Booteek Amps: Handmade by Marshall Heiser

INSIDE_BEST

Booteek amps are located in sunny Brisbane, Australia. I handcraft every amplifier and cabinet myself, one at a time, adopting time-honoured construction techniques and using only the best materials available today. Though inspired by classic tube combos I have known, owned and loved over the years, booteek amps brings a new twist to these designs to better serve the needs of the 21 century musician. Last, but not least, I familiarise myself with each and every amp after completion, playing it in and meticulously quality-checking before releasing it out into the wild.

About the Amp

It’s MAMA BOO….warmer than a Champ….louder than a Princeton….more versatile than a Deluxe! Featuring all the rich harmonic detail and touch responsiveness of a single-ended, class A circuit, paired with a 6L6-optimised power stage and feeding a colossal Hammond 125ESE output transformer. In addition to that 10 Watts of pure tone, she’s housed in a resonant and rattle-free, solid-pine cabinet with a 12 inch speaker. Don’t talk back to Mama!

This premium-quality, hand-wired, all-tube amplifier was inspired by a desire to find an mid-to-small size combo capable of both crisp, clean tones and creamy overdrive…and all at levels suited to a variety of playing environments. No expense has been spared with regard to component selection and attention-to-detail craftsmanship.

uses

  • recording
  • rehearsal
  • stage
  • bedroom

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DISTORTED TONE

CLEAN TONE

LIGHT OVERDRIVE TONE

(Please note: what you are hearing is a ’52 re-issue Fender Telecaster guitar plugged directly into the amp. All recordings are done with just a simple SM-57 dynamic mic: no effects, no EQ, no reverb).

FEATURES:

AMP:
● single-ended, class A all-tube amplifier
● 240V AC, 10watts output
● 12 inch, 8 ohm ceramic speaker: Eminence “Cannabis Rex” (with Tone-Tubby hemp cone)
● Fender/Marshall/Vox modes with 3-way frequency-response/gain selector switch
● 5Y3 tube rectification for legendary “sag” and natural compression
● cathode-biased: no bias set-up hassle, no technician required
● hum elimination: Hammond choke induction
● electrical safety features: AC power-surge protection & (filter caps) “bleeder” resistor

CABINET:
● solid pine, finger-jointed cabinet
● premium quality, voidless Baltic birch ply (back panels/floating speaker baffle)
● covering: tweed cloth – attached with traditional animal hide glue (allows for easy removal of tweed fabric for future refurbishment)
● finish: lacquered with nitro-cellulose (as did Fender in the 1950s)
● chassis support: hardwood dowels (oak)

COMPONENTS:
● premium-quality F&T/Sprague Atom electrolytic capacitors
● vintage-style Jupiter (or similar boutique) tone capacitor
● carbon comp resistors (some carbon film used in select areas for added reliability)
● dependable JJ 12AX7 preamp, 6L6 power and 5Y3 rectifier tubes
● quality vintage-style, vulcanised eyelet board (treated to ensure against “Tweed disease”)
● chrome-dipped Hoffman 5F2-A Chassis
● Carling switches, CTS pots and Switchcraft jacks/plugs
● 1/4″ speaker output jack

Tube Amp Theory: Uncle Doug and his dog Rusty

WARNING: Never attempt to open up your tube amp chassis or repair/modify it in any way, as lethal voltages may still be present for extended periods after the amp has been turned off and unplugged from the AC wall socket. Instead, take your amp to a qualified technician for inspection or servicing.

PLEASE NOTE: The following links and resources are provided strictly as items of theoretical interest only. I have no control over, or responsibility for, any third-party websites or material referred to.

How many times have you searched youtube for concise, accurate and clearly-explained information about a topic that’s important to you, only to be greeted by some frenzied bozo desperately trying to squeeze their fifteen minutes of fame out of the internet like dregs from a tube of toothpaste. Music blares, graphics swirl: you’re implored to subscribe in booming robotic voice. Ok, no problem, you’re on a quest with a mighty thirst for knowledge and willing to put up with whatever it takes.

You wait, wait, wait some more (2 minutes in and this fool is still talking about his holiday in Bermuda)….still nothing. Fast forward a bit. Was that something there? Rewind. You discover 15 secs of (inconsequential) information deeply nestled within the 9 minutes and 53 seconds-long “tute.” Unfazed, you gain your composure, click on the next offering….another bozo…uggh! (Yes, I’m aware this introduction has similarly delayed you on your quest, but be patient…treasures abound below).

If your topic of interest is tube guitar amplifier theory, then have a look at these videos by Uncle Doug, a former teacher who actually knows how to…..wait for it…teach! But don’t go thinking you’re going to fall asleep without all the usual CGI generated graphics and (phat) Techno beats supplied for those of with the attention span of a….(no need to finish that, those concerned would’ve moved on already), Doug’s diagrams may be drawn in pencil, but they’ll address most of your burning tube amp theory questions, and furthermore, Doug’s ever-faithful sidekick, cameraman and general bon-vivant Rusty will keep you in stitches exactly when you find the need to take some time out.

So, I hope you find these tutorials informative and enjoyable. Happy trails.

…and much, much more at Uncle Doug’s youtube channel HERE.

Amp Books: Tube amp publications and online technical resource.

amp-books

WARNING: Never attempt to open up your tube amp chassis or repair/modify it in any way, as lethal voltages may still be present for extended periods after the amp has been turned off and unplugged from the AC wall socket. Instead, take your amp to a qualified technician for inspection or servicing.

PLEASE NOTE: The following links and resources are provided strictly as items of theoretical interest only. I have no control over, or responsibility for, any third-party websites or material referred to.

If you’re interested in tube amp theory and design considerations, then you might like to check out the “Amp Books” website. While it’s primarily a vehicle for promoting Richard Kuehnel’s books, it also features a swag of interactive goodies and analyses including: “[online circuit] Calculators, Tutorials, Technology, and Classic Vacuum Tube Designs for Guitar Amplifier Circuits.” What I like about this site is its clear, methodical, modular approach to classic circuit analysis.

Single-ended Guitar Amps: Pros & Cons

There’s a lot of confusion around today about single-ended guitar amps. Put simply, every tube guitar amp employs either a single-ended or ‘push-pull’ power stage. It’s one or the other. I must say that I’m biased (pardon the pun) towards the former. If your all-tube guitar amp is over 15 watts then chances are you’re in push-pull territory. If not, then you might be lucky, maybe it’s single-ended. This post, consisting of three links (each increasingly detailed) is, in part, dedicated to clearing up some of the more common misconceptions.

Single-ended amps were once considered budget-priced, low-wattage amps for ‘student’ use. Their internal circuits were simpler than their higher-output, push-pull cousins and they also suffered from power-supply induced background hum (although some newer models – such as mine – have since solved that problem using chokes, additional power filtering, premium-quality parts and, to increase their volume considerably, larger output transformers).

It wasn’t that problems such as lower output and higher levels of background hum couldn’t be addressed back in the day. It’s just that manufacturers like Leo Fender didn’t see any reason to fix them since they weren’t ‘pro’ models (and doing so would eat into his tight profit margin). Well, that was until guitar legends such as Eric Clapton, Keith Richards, Joe Walsh and George Harrison discovered how single-ended amps provided sweet harmonic tone and distortion like no other amps. Now these amps are highly-prized collector’s items.

As a generalisation, single-ended amps have a purer tone due to their shorter signal path, greater harmonic content present at the power tube stage, and a keen sense of responsiveness and expressiveness when compared to push-pull amps. However, they lack the bass response, (as well as the lower hum/greater sound pressure levels as mentioned above) of the push-pulls. They also dissipate much more heat (as do Class A amps in general). It must be remembered though, that despite being relatively inefficient, single-ended amps can still sound as loud as amps rated much higher in terms of power.

My “Mama Boo,” 10 watt single-ended amp.

The first single-ended amp I owned was a beautiful 1960s Gibson GA-8 purchased from an American jazz guitarist living in Caloundra. Technically speaking, the amp was classed as “dual” (or parrallel) single-ended, meaning that it used two power tubes instead of the usual one.  For many years, I sincerely regretted selling that amp, but I was bitten by the bug. Now I make my own single-ended amps (see picture).

If you’ve never tried a single-ended amp then you don’t know what you’re missing! A lot of guitarists I talk to are unaware of what single-ended amps are, and of those that have heard of them, most have never tried one. Be warned however, that what these beauties offer in terms of pure sound and very musical, touch responsiveness is accompanied by some (mostly charming) quirks worth exploring before deciding if they’re the right amp for you.

George Harrison: Wall of Champs

At the Concert for Bangladesh, George Harrison used a “wall” of 4 single-ended Fender Champs

1) This first link leads to an interesting and informative forum discussion thread regarding the pros and cons of single-ended tube guitar amps. Best quote: “Playing through a Class A circuit is very much like, having the guitar plugged into your Central Nervous System. ” Well said. (LENGTH: 3 pages):

https://www.thegearpage.net/board/index.php?threads/single-ended-amps-pros-cons.575398/

2) If you’re still a tad confused about what constitutes a single-ended, push-pull or Class A amp, then check out the following Guitar Player article. In this online piece, Dave Hunter clears up some of the common misconceptions regarding these various approaches to tube amp design. It also deals with the topics of cathode biasing and negative feedback (LENGTH: 1900 words):

http://www.guitarplayer.com/miscellaneous/1139/all-about-class-a-amplifiers/15242

Some more examples of single-ended tube guitar amps

3) Kudos to you if you’ve made it this far. And if perchance having read both links you still thirst for more (technical answers, explanations and…diagrams!) then the last link will well and truly fill your tube amp cup to the brim. This article by Eddie Vaughn is both informative and an entertaining read (LENGTH: 10 pages/10,000 words). After reading it you’ll be an expert single-ended (or push-pull) tube amp spotter. Bon chance.

http://www.x3mhc.no/dokumenter/SE-v-PP-Part1.pdf

Conclusion:

All things considered, it seems that factors such as single-ended/push-pull, power ratings or even bias methods can’t indicate an objectively ‘better’ or ‘worse’ sounding  amp. One has to take into account what qualities matter most to you (and your chosen genre of music) and then just listen to the amp. More important perhaps, be aware of how you interact with the amp. When the day comes that you find an amp that’s responsive to your touch, and conversely, you to it, then this so often taken-for-granted front end of your signal chain will seem to become an extension of your body every bit as much as the guitar you are plugging into it.