Rudistor RPX-33 Dualmono Headphone Amp Mark II: Impressions and Review (with Pics!)

For SH Forum Members, this is a reprint from www.head-fi.org, the Headphone epicenter of the web. A "headphone amplifier" is a dedicated device that serves the same purpose for headphones (on that scale) as a power amp does for speakers. I'm still very early into this review, and follow-ups will be posted here and on Head-Fi.

Intro
Amp review time again! :he90:

Today, all the way from Italy, I received the latest version (Mark II) of Rudi's (Rudistor) RPX-33 dualmono headphone amp. Like the original, the new version is a totally discrete pure Class A dual mono amp. Dual mono means that it has separate power supplies and audio circuit boards for each of the 2 stereo channels. The Mark II differs from the original in that the power supply has been upgraded, and it has a new, more expensive volume pot in the form of the ALPS RK-40. It also sports a set of pre-outs to use it as a pre-amp in a speaker-based system.


Review Background
I'd like to point out, for the conspiracy theorists among our ranks, how my reviews work. FWIW, if anyone cares, I no longer write reviews of products I don't like (unless it's put out by a huge nameless, faceless corporation that will still be there tomorrow no matter what markl says on some message board). Sorry. It's not worth the headaches and bruised feelings with the manufacturer (as I've painfully found out, the phenomenon of us over-identifying with our gear is nothing compared to the way a manufacturer over-identifies with his own product-- ouch!). Also, I am one data point, and just because a product didn't work in my system doesn't mean it won't sound stellar in someone else's. I also don't have time to go on and on (as you know I tend to do ) about a product that didn't work for me.

So, when a manufacturer contacts me, I tell them that I won't post any negative reviews, just send the product back without comment if it doesn't work for me. If I like it, but have moderate/mild reservations, or most especially if I *love* it, then I will write it up.

Not everything I review was sent to me "free" as a review sample (and no, I NEVER get to keep the gear I review unless I buy them). Sometimes I make a purchase and write it up without the manufacturer's knowledge. In this case, I was contacted some time ago regarding auditioning a Rudistor amp, but that never came to fruition. Recently, I upgraded my source and became curious to hear some new amps, so I reminded Rudi of his previous offer, and he graciously volunteered to send me the RPX-33 Mark II.

And so, here it is. And here we go. :he90:


Web Site
http://www.rudistor.com/


Pricing
1300 Euros, or approx. $1650.00 US dollars.


Images
Here's a pic of the RP-33 on top of my RAM modified Sony XA9000ES. I really like the silver faceplate as it matches my Sony pretty well, and I love the look of brushed aluminum to begin with. For scale, you can see the headphone amp section of the Ray Samuels HR-2 on top of the Rudistor (as you know, the HR-2 separate power supply is attached via umbilical and sits on the floor).




Here's a close-up showing the two separate headphone jacks, labelled "High" and "Low" (more on this later).




Here's a look at the rear with all my cables.




Finally, here's a shot of the insides from Rudi's site:




Previous Headamps I've Owned
My memory is fading so I'm missing a couple, but here's a sample of the gear I've owned or been sent to audition, listed in the order I heard it (does not include amps heard at meets):

1. Headroom Home (circa '99)
2. Headroom Maxed Home (circa '99)
3. Earmax
4. Earmax Pro
5. Berning MicroZOTL
6. Melos Maestro
7. Ray Samuels HR-2
8. Ray Samuels XP-7
9. Ray Samuels Stealth
10. Ray Samuels Raptor

My current weapon of choice is the utterly marvelous Ray Samuels HR-2. It rocks. Period. I like it better than his tubed stuff (so sue me ).


My System
Source- RAM modified Sony XA9000ES CD/SACD player.

Interconnects- Virtual Dynamics David single-ended RCA.

Power Cables- Virtual Dynamics Nite II on my source, Black Sand Violet on my headamp.

Headphones: Sony MDR-R10, "King" of dynamic headphones.

Rudistor RPX-33 Build Quality / Fit 'N Finish / Ergonomics
It's a surprisingly heavy amp, a one-box solution as opposed to the two-box Ray Samuels amp. The casework is nice and heavy and bullet-proof. I really appreciate the silver brushed aluminum of the faceplate, looks very nice. RCA jacks on the rear are suitable beefy, typical of gear in this price range. All in all a rugged, well-built piece, it feels sturdy and robust. Fairly attractive, too, but not extravagant.

The volume knob is awesome, huge and shiny silver. it has a nice action, and provides a more gradual advancement in gain than the HR-2.

Speaking of gain, a quick word about the two headphone jacks, one labelled "L" for Low, the other "H" for High. No, they don't have different output impedences for low or high-impedence cans; instead, the difference is purely in terms of gain. Even though my R10s are low-impedence cans, I have them connected to the "High" jack, as I prefer the increased sense of dynamics I get from that output (YMMV).

One minor nit-pick. It's just me, but I have a *thing* about those little metal on/off switches the RPX-33 uses. It's one of those little spindly knobs that you flip, not a regular switch or button you press. They always look and feel kind of cheap to me, but there you go. I agree it's kind of stupid to spend a lot of time worrying about the on/off switch on your $1600 headamp, but you know how it is! :he90:


Day 1 Impressions
We are spoiled. SPOILED, SPOILED, SPOILED, I tell you!

I've been seriously into headphones since the early 90s. It wasn't until the late 90's that we first started to have a real CHOICE in terms of headphone amplifiers. Props must be paid to the trailblazers at the estimable Headroom. They are pioneers in the headphone arts and it's really them that popularized and validated the once ridiculous concept of a *headphone amplifier*. Yes, there was a time before headamps existed, and yes, it was the Stone Age of headphone audio, though it was not that long ago. How audacious and absurd the idea of a "headphone amplifier" once seemed.

Now, we take headamps for granted and have become blase about them and we actually *expect* a new headamp every week to be introduced or announced here in these very forums. If you've only recently come on board to Head-Fi, please know that this is NOT normal or how it has "always been". Everyone and his brother now has a headamp as part of their product line. Competition is stiff.

We are the lucky lucky lucky beneficiaries of all this. The envelope for the concept of "headphone amplifier" keeps getting pushed further and further downfield to almost absurd lengths.


At first blush, IMHO, the Rudistor RPX-33 Mark II is one formidable headphone amplifier. It pushes nearly every one of my audio hot-buttons simultaneously. This amp ROCKS.

Here are my disorganized, random, and hap-hazard thoughts/initial impressions. As time passes, I'll be able to put them in better order, and make them at least somewhat coherent.


1. BLACK background. A black black hole.

2. totally clean and CLEAR window onto the sound.

3. Hefty SLAM and grinding, pounding, full bass. TIGHT, TIGHT, TIGHT bass. This amp has a rock-hard GRIP on the sound.

4. Creamy, THICK quality. Firm, "present" sound. Very high "palpability" factor. You *feel* all the sounds as much as you witness them. Sounds tickle and excite the ear. This is a highly INVOLVING sound. You are called out from the side-lines and asked to boogie, which you will do with reckless, joyful abandon.

5. Sound comes to LIFE. It breathes, and seethes, and surges. It bubbles and errupts without losing shape or getting muddy or blurred or fraying at the edges. POWERFUL sound, incredibly FIRM and ROCK SOLID.

6. Absolutely non-fatiguing sound WITHOUT rolling the high frequencies. As I love to do, you can CRANK this amp up HIGH without harming your ears at all.

7. Totally OPEN and inviting. There is no "veil" or fog between you and the performers. YOU ARE THERE.

8. ORGANIC and NATURAL sound. It sounds just like life. This amp is anything but "THIN", reedy, spindly, or anemic. It's FULL, ROBUST and COMPLETE.

9. Deep, wet, and liquid sound. This is the antithesis of dry, digital, arid, analytical sound.

10. AUTHORITY. This amp speaks with such assuredness and authenticity, it leaves me slightly slack-jawed. Damn!

11. This amp takes no prisoners. It slays and conquers the music. It's in complete and total charge, and it's 100% right all the time, no doubt about it.

12. This is a "sleeper" product on these boards that IMO needs to wake up. It would surely excite and involve and enrapture many Head-Fiers. This is a REALLY REALLY GOOD AMP.

13. There is very likely a Rudistor RPX-33 in my future.


OK, so, on Day 1, sans any burn-in, as you can read, I'm pretty darn enthralled with the Rudistor RPX-33. It has a lot to offer, and I'm very very excited right now. However, as you and I both know so well, over time, little flaws will become more and more obvious. As time goes by, I will report on them as I hear them.

I am really really really turned ON by this product so I'll likely be posting more thoughts and editing this post as I go.

Stay tuned!

 

Damn. Damn, Damn. This amp is surely ON ANOTHER LEVEL. I can't believe how good it is. 100% in the POCKET. Anyone who ever said the R10 has "no bass" never heard it attached to the RPX-33. "Awesome" is such an over-used, de-valued term, but really, "AWESOME" is a percfect word to describe the RPX-33.

The RPX-33 is HARD CORE, off-the-hook EXCITING. Everything I could have wanted or expected in a headphone amp, the RPX-33 delivers. It provides PURE, RAW, FULL, COMPLETE sound.

If you ever wondered, "what does a headamp do?", the RPX-33 is the perfect answer. It will shut you up on that topic.

This is a REAL "High End" piece of audio without the usual "sissified", "weak" or "lame" sound we've come to expect from watered down pathetic gear that wants to impress by not offending. The RPX-33 has it all, everything I ever wanted or expected from a headamp is here in spades. It pulls no punches, but lets you have it ALL in VIVID GORGEOUS DETAIL.

Rudi (I know you're reading this), without a doubt, I will be purchasing the RPX-33. It's a real magical piece of audio, that suits my needs perfectly.

 

Day 2 Impressions/Observations
More fun! Here are my listening notes for Day 2. I've been burning it in 24/7.

1. No grain or "digititis".

2. Superb with electronica.

3. It's like the music is coming through a bigger pipe than before.

4. Makes everything sound good, even crummy recordings. The gear I gravitate toward always seems to make everything you throw at it sound good, even recordings you know are seriously flawed. I don't know how this works, it's a mystery to me. I've found there's gear that acts like a microscope on the master tape, showing in minute detail all the ways it's just plain *wrong*. That sound is seductive in its own way, but at the end of the day, I want to experience the MUSIC, not the TAPE. I tend to prefer gear that presents the illusion of reality that the artist and the recording engineers were going for. So, at the high end, I experience gear that is utterly literal minded and ruthless to the point of being unrealistic, and gear with an imagination that projects the sound in a way that makes it sound real and like an actual event. You'd think you'd trade-off a lot of detail or that gear like this would be "forgiving" in the bad sense of covering over or obscuring flaws. But I don't find that the case. The RPX-33 is a case in point; it's incredibly resolving, but it pulls off the music from the tape, it doesn't pull off the *sound* on the recording, if that makes any sense. You are listening to a performance, not a piece of tape.

5. I'm hearing A LOT of new information/detail/small sounds on CDs I know by heart. The RPX-33 is great at delineating between individual audio tracks in the mix. Instruments are nicely separated and complete in and of themselves. Complex mixes made up of a million tracks are easily discernable on a track-by-track basis. Yet the detail isn't crispy/digital/outlined/fake, it just "happens" naturally without effort as it should. It doesn't shove it under your nose, it's very naturalistic.

6. Music has that "lit from within" quality that is the hallmark of tubes. Don't get me started about tubes... I love the tube sound, but I HATE everything else that goes along with the tube experience. The extra expense, the reliance on shady tube dealers, the fact that they wear out and have to be replaced, etc. etc. It's a hassle and a mess, IMHO. With the RPX-33 you get a lot of the great tonality and analog-ness of tubes without all the problems.

7. TONE. The RPX-33 has it in spades. Sounds are more fleshed out, more nuanced, more completely *whole* than I've heard. Instruments sound more like themselves. It seems to paint its picture with a more diverse and complete pallette of colors.

8. It's stripped away some sibilance I didn't even know was there. S's are silky smooth as a baby's behind.

9. I get to re-experience all my favorite music. As you know, the best gear renews your music collection and allows you to see/hear it in a whole new light. But the RPX-33 does this without simply placing the em-PHA-sis on a different syl-LA-ble. It has so much pure resolution, you are definitely not hearing a re-shuffling of the deck, but a whole new thing. As it was actually recorded.

10. IMAGING. You are close enough to smooch your favorite female singer. It's BIG and BOLD, but *intimate* at the same time. Everything is starkly drawn and rendered. But on small acoustic recordings, it's just you and the performer, one-on-one. It does BIG and it does *intimate* with equal aplomb.

11. BASS. Once you've experienced the bass from this amp, you're spoiled. Nothing else will do. It's taught, solid, low, growling, sublime. Basso profundo.

12. I remember reading a while back an evaluation of Rudi's designs by another amp designer as "old fashioned" (I'm paraphrasing). I would say "tried and true". I would also argue that the proof is in the pudding. To criticize on that basis, it seems to me, is to criticize every single tube amp in production (even though this designer uses tubes in some of his amps); after all, how more quaint and out-dated can you get than tubes, for crying out loud? Me, I don't care how sound this good gets to me, so long as it arrives. And the RPX-33 delivers.

13. This is going to sound crazy, and I wouldn't have the balls to say it if a certain high-profile audio journalist hadn't recently said it first: you can tell a lot about a product by the way it handles/presents tape hiss. Yes, you read that right, tape hiss. Is it crispy and spiky, or metallic and harsh? Or, is it smooth, analog, warm and soft? What is the basic *texture* of the tape hiss? Is it louder than it should be, or is it thin or does it have some depth to it? The answers to these questions, IMHO, can go a long way toward explaining the sound you hear the component making with actual music. The RPX-33, I'm happy to report, has very soft, low, analog, smooth and refined tape hiss. That sound carries over to everything else. Sure-- flame away, I know what I mean and what I'm talking about here even if you don't!

14. RPX-33 succeeds at that near impossible trick-- give me a vibrant, vivid and lively sound, but at the same time don't tax my ears and cause me listening fatigue. I can listen to the RPX-33 at my preferred volume (loud) all day long without experiencing a shred of fatigue.

15. MUSICALITY. Despite its awesome resolution, this is one utterly *musical* amp. It's not cold or analytical. It's just plain yummy and delicious!


OK, so that's it for my early impressions. I'll follow up after a while and after burn-in is complete with some final thoughts. IMO, Rudi deserves a lot of credit for this amp, it's so so purely enjoyable. If you've followed my reviews, you know I can really lay into products that don't measure up. However, when I find something that I really like, I want to alert everyone to it. Yes, I do get carried away. But I LOVE music, and anything that connects me closer to it or enhances my enjoyment of it is worth trumpeting. The RPX-33 is one such piece.

At this moment, for me, the RPX-33 is one of the finest audio components that have ever cycled through my system (and there's been A LOT). Yes, the sheer level of *performance* it provides in the abstract is several steps ahead of what I've heard previously, but, yes, this Rudistor certainly has a sound of its own, no doubt about it. But, as you see, that sound is the exact one I happen to love.

I do believe it would appeal mightily to a large cross-section of Head-Fiers. It deserves your consideratiuon, and should be heard. I can heartily, happily, fully, unreservedly recommend the Rudistor RPX-33!

 

OK, so not every SH Forum Member is a headphone afficianado. If you were, you would clearly take a bigger interest in the following:


Day 5 Impressions (120 Hours Burn-In)
I bought her, she's mine, and you can't have her!


Value vs. Cost
I've been thinking back over my millions of audio purchases I've made over the years trying to pinpoint particular upgrades that gave me a jump in performance comparable to what I'm hearing with the RPX-33, and there aren't many. Going from a Sony V6 headphone to a Sennheiser HD580 in 1995 is up there, as is going from the Sony CD3000 to the R10 in 2001. Going from my $350 Infinity speakers to PSB Stratus Goldis in 1999 is probably the most extreme example.

But somewhere in that range is the leap in performance I feel I'm getting from the lovely Rudistor RPX-33. I have to say, it's making me totally reconsider the importance of amplification in a headphone rig.

In my mind, it was never necessary to spend ridiculously on an amp (half the cost of your source seemd about right). I went through a lot of headamps in the $500-$1200 range. All were different and unique, but the jumps between the lesser and better ones was always pretty typical for the usual audio upgrade.

The Ray Samuels HR-2 that I've used very happily for the last several years was the biggest improvement within the range of jumps I'd heard from a headamp, though it was not the most expensive. I really felt that it was about at the maximum end for what an amp could really be expected to do. I never ever had the sense it was a bottneck. The HR-2 was a very valuable tool for evaluating interconnect cables, and for evaluating power cord swaps on my upstream source. These modest to mild differences were clearly rendered on the HR-2.

And, when I recently upgraded my source from a sacdmods Sony 555ES to the twice as expensive RAM modified Sony XA9000ES, the humble HR-2 really let me hear the increase in performance quite easily. So again, even on this new source, I had no reason to question the HR-2.

Then I got the RPX-33 review sample. Yes, it is roughly twice the cost of the HR-2, but I was expecting similar performance level, maybe different flavoring. I wasn't particularly in the market for a new amp (I'm still fiddling with the cabling on my new source), but was open if I heard something I liked that justified the extra cost.

Boy did I! :3000smile Sometimes when you get a new piece of gear, even one you've been eagerly anticipating, there can be that decrease in enjoyment as it slowly struggles to earn your trust, and as you are constantly bracing for ways in which it might be deficient, slowly making up your mind whether it's up to snuff. Then there are those pieces where the connection is made instantly, and the quality is so obvious, you go straight into musical bliss, rifling your CD collection unable to wait to hear all your favorite stuff. I knew within the first 10 seconds of the first song I played through the RPX-33 that it was something else. It was love at first hear, the difference was unmistakeable to me.

Long story short, it just goes to show you don't know what you don't know. Until you've actually heard "better", you can't be sure there's "better" sound out there than what you have because you've never experienced it. It's all just so much speculation on your part. What would "better" sound like anyway? How do I know it's even possible?

There was a time I would have thought that $1650 for a headamp was an imaginable, but slightly excessive expenditure. Now I think $1650 for the RPX-33 is a bargain. Yes, it's still about half (less actually) of what my current source costs, so that ratio still holds for me, but I do now think it would still sound magnificent even on sources priced identical to the RPX-33 itself. If only I had the scratch to afford Rudi's RP010. I can only begin to imagine how that baby must sound.


Day 5 Thoughts/Observations
1. Sound is ruler flat, no anomolies, full extension top and bottom. Everything sounds REAL and natural; it continues to raise the hairs on the back of my neck. We always think our current gear is the most realistic until we hear something new that is even more like life. Only then can we hear its colorations, when they've been stripped away by something else.

2. Blacker background than even the HR-2, this continues to increase in blackness with burn-in.

3. Power to burn, it never breaks a sweat. But you might from all the boogieing and foot-tapping you'll be doing. When I'm not nodding my head along with the music, I'm shaking it in gleeful disbelief. Dynamics on the RPX-33 are at times jaw-dropping. On non-compressed recordings (i.e. things not mastered "hot" like most modern recordings are sadly), when large volume shifts occur, when big crescendoes happen, the pure drama of the change in intensity can be delightfully overwhelming.

4. Soundstage. Every time I get a new piece of gear I like, I say the same thing-- wow! BIG soundstage! DEEP soundstage! Yawn. Well, it's the same here, too, only more so. I love a big and deep soundstage, but I'm aware some people inexplicably get freaked by what they perceive as "exaggerated" soundstage (whatever that is! ). Maybe it has to do with some gear's tendency to spread the sound so wide, it gets thin and gauzy and loses definition and substance at the edges. The RPX-33 has this amazing solidity and stability to the sound that is the same at the center of the image to the very edges of the soundstage. This makes for an incredibly coherent stage. Every perfomer is clearly delineated in their own pocket, and carefully constructed mixes are layered in such a way to easily create the illusion of depth, with everything in its right place. 3D doesn't begin to describe it, because that sounds like a cheap special effect, instead of the way it's *supposed* to sound (like it does in real life!). If soundstaging/imaging are major hot-buttons for you (as it is with most closed-eye listeners like me), the RPX-33 is extraordinary. It requires ZERO effort to allow your minds eye to "see" all the performers, it's eerie-- you are THERE. Expansion of soundstage boundaries, increase in image stability and blackness of background, and removal of veils are just natural by-products of eliminating noise/distortion through better components and better circuits, and increased power you get with better gear. Don't be scared! It's *supposed* to sound like this!

5. Human voices are rendered beautifully and realistically- all the passion and nuances are right there.

6. Electric guitars are crunchy and chunky, without getting frayed or piercing.

7. Kick drums are insanely punchy, they just "pop". Drum sounds in general are very full, deep, and natural. Snares in particular are especially snappy, crisp, martial and taught.

8. Electric bass guitar (a real problem for headphones) is rendered far more realistically with the RPX-33 than I've heard. Impossibly tight, impossibly low and growling, snarling. It pumps and grinds with real heft and definition. It makes other amps sound hopelessly mid-bassy, by taking the whole bass expression down several notches in tone and depth. You are finally *starting* to get the kind of bass sound you naturally expect out of 8" woofers on a set of full-range speakers with 150 watts behind them. But I don't want to give the impression the bass is over-powering or out of proportion for you sensitive types. It never treads on other frequencies or over-projects in a distorted blown-speaker way. The RPX-33 has way too strong a grip for that to happen. Bass is one of the four major musical food groups, and should be solid part of the audio diet of every healthy red-blooded audiophile. It's good for you! The RPX-33 is wholesome vitamin-fortified USDA Choice.

9. RPX-33 demands to be listened to loud (never crazy loud-- SAVE YOUR EARS!). I'm not a low-volume listener, so I can't comment too much from that perspective, but in general, I find that most headphones don't sound good at low volumes, and most amps don't either. It all sounds kind of same-y and small to me. It when you open up the throttle you get to really hear what your amp and headphones are capable of. So, within the range of normal listening, I'm at the "loud" end FWIW (but not dangerously loud, it's never so loud I get fatigued).

10. On Day 5, I still have yet to find anything to actively criticize. It's all good, all enjoyment, all new undiscovered territory.


I actually have more notes but I'm out of time! (Aren't you lucky! ) That's it for now. I wasn't going to write again for another week or more, but I couldn't resist-- too excited! :3000smile


Just a quick edit to add these shots of the amp's innards:

 

Final Thoughts
While I've only had this amp for 2 weeks, I acknowledge it may be a bit early for "Final Thoughts", but my mind is 100% made up anyway. I don't need to hear anymore to know exactly how I feel, it's not like the difference is hard to hear. I listen daily and am lucky to have several hours per day I can devote to this hobby of ours. So, I know I have a full handle on the sound of the RPX-33 Mark II. It now has 250 hours of burn-in on it, though I feel it had fully evolved somewhere around the 180 hour mark.

I haven't been this excited by any single upgrade I've done to my system since I got my hands on a pair of Sony R10s back in 2001. The improvement for me is that big. Every minute with RPX-33 is a new epiphany, and a new joy. I usually have caveats, reservations, and nit-picks even with gear I like, but I'm at a loss to find anything to criticize with this Rudistor.

But there is one thing I've decided needs clarification/illumination or a little more thought. As I mentioned earlier, a few months back, I made a serious upgrade in my source from a sacdmods 555ES to a RAM modified Sony XA9000ES. This represeneted double the cost on the base unit and double the cost of the mods, so an extreme upgrade all around. Even though the difference between the two sources were immediately unquestionably apparent on my previous amp, the mighty Ray Samuels HR-2, it's certainly plausible I wasn't able to hear everything this new source had to offer with that amp. So there is the possibility that the quantum leap I'm experiencing with the new Rudistor could be as much as 50% due to the earlier source upgrade. It's possible that only now, with the RPX-33 in place, that I'm able to hear the RAM XA9000ES fully unleashed and unhindered in all its glory.

Whatever the exact percentage of cause and effect, the end result is pure bliss. This amp makes me happy happy happy. :3000smile It brings music to LIFE.

According to Rudi's site, he uses many sophisticated machines that go "ping" to measure his gear. :3000smile Given how clean, full, pure, vibrant, clear and black of background the sound from the RPX-33 is, I have no doubt whatsoever that this piece measures like a champ. But as a subjectivist, I know that measurements are not the whole story by a long shot. Though he doesn't talk about this on his site, my impression from the RPX-33 is that Rudi is a designer who actually LISTENS to his gear and uses his ears as the final judge as to the merit of any particular design. I'd be willing to bet his final designs are the result of a lot of trial and error, backed up by hours and hours of listening. Some designers are mere engineers and scientists; others are artisans. Based on the RPX-33, I think Rudi falls into the latter category.

For me, the RPX-33 achieves two seemingly contradictory goals-- it provides incredible resolution, cleanliness, precision and naturalness, but at the same time sounds deliciously meaty, full, vivacious, liquid, energetic, solid, powerful, and defined. You could swear it must be cheating somehow, adding tube-like euphony somewhere to make it all sound so damn good and tasty, but I'm at a loss to pinpoint where this might be happening. In the end, I don't think it's there at all. I think music is *supposed* to sound like this, the RPX-33 just gets out of the way and lets it all through. "Un-veiled", "unleashed", "unfiltered" and "unhindered" only begin to describe it.

I think this amp is totally capable of pleasing both sides of your brain-- the left side that demands truthfullness, honesty, and precision; and the right side that wants lushness, fullness, romanticism, and emotional expression and involvement. It fully indulges your masculine need for power, PRAT, control, and forcefullness, and balances that with your feminine need for emotional CONNECTION, closeness, and FEELING.

So why short change either half of your psyche? Pick up a Rudistor RPX-33 and watch all your synapses on every hemisphere of your gray matter light up in total, blissful approval? :3000smile


My highest possible recommendation for Rudi's breakthrough RPX-33 Dualmono Mark II. $1650? A BARGAIN!