Preamplification and high pass amplification of RS 2.5

I am currently horizontally biamping my 2.5s' with an Altec 9440A on the low pass (golden results), and a pair of Kenwood L-07M monoblocks on the high pass, via a Bryston 10b Active crossover unit, and the preamp in use is a Maverick TubeMagic D1+. The sound of the system "as is" is astonishingly good, downright superb. I have a twofold question, which, in ways, overlaps, and if there is "more perfection" to be had, I am unsure how to extract it.

When I obtained the Maverick tube DAC, (I had not begun biamping), I immediately recognized an upgrade in sound quality from the SS preamp that it replaced. At such time as I obtained the Bryston active XO, I biamped as described, to brilliant effect. The little tube DAC doesn't give any impression of being a weak link, but I simply don't have the prerequisite knowledge to identify a piece to replace it, and experience more of the same effect it seems to have.

As pure and smooth as the Kenwood monoblocks sound on the high pass, I can't shake off my curiosity concerning using tube amplification in their place. I'm sure the high pass doesn't need the 300 wpc@4 ohms my current configuration provides, but I am ever wary of underpowering the planar drivers.

So, in summary, this is my quandary, as it takes shape in my head. Ought I expect a marked improvement by going to tube amplification, and, if so, what products (and how much power) might sweeten the sweet spot I'm already in? It isn't as if I require monoblocks, but, I'm obviously not averse to the notion.

In a similar vein, I don't know which way to turn to upgrade the Maverick tube DAC. I don't comprehend tube electronics well enough to comprehend what makes the Maverick sound so good, so, it follows that I don't know how to enhance the effect, given that it can be done.

I've considered tube amplification on the high pass, and either a proven upgrade of tube DAC, or even a superior grade SS preamp/DAC in this scenario.

Any suggestions from you heavy Infinity experts out there? Thanks in advance for any advice.

kneeOhFight said:

I've considered tube amplification on the high pass, and either a proven upgrade of tube DAC, or even a superior grade SS preamp/DAC in this scenario.

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How do you run your Maverick tube DAC now? Have you tried the Tube Out on the Kenwood's? That would leave the Normal Out for the Altec bass amp. The Maverick tube DAC is a nice sounding unit. I have the Xiang Sheng DAC-01A version. I've upgraded mine a bit, with a better tube, and I've also replaced the op-amps. Both are mods which might be useful for you to try.

http://www.mav-audio.com/store/index.php/tube.html

I know from owners, and reviewers, that Infinity's like tubes; especially EMIM/EMIT based speakers. So, nothing wrong with continuing to use your Maverick until you decide what path to follow. Tube amps worthy of Infinity's aren't cheap!

I'm running L and R signal out of the Maverick tube outputs to a Bryston 10b Active Crossover Unit, which I (ever so thankfully) am using in lieu of the hard to find proprietary Infinity unit which is necessary for biamplification. My system sounds truly amazing as is. I'm just curious about if I can and how I can extricate more of the same superb results I'm getting now. Thanks for shedding some light on the matter, Stimpy Wan.

Hey, if your system, using the Maverick, sounds "astonishingly good, downright superb", don't sweat the small stuff. If your system sounds good to you, then it is good!

Maybe keep looking for the Infinity EQ Biamp unit, watch craigslist for bargains, watch Barter Town, borrow gear, flip gear. Try as many combinations as you can afford to try.
No other to way to find a more synergistic match.

If me, I always go for bang-for-the-buck gear. Mainly because it's cheaper, and offers value. For a tubed preamp, I'd be looking for one of these brands/pieces; ARC, Dared SL-2000A, Dodd Audio, Transcendent Grounded Grid, Rogue Audio, Van Alstine, or conrad johnson. Even Jolida. SS Amps; Acurus, Aragon, Hafler, Parasound, Sunfire, Threshold or Yamaha. Tube amps? That's tough. Maybe Antique Sound Labs, ARC, conrad johnson, Quicksilver, Rogue Audio, Van Alstine, or VTL. Dual Aragon amps, or a VTL/Aragon set-up, with a Rogue preamp, could be sweet!

Good luck!

Why not leave good enough alone and enjoy?

Certainly, one reason to bi-amp is to be able to put tube or tube-like amps on the high pass to get better - dare I say it - liquid mids/highs and use a solid state on the low pass for more solid bass. That's one of the reasons I went with the Aleph 2s in my setup. But the RSs need good power for the drivers so getting tube amps to satisfy that need may be costly. Though you are correct that they need not be so powerful relative to the low pass amp.

The only thing I noticed when I used a too small wattage amp on the high pass is that fast transients would be fine in the lows, but could not be satisfactorily handled in the highs as the tiny amp strained. So I'd be careful about that. YMMV.

Thanks for the comments. I might well end up keeping the system as is, because, the performance of this combination is startlingly impressive. That said, my glaring inexperience with tube audio, which led to my initial post, remains. It is my hope that someone who has experience and a degree of oversight on the topic of deploying tube amplification/preamplification of multiple Infinity planar drivers might weigh in regarding their results. The likelihood of replacing the Kenwood L-07M monoblocks with a different SS power source is remote, at best. The Bryston 10b Active XO is a permanent fixture. The chances that the Infinity unit created for the biamplification of the 2.5/4.5s' is even close to being in the same league as the Bryston XO are very remote, at best. The point that tube amplification of ample power for the high pass might be cost prohibitive is well taken. I suppose the primary question in my mind is whether the Maverick tube DAC (which, again, does not give the impression that it is any kind of weak point in the chain) is close to "as good as it gets", or, based on experimentation of heavy Infinity users, can be upgraded. I am not predisposed to kicking it to the curb, but, there are members here that have broad overviews about this topic, whereas my own is admittedly myopic. I'm simply out of my depth in terms of knowledge regarding the possibilities that might present themselves.

Gratuitous bump, in case any heavy Infinity lovers happen to look in.

I have a pair and get them running from time to time - they are awesome speakers.
I also have the external crossover, but have not used it for awhile as they run pretty well on a single amp. It may be me or my smaller selction of amps, but I didnt notice a lot of improvement - so Ihave left biamping pretty much alone and rely on a single very big amp.

Be sure to read the reviews of amps that you wish to use. Even though a prevailing opinion suggests that EMIM/EMIT-based speakers are amicable to high-power tube amplification (what the reason is, I have no idea), there is no "one standard" tube or SS sound. Maybe there used to be, but not anymore.

I've read numerous reviews that have said things like, "This SS amp has mids that are so liquid, I thought I was listening to tubes", and also "This tube amp has a graininess to it that made me think I was listening to an early SS amp." There is no 'tubes=smooth, SS=grainy but powerful' standard. Granted, good SS amps generally exert tighter control in the bass region.

Get a copy of "The Complete Guide to High-End Audio" by Robert Harley, and read, read, read.

My own setup uses SS amplification in all 6 channels (tri-amplification), and a hybrid line stage preamp (tubed output stage); I would not change a thing. This is speaker dependent, of course. I have low-sensitivity speakers which require a great deal of amplifier heft.

If I were in your shoes, I might consider a passive crossover and structural upgrade on the speakers before other electronic component changes. It might yield a bigger bang-for-the-buck result.

G~

kneeOhFight said:

The Bryston 10b Active XO is a permanent fixture.

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I assume you've worked out any phase shift and amplitude summing issues. That's one thing that can be improved on an active XO.

geoff727 said:

There is no 'tubes=smooth, SS=grainy but powerful' standard.

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So very true. My experience has been that more recent tube components sound a lot closer to the their SS counterparts and visa versa. Not necessarily a bad thing.

Kev_rat said:

I have a pair and get them running from time to time - they are awesome speakers.
I also have the external crossover, but have not used it for awhile as they run pretty well on a single amp. It may be me or my smaller selction of amps, but I didnt notice a lot of improvement - so Ihave left biamping pretty much alone and rely on a single very big amp.

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I have no illusions about what it takes to make ones' Infinity speakers sing. Either go heavy, or don't go at all. I'm sending 400 wpc on the low pass, and 300 of the same on the high pass. I'm convinced that combining 700 wpc RMS, as articulated by the amazing Bryston active XO into each speaker is the key to my superb results with biamplification. The difference to "not biamping" is jaw dropping, every time I fire the system up. I'm loving it.

Well, I use homebrew 200wpc SET monos on my RSIIb's and it's the best sound I've ever heard, anywhere. Single-amped. Better than the 500wpc Gilmore Raptor monos, better than passive biamping with the Gilmores on top and an 800wpc Crown on the bottom.

One can never tell until one tries...SET on big Infinity speakers! Whodathunkit!

Maxamillion said:

Well, I use homebrew 200wpc SET monos on my RSIIb's and it's the best sound I've ever heard, anywhere. Single-amped. Better than the 500wpc Gilmore Raptor monos, better than passive biamping with the Gilmores on top and an 800wpc Crown on the bottom.

One can never tell until one tries...SET on big Infinity speakers! Whodathunkit!

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Stated with enough conviction to convince me. That is a spectacular looking system. If you are so inclined, please do tell, and identify the electronics. I am seriously curious.

You can approach things differently - if your source is digital only, you can use digital crossover and then a dedicated DACs for lows and high frequencies. Digital crossover can be tuned much better than analog one with adding delays or phase shifts independently. It can also be used to tune speaker/room interaction.

kneeOhFight said:

If you are so inclined, please do tell, and identify the electronics. I am seriously curious.

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We're Not Worthy...!!!

Incredible story behind those amps! Probably the most spectacular pair of amps that I've read about! Just epic...!!! :yes::yes::yes:

Maxamillion will hopefully share the story here too.

The amps were designed and built by me. 6E5P input tube, 833C DHT output tube, 2300V plate voltage, 180lbs each.

The preamp was also designed and built by me. #26 DHT tube, with 5Y3G rectifier and 0D3 and 0A3 voltage regulator tubes.

Source is a Zero One Mercury CD/HD player.

More shots of the amp and preamp:

for_p1 said:

You can approach things differently - if your source is digital only, you can use digital crossover and then a dedicated DACs for lows and high frequencies. Digital crossover can be tuned much better than analog one with adding delays or phase shifts independently. It can also be used to tune speaker/room interaction.

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Point taken, but, I'm standing pat on the Bryston 10b Active Crossover. If it was any better, my head would explode. I do run digital only sourcing.

More than you ever wanted to know about the amps...the build thread, 77 pages and counting.

http://www.diyaudio.com/forums/tubes-valves/232484-midlife-crisis-my-833c-amp-build.html

Maxamillion said:

More than you ever wanted to know about the amps...the build thread, 77 pages and counting.

http://www.diyaudio.com/forums/tubes-valves/232484-midlife-crisis-my-833c-amp-build.html

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Excellent, thank you. I will soon be snooping on that, from the beginning.