Steel Guitar Black Box

Brad Sarno · Post by **Brad Sarno** » 1 Dec 2003 9:22 am

Just a heads up for steel playing tone freaks. I'm in the final stages of production of my new "Steel Guitar Black Box". It's an all-tube steel guitar pickup driver. Some would call it a tube matchbox. They say necessity is the mother of invention. So here it is. It goes right after the pickup and before the volume pedal, passive or active. It runs the tube at full voltage and uses only the very finest audiophile film/foil capacitors in the signal path. It also has a "secret" subtle voicing section that helps bring out the best in any steel pickup. The chassis is powdercoated black steel and is very rugged. It has simply an input and an output, a little light, and a power cord. No switches or knobs to go bad.

This thing works magic on steel pickups. It runs very, very clean. Everyone knows how sweet tubes sound but that tube amps are too heavy for their output power. In this age of solid state steel amps, the tube in the front end brings out all the sweetness and nuance of a steel pickup and drives the signal cleanly on down the chain, no matter where it's destination. It provides the buffering/impedance-matching benefits of an active pedal or a matchbox but the tone is superior. It's really stunning to hear the difference in a pickup's tone when it sees a tube instead of a transitor.

Once they're ready I'll put a mention in the buy and sell section but I wanted to give a heads up to those who are into tweaking their tone like many who hang out in the Electronics section. I've been refining this black box for about a year now and it's finally about ready.

What's really cool too is that we found that it's not only good on steel but just about any guitar pickup. The input impedance is high so it works magic on piezo acoustic type pickups too. A bass player friend has already ordered one for his Fender Jazz bass/Portaflex rig. It's also great for DI use. We way overengineered it and the parts inside would please even the most picky of audiophiles and engineers.

If people are interested, please drop me an email so I can get an idea of how many to get rounded up for the first run. I'm expecting to have them priced at $250 + s/h.

Brad Sarno

John Steele · Post by **John Steele** » 1 Dec 2003 10:19 am

Verrrry interesting, Brad. Good luck with it !
-John

Brad Sarno · Post by **Brad Sarno** » 1 Dec 2003 12:29 pm

Thanks John, it's really a killer piece of gear, if I DO say so myself. I had St. Louis' finest tube amp engineer/designer help with the finer points. I'll put up a webpage for it as soon as I've got product in hand. Hopefully within the next 3 weeks.

Brad

Jon Light · Post by **Jon Light** » 1 Dec 2003 3:15 pm

Hey Brad---I'm all eyes/ears too. Sounds most interesting. I look forward to your web presentation of this. In fairness--my interest is sincere but I wouldn't want you to put my name in the "put me down for one" order basket just yet. But if it's less filling and it tastes great, well......and Mmmmmmmm--tubey......

Brad Sarno · Post by **Brad Sarno** » 1 Dec 2003 4:29 pm

Thanks Jon, no sweat, there'll be plenty to go around. The coolest thing for me in this project is the discovery of how very different a pickup reacts to a tube compared to a transistor. There is an interesting thing that happens when a highly inductive device like a pickup feeds the input of a tube. It reacts differently, the dynamics, the harmonics, the tone, and the general mojo to use a technical term. There is a energetic liveliness that happens. To my ears it brings the pickup to life. Transistors, even FETs don't create this degree of synergy. To put a tube before the volume pedal really purifies the connection between pickup coil and tube. The tube in this particular situation is run very clean, it's not by any means an overdrive device. We even use a 12AU7 to keep it clean where a 12AX7 would drive too hard and create too many overtones. There are harmonic and dynamic differences between the use of a transistor and a tube. With a tube, the pick attack transients become very sweet and sparkly, not sharp and hard. The nuance and subtelty that gets enhanced is really noticable. I'm very psyched about this project. I'm surprised that I've never seen it done before, putting a clean tube buffer before the volume pedal.

Brad
[This message was edited by Brad Sarno on 01 December 2003 at 08:52 PM.]

Larry Behm · Post by **Larry Behm** » 1 Dec 2003 5:39 pm

Brad, I run a Mesa Boogie Studio preamp after all of my effects and after my volume pedal, it is the last unit before going to my amp. Am I getting the same benefit from the tubes as you mentioned above?

Larry Behm

Brad Sarno · Post by **Brad Sarno** » 1 Dec 2003 5:57 pm

Larry, the missing link there is that your pickup doesn't see a tube. If you've got a matchbox or a Hilton type pedal, you've at least buffered your pickup from the chain of effects, but still your pickup isn't "seeing" a tube. All of your effects are being driven before the signal ever hits the tubes of your preamp, which by the way is a great preamp. The Black Box would be perfect in your situation.

Brad

Brad Sarno · Post by **Brad Sarno** » 1 Dec 2003 6:01 pm

Oh wait, Larry, I just re-read your post. So you've got your volume pedal AFTER your effects? Even more reason to buffer the pickup. There is tone loss when a pickup has to drive a chain of effects on its own.

Brad

jim milewski · Post by **jim milewski** » 1 Dec 2003 7:50 pm

Brad, that sounds like a great device, I like the part about the tube smoothing the attack, if I understand correctly the tube input impedence is almost infinite, I always assumed tubes operate at high voltages, does this mean a step down xformer has to be used on the output, BTW I'm still loving the CDs you sent me, I don't know what you used to record live, but it is as fine as it gets.

Brad Sarno · Post by **Brad Sarno** » 2 Dec 2003 7:25 am

Hey Jim, thanks for the kind words on the recordings. Even though a tube circuit runs at high voltages, the signal is still a small A/C voltage. The high voltage is merely a D/C bias on the signal path which gets removed when the signal passes thru a capacitor. That's why capacitors are so critical in audio, they become like a lens thru which all the sound must pass while the D/C gets blocked. Different cap's sound different. No step down transformer needed for this part of the process. You will however find a step down transformer in a tube POWER amp situation right before the speaker, but this is signal level only in the Black Box. The cap's I'm using in the Black Box are very premium audiophile film and foil types. The main signal cap's are pretty exotic French made film and tinfoil from Angela Instruments, they're my favorite sounding caps for musical gear. The others are the premium 716P series Orange Drops, also film and foil.

Thanks for the interest.

Brad

Raj Natarajan · Post by **Raj Natarajan** » 2 Dec 2003 8:11 am

Brad,
Last night I tried for the first time, Electro-Harmonix's Wiggler tube vibrato/tremolo box with the steel. It sounded really good. I would like more spec on your gadget and possibly some web presentation of the gadget with pictures and possibly some MP3 files to listen to with and without your gadget just to get an idea how your gadget affects the sound particularly for the steel. Am I asking too much?

Raj Natarajan · Post by **Raj Natarajan** » 2 Dec 2003 8:14 am

Oh, I fogot to mention that this Wiggler has 2 12AX7s tubes in them. Gives a nice warm tone.

Brad Sarno · Post by **Brad Sarno** » 2 Dec 2003 8:17 am

Hi Raj, I'm actually in the process of doing just that. I'll have a webpage with photos, specs, and perhaps some soundbites with the device on and off. I like that idea.

Brad

Earnest Bovine · Post by **Earnest Bovine** » 2 Dec 2003 8:31 am

Brad
According to the advertising, some instrument preamps adjust their input impedance to match the impedance of your pickup.
Some let you do it manually. Others claim to sense it, and to do it automatically.
Do you think this is important?

Brad Sarno · Post by **Brad Sarno** » 2 Dec 2003 8:39 am

Ernest, I dont think that's really that important for guitar pickups. As long as the input impedance is on the high or "safe" side like most tube guitar amp inputs, the pickup will get to breathe nicely with no tone loss. The automatic or variable input impedance thing sounds like more parts and more things to cause trouble. However I have seen some very nice studio microphone preamps that offer adjustable input impedances to perfectly match the microphone. This box adheres to the KISS principle.

Thanks,
Brad

Karlis Abolins · Post by **Karlis Abolins** » 2 Dec 2003 9:00 am

Brad, I tried out your idea this morning. I have a tube amp that I designed and built this past year. The first stage is a 12AU7 then out to an effects loop and back to the splitter and amp stages. My first stage is probably very similar to your black box. I put my guitar straight into the first stage and put my equalizer and reverb (I'll try putting my volume pedal there as well although I don't use my pedal very much)in the effects loop. The sound is amazing. The high are clear but not shrill. The lows come through loud and clear as well. I also have more sustain at the same volume level. The biggest benefit appears to be above the 15th fret where I now get more sustain. The compression of the tube is the magic element in this process.
Thanks for the great idea. I think your black box will be a winner much like Jerry Wallace's Truetone pickups (which I am using on my guitar). Best of luck on your endeavor.

Karlis Abolins[This message was edited by Karlis Abolins on 02 December 2003 at 09:02 AM.]

Greg Simmons · Post by **Greg Simmons** » 2 Dec 2003 9:09 am

Brad;

Mucho congrats on your project - the prototype you had @ Scotty's in Sept. was very cool - I indeed will be going "Sarno-Sonic"

------------------
Greg Simmons
Custodian of the Official Sho~Bud Pedal Steel Guitar Website

[This message was edited by Greg Simmons on 02 December 2003 at 09:09 AM.]

Brad Sarno · Post by **Brad Sarno** » 2 Dec 2003 12:20 pm

Karlis, you get the idea exactly. Thats what this is all about.

Greg, thanks. You'll dig it.

Brad

Keith Hilton · Post by **Keith Hilton** » 2 Dec 2003 12:35 pm

Hello Brad! Glad to hear about your Black Box. I think this type of device is really a good idea, and needed. There are many who prefer the tube sound over the sound of transistors. This is especially true in the pre-amp section. It is really great that you are making the device where it will accept either a low magnetic pickup signal, or a pre-amped signal. This is the problem with many devices. For example I have a MXR Envelope filter that works great with a low level magnetic pickup signal, but won't work at all with a pre-amped signal. Also, I think the Boss DD-3 has this problem as it seems to work better before a pre-amped signal. I know the "Holy Grail" box reverb has this problem, because Tom Brumley had one when we played together at the Siloam Springs Steel Guitar Show. Tom got all kinds of noise until we put the Holy Grail reverb box in front of the pre-amped signals. Most well designed equipment will accept either a low magnetic pickup signal, or a line level pre-amped signal of about one volt. All Peavey amps will accept either type of signal, and so will the Hilton volume pedal. Brad, I know you have thought about input and output protection. You "must" have input and output capacitors to protect against DC. You also need input and output resistors to limit the current. Hartley Peavey and I go one step further and protect the input and output with boot strapped diodes that limit voltage to the level of the power supply. You also need protection agains radio signals-RF, suff like C.B. radios. Put a 39pf capacitor to ground on the input and it will get rid of the RF signals. You have to have all this protection Brad, because a person can generate 2,000 volts walking across a carpet. Havn't you had fire shoot from your fingers when you touched a door knob? Also there is a thing called sequencing! This means guys have several things hooked up in the signal chain. These devices never go on or off at the same time, they go off in a sequence and can cause huge voltage or current surges. Also, there are guys who don't have ground plugs on their amps. The grounding switch capacitor can leak causing a large voltage on the amp case. This means a large voltage can come down a guitar cord. It is easy to see 120, or even 600 volts in the case of a tube amp, come down a guitar cord. I found this to be a real problem on very old Fender amps that have paper capacitors,and ground plugs that have been removed. These capacitors need to be changed every few years and ground plugs put back on the power cord. Guys won't do the needed repairs because the amp still works even though it leaks voltage to case. Brad, you are a good friend and that is why I am giving you these helpful hints. Your friend Keith

Brad Sarno · Post by **Brad Sarno** » 2 Dec 2003 1:13 pm

Thanks so much Keith. I remember in Branson when you showed me the diode protection scheme among with some other issues. We've got a few measures at work for protection both for gear and humans. You just gave me a few more ideas to look into. Hopefully this Box will have all the bases covered. Some of these issues don't apply to an all tube circuit, but some do. We've definitely paid lots of attention to human safety because there is high voltage in there. I appreciate the community spirit and the support. I'll be in touch! By the way, my prototype into your volume pedal is pretty awesome sounding.

Thanks Keith,
Brad
[This message was edited by Brad Sarno on 02 December 2003 at 01:27 PM.]

Brad Sarno · Post by **Brad Sarno** » 3 Dec 2003 10:09 am

^^^
Brad Sarno

James Quackenbush · Post by **James Quackenbush** » 4 Dec 2003 4:15 pm

Brad,
Great idea, and LONG overdue !!..I was wondering with the various loads and impedences , have you tried this unit with a few different pedals ??...I see you have tried it with a Hilton and it works, how about any of the other brand pedals that are not active pedals like the Hilton ??....Thanks , and I look forward to hearing more on this tube pre/buffer/ ???....Sincerely, Jim

Brad Sarno · Post by **Brad Sarno** » 6 Dec 2003 8:54 am

James, the impedances of the box should enable it to work in just about any position in the chain. It's intended to go right after the guitar's pickup so the pickup "sees" the tube, before any effects or volume pedal. The input impedance is high to see the pickup and the output impedance should be just right to see a guitar pedal. The gain is pretty much zero or unity so it's not putting out hot line level but instead it's guitar signal level.

Brad Sarno

Gary Walker · Post by **Gary Walker** » 6 Dec 2003 10:57 pm

Brad, You have another interested customer and I will be glad to be among the first on the block to play one.

Brad Sarno · Post by **Brad Sarno** » 9 Dec 2003 7:26 am

Cool, thanks Gary.

Brad