen. 600ohm+tubes=

  IMO the majority of the solid state technology at your price range has gone backwards, emphasizing the use of op-amps (due to their low distortion, specs sell!) vs. discrete JFET class A, which require more skill and dedication to produce.
 
Other good options to look at:
 
Tube:
WA 6
DNA Sonett
 
Discrete SS:
Headamp GS-1
SPL Auditor (not really discrete but not simple commercial op-amp technology)
Burson HA-160

 

[average_joe]

Thanks for your input GuyDebord.  I kinda want to go for SS (if for nothing else looks, as my wife is picky about the looks of things in our place) and didn't even know about the SPL Auditor.  Although I don't think the SS amps I listed are simple op-amp technology.  If the tube amps sound much better, I will probably go that way, though.
 
NX-03:
The amp is completely linear from DC to 100KHz, and the damping factor is so high that this amp can easily drive small speakers.No capacitors are used on the signal path, no global negative feedback is used.
The amplifier use OPAmps as signal amplifiers and bias voltage servo actuator, in a simple but effective circuitry, with very short signal path, and usage of few selected components.
The current output devices are Darlington Bipolar transistor assisted by a solid state constant current generator.
 
HPA2:
[size=small]Unlike most amplifiers, it uses a unique current-feedback circuit rather than opamps, and is optimized for a wide range of load impedances (30-700 ohms).[/size]
 
M1:
Not sure
 
Auditor:
Core elements are the handmade SPL SUPRA op-amps running on 120 volts
 
GS-1:
[size=xx-small]Device Type[/size] [size=xx-small]Solid State (JFET, Bi-Polar Transistors)[/size]
 
HA-100
The HA-100 employs an advance discrete power supply and power filtration network, and, for the very first time, the Burson opamp technology has been channelled into a head phone amplifier. True to our design philosophy it is completely free of ICs (integrated Circuitries)
 
I guess I have more research to do.  Hopefully I will get more input

 

[average_joe]

bump

 

[downsize]

I owned a NX-02 myself .... and sold it to a great friend like a dang fool !!!!   It was just so very good, and now he won't sell it back to me. And get this :  Even though I own a crazy good amp, I WILL have another Rudistor one day !

 

[rosgr63]

The Rudistors are great amps.
skylab tried the RP3 at the Chicago CanJam and liked it.
They are one of the best amps for ultrasones.
I have two Rudistors and I like them a lot.

 

[rosgr63]

I told you they are good!
Quote:

I owned a NX-02 myself .... and sold it to a great friend like a dang fool !!!!   It was just so very good, and now he won't sell it back to me. And get this :  Even though I own a crazy good amp, I WILL have another Rudistor one day !

 

[downsize]

Quote:

I told you they are good!

 

Yup .... I'm thinking one day, there will be an RPX-33 in my future.

 

[average_joe]

Has anyone compared any of the above amps?  I have been trying to read up on the amps, but most of the posts I have seen just say the amp is good, but not any detailed comparisons.  I am thinking of just going for the Channel Islands Audio amp.

 

[downsize]

Quote:

Has anyone compared any of the above amps?  I have been trying to read up on the amps, but most of the posts I have seen just say the amp is good, but not any detailed comparisons.  I am thinking of just going for the Channel Islands Audio amp.

Yes, I have compared the Rudistor NX-02, Channel Islands, Woo Audio, and a Gilmore GS1 at a meet .... The Gilmore was very transparent, yet lacked the musicality and realism of the Rudistor, the Woo was overly warm and veiled, and the Channel Islands wasn't even in the same ball park.
 
You can't buy an amp from reading about them joe ... You can't hear an amp by it's specs or written words. You need to attend a meet, or try and find a concensus, such as the one about the Rudistor on this very thread.

 

[rosgr63]

Words of wisdom, I couldn't agree more!
 
Quote:

You can't buy an amp from reading about them joe ... You can't hear an amp by it's specs or written words.