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All-tube SVT heads
- Thread starter Aharon
- Start date
Thanks for the continued input.
Christw-
Yes the svt 4 pro is always run bridged which would give a lot of headroom. If the svt 2 pro is indeed in full working order then perhaps I was expecting too much power-wise.
Can you give some details about the context in which it wasn't loud enough for you?
Bassoballs-
I have wondered whether swapping out / experimenting with tubes would do anything for me. What ive read so far seems to indicate that it is unlikely to make any drastic changes, but who knows, maybe I have a bad tube somewhere (although they all appear to glow healthily).
The SVT sound is definately the most appropriate for my band and for me, Its just a case making that sound louder for live use.
Is there a vast difference in headroom between the 2 pro and the non-master SVTs? (blue-line, svt II, vr etc.)
If this does come down to a faulty tube, is it likely to be power or pre or could it be either?
thanks again
Christw-
Yes the svt 4 pro is always run bridged which would give a lot of headroom. If the svt 2 pro is indeed in full working order then perhaps I was expecting too much power-wise.
Can you give some details about the context in which it wasn't loud enough for you?
Bassoballs-
I have wondered whether swapping out / experimenting with tubes would do anything for me. What ive read so far seems to indicate that it is unlikely to make any drastic changes, but who knows, maybe I have a bad tube somewhere (although they all appear to glow healthily).
The SVT sound is definately the most appropriate for my band and for me, Its just a case making that sound louder for live use.
Is there a vast difference in headroom between the 2 pro and the non-master SVTs? (blue-line, svt II, vr etc.)
If this does come down to a faulty tube, is it likely to be power or pre or could it be either?
thanks again
I have found swapping out tubes has made quite a difference in my 2-pro. The V1 position and the ax7 in the drive section have had the most profound effect. Ive spent a lot of time trying different tubes (both NOS and current production). Ive also replaced the transformer w one mfg by Heyboer, replaced some caps with paper and oil type, and I use Winged =C= 6550's. I was always bummed out that my 2-pro couldnt keep up with my vintage SVT, so Ive been working on it trying to improve it. So far I'm very happy with the results.
This is extremely interesting.
So exactly how much more headroom are you able to get out of your vintage SVT? I am using the same power tubes (winged c 6550), although I cannot remember what was in the pre/drive slots.
Were you actually able to get more clean headroom swapping the pre/drive tubes? What exactly did you replace? How many, what brand, etc?
I am considering getting hold of a SVT VR, they seem to be unanimously prefered to the pro series heads, although the lack of gain/drive/master controls put me off, which is ironic given my current predicament.
By experimenting with different tubes I was able to increase headroom and increase low end punch and clarity. I was fortunate to have a large lot of NOS tubes to A/B in various positions. It was fascinating to me how drastic the amp responded to different tubes.
The low frequencies that require a lot of speaker cone travel take a disproportionate amount of power to reproduce. On top of that, the human ear is less sensitive to those ultra low frequencies. With that ultra low switch engaged, all you're really doing is cutting a lot of the midrange content out of your tone so that the amplifier has to work a whole lot harder to put out a level of sound that is perceived as as loud as it was without the switch depressed. In that sense, you're asking too much of the SVT.
I had an SVT-II with an 810e in a loud band and I ran out of steam, even with a midrange emphasis. They flat out needed to turn down. On top of that, I had to realize that the tube SVTs only really put out about 280w of clean power. In clipping, yes they put out more power but neither you nor I were looking for that. You'd probably be surprised to realize how much juice you've been asking of the 4-Pro. Certainly more than the "300w" of an SVT!
Here's an idea of how to make the SVT work for your band: I'd try running a two pickup bass with both full-on and running bass around 10-11 o'clock, mids at 2-3 o'clock with the selector on position 1, and seasoning treble or the ultra hi switch to taste. Don't use the ultra low though! This will give you a heavier low midrange emphasis but you'll still have the natural scoop of using a two pickup instrument. It might not sound as cool on it's own but it won't work the amp as hard and it'll sit a little better in a band mix. Using a midrange emphasis on a two pickup bass at or around 120, 250, or 1000 hz has always done a great job of letting me cut through. Add some overdrive and season to taste! I'm not guaranteeing this will work for you, but it's how I've made due in a lot of situations.
In your opinion which tubes gave the most headroom and low end clarity? did you switch from 6550's to KT88's?
Anyone else care to jump in on the tube-rolling side of things?
The low frequencies that require a lot of speaker cone travel take a disproportionate amount of power to reproduce. On top of that, the human ear is less sensitive to those ultra low frequencies. With that ultra low switch engaged, all you're really doing is cutting a lot of the midrange content out of your tone so that the amplifier has to work a whole lot harder to put out a level of sound that is perceived as as loud as it was without the switch depressed. In that sense, you're asking too much of the SVT.
I had an SVT-II with an 810e in a loud band and I ran out of steam, even with a midrange emphasis. They flat out needed to turn down. On top of that, I had to realize that the tube SVTs only really put out about 280w of clean power. In clipping, yes they put out more power but neither you nor I were looking for that. You'd probably be surprised to realize how much juice you've been asking of the 4-Pro. Certainly more than the "300w" of an SVT!
Here's an idea of how to make the SVT work for your band: I'd try running a two pickup bass with both full-on and running bass around 10-11 o'clock, mids at 2-3 o'clock with the selector on position 1, and seasoning treble or the ultra hi switch to taste. Don't use the ultra low though! This will give you a heavier low midrange emphasis but you'll still have the natural scoop of using a two pickup instrument. It might not sound as cool on it's own but it won't work the amp as hard and it'll sit a little better in a band mix. Using a midrange emphasis on a two pickup bass at or around 120, 250, or 1000 hz has always done a great job of letting me cut through. Add some overdrive and season to taste! I'm not guaranteeing this will work for you, but it's how I've made due in a lot of situations.
Thankyou for this detailed reply chris.
I am starting to think that the 2 pro might be working just fine and that I was simply expecting too much.
The ultra low is an absolute must. Sonically it works much better with the band and the mid/upper mids are there to provide the tune and harmonics. For me its the secret sauce of the SVTs, they just dont quite sound the same without it.
I am still open to the idea of retubing to KT88s but they arent cheap, and ive read that they could make the low end sound even less tight than it already is.
I was on the same quest that you are with the SVT's. I answered it with a 1001RB-II for that band after spending a lot of time asking questions on here about retubing for more power. It shook the house through that 810e. I found a new life for the SVT-II through a particularly efficient cab, a Genz Benz 610T-XB2. It sounded huge but I never got to throw it into the band I was in...
I would normally suggest an SVT-IIP preamp in front but that 4Pro has a full tube preamp. Have you tried a signal booster, for example an MXR Micro Amp, in front of the 4Pro along with cranking the gain to get more of the tone you want from that amp?
I would normally suggest an SVT-IIP preamp in front but that 4Pro has a full tube preamp. Have you tried a signal booster, for example an MXR Micro Amp, in front of the 4Pro along with cranking the gain to get more of the tone you want from that amp?
IME a tube amp has a lot more going on in the low end with all the additional harmonic information that the power tubes section seems to add
I had the same problem with the low end suddenly farting my cabs out earlier when I got a tube amp. I have never gotten a tube amp to reproduce the tight low end of a good SS amp but that's just IME
If you insist that you need the deep switch in for the tone you are going for then I am afraid you are asking either too much from your cabs or your head...
To push low low frequencies like that at high volume, you need lots of headroom and speakers that can adequately reproduce the tone
I had the same problem with the low end suddenly farting my cabs out earlier when I got a tube amp. I have never gotten a tube amp to reproduce the tight low end of a good SS amp but that's just IME
If you insist that you need the deep switch in for the tone you are going for then I am afraid you are asking either too much from your cabs or your head...
To push low low frequencies like that at high volume, you need lots of headroom and speakers that can adequately reproduce the tone
Thanks for the reply bovril.
It did seem to me that the drivers were moving a little more than they were with the SVT 4 pro, despite producing an equal percieved volume in the room. Perhaps the cab is a bad match for the head. It is after all only a 610 and its ported and I have no idea how efficient these warwick cabinets are.
I will say though that with the svt 4 the cab was putting out some very clean, tight powerful lows and has never made a farting noise in its life. The same was also true with a Mesa Bass 400+ which I believe has quite a bit more headroom than the svt 2 pro (coincidentally does not feature an ultra low).
If I could just have the extra headroom out the SVT 2 pro then I would be a happy bunny, but even if I got rid of the farting noise, the low end response might still be "uneven" sounding.
To get the most clean headroom, turn the master all the way up and use the input gain as you volume control. Alot of guys do this.
The Mesa 400+ has just as much power. IMO and IME, the Mesa has a different midrange signature than the SVT does, including a different mid cut if you roll off the mids knob. Apples to oranges as far as their EQ stack and inherent tone goes. Apples to apples with regard to output.
I've got an alternative solution... The Ultra Low switch cuts 20 db at 800 hz. Your mid selector on position 3 is set to 800 hz. The mid knob will offer 12 db of cut or boost. Try using the following settings to get a similar tone without wasting all of the amp's power.
Bass: 11 o'clock
Mids: Cut all the way
Mid selector: #3
Treble: Whatever you like
Ultra Low: OFF
Ultra High: On or off
It'll still be dumping most of it's juice into those low lows. I'd suggest rolling off the bass knob a bit if the cones are going all over the place. Some tube amps just don't play nice with certain ported cabs.
I've got an alternative solution... The Ultra Low switch cuts 20 db at 800 hz. Your mid selector on position 3 is set to 800 hz. The mid knob will offer 12 db of cut or boost. Try using the following settings to get a similar tone without wasting all of the amp's power.
Bass: 11 o'clock
Mids: Cut all the way
Mid selector: #3
Treble: Whatever you like
Ultra Low: OFF
Ultra High: On or off
It'll still be dumping most of it's juice into those low lows. I'd suggest rolling off the bass knob a bit if the cones are going all over the place. Some tube amps just don't play nice with certain ported cabs.
new svts have a fairly weak power supply and sag alot which is why they go farty in the low end. Upgrade the power supply and it'll sound a bit nicer cranked
to the OP: cab can't handle the low end. they always say it: Tube Watts don't always equal SS watts. it's not a fair comparison the 1600watts of the 4pro vs the 300watt 2pro . so don't expect quieter/restrained results.
also: Always keep a load connected to your tube amp.
especially if you're going to put a disclaimer a few threads prior:
also: Always keep a load connected to your tube amp.
You're free to do what you want with your own gear, yet please don't recommend others do this with theirs. Always keep a load connected to your tube amp.
especially if you're going to put a disclaimer a few threads prior:
It's definitely not a fair comparison however, 1 watt = 1 watt. Always. No matter where they come from or what topology is used. Tube, ss, hybrid, whatever. The definition remains the same.
I'm not sure about the 610 hlf not being able to handle the low end. I had a 410 hlf and it could easily handle outrageous lows. IMO the problem is the amp and it's settings. I think the OP is expecting too much from it.
I'm bringing the svt 2 pro and the cab home tonight where I have the svt 4. Going to do some hands on experimentation. I am assuming that the head is in full working order, according to the previous owner it was retubed about 8 months ago and they all seem to be glowing healthily. Did a test for microphonics and didnt find anything.
I think its safe to say the cab is fine. Possibly not a great match for the head, but in full working order and certainly not breaching its 900w capabilities. The lows are farting but when they do come through, they can sound very uneven and saggy. In other words I am almost certain its coming from the head.
Ive heard a few trustworthy sources say that the newer "pro" and "CL" heads cant keep up with the older SVTs or the VR.
Has anyone tried both and experienced a large gap in headroom and low end response?
I think its safe to say the cab is fine. Possibly not a great match for the head, but in full working order and certainly not breaching its 900w capabilities. The lows are farting but when they do come through, they can sound very uneven and saggy. In other words I am almost certain its coming from the head.
Ive heard a few trustworthy sources say that the newer "pro" and "CL" heads cant keep up with the older SVTs or the VR.
Has anyone tried both and experienced a large gap in headroom and low end response?
