SWR SM-400S

You got all the info by now. Very versatile. I think I have an early model...can't remember when I bought it but it was early 90's. I think it's one of the first SM400S. Prior to that there was only the SM400 which i don't think has "transperancy" and maybe a little less poop when it comes wattage.

It's got power and very dynamic equilization. It can be adjusted to suit any style. The fan can be noisy when it comes on which might be an issue recording but I just learned that if I run it stereo with the right output, the fan won't engage....this thing is so cool

This sucka has been indestructable! Like I said, I'm going on 15+ years. I changed the tube once for fun. It's been all over the country boucing around in it's road case (4 slots). I use it with a Korg racak tuner leaving 1 space for ventilation. It recently crapped out on me at a gig which bummed me out. I did a post-mortum and discovered that the 15 years of bumping around literally removed all the screws on the heat sync and capacitors. They must have been flopping around for some time before it shorted out. I rescrewed everything back together, replaced the tube and I was good to go! Amazing.

Old SWR guys (pre Fender) were great. I called them (pre fender) once for some input on cabs and distorsion boxes. Have not had a reason to call the Fender guys.

Been playing for 20+ years. Have only had a few other amps (a Randall head and some peavey combos). I would never replace this amp. No reason to. I play it with my 6 X 10 Goliath Sr and it pumps. Great for big stages yet small enough to cart around. I agree with other posters that I think this amp will continue to increase in value.

Features are listed below by other reviewers, so I?ll go ahead.
What I want to say is that this head is one of the most versatile ever made.
No matter which cab(s) you use, this head will always give you an efficient option:
You can go down to 2 ohms each side in bi-amp mode, with 300+300 watts, two 4 ohm cabs will still have enough power (250+250). Unlike others head the SM400S can be run bridged in mono down to 4 ohm, with 550 watts (400 watts at @ 8 ohm). If you usually bring only your head to gigs, and hook to the cab you find there, there won?t be bad surprises, and you?ll always be loud enough.
You can also use just one of the two power units (SWR recommends the left, ?cause it has the thermal sensor for the internal cooling fan)
Patching possibilities are almost endless, even tough I don?t use any.
Another vote for the D.I.: the signal going to the PA or recording console is top quality, and you can adjust its own level, regardless of master volume, sound men always love it.

I played for years with a Trace Elliot rig, but when I upgraded from Ibanez to Warwick I found myself needing for a more hi-fi head. I tried many, and this second hand SM400S was my choice.
I have two Warwick, a 1989 Thumb and a 1987 Streamer Stage II, both 4 strings equipped with EMG pickups and 2 way MEC electronics.
I?ve used many different cabs in our rehearsal: various 4x10 including a Trace Elliot 1048h, a Marshall, a Goliath II and an Ampeg BSE 410-H, and a couple of 1x15, EBS 15F and a Basic 2 Way. Actually I?m using the Goliath II + Ampeg BSE 410H, mono bridged. I played a couple of times with a front ported Eden 410 XLT, and it was pure bass heaven.
The quality of this head excelled with all the combination of cabinets, and many others I used during live gigs.
The only thin that I disliked was when I tried to use the bi-amp option in stereo mode, with the 4 ohm Marshall 4x10 and the 4 ohm EBS 1x15. Maybe I?m just a poor idiot, but I found the sound less efficient, and had to tweak with the eq, so I ended using the 2 cabs still with the head bi-amped, but each channel in mono.
Regardless of how many, and which cabinets I use, I always love how this head sounds. As I told before I just want to hear how damn good my Warwick basses sound, and the SM400S is perfect: usually I run the head flatten, and I often adjust to the room/cabinets with just the Aural Enhancer. This control boost some lows, highs and selected lowmidrange from its flat position (full counter clockwise) to 12 o?clock. Going from 12 to 2 o?clock it start scooping mids and boosting highs and lows, from 2 o?clock to full clockwise the effect becomes very pronounced, similar to the Trace Elliot pre-shape. I love to hear midrange growl, and so I keep it between 8 and 11 o?clock.
I don?t like to tweak a lot, but this head lets you shape your sound with an excellent 4 band semiparametric eq. section.
As I already said, usually I don?t need to dig into it, but if needed it?s a very powerful and sharp device.
I miss the dual compressor of my previous Trace Elliot head, and I don?t use the internal limiter.
This head takes the signal coming out of your bass, and makes it loud. Plug a crappy bass, and the sound it?s going to be bad, plug a weak sounding bass, and you?ll hear a weak sound. But the better the bass you plug in, the better will be the sound resulting. Warwick basses are famous for low-midrange growl, especially older neck through?s, and the SM400S lets both them bark like rabid dogs.
The tube preamp has some serious balls, push the gain, and you?ll hear it.
Sometimes people refers to SWR, or similar modern heads, as sterile hi-fi?s but I absolutely disagree: this head will sound sterile only if your bass and fingers will do too, it?s up to you and your bass.
By the way, the transparency know isn?t an effect blend, from owner?s manual:
?TRANSPARENCY CONTROL
The Transparency control is a shelving type tone control that cuts or boosts the high frequencies a full octave above the treble function. Shelving point for this control is about 5K Hz?.

This head was made in 1998, and it?s mine since about 2 years. I changed the preamp valve when I bought it, even though it wasn?t really needed. I don?t know if something happened to the previous owner, and for me 2 years are too short to rate this category.
As someone else said this head gets very hot, especially if used at its lower impedance limits. This isn?t an issue, its chassis is made in aluminium, an excellent thermal conductor, and it gets hot because it dissipates heat from the inside.
It?s a 2 rack unit, but needs 3 rack spaces, to prevent overheating.
I never blown any fuse, and I use it a lot (rehearsal and gigs with two bands, without backup)

I contacted them via e-mail, Kelly was very kind, and the same can be said of John Shannon from Fender. Responses almost always within a working day.

Been playing since 1992.
I can only say good things about this head.
It?s loud, it has a very high quality preamplifier, an accurate flat sound as well as powerful tweaking options, it?s one of the most versatile head ever made, it has a built-in tube driven D.I.
Once you find your own sound, it?s likely that you?ll need just one knob, the Aural Enhancer, to make little adjustments.
When i bought it i tried Eden, Ampeg, EBS , Warwick, GK hybrid heads.
They all sounded well, but i preferred SWR and Eden for my Warwicks. I choose SWR because here in Italy they're cheeper used, and because Eden can't go down to 4 ohm if bridged

Other have already listed the features, so I'll spare everyone the list. It has plenty of features, in fact probably too many. I tend to not use a fair amount of the things this amp has to offer. I've used the loop only twice, and tend to run it strictly in bridged mode to an SWR Triad.

I have a Sukop fretted five string. This amp and the Triad accentuate the very natural tone the bass has quite well. The amp can be used with any style and any guitar really. I've used it in country, metal, jazz, and hip hop bands and it always does what I want it to soundwise. I always brag about how good my amp sounds to all those goofy people that get the Mid-Range Ampeg stuff.

Oh dear. Houston, we have a problem. I am one of the many that falls prey to the blown fuse and power off feature of this amp. In well over a year of owning this amp, I have blown about 8 fuses, it has cut out on me in many practices, and twice during a show. I don't have another amp to use as a backup, and usually the amp does just fine, but I am always a little scared of what might happen if it gets too hot.

never dealt with them as I purchased the amp used and long passed warranty

If only it were a little more reliable, this may be the perfect amp. Such as it is I've been considering an Eden WT400 or maybe something a little higher in wattage.

I don't own an sm-400, but I do own a different SWR amp. I just wanted to mention, because it looks like it's unclear to a few people, that the transparency knob on this amp is basically a blend knob for the effects loop. That's why it comes after the master gain, and also why it adds noise if you're not using the effects loop. If you are using the loop, it blends in more of the effected signal. Not really a flaw, just a different way of doing things. Just wanted to clear that up, so this amp doesn't get a bad rap for no reason.

I bought this SM-400 back in early '96. I bought it used and was only 6 mos. old. with a still active warranty. This amp is extremely versatile. I've played everything from neu-metal to ska and reggae with this baby without a problem. Other reviews are right about the XLR out. I use the tube pre-amp in this thing all the time in the studio. It really fattens up a DI bass tone. Another great feature is the EQ. It's got a 5-band slider deal with individual db pots underneath. I can get just about any tone I'll ever realistically use; from glossy slap, to flat-wound thud. This is a stereo amp with two channels and a bridge jack (w/2 1/8" plugs). It's got an effects loop I never use. I wish the XLR out was on the front instead of the back (like newer models). This baby has a transparency circuit that is absolutely worthless. All it does is add noise. I use this amp all of the time. I gig 3-5 nights a week, and do occasional studio work. This amp bridged at 4 ohms is around 500 watts or so and is plenty loud.

My primary bass is a '95 American P-Bass that is heavily customized. In addition to the stock split coil humbucker, I've also added a BassLines Stingray replacement humbucker that's custom routed near the bridge. Because I also added the BassLines pre-amp, Both pickups are now active. This amp loves active pickups. I get an incredibly warm, contemporary and smooth tone from this amp. I've never had too many problems w/noise. Some RF interference, but that was probably the venue. The reason I gave the long-winded description of my bass, is because my bass is a master-of-all-trades sounding instrument. I don't use effects, and instead rely on right-hand position and p/u selection for different tones. With my mids rather flat, and my treble and bass cranked on the amp's EQ, I can go from Johnny Cash to Jaco with just a p/u selection. This amp has pre-gain for the tube pre-amp and a master volume for the solid-state mains section. I've played this head thru 8 x 10 SVTs with plenty of juice. PA 18 bins, 2 x 15s, 2 x 12s, 4 x 10s, etc. without a problem. By cranking up the pre-gain, you can really get some nice tuby grind. I've never had the master at 11, but it's always been clean and quiet.

Some of the other reviews I've read list complaints with heat-induced failure, unreliability and horrible customer-service. This surprised me. I've played coast to coast with this baby, and have literally abused it at times in the 6+ years I've had it. I/ve only ever had to replace the tube twice.

I've been playing professionally for almost 20 years and have owned a shit-load of great bass amps. With the exception of my '75 SVT head (which I sold - Oh why, oh why, oh why...) the SM-400 is the best sounding amp I've ever used. I own a GK 700RB that sounds good until the third set. Then it starts to fade. I hate that. It makes me want to use it for target practice. The SWR doesn't do that ever. If it were stolen, I'd be up shit-creek. I've heard the new ones aren't as good, and couldn't afford a new or old one anyway. But, I guess I'd have to. The only things I don't like is the lack of a chassis and that stupid transparency knob. As I stated earlier, I don't use effects. Instead of the flight case this came in, I wish it had an old-school chassis. This amp gets HOT. And with only a 2 rack-space case, I do worry about meltdown. If they had a nice, vented Sunn Coliseum, SVT, etc. style chassis, it would suit me mo-better. Don't ever turn the transparency past 11:00 even with passive basses. It's just there in case you want to sound like shit for no reason.
If you can find one of these older SM-400s, buy it. I have a feeling these are going to be highly sought after in the coming years. I'm not going to make the same mistake I made with my old SVT.

You can get any kind of sound out of it. There is a wery good eq section in it, and the amp has a lot of punch.
And the power? 2*300 w, 550 w in bridge. Lots of power!! Once it was blown away my GK speaker. dman. I'm thinking on buying an Swr speaker. I wish that i would be better.
The only thig I don't like in it is that the effect loop is after the master gain controll.

I play music styles from blues to heavy rock. I like wery much slaping. And the Swr is the best for that.

I didn't have any problem with it.

It is one of the best amps in the market. If you need clean sound, buy an Eden, if you need punchy sound, buy an Swr. :) That's all, if you want to buy the best proffessional amp. For me the 550w is enough, and if i need much more, i would buy an sm900. (or two).
Professional sound. You can use it in every situation, and every style. And it will be one of the best!

My SM-400 was manufactured around the end of '98. The band I play with covers anything from blues to jazz to hardcore rock and this amp hung on pretty well with most of those styles. I play it through an Ampeg 8x10 with a '74 Fender Jazz. Power wise, it struggled with the 8x10 (see reliablity below) but I've also used it with a SWR Henry 8x8 and a SWR Goliath III 4x10 and it handled pretty well with those cabinets. It's got a GREAT sounding direct out...one of the best I've heard.

This amp gets that hi-fi glossy bass sound almost perfect. If you crank the pre-gain with the tube preamp, you can get some pretty naughty distorted tones, but nothing like my old '76 SVT. It's fairly versatile. Great Marcus Miller tones with a Jazz.

Here's where this amp just SUCKS. I had it blow fuses almost regularly. It always had to have a fan blowing on it to keep it cool. Without the fan, after the gig you could cook bacon on this mofo. After blowing god knows how many fuses, it finally blew a power transformer (huge cloud of smoke billowing out of my rack). I sent it to the factory, they took 3 weeks repairing it (see customer support), got it back, and the first gig I used it on after having it repaired, it blew up again. I'm selling the damn thing now.

As far as friendliness, SWR's service techs were a bunch of fumbling asses. They took forever on repairs, and claimed that it was my fault that the amp blew up...TWICE. I babied this amp and used it according to the manual that THEY wrote. It was a pain in the butt getting a hold of the service guys....probably out taking a smoke break all damn day long. And when they did repair it, it broke as soon as I got it back....'nuff said.

This amp sounds great through the right cabinets. An Ampeg 8x10 probably wasn't a good partner for it, but hey, who has $1200 to go buy SWR's new 8x10? Surely not me. When it worked, it sounded great, but when it broke, thoughts of taking a blow torch, sledgehammer and/or a chainsaw to it seemed pretty logical.

"The SM400-S is a stereo amp with a bi-amp crossover, stereo balance, stereo effects loop, with 150 watts per channel at 8 ohms, 250 watts p.c. at 4 ohms, 300 watts p.c. at 2 ohms. Rated at a max of 4 ohms in mono bridged mode it delivers a min. 500 watts continous and 400 watts into an 8 ohm load. . ." blah blah blah
For the rest of us: this amp has a gain control, tube preamp, limiter, bass, treble, and transparecy knobs, 5 band semi parametric eq, "Aural Enhancer" circuit (im told it boosts bass and treble), volume, and a couple of thingys i've never used because I only have one cab (hartke Transporter 4X10)Also has various sundry hi and low inputs, preamp outs and effects loops and whatnot. I'll give it a 10 because any more controls would be confusing.

Using it with an Ibenhad GSR Soundgear and a '79 Rickenbacker 4001, Straight in with no effects. I play pretty much any style that catches my ear, primarily funk and Jazz. Amp has a naturally modern, glassy, hifi sound. Crank the gain, boost the lows and mids a bit, and it's a beauty.

It's pretty old, and it's from a respected brand, I guess I could rely on it, I'd use it in a gig without backup, mostly because I cannot afford another amp. I doubt I could get service on it, since it's a discontinued model

It isn't being made anymore.

Been Playing for two or three years now, my gear has been discussed elsewhere. I've only had it for a few weeks now, It sounds great. If it were lost or broken, I'd cry, but I probably wouldn't replace it, since I haven'nt seen another for sale. But overall, I love this amp.

It has a gain knob, a variable limiter, bass treble, and a high teble(called transparency) kn., four band paragraphic eq (vith overlaps), an aural enhancer kn.(the same that used in studio -and the same quality) , master vol., and an balance kn. . It has a bridged, 2left, 2right master output, stereo/mono effects loop, xlr output with level ctrl. . I think it's fairly enough. The only thing I miss is the balance pot of the effect section.

I think it makes an unique sound for every stile. It is so clean, and it has that great tube sound. It can transfer form 10hz to 40khz ... That's great. It sounds awesome.

It's a vey massive unit.

It is the best amp i've ever played, and i think this is my amp for lifetime. Sounds excellent, enough power(550w) what more do i need?

This "SWR Engineering" amp was make in 1998, serial #8888 the last year this model was manufactured. Discontinued in late 1998/early 1999 and replaced with the updated "SWR Sound Inc." SM500.
The SM400-S is a stereo amp with a bi-amp crossover, stereo balance, stereo effects loop, with 150 watts per channel at 8 ohms, 250 watts p.c. at 4 ohms, 300 watts p.c. at 2 ohms. Rated at a max of 4 ohms in mono bridged mode it delivers a min. 500 watts continous and 400 watts into an 8 ohm load.
I use this amp with an SWR Basic 2-Way 15 inch cabinet on the bottom with a Goliath III Jr. 2x10 bridged with a SWR BAsic Black Combo amp (120 watt 8 ohm, 15" w/le son piezo tweeter) used exclusively for effects created with the Korg AX1-B.
The SM400-S the best direct out I've ever seen with a tube direct pre eq. switch and a post eq. line out with pad and ground lift.

I play a Warwick Streamer Pro M 4, which is a hi-fi rock and slapping machine. The SM400-S is the perfect amp for this type of bass. The The transparency knob adds highs above 5 kh, if you want horn fuse flashing bite. It can get hissy with active basses (just turn it down, no problem), but it can also make passive basses sound like their active.
Perhaps the best feature is the 4 band paragraphic equalizer: each band has a multiple frequency adjustment with a graphic slider above to cut or boost the desired freq. + or - 15 db. You can double boost or cut certain Freq.'s because they overlap. Finding the resonant frequency of whatever cabinet your using makes the cab louder, and playing with the eq. can compensate for "dead spots" on your neck.
Very cool!

SWR recommends that the amp be racked in a 3 space case. One of the best attributes of this amp is that at 2 rack spaces it only weighs 18 pounds, but it needs the extra rack space for cooling because the intake vent is on top of the amp.
This amp has never let me down and I often hear comments on just how great the tone is from other musicians. This is the top of the orginial SWR Engineering design that began with the SWR 220. This amp is truly a classic.

Customer Support is where the SWR SM400-S Lovefest ends. Back in the day customer support used to be second to none. These days it really sucks. Call the manufacturer in Sun Valley, CA and you may just get some kid who gives you misinformation, (happened to me twice in '99). E-Mailed questions through their web site probably won't be answered unless it has to do with sales, and then it took 2 e-mails. SWR Sound is NOT the same company as SWR Engineering insofar as customer service. One wonders what other "changes" for the worst are going at SWR since founder Steve Rabe left as president to start-up Raven Labs.

Compared to Eden, Ampeg, Mesa, etc... the SM400-S is a unique animal.