Amp/Preamp Asylum: REVIEW: Antique Sound Lab MG-Si15 Integrated Amplifier (Tube) by Bosh

Model:	MG-Si15
Category:	Integrated Amplifier (Tube)
Suggested Retail Price:	$750.00
Description:	Single ended, parallel, line-integrated amplifier
Manufacturer URL:	Antique Sound Lab
Model Picture:	View

Review by Bosh ( A ) on March 19, 2003 at 01:33:08
IP Address: 24.44.146.121

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For those in a hurry, let me start by saying that I Triple-Dog-Dare you to find a better, genuine, single-ended tube integrated at the price. Now go away and get out your credit card. For the rest of you, the details now follow.
I won't bore you (too much) with personal details; but I should say by way of background that, over an on again, off again affair with audio covering some two decades, tubes have always beckoned. The small but hugely confident world of SET especially appealed, speaking about music--that's right--the "M" word, in a manner so poetic that no other sub-group in audio seemed to matter.
The price of admission, however, always kept me walking slowly past the club. Pretending not to look at that nerdy but still intimidating bouncer.
Enter the age of eBay and my first vintage push-pull equipment. Some great tube gear now affordable, a new dawn had come in terms of what I wanted from my rig. Unfortunately, a new understanding of the limits of my ability with a soldering iron came along for the ride. Then I tripped over something: a company called Antique Sound Lab.
The ASL MG-Si15 single-ended integrated amplifier has a modest, four tube compliment consisting of two KT88 outputs and two 12AX7 signals. My version (and Joe Lau, ASL's chief designer, seems to sneak in new and different "versions" of everything in his line while we're not watching)has three line level inputs: CD, AUX and, almost comically "MD" (for Mini Disc, still a fave rave in the far east, I guess).
It's rated output into 8 ohms is 5w in Triode, 15w in Pentode. And therein lies a tale.
The MD-Si15 allows switching betwen Tridoe and Pentode modes of operation.
It is very important that those 4WD/SUV owners among us are made to understand that this option is NOT "shift on the fly". To switch between modes, you must first power down. Count to 100 (saying "Mississippi" beteween each numeral). Shift. Power back up. The potential disaster that could result from hitting that switch while the amp is in full swing is the stuff of nightmares, not to mention jarring noises and unplesant smells. More on the "T" and "P" modes soon.
A very nice touch is the built-in bias meter on the front panel, allowing the user to adjust bias as needed (which is rarely after initial run-in) via pots in the top plate. This can be hot work, as the bias adjust pots are very close to the output tubes. But with the right screwdriver (long and thin) it's simplicity itself. And with a flick fore or aft of the bias-check knob mounted on the right side of the unit, you're assured things are as they should be Tubesville.
After the bias meter, all that's left to the thick, anodized front plate is a mode selector and volume knob and, if you want to get really specific, the silk-screened ASL logo. Pure. And simple.
Build quality is sturdy, suggesting equipment at rather higher price points. And it's a hefty little bugger, too.
The transformers may be hidden under plain jane black boxes, but their presence is felt the moment you go about lifting the amp from its box. I don't have the paperwork to prove it, nor have I actually weighed the unit, but I'd put it at roughly +25lbs: pretty serious mass considering such a compact package.
Around back you'll find the three, line-level imputs. Given the bargain this product represents, it hard to bitch about anything. Yet the inputs, as well as the loudspeaker binding posts, ain't in the same league as 'Best Buy' Harmon Kardon, let alone WBT. Still, I've yet to meet an electron that turns tail because of things like that. And as long as you mind the binding posts weekly, tightening as needs be, everything's just peachy.
In my model (see qualification above), all that's left back there is AC In for a detachable power cord. There are models of this very amp, I know, that feature Tape Outs and even outputs for a subwoofer. Heck, while I'm at it, I've seen the MG-Si15 with a mirror finish chassis while mine is sprayed basic black. The price does not seem to change with the bells, whistles or fancier skins. Joe, wazzup wid' dat?
The ASLMG-Si arives with ASL "branded" KT88s, which I'm told by those who know are made by Vave Art. And they're good tubes. The stock 12AX7s are JJ's. The power cord supplied is of a reasonably heavy guage.
So much for the hardware. Now on to the music.
First impression was Dead Black. I mean this thing made NO noise. Compared to the vintage tube gear I had been playing with for so long, and even compared with the contemporary, fairly upmarket solid state gear I owned and knew very well, this was a most welcome (and frankly unexpected) discovery.
I listened in Triode mode for the first month, maybe two, and was taken by the delicate, refined experience. Being "in between" phono stages at the time, all listening (not counting tuner) was redbook CD. Then something interesting happened...
My loudspeakers are fairly sensitive, single driver x-overless models rated at 96+dB efficiency. Listening at 5w in Triode, I "caught" myself selecting only acoustic, small ensamble and vocal fare. My musical tastes, however, go well beyond such confines and, damnit, I fought the impulse to "play for the gear" and went straight--at long last--for the amplified rock.
Ouch.
Can you say "clipping"? How about "smear" or "distortion"? I knew you could.
1 Mississippi 2 Mississippi 3....Let's give Pentode a shot, shall we?
Much better. Still not "great", mind you, but MUCH better. And in fairness to the whole micro-watt single-ended Triode cult I must point out that what this amp is really not "great" at is the compressed stuff. Most recorded pop-rock, especially from the 70's and 80's, is downright awful in terms of production quality, hyper-compressed to sound "good" on car radios and, wouldn't you know it? A SET amp driving sensitive 'speakers is just the thing to show that awfulness off.
I kept the amp on Pentode and went back to my jazz, my small ensamble classical, my pickin' and smokin' Garcia and my female vocals. And guess what? Everything I already loved about this amp was suddenly more, suddenly better.
I was getting more detail, more air and a LOT more soundstage in Pentode than I had been in Triode. So in Pentode it has stayed for the past few months. Sidebar: In the words of a friend who A/B'd Triode and Pentode modes with me (and who mixes both major market and 'audiophile' albums for a living); "Keep that switch there, in Pentode, and solder it in place so nobody can move it."
Here's the deal: You wanna' rock non-stop? Go elsewhere. With this amp, you've got a choice of 5 or 15w, fer'chrisakes. This will not recreate The Who at Madison Square Garden at full ear-bleed, nor was it ever intended to.
With this amp, I can and do listen to Led Zep and Bowie and Hendrix and the Stones and, thanks to a smallish room, nobody gets hurt. But the BEAUTY this thing is capable of only shines brightest when it's fed acoustic music. The sort of music wherein every detail, every nuance can be a thrill. A shiver. And with this amp, thrilled and shivered you WILL be.
That's it for stock, out-of-the-box. Now a journey, short, of tube rolling and mods.
----------------------------------------------------
As if this product wasn't already affordable enough, I had to go all Major Cheap Ass and buy a demo unit. As a result I took this baby home for so little it would make a grown man cry. But there is, as it turns out, no free lunch.
The MG-Si15 arrived with a "broken" pair of inputs. A direct result of the dealer using Mongo Humungo Interconnects with Death Grip Turbo Clamps. You get the picture.
A simple eMail to Joe Lau and, ye gods, the man responded. He not only replied, but did so from the thick of CES in Las Vegas. A week later replacement parts arrived from Hong Kong. I need one, he sent two. I insisted on paying. He never billed me. This, fellow travelers, is the sort of company to keep.
Another associate in the audio trade re-did my inputs, thanks to Joe's kind supply of the required parts. But he did it complete with an all metal, gold-plated, Swiss made replacement for the not-too-impressive, mostly plastic mode switcher that came inside the MG-Si. He also replaced the input-to-switcher wire with silver plated OFC solid core.
Since adopting the ASL, I've swapped the stock JJ 12AX7s for OS Telefunken Smooth Plates from a prior "vintage" purchase. And, by a stroke of good fortune, I've rolled out the Valve Art KT88s in favor of a pair of [real] NOS Genalex Gold Monarchs.
That's "good fortune" only if you think paying more for the tubes than for the amp they sit in is a good thing.
I can tell you this: the first "new" tubes to go in were the TFKs replacing the stock JJs. What had been sweet became sweeter, and I mean that in only the best of terms.
Before the Gold Monarchs went in, I had been in conversations with the designer of my loudspeakers; thinking a subwoofer might be in order to round out the sound. No more.
The G-GM KT88s (MOV) gave the little ASL more bottom end than I ever suspected was missing. And the nearly twitch-inspiring sense of detail and space has grown ever deeper and more musically involving.
With a detachable power cord, one can be forgiven for "screwing around", as it were.
I replaced the stock AC with a Virtual Dynamics Basic Power cord. I heard no improvement, yet I heard degredation. In fact, after the power cord swap, the kit sounded just like it did before. So I left the VD (!) in. It's as big as a fire hose, so big and heavy I have to use a support the keep it from tilting the amp back on its heels. But in terms of sonics, no harm (and maybe some good) done. And this little amp needs all the "Football Player" friends it can get.
Scroll to the bottom, did you? Okay.
Buy this amp.
If you don't like it, I'll buy it from you. In fact, I think everybody should own this integrated. If only to hear what music at home can really sound like. Even once.

Product Weakness: Quality of inputs and binding posts.
Product Strengths: Mids and mid/upper bass. Ease of operation. Price. And price. And looks. And did I mention price?

Associated Equipment for this Review:
Amplifier:	Antique Sound Lab MG-Si15
Preamplifier (or None if Integrated):	Audio by Van Alstine T-6 Phono Stage
Sources (CDP/Turntable):	VPI Scout/HHb pro studio CDP
Speakers:	Omega TS1-R Grandes'
Cables/Interconnects:	VPI (Discovery) for TT. Kimber HERO for CD. Monster M5501 for Tuner. Virtual Dynamics power cord for Amp. Absolute Power Cord for CDP.
Music Used (Genre/Selections):	All (almost)
Room Comments/Treatments:	See Inmate Systems
Other (Power Conditioner etc.):	Adcom ACE 515
Type of Audition/Review:	Product Owner

Product Weakness:	Quality of inputs and binding posts.
Product Strengths:	Mids and mid/upper bass. Ease of operation. Price. And price. And looks. And did I mention price?