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Topic: Tube amps |
Pierre Belliveau
From:
New Brunswick, Canada
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Posted 6 Apr 2020 3:58 pm |
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General question , i use a boss Katana and a Nashville 400 for Amps wich i love . I also have some guitar amps like a 59 Bassman 4x10 and a 70’s MusicMan 4x10 , and a boutique handwired 1x12 Marahall 1974x .. why is it that when i plug my steel in any of these guitar amps it sounds super distorded like i have a overdrive pedal ? Even at low volume , i can’t see to use tubes amps .. thank you
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Mullen G2 , D-10 , Webb 614-e , Hilton Pedal |
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Fred Treece
From:
California, USA
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Posted 6 Apr 2020 4:39 pm
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| The key to getting a clean sound on a tube amp is getting the preamp and power amp to cooperate. I have a Mesa Boogie that I set with preamp volume at around 5 and the Master around 3 or 4. Many people insist on setting the Master much higher than the preamp, which will definitely provide a clean signal but also results in a tone that is difficult to soften on a Boogie, to my ear anyway. I would think the Bassman and the MusicMan would work similarly. |
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Larry Bressington
From:
Nebraska
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Posted 6 Apr 2020 4:53 pm
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| You’d have to go very low to nil on the preamp and use the master to keep a good old valve guitar amp clean. Also the steel pickup is much beefier than a guitar pick up, you’d have to lower it considerably if using a guitar amp like a Marshall, hi watt, etc etc they do make steel guitar amps voiced for it like the milkman. Valves like Ecc83/12ax7 saturate easily. |
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Rick Abbott
From:
Indiana, USA
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Posted 6 Apr 2020 5:05 pm
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You can plug into the 2nd input to lower gain. I was using a tweed deluxe, set up with 6L6 output tubes, at gigs. I plugged into #1 Normal for rehearsals and #2 Normal for gigs. No, it wasn't very loud, but it was enough, and wasn't distorted. I had many, many compliments on my tone. In a living room, I'd use the Bright channel. #1 for acoustic and #2 input for slightly louder jams. A very efficient speaker is KEY to this.
A Goodrich Matchbox can help, as well. Turn down the gain; turn up the tone.
That Bassman should kill for a good "outlaw" tone. The Musicman should be great, maybe better, than the Bassman. These are just my opinions. Maybe the amps are biased too hot and need to be tamed down a shred.
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RICK ABBOTT
Sho~Bud D-10 Professional #7962
Remington T-8, Sehy #112
1975 Peavey Pacer |
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James Holland
From:
Alabama, USA
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Posted 6 Apr 2020 6:14 pm
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| Consider having your tube amps serviced, that made all the difference in the world for my pedal steel. I tried everything, changed pickups, cables, pedal, etc. It was the amp, needed caps, some resistors and a diode, and some tubes. And, I always get a better sound from my E9 with my tube amps [in good order] than my solid state [lower power stuff]. Solid State sounds pretty harsh on double or triple stops when they run out of headroom. Tube amps seem to flatter at higher volumes and manage headroom more gracefully. |
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Sandy Inglis
From:
Christchurch New Zealand
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Posted 7 Apr 2020 3:00 am
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Hi Pierre
Even though I have a background in Electronics, I'm trying to get my head around Valve Amps.
I am looking to change the valves in my Hi-Watt to improve the sound and found this article:
A very informative quote from https://300guitars.com/articles/preamp-tube-gain-factors-and-substitution-chart/
"The 12AX7 family of dual-triode preamp tubes consists of the 12AX7, 5751, 12AT7, 12AY7, 12AV7 & 12AU7. These are all pin compatible with one another, the only differences being the gain factor of each tube. A common substitution is to replace a 12AX7 with a 5751 or a 12AY7 to tame a preamp that tends to overdrive too easily, allowing you to get a better ‘clean’ sound out of your amp.
Tube Gain
12AX7 100 (40db)
5751 70 (37db)
12AT7 60 (35db)
12AY7 45 (33db)
12AU7 19 (26db)
It is important to note that the above is not carved in stone and any of these tubes can be substituted for any other. For example in the 4×10 5F6-A Bassman the stock first gain preamp tube is designated as a 12AY7 which has a gain factor of 45. Replacing it with a 12AX7 that has a gain factor of 100 dramatically changes the tone and feel of the amp."
My understanding is that not only does the Gain of the valve matter, but (apparently) the make/brand makes a big difference. My amp came with Rubys' which can be variable in sound and quality. I will probably look at installing JJ's.
I'm going to change one pre-amp valve at a time to figure out what makes the most improvement.
Sandy
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01'Zumsteel D10 9+9; Sho Bud D10 SuperPro; 6 String Lap Steel (Homemade); Peavey Nashville 1000; Fender Deluxe 85;
1968 Gibson SG; Taylor 710 CE; Encore Tele Copy; Peterson Tuner; HIWATT T40 C 40W/20W Combo |
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Tony Prior
From:
Charlotte NC
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Posted 7 Apr 2020 5:07 am
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you have listed a nice series of OLDER tube amps. Have they been serviced ? Tube amps require maintenance, unlike SS amps. An early sign of tube amps that require servicing is "grit or distortion" in some form. Plus please consider that a few of the tube amps you mentioned are not actually a totally clean platform compared to a N400.
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Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years
CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website |
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Gabriel Edell
From:
Hamilton, Ontario
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Posted 7 Apr 2020 6:01 am
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Most guitar players are looking for some overdrive so the amps are designed to deliver it, especially the Music Man and the Marshall. As previously mentioned, steel pickups typically have a hotter signal than regular guitar pickups, so they’ll quickly overload the preamp and make it distort.
If the amp has a master volume, crank that and use the preamp volume to set your level. Look at replacing the first preamp tube with a lower gain tube (as mentioned above).
That being said, you may never get the same clean tone out of your tube amp at higher volume as you get from a as amp, unless you move to a cleaner, more powerful amp like a twin reverb or dual showman.
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GFI S-10 P U, Moyo Volume, Fender Steel King, Fender 5F4 Super-Amp |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 7 Apr 2020 8:50 am
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Older tube amps were designed mostly for older single-coil pickups. Newer pickups, especially the humbucking variety, and put of several times the voltage of the older ones. This overloads the preamp, and causes distortion. One solution is to turn the amp up, as it forces you to use less volume pedal, and therefore less signal gets into the preamp. (Run the amp volume wide open, and use your pedal to control your volume.) In some cases, you can change the preamp tube, as others have suggested, but that can cause a tonal change, too. So, it's possible it may not have the desired effect.
Lastly, if you're using a powered volume pedal, know that they can (and should) be turned down to operate properly, and reduce the chances of distortion. I had the same problem using my Hilton pedal. When I first got it, it overpowered all of my amps, so I had to turn it way down to avoid distortion. (Very shortly afterward, I went back to a standard pot pedal.) |
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Dave Mudgett
From:
Central Pennsylvania and Gallatin, Tennessee
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Posted 7 Apr 2020 9:31 am
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| Quote: |
| a boutique handwired 1x12 Marahall 1974x |
I have one of these. Forget about clean headroom with a hot pedal steel pickup. These amps break up early, that's the reason guitar players like 'em.
This circuit was designed around a 12AY7 as the front-end V1 preamp tube. The reissues shipped (and I think still ship) with 12AX7 (nominal gain 100) there. That cuts the clean headroom down a lot. Some guitar players prefer 12AX7 because they want earlier breakup. If you haven't already, try a 12AY7 (nominal gain 45). If that doesn't do it, you could try a 12AU7 (nominal gain 20).
I have an original '57 Bassman 4x10, which is basically the same circuit but with 2 instead of 4 inputs. I use a military-grade 12AY7 (6072), it has plenty of headroom with my Lawrence pickups through a passive volume pedal provided that I don't crank it up too much. In terms of clean volume, it cannot compete on a real loud stage with a dedicated loud-and-clean pedal steel amp like a Peavey Session/Nashville 400/1000, Webb, or something like that. But with a reasonable stage volume - drummer and bass player but not insanely loud - it works great.
| Quote: |
| a 70’s MusicMan 4x10 |
The 65-Watt version is fairly similar to a Fender 4x10 Super Reverb. They also made a 130-Watt version, I think the preamp section is the same, which is solid-state. If dialed in correctly, with the master volume all the way up and the preamp gain set to get to the level you need, this should be very clean. The 130-watt version in particular is a beast - way too loud and clean for most guitar players.
But with the exception of the 130-watt version of the Music Man, none of these particular tube amps are really designed for real loud-and-clean applications that most pedal steel players want. Except for the Marshall 1974X, they can be adapted for reasonabe clean volume at reasonable levels. But you might prefer something like Twin Reverb. Silverface Twins can be had quite reasonably.
As mentioned, with these amps, the #2 input is lower gain. Some of the powered volume pedals can give you significantly more than unity gain. Same with some effects. Some rack units operate at line-level - they will often overload amp inputs badly. So if you're using a powered volume pedal and/or a bunch of effects, you may be overloading the effects and/or the front end of the amp. Try plugging directly into the amp - see if the distortion is still there. Now try with the volume pedal - as Donny suggests, if it's powered, turn down the gain. Add any effects one by one and see how they work.
Then of course, there is the state of the amps themselves. Are the electrolytic capacitors in good shape? How about the tubes? Other components? How long has it been since the amps were serviced? What pickup(s) are you using? It's hard to be definitive without knowing your exact setup. |
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Michael Hill
From:
Arizona, USA
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Franklin
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Posted 7 Apr 2020 5:42 pm
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Most likely because your guitar amp speakers can't handle the steels pure tone because they were chosen to provide paper distortion along with tube break up for rockin' out...Steel speakers are more high powered and designed to be ultra clean so the amp distortion is pure tube and not paper when that happens.
Paul |
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Kevin Fix
From:
Michigan, USA
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Posted 7 Apr 2020 6:27 pm
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| Had a Fender Twin Reverb that was probably made around 1968. Was the best tube amp I ever had for tone. Been using NV112's for the last 12 years. I also use a Steel Guitar Black Box which I am happy with the overall tone. I have used other amps over the years on occasion. Never could dial one in to sound good. Were not built for Steel Guitar voicing for sure. |
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John Limbach
From:
Billings, Montana, USA
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Posted 8 Apr 2020 5:39 am
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| Sandy Inglis wrote: |
"The 12AX7 family of dual-triode preamp tubes consists of the 12AX7, 5751, 12AT7, 12AY7, 12AV7 & 12AU7. These are all pin compatible with one another, the only differences being the gain factor of each tube. A common substitution is to replace a 12AX7 with a 5751 or a 12AY7 to tame a preamp that tends to overdrive too easily, allowing you to get a better ‘clean’ sound out of your amp.
Tube Gain
12AX7 100 (40db)
5751 70 (37db)
12AT7 60 (35db)
12AY7 45 (33db)
12AU7 19 (26db)
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My Traynor Bassman from 1973 used a 12AX7 in the first stage of the preamp. They did not use a bypass capacitor across the cathode resistor of that tube, I assume because if you were playing bass through it you didn't need the extended low freq response that the bypass cap would bring to that stage. Since I only play steel, I decided that I did want to lower the bass response and added the bypass cap. One unintended result was that it also increased the gain by a factor of 40-50%. Rather than mess around with changing the gain factor of the circuit, I simply substituted a 12AY7 there. That brought the output of the first stage back to almost exactly where it had been before adding the cathode resistor bypass cap.
Putting a lower power version of that tube family is also helpful if you're playing (like me) old time Rickenbacker lap steels. The horseshoe pickup, especially on my 1934 A22 is a real screamer and wants to overdrive the preamp stages with 12AX7 unless I dial back the gain control to a very low level. Also the reason a lot of amps use something like a 12AT7 in the phase inverter where you typically don't need the higher gain of a 12AX7. |
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Steve Mueller
From:
Cincinnati, Ohio, USA
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Posted 9 Apr 2020 9:05 pm
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John,
That's great and very usable tube info. Now for some experimenting...…!
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2016 Williams D12 8 x 8, 2015 Williams D12 8 x 8, 2023 Williams S12 4 x 5, Milkman Amps, 1974 Gibson Byrdland |
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Bill Duncan
From:
Lenoir, North Carolina, USA
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Posted 10 Apr 2020 6:52 am
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I always try to make sure the speaker impedance matches on my tube amps. However, I believe all things being equal a 16 0hm speaker sounds best in a tube amp for pedal steel.
So, someone tell me if that is just my imagination, or is there something in physics or electronics that would tend to bear that out.
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You can observe a lot just by looking |
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Jason Goodell
From:
North Carolina, USA
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Posted 17 Apr 2020 5:44 pm
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My guess is one of two things is happening. First the pickup(s) in the steel have a lot of output and are driving the amplifier to distort. Two the volume on the amplifier is set high enough that the amplifier is overdriving on its own, which will happen even even if the steel's volume is low.
I doubt the pickups in a steel guitar have enough output to drive an amplifier that hard. My guess is going to be that the amplifiers' volumes are set high. I've owned a 59' Bassman and from experience that amplifier is going to start overdriving with the volume set at 3 to 4.
I don't know what your steel is, but for my Stringmaster I turn the amplifier on to about 2 or 3, turn the steel volume all the way up then back the volume off until I just hear the tone change. Then I slowly turn the amplifier volume up while strumming the steel and sliding bar up to about the 16th fret, and I stop turning up the amplifier's volume when I just begin to notice the amplifier overdrive. For most Fender tube amplifiers that usually somewhere between 3 and 5 on the volume. Tweeds are usually closer to 3, blackface are usually around 4, and silver face are usually 5. That will be the maximum clean volume available from the amplifier.
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Physicist, software engineer, hobbyist amplifier builder, purveyor of dad-jokes, and guitar player of many of its forms. Not necessarily in that order, and with no guarantee or warranty. |
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James Holland
From:
Alabama, USA
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Posted 18 Apr 2020 4:24 am
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| Donny Hinson wrote: |
| Older tube amps were designed mostly for older single-coil pickups. Newer pickups, especially the humbucking variety, and put of several times the voltage of the older ones. |
Very true, my pedal steel pickups' impedance are around 18k, my '65 ES-330 is around 8k, my telecaster is closer to 6k.
A Nashville 112 has input impedances of 220k and 68k for the high and low inputs.
I think the typical Twin's input impedance is 1M and 68k?
What's the rule for impedance matching for clean operation? 10:1, amp to pickup?
Regardless, I get a really nice glassy sound thru my Twin's with my pedal steel guitars, or my telecaster. My conclusion, is most all emag pickups are compatible with older or newer amps, as long as everything is in good functional order. |
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Dave Mudgett
From:
Central Pennsylvania and Gallatin, Tennessee
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Posted 18 Apr 2020 6:59 am
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| Quote: |
| I think the typical Twin's input impedance is 1M and 68k? |
Nominal Input 2 impedance with respect to ground is about 2x68K = 136K. The drop in voltage is due to the voltage division - the circuit has 68K between the hot input and tube grid, and 68K to ground. It also sees a parallel 1M resistor to ground from Input 1, but the impedance change is the range of the tolerance of the resistors. Same deal with the additional 68K additional input resistor on Input 1 - technically the nominal input impedance is 1.068M.
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| What's the rule for impedance matching for clean operation? 10:1, amp to pickup? |
Yeah, in that ballpark, that would be the minimum. But even with a 10:1 source output impedance to amp input impedance, you're still dropping about 9% of the signal voltage over the source. And in practice, this will be quite a bit more at resonant and very high frequencies due to the resonant peak and rising inductive reactance due to the pickup coil in a magnetic field. I generally use a unity buffer if I feel the desire/need to use Input 2. |
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Dave Grafe
From:
Hudson River Valley NY
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Posted 18 Apr 2020 1:07 pm
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| Fender tube amps are the bomb, and have been used for some of the greatest PSG recordings of all time, but until you hook up JBL speakers you don't know what you've got. Some folks will perhaps think that a brash and/or bombastic statement but I've been around some and that's my story plain amd simple. |
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