"Voiced For Steel"

Steve Lipsey · Post by **Steve Lipsey** » 31 Jan 2014 11:46 am

Well, here are a couple more stories I've heard about this topic:

-"Tube amps have a built-in mid cut", but Tim has told me that this is due to use of modern tubes, and that the NOS American (pricey) tubes are more flat in response, as Leo Fender intended.

-"Everyone cuts their mids for steel" - But I believe that is only in solid state amps, because "solid state amps have honky mids, so you get rid of them, unlike tube amps, where mids are sweet" (heard from a number of sources).

-"Some steels and/or amps have really weak tone above the 12th fret" - well, you cut your mids, what do you expect?

Comments welcome...

Will Cowell · Post by **Will Cowell** » 31 Jan 2014 12:04 pm

Tim, I just have to disagree with you on this tube thing. Tube amps - taken as a whole - may well have that "scooped" mid range tonal response you describe, but it does *not* come from the tubes themselves.

The 12AX7's response (just the tube) is flat from DC right up into the RF range. Same for other tubes. There is no noticeable deviation from a flat frequency response until you get into the 10's of MHz.

I realise I'm putting my neck on the block here, but with a Master's degree in electronics and over 40 years using these devices in all kinds of equipment I'll take my chances.

I think the response you describe comes from other components in the amp: transformers and other passive devices external to the tubes.

chris ivey · Post by **chris ivey** » 31 Jan 2014 12:09 pm

Jim Cohen wrote:

But I'm an admitted ignoramus in such things

the steel king is a fender amp.

Jim Cohen · Post by **Jim Cohen** » 31 Jan 2014 12:10 pm

See! I just proved it! LOL!

Thanks for that, Chris...

Tim Marcus · Post by **Tim Marcus** » 31 Jan 2014 12:14 pm

Will Cowell wrote:I think the response you describe comes from other components in the amp: transformers and other passive devices external to the tubes.

regardless of where it comes from, there is truth in what I said. It might not make sense on paper, but in a tube amp, the 12AX7 itself has its own midrange scoop and character. Different brands, years, variations affect the scoop. Millions of guitar players, amp builders, tube resellers, hi-fi enthusiasts etc hear it. I do not have 40 years of engineering under my belt, but I have 25 years of playing through tube amps and its a real thing. Thus the old joke:

How many guitar players does it take to change a light bulb?

Just one, but he'll do it a hundred times until its perfect

rodger_mcbride · Post by **rodger_mcbride** » 31 Jan 2014 12:49 pm

What about the current octal amps/preamps? Scooped midrange too?

Larry Robinson · Post by **Larry Robinson** » 31 Jan 2014 3:17 pm

I have to agree with Will Cowell. A vacuum tube is a linear amplifying device. It reproduces what is applied. I've never heard of tubes having scooped mid-range. A scooped sound is a result of components. I've been playing for 55 years and have never heard anything described by Tim Marcus, but that doesn't mean he hasn't heard it. That said, just because he hears it doesn't make if true.

Jim Cohen · Post by **Jim Cohen** » 31 Jan 2014 3:18 pm

Larry Robinson wrote:That said, just because he hears it doesn't make if true.

Ladies and Gentlemen, we have just entered... The Twilight Zone...

David Rogerson · Post by **David Rogerson** » 31 Jan 2014 5:21 pm

Man, this thread has certainly opened up from my original question. Great!!
In the same vein I would like to make request. Given that there numerous mods already out in the common domain that can be done to Fender amps. e.g. Silverface to Blackface etc., what specific mod can be applied to a 1974 Silverface Twin with 2 JBLs.? (my amp.)
I hope I'm not being too cheeky here but if you don't ask you don't learn & seeing that this such subjective topic & at the mercy of personal opinion I think it is a fair question to pose. Any takers?

Tim Marcus · Post by **Tim Marcus** » 31 Jan 2014 6:27 pm

Larry Robinson wrote:I have to agree with Will Cowell. A vacuum tube is a linear amplifying device. It reproduces what is applied. I've never heard of tubes having scooped mid-range.

huh, we must live in different worlds - I have never heard of a tube not having a unique sonic character. I can take the same amplifier, and swap in different 12AX7 tubes all day long (which are, as you say, linear amplifiers) and each one will sound slightly different than the next. Some alter the midrange frequencies more than others. There is an entire industry of tube resellers who voice amplifiers using just the tubes.

Sure, caps and resistors make a huge difference too - but once that is settled, the tubes do in fact change the midrange. I wish I was making this up but I'm not. Tubes have the advantage of being electronic devices which are constructed mechanically - subtle variations in design, cathode coating, plate size, etc have an effect. I wish it was one of those "between the headphones" things but I can honestly say that tubes have a sound to them - some more scooped than others.

Ken Greene · Post by **Ken Greene** » 31 Jan 2014 6:40 pm

I have an old Fender Super that sounds great with pedal steel. Also, I recently picked up a Lab Series L9, haven't really tried it much yet, but I'm wondering if anyone has tried one of those.

Dave Grafe · Post by **Dave Grafe** » 31 Jan 2014 11:17 pm

The mid-scoop in Fender amps is not due to the tubes at all, but to Leo's tone control circuit. The flat, "un-scooped" Peavey amps do have sweepable mid control to do the same thing a bit more scientifically, which is somewhat easier - i.e. less expensive - to implement with op-amps than with tubes.

"Voiced for..." is a marketing phrase, very often created and applied by folks who have never actually played the instrument in question. One exception is the work of the folks at Telonics to re-create the "voice" of the vintage JBL speakers, but this work centers on a specific, measurable essence, not a broad class of instruments and approaches.

Take responsibility for your own brains my brothers and sisters, go get you some http://www.duncanamps.com/tsc/ and so be edified...

Steven Paris · Post by **Steven Paris** » 31 Jan 2014 11:26 pm

A.E. once said "The things that really matter often can't be measured. And the things that can be measured often don't matter".
I don't know exactly what it is, either, but Tim is exactly right--same amp, same speaker, same guitar----swap different tubes of the same model in, and THEY SOUND DIFFERENT! Linear or not.

Will Cowell · Post by **Will Cowell** » 1 Feb 2014 1:35 am

Actually, Tim has a good point. These things are never absolutely black and white. Soviet 12AX7's sound different from the Chinese ones, and so on.

Cathode construction and coating, plate shape and length, etc do make tiny differences, because they are part of the stray capacitances etc that add to the effect of the external R's and C's that make up the circuit frequency response.

But the external components contribute the lion's share, these internal effects are very subtle, and none of the tubes have that "scooping" effect - that definitely comes from the circuit designed to go around the tube. The tube is a more or less linear amplifying device, depending on bias and other circuit externals.

Ray McCarthy · Post by **Ray McCarthy** » 1 Feb 2014 3:35 am

Isn't it in the delivery of various harmonics that the tubes differ--not in the response of the base frequency?
Also, on my Peavey N-112 amp it says "high definition studio instrument amplifier", but somewhere in the literature it says the speaker is voiced for steel.

David Rogerson · Post by **David Rogerson** » 1 Feb 2014 3:54 pm

Dave, you make some good points - one has to do ones own research, given that sound & tone are open to individual assessment. No one should dictate your opinion to you.
I tried to download from the Duncan Amps site but I can't access it with my MAC laptop.

Jim Bob Sedgwick · Post by **Jim Bob Sedgwick** » 1 Feb 2014 7:32 pm

How many steel players does it take to change a light bulb?

6... One changes the bulb, the other 5 say..

Hell, I can do that

Marty Broussard · Post by **Marty Broussard** » 1 Feb 2014 9:52 pm

Dave,
I tried with my IPad....no dice, but it works good with my old laptop. I've been tinkering with it and it is very informative. You can plot several settings to see how the controls work and you can change the values of the circuitry components. It may not plot things exactly as they would be but it sure helps in seeing how the controls interact.
Btw, I scanned the forum to obtain some of the settings that various members use with Twin Reverbs; it's VERY interesting how similar the shape of the plots are.

Steven Paris · Post by **Steven Paris** » 1 Feb 2014 10:52 pm

A quote from â€œThe Tube Amp Bookâ€ by Aspen Pittman called the â€œAmp Volume Shell Gameâ€:
â€œ This is a test I do a lot of times for folks to show there are differences in power tubes---generally to demo high quality tubes such as the Groove Tubes 6L6GE versus the Sovtek 5881WXT (which is a very popular tube which comes stock in a lot of amps).
Take two Fender 50 w Bassman amps, or any two amps which are the same,. In one amp, install a duet of GT-6L6GE tubes, leaving the stock tubes in the other. Connect them to like speaker cabinets. With a signal generator and a 1000 or 400 Hz tone, and a db SPL meter, set the amps where the non-GE tubebd amp will ouput a level of 80db one meter on axis. On the GE-tubed amp , set the level to 70 db, -10 db down from the first amp. The tone controls should be set the same.
Have a player play for a few minutes. Switch back and forth using a common A/B switch. Only use one amp at any given time.Bet the folks in the audience which amp is louder.
90% of the time the GE-equipped amp will be chosen. It will also have a 15-to-20 degree wider soundstage image. The reason for this has to do with the Fletcher-Munson curve, and some other physics. Bottom line is: with better and more articulate tubes, there is just a lot more complexity in the recipe, spices in the soup, so to speak.

Paul Arntson · Post by **Paul Arntson** » 2 Feb 2014 12:32 am

Interesting reading on the subject:
http://www.guitar-list.com/guitar-scien ... amplifiers

Marty Broussard · Post by **Marty Broussard** » 2 Feb 2014 6:32 am

Enjoying this discussion.....keep it coming folks.

Mark Fowler · Post by **Mark Fowler** » 6 Feb 2014 8:05 am

I don't know much about voiced for steel but simply trying different preamp tubes (tube rolling) will certainly make a big difference between brands and if new or NOS.

Those on line tone stack calculators aren't that accurate in a real circuit.

Mark
Fowler Valve Amps

Tim Marcus · Post by **Tim Marcus** » 6 Feb 2014 8:38 am

Mark is right - I have tried the duncan calculator to find values for a bass amp. The results looked great on paper but in reality they were way off. Better to use the ultimate tool for tone stack calculating: your ears.

Joshua Gibson · Post by **Joshua Gibson** » 6 Feb 2014 3:07 pm

okay, before anyone jumps on Me...this is just My two-cents worth

, I've seen repeated posts about "every steel player" cutting the mids to either an extreme or off altogether...I realize Our ears are all different but there are a good number of Steelers I know that actually BOOST the mid/shift considerably, Myself included, NOT being confrontational but just wanted to add that into the equation.

Ken Campbell · Post by **Ken Campbell** » 6 Feb 2014 4:20 pm

I boost hi mids a teeny bit.....

The Steel Guitar Forum

"Voiced For Steel"

Tube sound

Yeah