Saturday, October 30, 2010

Almarro A-318B SET Tube Amplifier - Photo Essay and Mini Review

Photo Essay

Beautiful and classic workmanship. 18 watts of single ended power. Tube complement - 6SL7, 6SN7, 6C33C.
8 Ohm and 4 Ohm speaker taps, 3 inputs and an IEC inlet with user accessible fuse holder.

Russian 6C33C double triode. From Soviet era missile and Mig Foxbat service to consumer audio. How the world has changed !

Volume control.
 Carved logo on the front panel.
Input selector. There are 3 inputs. The first indent is mute.

RCA 6SN7 GTB and Sylvania JAN VT-229 tubes

Power transformer is inside the chassis. The exposed center "transformer" in the first photo is in fact a power supply choke.

Russian K42-Y2 coupling caps. A surprise, quite uncommon in commercial gear.


The Almarro A-318B is quite an unusual beast. Single-ended triode and assembled by hand in Japan, the A-318B is affordable, beautiful and powerful - typically these words are not seen together in the same sentence.

Being an integrated amplifier, you save quite a bit of useful money. Total up the cost of a preamp, with an additional power cord, a pair of interconnects, footers, etc, and you realise that the savings are not insubstantial.

Despite its compact proportions, this is quite a heavy amplifier, tipping the scales at close to 20 kg. Much of this weight comes from its massive power and output transformers. The next thing that hits you is the sheer amount of heat produced, not just from the very hot running 6C33 power tubes, but from inside the chassis. An hour or two of operation even in an air-conditioned room will guarantee you a nice and toasty top plate and volume knob.

Operation is generally fuss-free and uneventful except for two things. First, the bias tabs (sitting underneath the tube socket base) may be accessed by itchy fingers - owners with children please take note ! The position of the two tabs are dangerously close to the top plate and accidental contact is not only possible but very likely, especially if you have a habit of biasing your amp in your dimly lit man-cave, after a beer ot two. It is far safer to take the bias from the two metal screws directly above the tabs on the ceramic tube scoket base. Secondly, I had intermittent contact with one of my power tubes. This traced back to a slightly loose tube socket. My amp is about 3 years old and was bought pre-owned. Anyway, I re-tightened the sockets with insulated needle nose pliers (you have to turn the amplifier over and take off the bottom plate to do this) and did not have any further incidents.

Right off the bat, it is obvious that the Almarro has more drive than its low power suggests (18 watts SET, but my set was delivering probably close to 15 watts at maximum due to my choice of a slightly lower bias point).

In the lower frequencies, the Almarro is no shrinking violet and has enough grunt and slam when driving my Focal Micro Utopia BE speakers (90db sensitivity, 8 Ohm load). The bass is not the most extended or deep (leave that to my Class D amps) but has sufficient heft and articulation. That being said, the Cary SLI-80 has deeper and more powerful bass.

Coming to the midrange, this is probably where the Almarro defines itself. Vocals have a beautiful glow and are open and realistic. Brass instruments and strings are equally well portrayed, with more emphasis on tone and acoustic space.

High frequencies are similarly open with cymbals shimmering in the right way with correct emphasis on both the transient and the decay.

The Almarro is a beautiful amp designed to appeal to the emotional side of things. From the logic side, the Almarro does not have the best of extension at both frequency extremes. It is easily bettered by the Cary SLI-80 in this respect. Resolution is good but not world class. Soundstaging, imaging and separation are acceptable to slightly above average. Despite all this, the listener is too busy listening to the beauty of the Almarro's tone to notice or care about such things. The feeling of holographically "being there" is a strength of this amp How the Almarro manages this without being a champ in imaging and soundstaging is baffling !

Asking my partner for a second opinion, she concluded that the Almarro was beautiful but somewhat emotionally draining, while the Cary was more balanced. I reckoned that this has more to the do with the high level of emotional engagement of the Almarro.

If you are the sort of listener that wants to be able to feel the emotion of a violin concerto instead of being able to discern the exact placement of all performers of the stage, bowing technique, what they had for lunch, etc, the Almarro is definitely for you. As long as used sensibly with speakers of suitable ease of drive, the Almarro is able to deliver a slice of high-end at real world prices.


Ken Moreland said...

Greetings to Sunny Singapore from rainy Ireland.Looking forward to hearing more about this amp, I am considering buying one. Right now I have a Unison Research S2K KT88. I heard the valves in the Almarro take a long time to settle and need hourly adjustment.
Best regards,

Eric said...

Ken, thanks for your question and comments. Guiness in Dublin is like nothing I've ever tasted ! I will post more about the sound in coming days. The power tubes are reputed to take a while to settle down, but after that, very little adjustment is needed. Could you share more about the rest of your system ?

Ken Moreland said...

Eric, Glad you enjoyed the Guinness, I'm very fond of it myself. My system consists of JMLab Focal 927be speakers , Nanotec Golden Strand cables, Unison Research S2K amp, Acrotec 8N interconnects, Benchmark DAC1, Oyaide cable and then most exciting a JKMods MK2 Hiface fed by a Sony laptop, I also have Teac VRDS-10 but it's no match for the Hiface.
John Kenny is an Irish guy modifying the Hiface. Regards,

Eric said...

Ken, I have the Focal Micro Utopia BE speakers. The 927BE should sound similar except with a more full bodied sound and deeper bass.

The pairing of the Almarro with my Focal speakers is beautiful and artistic. The midrange and tone is breath taking. That being said, the Almarro being a SET amp with limited power had neither the grip nor the extension of my more powerful push pull tube amp (Cary SLI-80). The Almarro is an amp for the heart while the Cary is an amp for the mind.

2A3 Maniac said...

Eric, I agree that the Almarro really is a fine amp. Indeed the electric design is relatively simple (e.g. no tube rectifying due to 250 mA needed for the 6C33C - too much for 5U4G or similar rectifiers). But I have heard them connected to Auditorium 23 Hommage SoloVox speakers - really wonderful "low budget" combination!
Kind regards, Carsten

Eric said...


You are absolutely right. The Almarro punches well above its price bracket, especially when coupled with a sympathethic speaker load.

Vlad said...

This is very good sounding amplifier,i like it !

Sting - not the english man in New York! said...

Hi Eric,

What is the value of the yellow caps?. I've seen in the other sama 318B but it was grey color twin caps?. is that a std caps?

Sting - not the english man in New York! said...

contemplating of getting this or A205AMKII which is easy for upgrade. I'm using Zu druids MKIV/08 btw...

Eric said...

Hi Sting,

I don't remember the value of the yellow cap. But the caps that people usually change are the coupling caps, in this case, the Russian K-42s.

With a sensitive speaker like the Zu, it makes perfect sense to pair it with an amp like the A205a. The local dealer for Zu recommends this combination highly, together with the Leben CS300.

Sting - not the english man in New York! said...

Thanks for reply. You are saying the A205MKII is a better option for Zu instead of A318B?

Eric said...

Hi Sting,

Yes, I believe that the people at Zu also recommend the A205. The A318B runs extremely hot, and can sound a bit bright. The A205 is a very sweet amp.

Analogue Bass said...

Hi Eric,
I am also an audiophile at Singapore, currently using Naim Nait 5i with Tannoy Turnberry SE. I like this combination a lot but looking to try out some good tube amp with the Tannoys. Thinking about Leben CS300 or Almarro 318b.

Any idea how the Almarro 318B compares with Leben CS300 ? Do they compromise on PRAT to get good tones by any chance ?

Eric said...

Hi Analogue Bass,

I have never directly compared both, so I can't really say. From what I can recall, the Leben has a warmer and lusher tone.

The Almarro excels best in handling more demanding loads that wouldn't otherwise work with flea powered SETs.

Why not try a second hand set ? They are really going for give away prices in Singapore.

Sky walker said...

Hi Eric,

I bought a new Almarro 318B and it has an intermittent popping sound from the left speaker. It can runs for hours without problem and the next time I turn it on the popping sound come back.

Have you experience it and what can be the possible case?

Eric said...

Hi Skywalker,

It sounds like a problem with the tubes. Try first with the power tubes. Swap left and right power tubes (turn down the bias before you do this). If the popping moves from left to right, its a power tube problem. Best to replace both tubes at the same time.

If this doesn't fix anything, you need to check your preamp tubes next.

For the preamp tubes, you will need to substitute new tubes to find out whether the problem lies there. Try each tube, one at a time to eliminate the problem tube.