Laconic Lab Night Blues Tube Transformer Coupled Amp

6N24P (6Н24П), dual triode is an equivalent to ECC89.
6J1P-EV (6Ж1П-ЕВ), pentode is a direct equivalent to 6F32 and somewhat-compatible to EF95.
Both of stock pairs were made in the 80s by Voskhod (Kaluga city). Easily obtainable and cheap, if you'll need to stock them up, don't hesitate to ask for assistance.

 

6ZH1P (driver/input)
6N24P (power tube)

 

Thanks both

 

Finally i have solved the problem.

In the meantime, i was suffered from consistent noise, regardless of whatsoever input that fed from, and no matter how volume knob rotated.

So i have to touch them to get an advise.
Ok, Fedor from Laconic lab has told me about how to fix the power noise.

Then, now the noise was completely gone, only i can hear a black background.
Some leads are not formed exactly, but works fine and Fedor confirmed this.

[ You need two capacitors that meet this condition: VDC 250~400, 0.1~0.47㎌, polypropylene ]

And my NBM is a unit for 220VAC.

 

I just received the unit, and it sounds good. However I have similar problem as well which my left channel has slight buzzing once in a while. Think i need to contact them already.

*****************

Everything is fine now after I swapped the tubes position. Think I had a loose tube connection.

 

Just wanted to let everyone know I ordered one on Feb 12 (Sunday) from @t3hwx9 and received it today in New Mexico - probably would have gotten it yesterday if not for President's day, so basically one week from order to receipt. Tracking by EMS post, and then by USPS in the US. This is a 220V unit but I had a spare 110/220 volt converter lying around. Sounds very nice. Kudos to @t3hwx9 for great service, and for @Marvey for posting on this to begin with.

 

Holy cow! I've had stuff take longer to get from the South Bay to where I live in the North Bay! That's awesome!

 

Yeah, that was pretty impressive. Oh, forgot to add, cost $465 total.

 

Been listening to this for a few days straight.

Mojo > LNBM > unmodded HD650

It is been quite sometime i converted to Stax so immediately I noticed a very different of sound presentation when I put my unmodded HD650 on.
Airiness and stage width is noticeably reduced compared to my L700 but the depth of the Dynamic setup is definitely the strength. Soundstage, clarity is obviously improved compared to sound straight playing out from the Mojo.
The HD650 now is no longer 'veiled' but the haziness (too warm?) is still present. So without much pondering I KISS modded it to release its greater potential. I didn't perform the coin Mod though.

Mojo > LNBM > KISS modded HD650 (Without Coin Mod)

Now it sounds much faster and clearer. Without the haziness from stock the treble is even better. Soundstage is not its strength but the 3D and depth is very good and in my opinion is slightly better than my L700.
The only attribute that is not interesting enough is the bass quality. It is a bit bloomy and the bass texture is average at best. Perhaps my Mojo is the limiting factor there. I believe something like Modi Multibit should reduce the warmness even more with greater slam.

Compared to my Electrostatic Setup (Apple to Orange):-

Mojo > Modded SRM-007tii with 6S4A tubes > L700

My E-stat setup is still better overall. With the new dynamic setup I have the urge to upgrade the DAC to overcome some small shortcomings but not with my E-stat setup. Honestly speaking I didnt find a single flaw with my current E-stat and i foresee I can stick with it this way for a very long time (its been a year already). The biggest strength of E-stat to me is the instrument separation. One thing i wanted to highlight the L700 bass is GREAT to me. It is very apparent and better than the one from my dynamic setup so I cant really understand why people called it limp dick bass on L700.
However, when i need a different presentation of sound i will still put my modded HD650 on with LNBM. Dynamics have more weight in tones, more obvious planktons and sound 'rougher' which is good for some rock music I think. For gaming, Dynamics are better.

So, is LNBM a keeper? Hell yes.
It sounds wonderful out of the box at around $450. It still has great potential to improve with longer burn-in time and better source.
For my case it pairs well with HD650, who knows it matches even better with some other transducer like HD800, Utopia...Who knows? With Stax you pretty much stuck with much fewer choices.

 

It sounds very pleasant with SDR modded HD800- it's quite a good inexpensive option for driving them. For the price, it's quite a resolving amp.

NBM+used HD800+SDR mod is a reasonable audio bargain, in fact. Quite tidy HD800 can be picked up reasonably cheaply, if you're in no hurry.

 

I'm really thinking to purchase this amp. Even though I don't have a Russian address and I live in the USA, I do have family in a country not too far from Russia so I wrote them via email to enquire about possible shipping to there with the 115V version of this amp. They already got back to me:

Добрый день! Купить можно стандартную версию на 220-230 вольт.
Когда напишите адрес в Венгрии, то можно будет посчитать стоимость доставки.
Версию со 115 вольтами, можно в количестве не менее 10 штук. и с 50%
предоплатой заказа.

Федор.

Basically, now we need to pre-order ten units if we want the 115 Volt version and pay 50% upfront. Not sure if there's 9 other fellow SBAF members around who would be interested so we could team up for a 115V version of this amp?

 

Incidentally, I have a 220v unit for sale, at a decent price for contributors/friends. Need to clear space on my desk for a Gungnir Multibit. Three amps at once is too many to listen to anyway, it's a waste, letting it gather dust!

 

im in!

 

This will be a 2 part impressions post because the pair of headphones that I really purchased the NBM for aren't here yet (ZMF Eikon) but being transformer coupled it should play well with low impedance cans also, right? My current "daily driver's" are the Hifiman HE-400S headphones and mine have a custom Dyson cable, Focus A pads and are grille modded, as shown in the picture below. They are extremely comfortable, have a fairly flat frequency response with the Focus A pads and sound both clear and very open with the aforementioned grille mod.


In the background of the picture there is the NBM, the Metrum Musette and the Jotunheim. I mention this because, to me, the NBM and the Jotunheim have a lot in common. After a couple of nights of listening I am just about ready to call the NBM the Jot's Russian Cousin with Tubes. They share some strengths and pretty much everywhere the Jot is strong the NBM is also at least as strong and in some cases stronger (except for bass tightness, on which the Jot is noticeably better).

In terms of its strengths, the NBM bests the Jot in plankton by a good margin (always a good tube amp's forte) and instrument separation/air while removing any trace of upper mid/treble glare and harshness that the Jot can sometimes be guilty of. I do want to interject here and say that on its own I don't notice the Jot's treble harshness/hardness and it is only when I quickly go back and forth between the NBM and the Jot that I can tell the difference. The NBM's treble is just nicer and smoother to listen to without loosing out on any detail which I think is quite a feat.

The NBM isn't head and shoulders above the Jot (except for maybe plankton - I'm listening to it right now and I keep hearing little things in my music that I haven't heard before or I've forgotten about) when listening through the HE-400S but then again the HE-400S isn't known for its ability to scale endlessly. Both the Jot and the NBM being fed from the Musette are probably hitting the limit of what the HE-400S is capable of doing and this is not a bad thing by any means.

A couple of other comments here before I end this "Part 1" impressions post: I prefer the HE-400S out of the High Z jack. Maybe it's a planar thing? Honestly I can't hear a lot of difference. In either jack for most modern recordings 9 o'clock on the volume pot puts the 400S into ear splitting volume territory. Seriously. This thing's stock gain is higher than the high gain setting on the Jot. I would seriously like to know how much voltage the NBM is able to swing and what kind of wattage it is capable of producing.

I posted a message on Laconic's Facebook page but they told me to read the documentation that came with the amp or check their web page. Rather inconveniently they do not list the couple of pieces of information that I really want to know. Stuff like output impedance, power output and how many watts of juice it needs are nowhere to be found.

Anyway, purchased from an SBAF'er in the UK and shipped FedEx International the NBM cost me about $480 to my door. From what I have heard in my short time with it I am already confident in saying that if you liked the Jotunheim but wanted a better version with the advantages that a well made tube amp brings then you should seriously consider the NBM. Or if you liked everything about the Jot but thought the upper mids and treble were harsh then the NBM is probably the amp for you.

More to come once my Eikon arrives....

 

Absolutely they are. Great sound quality and comfort. They are the first pair of headphones that I have ever owned that I could legitimately wear all day long without some sort of pain somewhere.

 

Here's a detailed measurements review of the NBM:

http://reference-audio-analyzer.pro/en/report/amp/laconic-night-blues-mini-hi.php

According to that website, the H output impedance is around 62 ohms, the L output impedance is around 28 ohms. With the HE-400S having a flat impedance of around 22 ohms, the maximum voltage would be around 1 volt out of the H output, or about 54 mW. The ZMF Eikon has a 300 ohm impedance, fairly flat except for a spike up to about 470 ohms at around 1.5 kHZ according to the InnerFidelity tests. Interestingly enough, the InnerFidelity tests also should a dip in the frequency response in that region, so the H output should fill in that dip better than the L output. The NBM should be able to deliver about 30 mW from the H output and 15 mW from the L output into the Eikon.

I measured the power consumption of the NBM at 30 watts, but that includes 7 watts for the step-up transformer from 120 to 240 volts.

 

Awesome information, thank you very much. I took a wild stab at power consumption being around 50 - 75 watts based on other amps of similar designs and then doubled that highest number and bought a 150 watt step-up transformer from Acupwr. Based on your measurements it is complete overkill but then again I would rather err on the side of caution for a device that is not easy to replace.

Do those power numbers seem very low? Of course it isn't about absolute output as there are other factors at work but less than 100 mW is somewhat surprising.

 

Well, the 6N24P dual triode output tube has a max plate rating of 1.8 watts/secion, so it's no powerhouse. For comparison, the 6SN7 has a rating of 2.5 watts/section, and the GTA/GTB versions have 5 watts/section. But, remember that 50-100 mW is 17-20 dB above 1 mW. I didn't see any sensitivity specs for the Eikon, but the HE400S has a reported sensitivity of 98 dB (presumably for 1 mW) so it can play very loud on the NBM. OTOH, won't do for the HE6, with its 50 ohms impedance and only 83 dB sensitivity.

 

Wow, the more time I spend listening to the NBM the more impressed I get. I just listened to "Ocean" by the John Butler Trio which is about an eleven and a half minute acoustical instrumental that features some really gorgeous and impressive guitar work. On the NBM it was the most nuanced and beautifully detailed that I have ever heard it. It felt like I was sitting in a room listening to the musicians playing live and could just about see each one sitting in his place. Pretty amazing stuff.