My first David Berning piece - Linear Tube Audio MicroZOTL 2.0

StevenZ

Pending Gold Star Member
Been on the hunt for a while looking for a good preamp for a new amplifier that I've recently purchased. I say recently, but actually I bought it back in late April and only delivered a few weeks ago. This amp being from my buddy's company Artisan Acoustics which is aptly named AmpOne; his first amplifier offering.

Knowing that this amp has an unusually low input impedance of 14.5Kohm I needed to find something that would both offer the drive I need as well as transparency. See this amp is quite good and it doesn't have an input buffer like most Class D amplifiers I've used so what you feed it is what you get out it.

I've been using my Gustard DAC-X22 as a preamp which is getting me by for the moment, and briefly I used the preamp section of a Nakamichi TA-3A to drive the amp with great results. However, I was on the hunt and took a gamble on a little all-in-one type of unit that Linear Tube Audio offers based on David Berning's original MicroZOTL (out of production).

Strangely, aside for a few mentions of it on Audiogon's forum I didn't actually know much about this unit other than it could be used as a preamp and had been compared as an alternative to Ed Schillings "The Truth" preamp. Which happened to be another consideration of mine, though the very small amount of volume travel on Ed's preamp scared me away from purchasing.

Talking with Mark at Linear Tube Audio assured me that the MZ2.0 would drive my amp like I had been so worried about so I took the plunge and ordered one up, without the linear power supply. I'll end up buying the LPS eventually as budget allows. However it wasn't till this morning that I even started looking at reviews and was quite shocked at how glowing nearly every single one of them is.

I've heard a pair of Berning monoblocks before at a local guy's house, driven by a Shindo preamp and on some heavily modded Magnepan 3.6R speakers. The pairing of everything worked well and luckily I had heard this guy's stereos with a multitude of different amplification before the Bernings and felt the Bernings offered a touch of "soul" and realism that no others he had used before could match. So in a way, I believe the Berning preamp should work out well for me.

After purchase I was emailed with a production date of 7-10 business days, so I hope to have a bit more to report on in the coming weeks. Excited for it's arrival is a drastic understatement.

-Steven
 
I absolutly love mine, i initially used it for my headphones but found it was also great with my 300b amplifier. I am planning on rewiring it so that it has better ground and signal return (all the rcas use the chassis and maybe put a switch in to select headphone/speaker/pre outputs - one thing i did recently was to change the headphone jack out for a 4 pin xlr and that seemed to make a difference.

Fwiw the tubes it comes with are really good and i wasnt able to better them with NOS. mine is an older one that dosent do 12v so i cant run the 12Xxx tubes but hear there a good and cheap alternative.
 

StevenZ

Pending Gold Star Member
Awesome! Yeah I opted for the 12SN7 NOS tubes just to get that out of the way.

Did you get the linear power supply?
 

StevenZ

Pending Gold Star Member
Finally got a shipping notification last night. Unfortunately they decided to ship with UPS and the deliver date is next Tuesday. I'm praying it arrives in good shape. UPS is notorious for destroying my packages in transit. I've had much better luck with everything sent via FedEx. So we'll see.
 
Finally got a shipping notification last night. Unfortunately they decided to ship with UPS and the deliver date is next Tuesday. I'm praying it arrives in good shape. UPS is notorious for destroying my packages in transit. I've had much better luck with everything sent via FedEx. So we'll see.


My micro zotl came by post from the states to the Uk and the box was a bIt battered but the amp is packed REALLY well, unless they have changed the way they pack them im confident you dont have anything to worry about
 

StevenZ

Pending Gold Star Member
My micro zotl came by post from the states to the Uk and the box was a bIt battered but the amp is packed REALLY well, unless they have changed the way they pack them im confident you dont have anything to worry about

That's reassuring. Thank you
 

StevenZ

Pending Gold Star Member
Arrived safely this morning. Was able to only listen for about 2hrs though and right off the bat it's VERY impressive. In fact it has completely transformed my stereo. Which I did NOT expect.

I figured it would add a little mid-range warmth and body but nothing like what I'm hearing, and I haven't even scratched the surface on breaking in. It's pretty wild just how much more music it's extracting.

But here's my big question. Is it actually unlocking the information that was already there or is it adding to the signal? @joe83 what is you opinion on this?
 
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StevenZ

Pending Gold Star Member
I guess another possibility is that it's entirely possible that there was a gross impedance mismatch between my amp and source initially which could have led to my initial displeasure with my amp. I'm not entirely sure.
 
But here's my big question. Is it actually unlocking the information that was already there or is it adding to the signal? @joe83 what is you opinion on this?

Hi Steven, when i first started using mine i was without any cart for my turntable setup and so spent the first two weeks listening to digital files, i felt that the microzotl was very transparant but possibly unnaturally so, i read up about it online and found out a bit more about how it works and was a bit concerned that info could actually be missing/discarded. When i got another cartridge (a denon 103) i was able to use my turntable and phono amp, which is what im most familiar with i came to the conclusion that the microzotl is just a very transparant preamplifier it puts out what you put in... I have spent quite a lot of time using it as a headphone amplifier recently and im sure that thats the case. I have never felt its adding annything to the music just that its able to present whats there.

I did find that the amp changed a little bit over the first week or so and that I feel that the tubes it came with didnt need changing. I swapped in some NOS ones and there really didnt seem to be any advantage, i have the stock tubes installed at the moment.

Good to hear its working well with your power amp, its possibly not the easiest preamp to match up.
 

StevenZ

Pending Gold Star Member
I took out the GE 12AT7 it came with this morning and swapped in some NOS Amperex Bugle Boy (Made in France) 12AT7 and it seemed to clean things up a bit. It's nice that the MZ2 is so receptive to tube rolling, for me at least. The GE is a great sounding tube and I can definitely see/hear why they put them in as stock tubes. They're full bodied and warm sounding while still maintaining a very good amount of detail. I can see myself putting these back in if I grow tired of the leaner sound of the Amperex. The Amperex seem to give a better sound stage though, but just slightly.

Two very different sounding tubes for sure. Doubt I'll roll different 12SN7 though as I paid for the upgrade. But worth mentioning the 12SN7 that came with it are Honeywell brand.

What brand of stock tubes did yours come with?
 
I took out the GE 12AT7 it came with this morning and swapped in some NOS Amperex Bugle Boy (Made in France) 12AT7 and it seemed to clean things up a bit. It's nice that the MZ2 is so receptive to tube rolling, for me at least. The GE is a great sounding tube and I can definitely see/hear why they put them in as stock tubes. They're full bodied and warm sounding while still maintaining a very good amount of detail. I can see myself putting these back in if I grow tired of the leaner sound of the Amperex. The Amperex seem to give a better sound stage though, but just slightly.

Two very different sounding tubes for sure. Doubt I'll roll different 12SN7 though as I paid for the upgrade. But worth mentioning the 12SN7 that came with it are Honeywell brand.

What brand of stock tubes did yours come with?

Mine came with current production tung-sol tubes, i have an older unit and cannot run 12SN7
 

StevenZ

Pending Gold Star Member
Ended up sending back the LTA. for whatever reason on start up a couple days after received it damn near blew up my speakers. I waited probably 30 seconds after turning it on to power up my amp, which was fine before but that day it seemed to be banging my speakers drivers back and forth popping each time for about 20 seconds. That's all it took and off it went.

The unfortunate part of this is that the guys at LTA weren't exactly friendly after I requested to return it. In fact other than them sending me a return shipping notice they cut communication with me. All said and done I got my refund however they could have been a little more communicative after the return request
 
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TubeHiFiNut

Administrator
Ended up sending back the LTA. for whatever reason on start up a couple days after received it damn near blew up my speakers. I waited probably 30 seconds after turning it on to power up my amp, which was fine before but that day it seemed to be banging my speakers drivers back and forth popping each time for about 20 seconds. That's all it took and off it went.

The unfortunate part of this is that the guys at LTA weren't exactly friendly after I requested to return it. In fact other than them sending me a return shipping notice they cut communication with me. All said and done I got my refund however they could have been a little more communicative after the return request

Sorry to hear this happened. :(
 
Sorry to hear that. I wonder what was going on there? I have heard that OTL power amps can be dodgy with speakers sometimes.
 
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