Benchmark LA4 vs Linear Audio Tube microZOTL Preamplifier (Level 2)


I have enjoyed my LA4 preamp, but I want to see if a quality tube preamp would be more to my liking. I have ordered a LTA MicroZOTL Level 2 and it should be here in a few weeks.

My current set up:

Acoustat 1+1 with a SPL Crossover and dual Rhythmik F12SE subs

Innuos Pulse paired with an Innuos Phoenix USB

Bricasti M1S2 DAC

Marantz 8003 SACD (rarely used)

Technics SL1500 turntable with AT VM540ML cart upgraded with a RigB body

Pass Labs XA 25 power amp

Upgraded, but not excessive, cable

I have a month to compare the two preamplifiers and decide if I should make the move to the dark side (tubes). Everything I have read suggests the MicroZOTL L2 should improve stage presence, separation, and depth without significant detail loss. I do 95% of my listening through Qobuz and Sense with the rest from vinyl. The SACD player is only used for the occasional SACD not offered as HD through Qobuz.

Prior to settling on the LTA I listened to a used Electrocompaniet EC 4.8 Mk2 (had not settled on trying tubes yet.) (poor detail when compared with LA4 and narrower soundstage).   I also wanted to try a Pass Labs XP 22, but could not find a used one to try at home (also prior to the tube exploration).  I auditioned a used ARC 5SE (decent soundstage, but suppressed high end and the bass was underwhelming). 

I am looking for any guidance or suggestions the Agon community might have for me.

Thanks in advance!

Ralph

thriftyaudio

@thriftyaudio For all of my 2-channel listening I use the HPA4 (same as the LA4) and the Holo Audio Serene. The Serene is almost a copy of the HPA4, just a tad warmer. The Serene also sounds nice with Class A amps, such as my CODA #16. Though I keep thinking of trading it for a LA4.

Another preamp that I owned and is always regarded as sounding like a tube preamp is the solid-state CODA 07x (the most recent model). As with many tube setups I found it too noisy in relation to my LA4 (owned before the HPA4).

 

Have you considered using a tube DAC with the LA4? That way you can have the best of both worlds, except for your turntable.

I also have SACD's and use the GEERFab D.BOB to play the DSD stream on my DACs which are better decoders than the OPPO player. Your Briscati DAC should be great with your SACDs. I feel the disk playback seems a bit better than streaming. A shorter path in many ways.

GeerFab Audio D.BOB Digital BreakOut Box (OPEN) – Upscale Audio

@thriftyaudio I used to run XP22 with XA-30.8 then upgraded to X260.8. Big difference across the board. Had Audio Research Ref6 for few weeks as well. Bass was phenomenal. I ultimately preferred the XP22. My DAC is Bricasti M3.

Before you splurge on a new preamp, I would encourage you to try the Bricasti M1S2 preamp section. One other point I would like to make is that the Bricasti DACs sound their best via their XLR outs. It’s very possible that you would get much better results if you upgraded your amp, instead of preamp. Just a thought…

But if you want to go ahead with a preamp upgrade, I would highly recommend XP22. Just run your DAC using XLR cables into preamp. 

FWIW, I replaced a LA4 with a Pass XP-12 and was very happy with the results. I liked the LA4, but it is not as musical as the Pass. 

I’m very happy with my LTA MicroZotl level 2 preamp. I’m using it with a Coda No 8 amplifier.

I bought my LTA lightly used from a guy that moved to a high dollar integrated amp. He had upgraded the tubes to NOS Telefunken ECC801S. I experimented with several other tubes including the ones that he said came with the preamp. I did not like the tubes that shipped with the preamp. I’ve tried NOS Siemans ECC801S which are very nice and less expensive. Brimar Yellow T are warmer sounding and should be available from Tube Depot. In my system, I prefer the Telefunken, but would be happy with the Siemans.

@thriftyaudio - I own the LTA Microzotl preamp level 2. I think you are going to love it. When I first plugged it in, I was shocked what an improvement it delivered compared to my older tube preamp.

Let us know what you think once it arrives! 

@yyzsantabarbara I was hoping you would contribute.  We seem to have similar tastes in audio.  I am hesitant to try a different DAC since I just purchased the Bricasti M1S2 a few months ago.  I compared it directly to a Chord Dave with M Scaler and a Mola Mola Tambaqui (both in my system) and the Bricasti was the clear winner.  Even used it was a bit expensive so I want to hold onto it and enjoy the music.  I like the various filter options it provides to match with recording productions.

@audphile1 thanks for the recommendation.  I have tried the M1S2 without a preamp in line, but the sound became muddled at higher volume.  The LA4 does a better job with the M1S2 than the DAC does by itself.  I am holding out hope that Pass Labs will release a dual monoblock version of the XA25.  I will definitely upgrade the power amp for them!

@zlone thanks for sharing your experience.  I really wish I had found a used XP22 to try in my system.  Maybe I will find one in the next few weeks to compare with the LTA and Benchmark.  The added benefit of a Pass Labs preamp would be the ability to turn the XA 25 on/off with the remote.

@sls883 ​​@bluethinker I have heard nothing but praise for the MicroZOTL Line 2 form several sources.  I have a new one on its way with three sets of tubes (standard plus two different upgrades tubes).  I will not be purchasing additional tubes for this comparison, but I will try all three sets of the supplied tubes.  It should be fun!  

Maybe I will keep the LA4 and switch back and forth.

@thriftyaudio I think you'll like it.  I had two different conrad-johnson preamps before the LTA and I prefer the LTA.

I'd be curious to hear which tube types you try and which ones you like. 

@thriftyaudio - Out of curiousity, what are the alternate tubes you’ll roll with the LTA preamp? I’d love to hear your impressions as I’ve only heard the stock NOS tubes it shipped with.

@bluethinker ​​@sls883 The three tube types are "stock tubes" plus

  • Free Premium Tube Upgrade: Receive a FREE Gold Lion + Ray Reserve 6SN7 tube upgrade with your MicroZOTL Preamplifier purchase

  • as part of the 2024 holiday deals.

@sls883 it will be interesting to get your thoughts on the tubes.

The 12AT7 that came factory in mine were branded Trigon.  From what I was able to learn, they are probably a rebranded something.  They aren't great. 

I have Sylvania bad boy 12sn7gt and RCA 12sn7gt. I don't recall which pair is installed. 

"Maybe I will keep the LA4 and switch back and forth."

Great choice. Get another preamp for variety. If your power amp has a front facing switch to toggle between RCA and XLR inputs, then you can even have 2 preamps hooked up at the same time. You need to see if your Bricasti is good with having the RCA and XLR outputs connected at the same time to 2 different preamps. In my office, I have my Yggi+ OG DAC connected to 2 preamps and a tube headphone amp at the same time.

BTW - My Schitt Yggi+ OG was compared this weekend to the Dave and the Tambaqui at a pretty cool headphone event. I was not there but I got feedback that both DACs were slightly favored over the OG.

"The LA4 does a better job with the M1S2 than the DAC does by itself."

I found that all DACs I had in my system were better served by the volume on the LA4. The only one that came close was the Lumin X1 that has a special Leedh volume control. Even that had a slight gremlin at the lowest volume levels.