Brief Review: Almarro A205A Mk II
Brief Review: Nagra BPS vs Micromega MyGroov vs Schiit Mani
Last time I tried to fire up my Almarro amp, it produced some crackling noise and I turned it off immediately. A few days ago I decided to try it again. I noticed the transformer fuse cap (not the power fuse; on the side) was not entirely properly seated so I corrected that. No problem now! Strange.
Almarro A205A Mk II
This amp needs no introduction. The younger (and more sensible) Jeff Day owned the original and reviewed both for 6moons (link for Mk II which contains link to Mk I). He preferred the the Mk I by a little, but only recently discovered that his Mk I had the stock caps replaced by Jensen (see Positive Feedback)! That is, the Mk I was sent to him for review without telling him that it had the coupling caps replaced!
This is not unheard of. Many years ago, in HK, we went to a shop to hear a bargain Chinese amp, and it sounded reasonably good. My friend insisted on the one on demo and took it away. Another friend who bought one never got the sound he heard at the shop, just slow and soft. Finally they compared the innards. Guess what! The demo was modifed to fixed bias from the original's auto-bias! Of course that sounded punchier! Deception! That's not all, some years later, someone's had a problem with one of the output transformers and found out that the big potted transformer only has a much smaller one inside! So, size and weight can still be deceptive.
Although 6moons was the only review at the time, this model sold pretty well, and you often see it turning up second-hand, many modified with V-caps by the dealers. I bought mine second-hand many years ago and rarely used it. I substituted it for the ss Akitika and used the 16 ohm tap for my 15 ohm loudspeaker in my Streaming System:
CDP: Micromega Stage 2 or Magnavox CDB-492
Bluetooth: Dayton BTR-01 digital out to Micromega MyDAC
Analog: Technics SL-1200 Mk II, Denon DL-103; Micromega MyGroov
Preamp: Yamamoto CA-04L
I started with an RCA 12AX7 and a pair of Sovtek EL84. I was immediately grabbed by the excellent sound. Although just 4.8 wpc, it did not sound anemic at all. As a matter of fact, the bass was fuller and better shaped than the Akitika amp! There was a trace of leanness at the top. I rolled in a pair of old-stock Mullard's (one of their better tubes). Now, very sweet indeed! It really doesn't need a preamp. I used it directly and it was just as beautiful, but I need more than 2 inputs.
This is an amp with a very small footprint, yet it is laden with features. 2 inputs, headphone output at the back (decent) and, best for people like me, choice of 8 ohm and 16 ohm taps instead of the more usual 4 and 8 ohms. It generates some heat, but is not excessive. A great choice in a smaller space.
I did open mine. Guess what! Although the designer recommended value for the coupling cap is 0.01 to 1.0 (stock is 0.047), mine is 2.2 Sonicap!!! Someone before me must have wanted for bass! However, after listening for days, I don't think there is anything that I need to change, the bass certainly was not slow nor bloated, though one day I may still restore it to official value and see what it is like. Also, the signal wires going from the volume pot (below pic, silver colored) to the 12AX7 look different from the pics of Jeff Day. I was suspecting they were changed too. I googled the cached pictures of the many second-hand units and found a couple identical to mine, so I concluded they were stock. Power supply caps can be different too. So Almarro had some variations over its production span. My unit (serial # E16869) is likely a later unit.
For not much money on the second-hand market, often with extra's, this is an excellent starter SE amp employing one of my favorite tubes. The Almarro is definitely better than the Wavelength I heard more than 20 years ago (not the Junior, likely a simpler precursor). I'd advise those interested to look at the innards carefully to see whether there had been mods.
pic of BPS from 6moons.Nagra BPS, Micromega MyGroov vs Schiit Mani
There is no miracle. Although the Schiit Mani is a good buy, it is outclassed.
The Nagra BPS is a fantastic battery operated phonoamp which I have written about here. It is not cheap, but I regard it as a bargain. In this system its incisive (but not oppressively so) nature is displayed to perfection.
The Micromega MyGroov also shines even more than before. Its detail retrieval is more than Schiit, almost approaching Nagra, while tonally it is warmer than the BPS. It is staying in this system. MyGroov is now not available stateside, but in Europe and The UK you can get one for Euro/GBP 200 (including VAT), a great bargain!
I have heard the Almarro EL 84/6BQ5 amp mated with a pair of TAD 300 speakers (known as not easy to drive) some 10 years ago, It was amazing to me and grabbed in my mind. Got another chance heard Tiny Triode partner with ESL 57, also EL 84 amp. I'm know I like the sound of EL 84. My long time friend Tony L, a crazy diyer, produced almost all kinds of output tube amps at his basement, I have heard all of them at one evening, the best I like most are 6V6 and EL 84. This confirmed to me an EL 84 amp I should grab one.
ReplyDelete3-4 weeks ago, I bought a pair vintage Eico HF 30 at eBay, condition is pretty good for an old guy around 50 to 60 years old armed with 4x EL 84 each channel, I hooked it up with my ESL 2812, it was disappointed, lack of gain to play with new ESL, I tried 16 ohms taps, 12% output voltage more, I saw the light is coming in. I know the Tiny Triode 25W is well mated with ESL, this Eico said to be 30W Pentode push pull parcelled, should have more power than the 25W TT? I started tracking each parts according to the diagram, they were modded to Triode ISO Pentode! Surgery must be done again, this is quite normal to an old guy, no complain! Pentode output voltage is again 12% more than Triode, they sound wonderful, not less not more power to the ESL, just fitted, still use 16 ohms taps, EL 84 amps are very different to me, tight bass with some kind of hollow, high is higher and prolong to the last bit, human voice are sexy, those are compare to my SS amps. Old age are always having troubles, now I suspect the power trans can't stand for long time playing? say 4 hours? They are cooking upto 72C and 66C at 3 hours and this is the maximum I dare not to continue. Is this normal with a vintage amp?
Great to hear from you! Completely agree, 6V6 and EL84, 2 of the very best tubes! The EL84 has the best bass for sure, better than EL34! Yes, the TAD TSM-300 are not as efficient as it seems to be; not easy to bring out the bass (best I heard was not with tube, bu the Pass procupine, the super-hot Aleph 3).
DeleteWell, all these Parallel PP amps run very hot. The Tiny Triodes are very hot too.
Eico Power transformers do run quite hot (I had the HF-81, great EL84 amp; and HF-87, a bit coarse; I still have the integrated ST50, great amp) but they have a good reputation (unlike Heath power trannies). Probably no problem. Maybe get a small usb fan and just blow on the trannies. Can also use some thin sheets of metal (bend them to L-shape) to shield the trannies from the tubes.
My Almarro power trannie gets pretty hot too, and its just 3 tubes. You have 8 per side, phew!
I think the 2812 is harder to drive than the 57. Not entirely sure Tiny Triode will match or not.
Error, not HF-81, HF-86 stereo EL84 amp, very sweet.
DeleteEico HF-81 also sounds extremely good, I guess same transformers as HF-87, in integrated format
Deletetypo, same as HF-86.
DeleteHave either you or mrgoodsound ever heard of Devon Turnbull? He's a former graffiti artist/street wear hypebeast designer who sells Altec speaker kits and tubeamps under his Ojas label.
ReplyDeletehttps://www.instagram.com/p/B7d_CGPld9B/?utm_source=ig_web_button_share_sheet
No, but it is a fun link! It's so crazy and enchanting that younger people (or not so young anymore) dig tubes and horns, an indictment to the blandness of sound reproduction (and other things) of our age.
DeleteReminds me, decades ago, when NoHo and NoLita were not so gentrified, there were a lot of art galleries. I was stunned one evening to see a pair of vintage amp chassis (without tubes) spray-painted silver and integrated into the window art. AH, those were the days!
Integrating Altec horn with whatever bass is HIGHLY challenging, to say the least.
Perusing Ojas webstore, it appears he sells assembled Isamu Asano 2A3 SET kits and tripath chip amps at quite a mark up. At least he sells Belden speaker wire at a reasonable cost.
Delete"The first Single Ended Triode amp I ever built was a 2A3. It seemed like a good entry into SET but I saw it as just that. In the years since I have built, owned and auditioned all of the popular output tubes and topologies: 300B, 211, 845, 45, 811 tubes running in single ended, push pull, parallel, etc. But I always come back to the trusty 2A3. For me, it has plenty of power and a great tonal balance."
I had not, good for him, although I wonder if he has sold any of his 2A3 amplifiers at a price of $8,000? I am not quite sure who that appeals to
DeleteDJ, thanks for your advice.
ReplyDeleteI put 3 layers of foil baking sheet fixed with duct tape outside, power trannies temperature going down to 65/62 degrees C, and keep stable at 3 upto 4 hours play time.
When changing value of a coupling cap, the modifier should look at the grid resistor of the next stage to determine what the bass roll-off point. In your case, judging by the photo, the grid resistor is 470K (color code: yellow, violet, yellow) and your current cap value is .22uf, which is plenty enough. I would reduce it down to .1uf to speed up the sound a touch but if stock value is .047uf might be a little light sounding. It really depends on taste and the tonal balance of the rest of the system. You just have to experience a little. My own experience is to get the cap value as small as possible without lose bass heft. In the old days of Wondercap, they falsely suggested people to "upgrade" all coupling caps to bigger size in order to charge more. It only slows down the sound and prone to pick up noise and interference. There were a lot of bad trends in the 80s!
ReplyDeleteThank you for the up and I agree with everything. Your approach would be what I'd think is most musical. When it comes to caps, my own feeling is always the smaller the better indeed.
Delete