3000 >+DOLAR

The 6550 tubes could cost you a fortune nowadays. Typical coke-bottle '60s 3-hole triple O getters Tung-Sol runs about $75 a pop (if you are lucky). The black-plate ones (the very best 6550 ever) would be $150 per tube. With that much money, get the GEC KT88 instead!

Don't bother with the GE ones...they are several cuts below.

And those Tung-Sol re-issue....don't bother!

Althought I'd suggest against buying any Sonic Frontiers preamps (Line 2, Line 3, and SFL1, see my other reviews), I never any problem recommending SF made amps (Power 2, Power 3).

The SFM160 used to be their flagship tube hybrid amp before the Power series. I was very impressed with Power 2 and Power 3, both of them I owned before, and was Stereophile Class A rated. However, I think both amps do not sound tube enough. It's too tube hybrid, like the VTL sound: Very clean, dynamic, good extension, but it's not tube enough. The other end of the spectrum would be Cary and Audio Research amps, which are warm and sweet to a point of nearly syrupy, scarifying imaging and attack quite a bit.

The SFM160 is a nice somewhere-in-between. It has the liquid mid and airy the great tube amps that I owned before (notably KR VT6000). This is a grand theft when it's only $1700 and you get 160wpc which could drive almost any speakers out there (may be except SoundLab A-1 and the Martin Logan CLS). What I like most about the SFM160 is that it's not that equipment discriminating - it works well with different preamps and speakers that I mix-and-matched.

And reliability-wise, this is nothing like the sorry SF preamps that I owned before. There is no auto-bias, and you're suppose to re-bias every month or so but what you need is only a screw driver and nothing else. Bias each tube takes a few seconds. How do you beat that?

This pair sounds the best with Telefunken E88CC gold-pin. Amperex PQ white label USA is next, followed by Siemens E88CC gold-pin.

A top notch product that rarely found in used market for a good reason.

Everything about it.
Enough power to drive any medium to high efficiency speaker
Never get tired listening to it

If anything, get a better power cord
Speaker terminals need upgrading

This is for the SFM-75.
How do I start? Build quality is fantastic. Good parts used, otehr than maybe the speaker connectors could be a bit better. Nice look with the stainless steel base and black cage.
The sound is amazing with 6550's and Gold Aero inputs.
Such low freq control, great depth, realistic vocals, and great definition un the upper regions.
Kicks the crap out of the Bryston 3b-ST I had before these.
Also picked up the SFL-1 preamp, and with an older RCA Black Plate tube, and Carey CD-301 tube cd player, this combo really sings.

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too many to list

Tremendous Power, midrange. Onboard bias meter. Build Quality, looks.

Very large. They take up quite a bit of room.

This was my first step up from a Denon Receiver. I was originally going to buy an Audio Research VT100 amplifier, then one day I was in a shop looking at some Audio Physic Tempo Speakers and noticed these on the shelves. I had heard of them before. Just on an afterthought I asked the audio consultant to hook them up. I was after all in the market for an amplifier as well.

Beautiful sound. Midrange to die for. I didn't buy the speakers, but I did buy these. (I held out for AP Virgos) I had been listening to several tube amplifiers (VTL, AR, CJ), and truthfully I liked them all. I liked the onboad biasing meters, and the fact that they can be jumped to 8, 4, or 2 Ohm loads. This means they can drive anything.

These I would characterize as being very forward in the midrange with a sense of warmth around the instruments. You won't mistake these for solid state amps. They excel as vocals, and instrumental timbres. I listen to a lot of jazz, classical soloists, and folk music. I don't think they really have any weaknesses - except that they take up too much space and don't fit into my room very well. I would have preferred an enclosed stereo amp. They are quite good at casting a three dimensional soundstage. The bass coming from my system is remarkable as well, very strong and controlled. I don't listen very loud, but I never feel like these amps are hurting for power. When hearing spoken words, it seems like another person is in the room with you. On the Diana Krall 'All For you' album, it seems like a giant keyboard is suspended in air, and you can point to the keys as she's playing. Very cool.

I am running Audio Physic Virgo's , an Adcom 750 preamp, the Sony XA7ES CD player, and Nordost Red Dawn cabling. I knew I wanted Audio Physics, I know they used to demo with these amps. That was another factor in my purchase.

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My first REAL amplifier.

Beautiful mid, ability to play loud with great imaging and soundstaging.

High is a little roll off and lacks serious bass punch.

The SFM 160 monoblocks is beautifully build inside and out. From the aluminum body to the internal components, MIT, Solen, Cardas wire etc, the 160 was one of best value on its day, given the build quality, sound quality and power (160 tubed watt!!!!).

My components consist of the following:
PS Audio Lamda Drive, Ultralinks II(nonHDCD), SonicFrontier SFL1 Signiture Preamp. XLO 1.1 signiture interconnects and XLO type 6 spk biwires. (Yes, they are from the same period, year 1995-). Avalon Avator speaker.

I have only used the 160s on my Avalon spk therefore the sound impression is based upon this set up. My Avalons are not considered as easy load for any Amplifier. Rated only 85db and 6ohm nominal, they do demand something with large current to drive them properly. With the 160s my Avalon sings with a very large voice. Strings, piano, percussion, or any given solo instrumentation the sound is just beautifully liquid, smooth, and deliver with ease. On some better recording such as 24bit recording ( or any audiophile recording for that matter), the tonal balance is something that even much higher priced items (I have visited many friend, audio store and listen to many many setup before and after I purchase my current gears) can hope to achieve. The imaging is just superb and it has the ability to throw a huge soundstage. Low level detail is excellent for a tube amp.
If I ask for improvement I could use a little more air on top and certainly the bass impact can be better. I understand if the amp is matched with speaker with higher sensitivity, woofer with lighter mass such as the ProAc response 3.5 or any ProAc speaker it should prove a even better match. Better yet, pick a good three way and drive the high and mid with the 160, and use a solid state for the bottom range.
Another method to push the 160 a little harder is....according to a audiophile magazine in Hong Kong, is to set the bias at 65v. But only when you are using the KT99A!!!!!! It is due to fact that the KT99A has a higher headroom compare to 6550 KT88. With the 6550 or KT88 the bandwidth should be adequate with the recommanded 50v. I have yet to experiment on this but I doubt that the difference can be that great.
I have heard setup like Jadis amp with Hale speaker, CJ amp with audio physics etc etc. These components are much more expensive than the 160+Avalon. Yes in some area they could best my setup but if you are into classical, vocal, string, jass(yes including the bass) you will have to spend much much more to equal the 160s. Of cause for headbanger solid state is the way to go. 160s are no longer avalible. SonicFrontier replaces it with Power Three which is a even better amp, but unfortunately they are much more expensive as well.
These monoblocks deliver music. I am no profession critics on audio components, and certainly my decriptions on the sound of the 160s is very limited, yet all I can say is that this amp deliver music like nothing else. It has that ability to draw you into the music and once its on, you really don't want to stop. If you are a fans of the above mentioned types of music, run to your nearest second hand store and hunt for a used pair of the 160. They are just wonderful for the right kind of music.

*That missing one star is based on the relatively mellow bass.

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Allegro 50w tube integrated tube amp.