200 Watt SVT? How to do it?

[coreyfyfe]

Mmmm.... Fuzz.

A little taste of MC5's Ramblin' Rose

-Gibson RD Artist without the Moog preamp. Just the stock pickups rewired like a jazz bass. Tone rolled all the way off, neck pickup only.
-V9 Head (Magnavox-era SVT) Volume at about 2:30.
-TL606s loaded with EV15Bs
-EV RE-20 dynamic mic to digital recorder.

(let me know if the clip doesn't work. Sometimes I have issues encoding MP3s outside of iTunes.)

That, to me, sounded like a pedal. What fuzz pedals have you tried? I run a messdrive for fuzz and through my SVT (and my V4) with a vintage 8x10 it sounds like the speakers are tearing to shreds (seriously, I thought I broke something the first time I used it). With modern cabs and my standard settings there is usually a bit too much high end, but it can be rolled off a bit on the pedal.

Back to your idea - I would think a V4 with upgraded transformers, 6550s, (and maybe a filament transformer as paul often recommends with the 6550 mod) would be the better route. That way you would be spending less than an SVT and still get the same or close to the same sound.

Or just get an Orange AD200. I don't like that amp because it gets into spongy dirt territory too soon, but if dirty dirty tone is what you're looking for I think you should stop worrying about the amp sounding like an ampeg (which it probably wont if you modify it anyways).

 

[JimmyM]

well demands like that are what keeps small builders in business. that's your best route.

 

[fu22ba55]

Thanks everyone for chiming in:

Summary thus far:

-----------------------------

Possible Solutions

I don't see why it should be so difficult to go and get some transformers that are ideal for four output tubes. Expensive, but plenty plausible as far as I know.

The other route is to boost a 100W amp to 200W. Using a quad of 6550s or KT88s will give you the desired power but not with the current OPT or PT. These will both have to be replaced. Probably a transformer company like Mercury Magnetics could supply both. Obviously the components in the 100W amp will have to be modified to handle the increased voltage and current requirements. Not a walk in the park but doable. This way at least you'll not need to do too much chassis/metal work and your cosmetics would be taken care of.

Rewire the plate supply rectifier as half wave, adjust filter caps to work if you get hum. Cheaper and more practical than dummy loads and new output transformers if you can't just pull two tubes.

Actually, add an additional half wave rectifier/filter just for the output tubes, and move the output transformer B+ connection to that. Then you can go back to 300W easily later.

Should be about 200W.

you could lower the plate voltages, so six 6550's will put out less power (watts) and clip sooner.

Another thought off the top of my head is to install EL34s. Six of them, properly biased, should provide around 200W at the voltages of an SVT. The base wiring may have to be modified to make sure G3 is connected to the cathode.l

Has anyone suggested using yellowjackets yet? It will change the tonality of the amp, but you'll be able to drive the powersection into glorious tube crunch at alot more reasonable volumes.

http://www.thdelectronics.com/pdf/yj.pdf

Potential Problems:

The only stress I can see (and I am not an expert) for the OPT if pulling output tubes is that the output impedance of the amp would go up (I think - Google around to check me), so you would need to be mindful of that.

One side effect of that is an increase in plate voltage supplied to the remaining tubes, assuming the original power transformer is used.

The problems I see in the OP is that to take a 300W amp and drop it down by removing a pair of output tubes is that the output transformer will no longer match to any normal load. The power transformer would still work fine. The OPT would have to be replaced with one with a suitable primary impedance.

theres no way el84's will survive in a svt.

also @ paul, not sure i'd want to run el34's at that kinda voltage without properly regulated screens. They can take it but i think you'll burn through them far to quickly

 

[coreyfyfe]

Addendum to my last post - here's a good starting point - http://cgi.ebay.com/1974-Ampeg-VT-2...742?pt=LH_DefaultDomain_0&hash=item2309b5b93e

Things not working as is so you have a problem amp to start with, drop in new transformers....

 

[fu22ba55]

i'm just glad i don't have these problems. i'd be broke!

I've got 99 problems, and a working 200W SVT ain't one!

 

[fu22ba55]

Addendum to my last post - here's a good starting point - http://cgi.ebay.com/1974-Ampeg-VT-2...742?pt=LH_DefaultDomain_0&hash=item2309b5b93e

Things not working as is so you have a problem amp to start with, drop in new transformers....

Oh hell yes, THAT'S what I'm talking about. I'll ping my amp tech tomorrow and ask him if this is a viable starting point.

Nobody would be pissed if I cut up this roached-out V4, would they?

 

[JimmyM]

i think you'd be safe from the collector police with that one, yes

 

[fu22ba55]

That, to me, sounded like a pedal. What fuzz pedals have you tried? I run a messdrive for fuzz and through my SVT (and my V4) with a vintage 8x10 it sounds like the speakers are tearing to shreds.

It's nearly impossible for a recording to capture the dynamics of the totally squashed output stage... you can totally tell the difference (as opposed to a pedal) as it comes off the stage. The output stage is very dynamic and responsive to how much you dig in to the string.

That said, I'd love to try a messdrive if it sounds like you describe. I've tried mostly Big Muff Pi's in the past. I also just picked up a Sanford and Sonny Bluebeard that's in the mail to me as we speak.

Back to your idea - I would think a V4 with upgraded transformers, 6550s, (and maybe a filament transformer as paul often recommends with the 6550 mod) would be the better route. That way you would be spending less than an SVT and still get the same or close to the same sound.

Remains to be seen whether it's easier to add watts or remove them, but your solution sounds cheaper for sure...

Or just get an Orange AD200.

I've got my eyes peeled for an early 70's one. Not to keen on a newer wanna-Bieber version.

 

[ishouldbeking]

That, to me, sounded like a pedal. What fuzz pedals have you tried? I run a messdrive for fuzz and through my SVT (and my V4) with a vintage 8x10 it sounds like the speakers are tearing to shreds (seriously, I thought I broke something the first time I used it). With modern cabs and my standard settings there is usually a bit too much high end, but it can be rolled off a bit on the pedal.

Yeah, I didn't read the text before listening and just assumed that was a fuzz pedal. I've played quite a few that can do exactly that, if not nastier while still sounding great. Stuff like an Earthbound Supercollider or any number of similar evil fuzz pedals. I forget the url, but there's a bass fuzz review site (something like bassfuzz.com, but probably not exactly that) with tons of pedals described.

As for the thought experiment, I'm sure you could do it. But it does seem like from what you're describing the Orange AD200B or possibly even the Thunderverb would hit your sweetspot a lot quicker. If you're even considering a Reeves as a backup option, i think the orange makes far more sense for you. the Reeves is far more clean and hi-fi than an SVT to start, whereas the Orange is inherently more gnarly... seems like a pretty straightforward choice. I know they're not available everywhere, but a local shop has had one near me for a couple years now (Truetone in Santa Monica). I know you consider Orange to be trendy at the moment, but who really cares? Get an Electric or Matamp if it's really that big of a deal... hardly anyone besides TB lurkers even know those brands. Maybe look at the Verellen amps too... they're designed to do this sound.

 

[fu22ba55]

What about building a 200W all-tube slave from scratch, based off of an SVT schematic, and dropping a genuine turret-board B15 on top? That would be pretty mighty... And mighty expensive.

Heck... that's almost a viable product idea. A 200W ampeg-clone slave, ready to accept any fliptop head? Could you even scavenge the 30W from the fliptop for an additional 30W?

 

[Korladis]

Who the hell is Justin Bieber? I have heard this name several times over the last month, referenced as if I'm supposed to know who that is.

 

[Korladis]

Yeah, I didn't read the text before listening and just assumed that was a fuzz pedal. I've played quite a few that can do exactly that, if not nastier while still sounding great. Stuff like an Earthbound Supercollider or any number of similar evil fuzz pedals. I forget the url, but there's a bass fuzz review site (something like bassfuzz.com, but probably not exactly that) with tons of pedals described.

As for the thought experiment, I'm sure you could do it. But it does seem like from what you're describing the Orange AD200B or possibly even the Thunderverb would hit your sweetspot a lot quicker. If you're even considering a Reeves as a backup option, i think the orange makes far more sense for you. the Reeves is far more clean and hi-fi than an SVT to start, whereas the Orange is inherently more gnarly... seems like a pretty straightforward choice. I know they're not available everywhere, but a local shop has had one near me for a couple years now (Truetone in Santa Monica). I know you consider Orange to be trendy at the moment, but who really cares? Get an Electric or Matamp if it's really that big of a deal... hardly anyone besides TB lurkers even know those brands. Maybe look at the Verellen amps too... they're designed to do this sound.

Also, if you have the dough, Verellen will pretty much build you what you want. A 200 watter that sounds like an SVT probably wouldn't be that hard for them.

And yeah... nobody but TBers know Electric/Matamp.

 

[funkybassinator]

What about building a 200W all-tube slave from scratch, based off of an SVT schematic, and dropping a genuine turret-board B15 on top? That would be pretty mighty... And mighty expensive.

Heck... that's almost a viable product idea. A 200W ampeg-clone slave, ready to accept any fliptop head? Could you even scavenge the 30W from the fliptop for an additional 30W?

Dude, I think you're insane. In a good way of course...

 

[fu22ba55]

Stuff like an Earthbound Supercollider or any number of similar evil fuzz pedals.

I do think I'll have to spend some quality time with some more of these boutique-y fuzz pedals to see if one hits the mark.

As for the thought experiment, I'm sure you could do it. But it does seem like from what you're describing the Orange AD200B or possibly even the Thunderverb would hit your sweetspot a lot quicker.

Eyes peeled for an AD200B for sure. (or the right Matamp/Electric/Green, etc...)

Maybe look at the Verellen amps too... they're designed to do this sound.

I do like the sound of the Meat Smoke, which would kind of work like a master volume SVT, but they're still 300W.

 

[coreyfyfe]

It's nearly impossible for a recording to capture the dynamics of the totally squashed output stage... you can totally tell the difference (as opposed to a pedal) as it comes off the stage. The output stage is very dynamic and responsive to how much you dig in to the string.

That said, I'd love to try a messdrive if it sounds like you describe. I've tried mostly Big Muff Pi's in the past. I also just picked up a Sanford and Sonny Bluebeard that's in the mail to me as we speak.

I'll try to get a quick recording in for you tomorrow after work. Hopefully I can get home and get something tracked before my upstairs neighbors get home.

 

[coreyfyfe]

Maybe look at the Verellen amps too... they're designed to do this sound.

Forgot all about them! If you can, check out the minus the bear song "Animal Backwards". The last time I saw them I was standing directly in front of his verellen/ampeg 8x10 (ok, about 10 feet in front of..) and the amp on stage sounded exactly like the bass tone on that song. His FOH sound was coming off of a sans amp something-or-other.



(no idea who made this video but the bass comes in at about 35 seconds)

 

[coreyfyfe]

I do like the sound of the Meat Smoke, which would kind of work like a master volume SVT, but they're still 300W.

You're too hung up on the wattage. Crank the master for output distortion and control your level with the gain. If you're talking gain only amps, yeah the wattage will have a big impact on overall volume, but if you have a gain and master you should be able to slam the output tubes with the master and use the gain to set your volume.

 

[johnk_10]

as far as pedal distortion goes,i really think a tube screamer is capable of being very touch sensitive if dialed in properly.

as far as tearing into that beat up VT22, i think it would make a fine platform for a custom 200 watter.

as far as a verellen tube bass amp. i never thought of ampeg at all, judging from the sound clips that i've heard. IMO, they're not even close to being in the same league as an SVT.

now a Reeves 225, that's an entirely different story.

and i haven't played thru one, but building one on the weber 200 watt platform (but using higher quality USA components-i.e pots, jacks, caps etc) might be able to get you there.

that said, my sound city bass 150 can produce a huge, punchy distorted sound when pushed really hard, and feels like 2/3's of an SVT. my fender studio bass or super twin heads also sound surprisingly similar to a 100% tube 200 watt version of an SVT, and i've thought of them being that since the 70's.

 

[fu22ba55]

that said, my sound city bass 150 can produce a huge, punchy distorted sound when pushed really hard, and feels like 2/3's of an SVT. my fender studio bass or super twin heads also sound surprisingly similar to a 100% tube 200 watt version of an SVT, and i've thought of them being that since the 70's.

...And edbass has got me on the lookout for the *right* Sunn 2000S...

I know there are amps out there that can do it, and after I get this all out of my system, I will probably find one of them, or have one built. (I've had discussions with my tech on more than one occasion about a custom build.)

I was just hoping there was a relatively painless < $500 mod to an existing, working SVT that would safely cut it's power by a 3rd. I imagine if there already was one, people would be doing it already and we'd know about it.

 

[johnk_10]

...And edbass has got me on the lookout for the *right* Sunn 2000S...

yeah, my 2000S can do it as well. absolutely wicked amp and one of my all time favs.

...I was just hoping there was a relatively painless < $500 mod to an existing, working SVT that would safely cut it's power by a 3rd. I imagine if there already was one, people would be doing it already and we'd know about it.

have your tech look into lowering the plate voltages on the output tubes. it should run under a $100, and you could even install a 2/3rd's-full power switch somewhere to so you could have it both ways. it might require a re-bias, but you probably could even make it change it's bias when it is switched. alot of guys do it on guitar tube amps all the time.

the reason you never hear of someone doing it on a bass amp is probably because most bass players are always wanting more power, and not less.