Why are Ampeg SVTs so popular?

[Nevada Pete]

When Ampeg first released the SVT there were no 10 inch loudspeakers capable of handling 300 watts RMS even in an 8 X 10 configuration. So the original SVT was designed for use with two 8 X 10 cabs. The original idea of using multiple small drivers to achieve big bass response was published in Radio & TV News which later became Electronics World as the "Sweet 16" (I don't remember which one of the two the "Sweet 16" article was actually in). Ampeg made it actually work.

With modern voice coil / loudspeaker designs and construction techniques one 8 X 10 cab is sufficient to deal with the liquid thunder from the SVT. However, many have reported with the Fearful 15 X 6 for example that adding an additional 3015LF cab adds depth to the bass even if you don't drive the rig any louder than usual. The same would be true for running two 810e's.

There was a power trio in the San Francisco Bay Area called "Bash" that used twin Ampeg 810's on each side of their drummer, obviously two for bass and two for guitar. The effect was stunning along with their excellent musicianship which was outstanding in and of itself.

The sealed design of the Ampeg 810 that's pretty much done at 55Hz. works really well on live stages for many reasons, one of which is that it doesn't muddy up the open drum microphones with low frequencies. Back when Swanson Sound was using lets say 2 to 4 JBL 4550 bass cabs on each side of a stage, for example, Tom Coroda always rolled off the bass at 80Hz., 12db / octave. I never noticed any lack of bottom end at the time. Just saying.

 

[7615]

Why aren't they still around? Did someone just say, "you know, I dont think we should keep building this perfect amp. Let's let Ampeg make all the money"?

Is that what they said?

Years ago I bought a new SVT, loved it, and then I found a used Fender 400. I sold the SVT within months - just saying... no comparison - band members all agreed wholeheartedly saying the tone was better - something I noticed as soon as I plugged it in. The SVT was more convenient with the head sitting on the 8 10's - but the tone was significantly harsher than the Fender.

Is your theory that if something is more popular it is better? In my experience popularity rarely equates to better.

 

[baxter_x]

Tom Coroda always rolled off the bass at 80Hz., 12db / octave

Funny this is where I set my HPF filter. Maybe a little lower, but around that very frequency

 

[Leo was right]

Is that what they said?

Years ago I bought a new SVT, loved it, and then I found a used Fender 400. I sold the SVT within months - just saying... no comparison - band members all agreed wholeheartedly saying the tone was better - something I noticed as soon as I plugged it in. The SVT was more convenient with the head sitting on the 8 10's - but the tone was significantly harsher than the Fender.

Is your theory that if something is more popular it is better? In my experience popularity rarely equates to better.

Just think about Microsoft Windows.

 

[Wasnex]

Is that what they said?

Years ago I bought a new SVT, loved it, and then I found a used Fender 400. I sold the SVT within months - just saying... no comparison - band members all agreed wholeheartedly saying the tone was better - something I noticed as soon as I plugged it in. The SVT was more convenient with the head sitting on the 8 10's - but the tone was significantly harsher than the Fender.

Is your theory that if something is more popular it is better? In my experience popularity rarely equates to better.

When I bought my first SVT I had a blackface Fender Twin. To this day I still typically prefer the tone of the Fender, but not everyone does. Lot's of people complain about the baked in mid scoop in the Fender tone circuit. The SVT has a small broadband peak in the same frequency band.

Since we are talking subjective opinions it's not possible to argue which amps is objectively the best. But I believe there is a compelling case that the SVT was/is a more successful design. The sound of an SVT and 810 became iconic and had a huge influence on music. I don't personally care for the sound of the 810 myself, but I think the SVT is a very good sounding amp that is far more flexible and versatile than most people realize. Try an SVT with your favorite speaker, you might be surprised.

 

[7615]

Just think about Microsoft Windows.

Exactly IBM's OS2 was a far far better operating system than Microsoft. Faster, more stable , (I had both) and in every way OS2 was a superior product. I would run Microsoft on the OS2 platform to run Microsoft software - ran better than if I just used the Microsoft platform.

So why did OS2 disappear - Microsoft was cheaper and PC's came with. IBM wanted full cost of its operating system not realizing better is not a criteria for the average user who browses a bit and gets e-mail.

 

[7615]

When I bought my first SVT I had a blackface Fender Twin. To this day I still typically prefer the tone of the Fender, but not everyone does. Lot's of people complain about the baked in mid scoop in the Fender tone circuit. The SVT has a small broadband peak in the same frequency band.

Since we are talking subjective opinions it's not possible to argue which amps is objectively the best. But I believe there is a compelling case that the SVT was/is a more successful design. The sound of an SVT and 810 became iconic and had a huge influence on music. I don't personally care for the sound of the 810 myself, but I think the SVT is a very good sound amp that is far more flexible and versatile than most people realize. Try an SVT with your favorite speaker, you might be surprised.

Undoubtedly the SVT was a more successful design. You may be right about the 8 10's. I loved my SVT and played it for a couple years but one day walked into my local music store and a used Fender 400 was sitting there so I couldn't resist. I only used the 3 speaker set up once - total overkill for my application. I had a voice of the theater cabinet 3 foot cube. I thought it was a 15" Altec Lansing but I spoke with the guitarist - whose memory is better than mine - and he said it was an Electro-Voice. At any rate I compared the 2 heads through that speaker and the Fender was the one I didn't sell.

 

[Wasnex]

Undoubtedly the SVT was a more successful design. You may be right about the 8 10's. I loved my SVT and played it for a couple years but one day walked into my local music store and a used Fender 400 was sitting there so I couldn't resist. I only used the 3 speaker set up once - total overkill for my application. I had a voice of the theater cabinet 3 foot cube. I thought it was a 15" Altec Lansing but I spoke with the guitarist - whose memory is better than mine - and he said it was an Electro-Voice. At any rate I compared the 2 heads through that speaker and the Fender was the one I didn't sell.

FYI, the Orange AD200B sounds and feels a lot like an old Fender amp if you max out the Master and run the Gain low.

 

[7615]

FYI, the Orange AD200B sounds and feels a lot like an old Fender amp if you max out the Master and run the Gain low.

I have sold all large amps since. I now play combo's - GK and Mark or even better the clubs' amps - that weigh less than 40lbs or in the case of the house amp - nothing.

100 lb plus bass rig days are well behind me.

 

[primusfan1989]

Is the SVT the holy grail of bass amps?

Its a matter of taste really, I personally don't care for Ampeg bass amps (not including vintage portables amps, they're pretty badass). SVTs are a bit too "chewy" for my tastes, I can think of like 20 different rigs id take before a SVT

 

[tom dicus]

When I bought my first SVT I had a blackface Fender Twin. To this day I still typically prefer the tone of the Fender, but not everyone does. Lot's of people complain about the baked in mid scoop in the Fender tone circuit. The SVT has a small broadband peak in the same frequency band.

Since we are talking subjective opinions it's not possible to argue which amps is objectively the best. But I believe there is a compelling case that the SVT was/is a more successful design. The sound of an SVT and 810 became iconic and had a huge influence on music. I don't personally care for the sound of the 810 myself, but I think the SVT is a very good sounding amp that is far more flexible and versatile than most people realize. Try an SVT with your favorite speaker, you might be surprised.

The only point I was trying to make, besides being in jest and friendly humor, is if the Fender were so much better, why did they not last but a couple short years with their iconic 400PS? All while the SVT has been non stop for 50 years. I love the sound of my Fender and nothing, not even my Ampegs can make up for that. But no Fender will ever sound like my Ampeg, and my personal choice of I could only have one? Ampeg SVT any day of the week. But that's my own opinion and I have nothing but respect for anyone else's, that's for sure. I was just following up with a comment someone made that seemed a bit harsh, that the Fender is the end all, be all, of tube amps. I just, with respect, disagree with those few posts a while back, nothing more. And if I've completely confused you? Just think how I feel stuck inside this fat guys head!

 

[Leo was right]

Undoubtedly the SVT was a more successful design. You may be right about the 8 10's. I loved my SVT and played it for a couple years but one day walked into my local music store and a used Fender 400 was sitting there so I couldn't resist. I only used the 3 speaker set up once - total overkill for my application. I had a voice of the theater cabinet 3 foot cube. I thought it was a 15" Altec Lansing but I spoke with the guitarist - whose memory is better than mine - and he said it was an Electro-Voice. At any rate I compared the 2 heads through that speaker and the Fender was the one I didn't sell.

If my memory is good, the "Voice of theatre" was the Altec A7 model.

 

[ThisBass]

Let me share with you another consideration about "moved air volume" and about the way why it relates NOT automatically to SPL.

The 3012LF provides Xmax 9.1mm, Sd 540 sq.cm, Pe 450 Watt rms.
Another driver of a different manufacturer (lets call this driver xy) may provide Xmax 5.0mm, Sd 540 sq.cm, Pe 450 Watt AES.
Both drivers come with a 3" VC

As mechanical limits are considered as to be the main limits how loud a driver can push sound into the room, this means that (based on moved air volume) the 3012LF should be capable to push +5.2 dB more of SPL into the room which was quite a lot of addtional volume.


The following pic shows a modelling for both drivers (3012LF and driver brand xy) loaded into the same 212 cabinet design.
System input power is 900 watt, each drivers is rated for a power handing of 450 watt (rms respectively AES).

Its hard to tell any difference between the two, Id call resposne and efficieny as "just the same".

The charts for acoustical power show a noticable deviation for max SPL.

due to its highish Xmax the 3012LF can really push about +5dB more of SPL than driver xy. The thermal limitation of 128dB between 50..200Hz is of no concerne cause bass guitar signals show rarely a smallish crest that equals 3dB like it is for a sinusoidal waveform which is used in the modelling program.

Lets consider what would happen if the 3012LF was loaded into a large cab volume by rather lowish cab tuning just to get some extended low end versus the cab design above.

f3 for yellow 3012LF is about -10Hz down versus driver xy

So lets see what now happens to acoustical power

That's a very interesting outcome cause its now hard to tell which cabinet can really push more of noticeable loudness into the room. The 3012LF cabinet shows better low end extension but that's not suitable to call the 3012LF cabinet as louder cabinet. The driver xy shows some better efficiency of about +1dB which is also not suitable to call this a benefit versus 3012LF.
Interestingly between 50..60Hz driver xy can push some more acoustical power than the 3012Lf although Xmay of xy equals about only 1/2 versus Xmax of 3015LF.

I think the 3012Lf cabinet might push some more of max acoustical power into the room but, the improvement versus driver xy was way less than Xmax numbers might give reason to expect. It can be seen that highish Xmax can be traded for anything. It depneds on the design if a highish Xmax number was used to improve max SPL or alernatively was used to desgn for extended low end.

As long as the cab design parameters in particular are unknown its not valid to claim that a driver with twice the Xmax of a different driver will push twice the air volume thus will push +6dB more of max SPL. As usual it all depends, there is no-free-lunch.

 

[ThisBass]

Sensitivity for a single 3015LFs is listed as 98.4dB, so a pair should come out at 101.4dB with 900W RMS power handling. Perhaps the pair of 3015LFs will loose a few dB of sensitivity to fEARful's the passive crossover.

I don't think that losses in the passive crossover is of any concerne cause crossover frequency is too high just to suck off much of power.

Lets assume the loss in the crossver equals 10% of distributed power. For any bass guitar application most of power density is (almos always) settled at the lowish side of the spectrum and only less power distribued beyond 800Hz.

Lets assume a worst case scenario: 30% of total power distributed into the spectrum above 800Hz and 10% losses in the crossover. In total the losses would equal -3% which would equal a loss in total sensitivety of -0.13 dB


edit, I think most of DIY folks like it to design crossover networks to be very robust versus full power handling of the cabinet respectively "worst case" voltage scenario. There is nothing wrong by doing it this way but it (often) means misunderstanding the facts. In Germany we call it this way "mit Kanonen auf Spatzen schießen" which in your language may mean: trying to shoot sparrows with cannonry

 

[Wasnex]

The only point I was trying to make, besides being in jest and friendly humor, is if the Fender were so much better, why did they not last but a couple short years with their iconic 400PS? All while the SVT has been non stop for 50 years. I love the sound of my Fender and nothing, not even my Ampegs can make up for that. But no Fender will ever sound like my Ampeg, and my personal choice of I could only have one? Ampeg SVT any day of the week. But that's my own opinion and I have nothing but respect for anyone else's, that's for sure. I was just following up with a comment someone made that seemed a bit harsh, that the Fender is the end all, be all, of tube amps. I just, with respect, disagree with those few posts a while back, nothing more. And if I've completely confused you? Just think how I feel stuck inside this fat guys head!

I am sorry if any of my comments have offended you.

Here's my take: The SVT is iconic while the 400 PS is an interesting, but essentially unimportant historical footnote. The 400 PS may sound better to some, but IMHO there is a good reason the design was not commercially successful. Few musicians would be able to afford or transport three huge speakers, so the design was inherently impractical. Additionally, I believe they were even harder on the tubes than SVTs and more challenging to work on.

You indicate you love SVTs. I have not bones to pick with your choice in bass amps. I own a 69, and 87, and an 8-Pro that can be dialed in to sound pretty authentic as well. I love my SVTs, but I have lot's of other amps that I love equally as well.

Rock on brother .

 

[JGbassman]

I’ve had an SVT I bought for a show opening for Yngwie Malmsteen and MR. Big in the late 80’s/early 90’s to replace my old backline and was amazed by how easy it was to get a killer sound. I’ve never looked back.

I still own the same rig. I don’t bring it out for the club gigs, but bigger events and pro stages I’ll set it up. Using a hand truck to move it makes simple work out of the haul.

I have many other amp systems I really like, but there is only one That sounds like it. If I could only have just one, that would be it.

 

[Nevada Pete]

[7615] I had a voice of the theater cabinet 3 foot cube. I thought it was a 15" Altec Lansing but I spoke with the guitarist - whose memory is better than mine - and he said it was an Electro-Voice.

If my memory is good, the "Voice of theatre" was the Altec A7 model.

That is correct. The venerable Voice of the Theater was all Altec Lansing, including the woofer which left something to be desired for PA use. The Voice of the Theater cab 7615 speaks of may very well have had the woofer replaced with an EV model, but stock they were Altec all the way. We used the A7 boxes to good effect loaded with a JBL D140 and topped with an Altec 311-90 sectoral horn and 288c compression driver. This worked great for side fills, especially if you could get it up off the stage floor some. The A7's fell out of favor when JBL came up with their iconic 4560 bass cab and 2440 compression driver with radial horn.

 

[Wasnex]

[7615] I had a voice of the theater cabinet 3 foot cube. I thought it was a 15" Altec Lansing but I spoke with the guitarist - whose memory is better than mine - and he said it was an Electro-Voice.



That is correct. The venerable Voice of the Theater was all Altec Lansing, including the woofer which left something to be desired for PA use. The Voice of the Theater cab 7615 speaks of may very well have had the woofer replaced with an EV model, but stock they were Altec all the way. We used the A7 boxes to good effect loaded with a JBL D140 and topped with an Altec 311-90 sectoral horn and 288c compression driver. This worked great for side fills, especially if you could get it up off the stage floor some. The A7's fell out of favor when JBL came up with their iconic 4560 bass cab and 2440 compression driver with radial horn.

I played my SVT through the Yamaha equivalent a couple of times and it sounded really nice. Had to dial the horn way down.

 

[bobyoung53]

[7615] I had a voice of the theater cabinet 3 foot cube. I thought it was a 15" Altec Lansing but I spoke with the guitarist - whose memory is better than mine - and he said it was an Electro-Voice.



That is correct. The venerable Voice of the Theater was all Altec Lansing, including the woofer which left something to be desired for PA use. The Voice of the Theater cab 7615 speaks of may very well have had the woofer replaced with an EV model, but stock they were Altec all the way. We used the A7 boxes to good effect loaded with a JBL D140 and topped with an Altec 311-90 sectoral horn and 288c compression driver. This worked great for side fills, especially if you could get it up off the stage floor some. The A7's fell out of favor when JBL came up with their iconic 4560 bass cab and 2440 compression driver with radial horn.

Altec Voice of the Theaters were all over the place during the 70's for bands. Wish I had picked up a few of them.

 

[Nevada Pete]

I played my SVT through the Yamaha equivalent a couple of times and it sounded really nice. Had to dial the horn way down.

View attachment 3196450

I'll bet that flapped your bell bottoms!