I see you listed your Pass monos. Did you go BATty?
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Much better (to my ears).
In comparison, the Pass don't control the woofers of my Wilson Sophia 2's as well. The Pass is much warmer sounding and rolled off on top.
The Bat is a tad less smooth in the highs, but much more airy, the bass is tighter and more satisfying and overall tonal balance feels more correct.
07-08-10: MadfloydIt was well established in another post that there was an improper preamp match with the Pass Labs amps in Madfloyd's system. The preamp he used had a very high output impedance of over 2k ohms. Therefore, what he heard in his system was not the fault of the Pass Labs amplifiers, but with a poor impedance match.
I imagine one will be hard pressed to find another person who hears Pass Labs XA-.5 series amps as being rolled off on top and not in control of the bass when the amps are matched with an appropriate preamp (not hard to do).
07-09-10: KeithrI have not had VK600 in my system.
impedance mismatch i thought would only be an issue on the bass, not on the top end.Not necessarily. Regardless, has any other owner commented about a rolled-off top end on XA-.5 series amps? I haven't found any, but I'm interested to read comments from XA-.5 owners who have experienced this (along with accompanying equipment).
Tvad, when I compare these two amps, input inpedance had nothing to do with it.
My main SS preamp is an H20 Fire, which has no problem driving the Pass.
My other SS preamp is a Parasound JC-2. I've used many other preamps with the Pass as well, including the Pass XP-20.
When I say 'rolled-off', I mean in comparison to other amps, i.e. the Pass is slightly darker sounding than my Bat, or other amps that I've owned (Theta Citadel 1.5 comes to mind). This is with solid state preamps, NOT tubes.
Yes, I tried a couple tube amps that were not good matches with the Pass (Ref 3, Audio Valve Eklipse), but that hardly means EVERY preamplifier I've tried has been a mismatch.
No amp does everything well. Pass amps are biased towards great midrange and in my humble opinion, aren't the last word in bass control.
Thanks Madfloyd for being specific about the preamps you used. I don't recall previously reading about these pairings.
I disagree completely with you on your comments about midrange, rolled-off treble and bass control pertaining to the XA-.5 series amps.
Those on the hunt can only hope your comments causes others to develop some audionervosa and dump their Pass Labs amps, thereby providing some buying opportunities. There's always a silver lining.
Well, I'm just saying what my ears are telling me, in my system, my room etc (although at least two other audiophiles agree that the Pass is warmer than the Bat in my system and that the Bat has better bass).
From what I read, Class A sound is warmer. For example, see keithr's post in this thread:
Those on the hunt can buy mine which are for sale here on Audiogon. :-)
There's nothing wrong with any of the items and I've tried them all with the Bat. I'm not selling them because they sounded 'bad', I bought some of them simply to audition to see if they bettered my current fav.
Some I would prefer to keep (especially the Fire) but cannot afford to at the moment.
It's been a great learning experience and I have now found a combo that works for my taste and my room.
Interesting. The Joule is highly regarded for its bass (at least that was the focus of Harry Pearsons review in TAS).
Id love to try a BAT preamp (and hopefully will someday), but somehow Ive also got the impression (from reading posts here) that it would be darker sounding than the Joule. I could be wrong of course, but like bass, the highs are something that can be problematic with tube preamps so I worry about this.
I thank you for your thoughts.
I am demoing the Joule LA300 right now. It is a very nice preamp. Great microdynamics, and upper midrange. Compared to the Rex, the bass is not as articulate or defined. The Joule goes low, but the quality of the bass is not on par with the BAT. The Rex holds-up better with orchestral pieces. The Joule sounds excellent with smaller ensembles.
I have not made-up my mind as to which I prefer. I kinda want the upper frequencies of the Joule, and the lower frequencies of the BAT...
Hi Madfloyd, I've really hit paydirt with my current combination. I considered the VK150SE, but not so much the BAT SS. I was reluctant based upon room size to go with the BAT tube amp, although the Rex amp would be very interesting. I still think the Pass gives a more relaxed and flowing presentation compared to BAT VK150SE, but the BAT amp has great texture, detail, and dynamics.
I did check the Joule unit and made sure the jumper was on the lowest impedence setting. Whether the Joule 300 has better bass than the 150, I cannot say. Two minor confounders between the BAT and Joule, is the difference between RCA vs. XLR, and I am using Cardas RCA vs. Jade Audio XLR. I do not think this would account for the difference I hear.
I thought I would be able to extrapolate the experience of the 300 to the 450. The Joule has a slightly more natural and organic midrange. As of tonight, I think the difference in lower frequency response on the Joule would preclude my long-term enjoyment, based upon the type of music I prefer. It just does not seem to hold-up as well with orchestral pieces. I will be listening to the Joule over the next week to see how things wear, but I do not think I can buy the 450 without a home demo. I will probably work with the Rex, and try a combination of different tubes to get a balanced sound. It will also be interesting to put the BAT back into the system after adjusting to a different preamp for a while. One good thing about both these preamps is that they are dead quiet, an absolutely essential quality for my listening.
Most pieces of equipment are about trade-offs. I've found many with no perceived trade-offs to my ears, but tube preamps definitely have different flavors.
After having the Joule LA300 in the system for several weeks, I am very happy to have the BAT Rex back.
The Joule overall is smooth and warm, and has a pleasant midrange that immediately stands out. It made pop, rock, and jazz sound very nice, even with less than the best recordings or even subpar performers. For classical solo and small ensembles, it had a very good and inviting sound.
The BAT makes brass bite, massed strings shimmer, woods vibrate, and violins sparkle. It excels at texture, detail, lower end defintion, and dynamics. It provides some excitement, and a live feeling. Large orchestral pieces are well delineated and powerful. You can dial-in the excitement and dynamics by adding NOS 6H30 tubes. I find using all 8 NOS 6H30 tubes to be a bit over-the-top for my taste. Right now, I have a pair of NOS tubes, and the other 3 pairs are new Sovtek, and it seems to provide a very good balance.
Perhaps the BAT is simply synergistic with the Pass XA.5. The Joule LA450 seems very interesting, but without a home demo, I am unlikely to take the plunge. Right now, I am very satisfied with what I hear.
I also have experience with both REX and LA-300 and in many respect it matches yours and as a cello player I prefer "300" - its sounds (mosatly midrange where life is) more authentic to my ears, more as real cello including bottom octaves.
REX has tremendouns power supply, technologically may be better then "300" and its bass control is iron clad, no question here. With LA-300 I have similar bass, may be not as tight but somewhat richer and more accurate and I prefer it again (very slightly) by Joule-Electra. This preamp drives my Spectrons amps and B&W 802N speakers
Two points: for my ears the Cardas wire always show very good midrange but somewhat weak bass. I am not familiar with Jade Audio but all hi-end J-E preamps have David Elrod hook-up wire and I listen with David's interconnects which clearly add to the synergy.
Secondly, if you prefer XLR and very powerful power supply then you should compare REX not with "300" but with LA-450ME. Its power supply contains three times more energy then LA-300 and in separate chassis( and while its less important REX and 450 cost about the same while 300 is about 50% cheaper....)
To say that you made poor choice with REX - nobody will.
Hi Dob, I appreciate your observations.
I did ask about getting the LA450 for demo, but that was not possible without purchasing it. I agree that the Cardas cables and RCA connectors need to be considered in the comparison, which is why I offered that caveat. I personally think Cardas adds a haze to the midrange, and is soft on the top and bottom.
But I actually think the Rex has a better and more realistic midrange in my system. This surprises me, because the Joule midrange was quite intriguing for a week. But as time passed, it became smooth, less intersting, and less real. Perhaps the Joule is too cloying with the Pass amp, and it is a synergy issue.
I do believe the LA450 is a different beast, and would probably provide much more power and control. But for now, my curiosity has been addressed.
In any event, it is clear you are a music lover, and I am sure the combination you have put together is wonderful in it's own right.
"I love my Joule LA-150 SE but I do wish the bass was better... "
You should have very good bass. Check you impedance matching (already mentioned above) and cables.
If you can afford David Elrod Gold Statement then you would improve your bass (and midrange and tops and your life) very substantially.
If its too expensive - I use for my power amps the most recent power cord by Spectron Audio, Thunderbolt which is 3.5 time cheaper then Elrod. Nobody beats Elrod overall, nobody ...but in my system, with Spectron power cord, the bass is better: much deeper, tighter etc. My ears are not that they were 100 years ago but with deep bass its easy, I judge it by vibrations in my chest and my guts - I am sure you know what I am talking about and with Thunderbolt, its unquestionably "greater" experience (for me).
Elrod speaker cables (starting from silver and relatiely affordable) are excellent and will bring your missing bass, pronto!!!
I don;t know good and affordable interconnects to recommend, sorry
All The Best In you Quest For Bass
"The Joule LA450 seems very interesting, but without a home demo, I am unlikely to take the plunge. "
When I was buying my LA-300 (to match Spectrons and Watt/Puppy 8) I been told by Simon Thacher that I have 30 days money back guarantee minus shipping and some re-stocking fees.
I fall in love with this combo and live immensely HAPPY!!!
I believe both Spectron and Joule-Electra are committed to constant improvments (I already upgraded my LA-300 once) but with speakers I had to order new generation (Sasha) no upgrade and with good $$$ (Im waitin' still but I know its worth it).
At anyway, you could have the home demo of LA-450 but REX is more then excellent preamp as well considering its relatively high output impedance. Enjoy!
Hi Mike, I inquired about arranging a demo for the LA-450. At this time, it does not seem possible without buying the unit. There are no extra LA-450s out there. Judd makes one to order, and it seems that dealers don't want to be stuck with an expensive piece they may not move for some time.
I also really like the build quality of the Rex, the digital volume indicator, and the remote control.
I am late to this party but I have a LAP 150 MKII just upgraded to Signature edition. I received my preamp back in August so I now have it broken in. The upgrade added a lot of needed bass as well as overall better performance. My Savoys have 4 12" woofers per speaker and I can feel the difference with the upgrade. Jug did tune the impedance to match my Spectron amps. I am not sure what made the difference but I am quite happy with results. I am surprised you do not have bass from your LA 150SE preamp. I know of 2 things which also helped my bass were Elrod power cords and short Spectron Remote Sense Signature speaker cables. This all added up to better bass. I have not tried either amp but Pass was on my list so I cant help you there.