Roger Cox - Creator of the Ampeg SVT Bass Amplifier System

[@wallymarx9646]

Fender Precision through the SVT is the ultimate bass tone. My best shows ever were on big stages pushing SVTs to top volume. Kudos to the Ampeg team.

[@rcrieder]

Every bass player to this day, owes you a debt of gratitude. Salud!

[@Microtonal_Cats]

I had an SVT with my band Bomb. I loved it. Made cool albums with it and took it on tour all over USA and Europe. Since it was so heavy, I told people it stood for "Severe Vertebral Trauma."

[@bananahammock334]

The Fender bass and SVT is such a magical combo. If one wasn't present for testing/tuning of the amp/cab I have to wonder if the history of rock and roll would have been different.

[@osXcanada]

Any bass guitar is a magical combo with an SVT.

[@tomaburque]

History has validated his design, to say the least.

[@timmotel5804]

Excellent. Very interesting and educational. Thank You All for this fine video.

[@DanAdlingtonOnline]

I have a Ampeg SVT Head in my own studio. I love it.

[@rustyrobinson8027]

Thanks for creating the best bass amp of all time 👍🇺🇸

[@Ace96x10]

Well said. Only amp as good imo is a 100 watt model 1959 Marshall MK2 Plexi. Same tone really. Just fantastic.

[@thedevilinthecircuit1414]

A hearty salute to Roger Cox! Thank you sir!

[@donbarile8916]

I had an SVT gifted to me in 1971, got it at Lipham music in Gainesville, Fla. But I was a guitarist... so the thing wouldn't breakup and I hated pedals. I plugged a Fender Bassman amp output into the SVT input and it was a real screamer. I was running 2 dual showman cabinets with it. Even did a radio commercial for Lipham. Different times. 😎

[@KennethMoyer-t3y]

Best bass amp I ever played through.

[@rigelloar7474]

I have owned and played Ampeg B-15N, SVT, and V-2 amplifiers, all GREAT amps!

[@cliftontorrence839]

Portland Oregon hosts an annual 4-5 stage "Blues Fest" wherein the management always rolls out several older twin speaker stack single head SVT 300 watters for the backlines . As a bassist, i've always appreciated that upwards of 50 acts could roll in, plug in and have a high quality consistent, reliable sound.

[@grubbetuchus]

For me, this was so great to hear this guy being interviewed. I wish the interviewer longer and I wish it were filled with just more stories and information. I love my Ampegs. I'm a guitar player. Two V-2 heads and a VT-40 combo.

[@erikvaldur3334]

I love old Ampegs. I've had an SVT, a few V4b amps, a V4 , VT22. B15N , SB12 I think it was. Then a few Oliver's as well. Best Oliver was a P500 powerflex 2-15" combo where the head came up out of the cab on a threaded rod. Jess Oliver told me Ampeg owned the rights to his flip top so he had to come up with another plan once he was on his own. Dennis Kaeger from Ampeg was my old amp tech. Then when I got into Oliver's I used Jess. Why not go right to the source when he was still with us. Jess was in the next state from me. I loved hearing the stories from the old Ampeg days from those guys. I spent many hours at Dennys ' place when dropping off or picking up amps there. He loved to talk and I loved to listen and learn. These guys are pure gold. They were the pioneers.

[@robertbright-jc3sd]

The absolute “BEST BASS AMP AND SPEAKERS EVER MADE.”!!!!!

[@1mespud]

Still the proud owner of a '94 Ampeg SVT Pro 2.

[@martyswaney1098]

I played though two mid 70's SVT's for many years, my ears are still ringing as I write this. Incredible amp, the midrange boost is awesome.

[@Asturiano53]

Me too!

[@billsmith2212]

I owned a Fender PS 400 . There were 3 - 135 Watt outputs . That was purchased for $ 275.00 on a closeout . It weighed about 90 + pounds . At the time Traynor also had a similar amp and speaker cabinet with 8 - 10" speakers . Unfortunately , tube amps require maintenance and at high power are heavy . I believe a custom SVT amp for The Monsters of Rock tour was made . It was basically a double speaker cabinet with 16 - 10" speakers and a 600 watt head .

[@thesanfordmethod1905]

Now THIS is an essential KZbin video !

[@tomcoryell]

Thank You Roger! No amp/ bass combination ever beat a Precision bass into the SVT. Interestingly, when the bassist in my band played through one he always disappeared when it was time to load HIS BASS AMP into the van.

[@RedArrow73]

Oh, yes, a Rickenbacker into an SVT is actually the penultimate.

[@tomallen5837]

I loved my SVT bass head... truly a magical sound. I wish I had it now in my semi-retirement. And I'm actually more physically fit for it having lugged it around to all those gigs in the 80s!!!

[@kevind2760]

Roger Cox is one of the best people I've ever met, and a great mentor.

[@stevebogucki5494]

I owned and played my Rickenbacker4001 through my SVT dual cabinet rig for about 10 years starting in 1974. It was clean, crisp and damned loud. My tinnitus is a constant reminder of the good old days. I listen to the tapes of my band, and regardless of the venue, it cuts through with that sweet Rick sound. When I switched to my P-bass, I had to turn it way down - or dancers would bleed from their eyes. (kidding) Thanks, Roger.

[@timmotel5804]

Good Day. Yes. The "tinnitus"... Best Regards

[@TheStratpicker]

I have a humble SVT micro head, which through a 15" Celestion loaded cab sounds terrific and respects the Ampeg tone totally. Very happy, with this compact and more affordable iteration. Not the same thing, for sure, but I love it.

[@MarkTurner-vs7uc]

These were all around in the 70s, the best bass Amp ever made. The old V 4 b is also a fantastic Amp. SVT Jr. Marshalls and Ampegs together are magical . In the 80s ,we got this stuff from the older guys for cheap. What a time.

[@rongraham1951]

Had an Ampeg portaflex bass amp in the early 60's don't remember the model it used to flip into the speaker for storage and had wheels on a flatbed that unscrewed I had a fender bassman amp prior but found the ampeg much better to travel with. Loved the sound of my Ampeg Amp

[@James-eg3nf]

This amp’s sound is so legendary that Universal Audio (UA) has an SVT modeler plugin that I use for all my studio bass work. Having played real Ampeg heads and cabs (including SVTs) , I can confirm it’s very realistic.

[@livewire4495]

Very Interesting! I love AMPEG. Thanks Mr. Cox for all the wonderful Information. I have been using a SVT V2 for 40 years as a right channel in a Stereo Guitar Rig. (In my line of sight as I type) I had a Refrigerator Cabinet but sold it and bought an Altec Lansing 2-12, Cabinet W 28", H 24", D 11". Half the weight of the Ampeg, but still well over Fifty Pounds. It's a Bass Cabinet, but This rig is a Mid-range Monster. I now use it in a Three Amp Rig. Fender Dual Showman, Ampeg Gemini II, and the Ampeg V2 with an ABC switch. I set the V2 tonally to sound like a Marshall. The Gemini II is set Full Range and Sweet. The Fender Set up is Clean On the edge of break up. Works well with all my pedals. This combo allows me to do covers with a complete selection of tones. It's old school and it's just ME and I dig It. Thanks Again!

[@miner49er79]

Love them so much . Thanks Roger and the 3 other guys. I used to have this small car with this huge SVT cab sticking out of the trunk. It was hilarious 😆.

[@bobsbarnworkshop]

Very cool information! Our bass player back in the 70’s had an SVT head, the 8x10” bottom and a V4B bottom we affectionately called “the refrigerator”! I had the SST with 2 powered 4X12” bottoms! Our rhythm guitarist had two B-25’s!! Took 3 vans to move our gear around !!!

[@RedArrow73]

I take issue with one thing Roger said abt The Sones' use of SVT's. On the 1969 tour there was a solid backline of nothing but SVT's, meaning Bill, Keith and Mick Taylor played thru them.

[@jayletter5209]

They used SVT & B42X cabs on that tour. Keith stood in front of a row of 3 SVT heads / B42X cabs (the 3 to the right of the drums). The B42X cab was a huge ported 4x12, slightly shorter but wider than the 8x10.

[@AmpApps]

Loved every minute! Thank you all. 🔊

[@Rick_Erickson]

@ 11:30 he comments that the amp was flat to 20 Hz, which is true for the original power amp section, but the preamp response was limited by the output capacitor of the 6C4 cathode follower stage. I had a customer complian once that his 5 string bass low B was not coming out as strongly as his other strings. I folowed each stage and landed at the cf as the point that the low freqs were being lost. Increasing the .1uF cap to either .22uF or more likely .47uF gave him the bass response he wanted and had the added benefit of reducing 60Hz hum from the preamp as the return impedance to the cf was lowered by the larger cap value. I have only done this once, but will gladly do it if requested by a customer. I generally try to not change the original circuitry if the customer likes the tone he gets from the stock unit. I do have a similar story about the Made in Viet Nam SVT CL, but the actual source of the lack of bass in that amp, compared to a Made in USA SVT CL was from a component in the power amp section. Similar problem, different solution.

[@doobie8425]

Would love to see a video on this! Question. Could this be done to the ampeg PF 800 ?

[@thechuckster6838]

There is just a certain magical tone that happens when playing out of an SVT. It is unmatched by anything else. I played the country with two heads and two V6B cabinets throughout the late 70's and well into the 90's with them. We used to play at a club that was always loaded with Hell's Angels guys. They loved the band enough that whenever we were playing there, they would roadie for us the entire night. I remember one such member carrying my two heads (one in each hand by the handle) to the truck outside, and I remember thinking that I would hate to be in a fight with that guy as he carried them effortlessly as if the cabinets were empty. Those amps never said no to me, and the sound was to die for! Today, I play out of an Epifani UL410 cabinet with a Crown power amp and and a Sansamp RBI front end. I still own two SVT heads and I've retained one V6B cabinet. Every so often, I will power them up, plug in a Musicman Stingray bass and there I am all over again!

[@rfliegler]

Nice to see you. Excellent interview. Looking well 👍

[@markericburke5303]

My SVT cabinet is a carpet one and it's in incredible shape all original speakers

[@bobbyd4400]

One of the fist shows i went to in 1998 was the verve and the bass player played through one of these rigs and i could feel it in my chest from quite a distance to this day many shows later never felt anything like it again

[@alexp8157]

My 73 svt is great can't imagine playing without it getting old is a drag

[@jerrymckenzie1858]

I only played an SVT once, but it was a life changing experience!

[@monkeyfinger7949]

I love hearing these music gear war stories from the engineers that made music history.

[@raybassman7536]

I used to run my 1974 SVT head through 2 JBL E-140's I put in my own custom built ported 2-15 cabinet. My own design, but ( to JBL specs on the porting). Sounded perfect, outdoors or in. The JBL's were a mid desiged speaker. I never had to use the ultra high switch. I ran the middle rocker switch in middle position at 800Hz. Ultra low off. regular knobs- mid at 2 o clock, treble at 2 o clock, bass at 3 o clock. This was great with the JBL's and my P-Bass. The tone I lived by. You could hear the notes clear with an edge on the notes, without being clangy.

[@G8GT364CI]

Good settings anyway, that's about how I play them too with SVT cabs, I do use the ultra hi though.

[@Rocksite1]

I'm a guitarist (wannabe), but my first experience with an SVT was with a used one at a music store which I played just out of curiosity. Two narrow cabs with four small speakers in each, under the head. Plugged the bass in, and played a few notes. Really clean sounding. A bit disappointing. Cranked it up, and it wasn't so much that the amp was distorting, but the cabs had this wonderful distortion themselves. Only if you played it loud enough. Really impressive.

[@airgead5391]

I owned an SVT III pro. I went with the new amp to a very skilled tube amp technician. First he pulled out all Chinese small signal tubes and dropped them into the waste bin and replaced them with NOS. He checked the max power output: 160W. He told me the driver circuit wasn't up to the task and probably should modify the amp with an 6BH7 tube. (would have been the LTP phase shifter I think) Also replaced the output tubes for better ones, which reduced the distortion about a factor 2 or more. Anyway: after that I used the amp for my double bass with a 12 inch cabinet. I got loads of compliments about the great sound.

[@Comrade_Collects]

Cheers! Was a great watch the whole way through 🤘🍻

[@acoustic61]

I still service SVT's from time to time.

[@johndrx165]

I had a 1969 I used in 1980-1982. Best amp I ever had. Sold it out of need for cash. Tried to buy it back, but guy would not sell it back to me. I ran it through a custom cabinet with 2 15" JBL E-140s.

[@raybassman7536]

I used to run the E-140's too for years, they are a slightly mid/brighter 15, so I did not have to use the ultra high switch on the SVT.

[@SanFranciscoFatboy]

wooo hoooooo !!!!!!!! i still got mine w/ a 2006 p-bass :). i never new the story of the cabs....

[@nasticanasta]

My cousin had an SVT stack and loved it, sold it when he got married, and regrets it ever since.

[@paulnicolosi4792]

I loved playing through it back in the 70’s, but it was a pain in the ass to keep in good repair, as it was ‘always’ breaking down. Replacing the tubes was a regular thing, which was expensive.. And then, you had a weight issue. Just the head was around 100lbs 😵‍💫 But at the end of the day, it was an amazing sound!

[@2sc458]

I saw Motorhead in about 1982 at the Keystone Berkeley. I was standing in front of Lemmy's SVT rigs. OMG, that was -effing loud. It sounded like the meanest guitar.

[@Lollygagger-k4p]

When I was 20 in 1976, I had a V4-B and a Fender Tele bass. We rented a house five blocks from the zoo in Seattle, and another 800 yards from the big cat compound. You could hear them roaring at feeding time on occasion, but I could get them roaring with that rig - from the basement. I got a letter from the city asking me to "modify things" on behalf of the zoo. It was the nicest sounding bass/amp combo I have ever owned. Later I acquired an Acoustic 130B head, to get the cabinet to sound more clear at low practice volume. But the Ampeg head would make theTele with round wound strings growl like a Ricky.

[@Jim-be9vq]

Roger your a musical Hero.❤

[@HamiltonMechanical]

WOAH. I'm at 36:07 and just now learned that some amps were made with magnavox. That's awesome! my mom and aunt worked at one of the factories here, we had one in Knoxville and one in Greeneville. One of my relatives died of a "heart attack" but it was actually a work related incident that they covered up. Really strange stuff you find while researching your genealogy! lmao

[@terryeckert5105]

Did the early SVT's use 7027 output tubes?

[@danielgrove7782]

I got to play 68 tele bass through svt...pfm..i finally got a tele bass..alass my back cant do a svt...still the best i ever heard

[@duncan-rmi]

in a sealed box, at low frequencies, two near-identical drivers pulling or pushing in the same direction, with sufficient power, will "arm-wrestle" so that one of them gets pulled inside out by the other. is that what you were seeing?

[@michaelorton9887]

Great interview

[@josephesposito3499]

Thank you Roger for designing an iconic amplifier. Can I ask Roger or anyone, can I wire 6 speakers for my Hiwatt DR103? I weant to output my Hiwatt to SIX speakers

[@rquance1]

Thanks so much for the SVT. I really enjoyed them but now I play the SVT Pro 4 into either one 15 inch subwoofer cab that can take all of the amp can put out beautifully or the Ampeg PRO410HLF 600 watt cab that really pushes the lows better than the Subwoofer cab. I play the system down to 15 htz and it flaps my pantlegs on my dress pants. Lol PS. I play Fender and Greco/Kustom Bases.

[@projectmoon13]

Proud owner

[@terryeckert5105]

Was Bill Hughes involved with the development of the SVT?

[@rokonikolic731]

Does somebody know why they only put 2 and 4 ohm output on the SVT heads?

[@motomoog]

I just purchased a SVT 8-10 cab from the 90s my concern is the right side of the cab is a much lower volume then the left side. Anyone know why? Any speaker repair shops around Riverside OC, San Diego or LA CA?

[@robnamowicz8073]

Sirs, is there an audiologist you recommend to correct speaker buzz in the right ear? Thanks, Oh, as an audiophile your society is very appealing. Are any rock and rollers members?

[@streamofconsciousness5826]

You have a great Job if you have a Bass in your office.

[@Ontariosound]

Keith and Ron used them at the El Mocambo live recording

[@thebenefactor6744]

Thanks, Roger, for many memorable moments you gave me on stage where you allowed me to be the absolute, mother lovin', kingdaddy boss for many a night. My pant legs flew like flags.

[@bigbri7519]

I have a 6146b SVT dated Sept. 1969.

[@jayletter5209]

I read an interview with Roger (and Bill Hughes) in some bass magazine where he said that Stewart Hegeman designed the Ampeg V4B. I've always been curious whether he meant the amp itself or the 2x15 folded horn cab..

[@JustK009]

The SVT is the alpha and omega of bass amplification

[@SuperMcgenius]

Regarding bass cabinets, a poorly braced cab will give you a fat blurry Sound, a well braced cab will give you a tighter and punchier Sound. I did notice in the background he has a pair of dipoles Magnenpan speakers, i’m gonna guess he also has a pair of subwoofers.

[@WilfMurray-rz2uk]

As a drummer I remember loving the sound this bass rige. Played in a disco band with mini moog bass and my bass drum into this amp. We kicked ass.

[@janetyer7147]

With electric bass, a lot of energy is in the harmonics overtones, and 2nd harminic can exceed the fundamental. John Atkinson at Stereophile is a bass player, and wrote this subject matter several times in different articles while he was editor there. One excerpt is quoted below, with a link to that article further below. "Despite what might be thought, the frequency spectra of electric (as opposed to electronic) instruments is complex. Fig.3 shows the spectrum of the low E string of the Fender bass, taken directly from the instrument's output. The fundamental frequency is 41.2Hz-the left-most peak-but the second harmonic at 82.4Hz is actually 11.8dB higher in level! (You can also see that the bass, being a high-impedance, inductive source, picks up a little 60Hz hum-the small peak at -80dB circled in white, between the fundamental and second harmonic.) Harmonics sticking up above the FFT analyzer's noise floor can be seen all the way up the 17th at 700Hz, which lies 65dB below the fundamental level; as with any instrument, it is the precise ratio of the harmonics, detailed in Table 1, that gives the Fender bass its characteristic tone." - Johm Atkinson www.stereophile.com/features/338/index.html

[@G8GT364CI]

You can control the amount of 2nd harmonic with the mid control in the 220 hz position. With the ultra lo you can almost entirely get rid of it, course all it does is vibrate the walls. The SVT preamp gives you almost total control of the sound of an electric bass.

[@davidgbrown5932]

This is true of the double bass as well. You need to hear a lot of upper harmonics , finger attack etc. to reproduce the natural sound of the instrument. A lot of sound men don't realize this and boost two much low freq information. The ear actually deduces the fundamental from the harmonic spectra which is why, on the phone, you can determine someone has a very deep voice even though the phone speaker can't reproduce the fundamental. I bought the recent Yamaha/ Ampeg P50T tube head which is like a V4B at only 50 watts. Lovely amp! Thanks for this great discussion.

[@G8GT364CI]

When he talks about "schooching" the upper bass stuff down to make you think you have more low bass I believe he meant to talk about the ultra lo switch not the ultra hi. 10:50. I've been using them since 1975 and currently own three 70's heads and two original flatback 8 x 10 SVT cabs from the early 70's with all original speakers. I don't always used the big SVT cabs but always use the heads with a variety of 4 ohm Ampeg cabs. Still the best sounding and most reliable bass amp going.

[@jayletter5209]

I thought the same thing but he does say "ultra low" (kinda muffled) right at 11:00 - it's just the cut & paste editing makes it sound strange

[@jayletter5209]

(Sounds like he says "overload" to me)

[@SMWTMS]

As noted in the description, the garbled sound quality is the internet communications provider, and not the editing. The image stalls at times too, again the internet communications provider, not the editing. Roger’s words are, “The amplifier had an ultra-high switch, ultra-low, and it had that mid-range, on channel one. And that mid-range boost and cut. Three different frequencies, and I don’t know what they were. We talked, Dennis, about ultra-high and ultra-low. Ultra-high was a capacitor that bypassed from the wiper on the volume control to the high side of the volume control. Ultra-low scooped a bunch of stuff, upper bass stuff, leaving you thinking you had more low bass. And it didn’t take more power to do that which would be the bad side of boosting low bass.”

[@G8GT364CI]

@@SMWTMS Thank you.

[@joeMW284]

Old 8x10's with the lower wattage speakers sound a lot better than the new higher wattage cabs imo. The new ones almost sound scooped. The low watt cabs are also way more efficient. You don't need to crank the amp nearly as much. I wish you could buy something similar to those original speakers. 32 ohm speakers are really hard to come by.

[@josephesposito3499]

Thanks to Roger for an iconic amplifier that even guitar players like Mick Taylor used. The Rolling stones best sound is when they used Ampeg Amps, after Mick Taylor and Ampeg left the stones they went back to sucking like they always did.

[@RedArrow73]

And Conversely, Bill Wyman continued using Ampeg with his Rhythm Kings band.

[@chrismixsupervisor3290]

Kewl !

[@curtiseverett1671]

I would like to have a VT40

[@joshdavis9410]

I'm about to sell my top loader in MA 😉

[@HollywoodRecordingStudio]

Roger Cox - my ears thank you! However, I will send you my medical bills for my back from all those years of lifting these!

[@RedArrow73]

For testing purposes, testing with a Fender, which 95% + of customers were likely to use, was the right call.

[@5150show]

Stones ‘69 US tour

[@perrysantoro5901]

I had 2 of em

[@andrewgillis8572]

without this amp I expect NEITHER Larry Graham nor Rocco Prestia could have made their (Bay Area) bass innovations

[@RayBecker]

Nothing and I mean nothing sounds as good as a 1970's SVT into an 810. It's a workout but at least Roger put a beefy handle and some wheels on that cabinet. Bass should be felt, not heard

[@randyclere2330]

GOD… of the LOW END!!