Carl's Custom Amps British Bluesmaster 20W to 1/10W JTM-45 Style head with Power Scaling

Carl's Custom Amps

British Bluesmaster 20W to 1/10W JTM-45 style head with KT66s
Finally a JTM-45 with the ability to control the volume!

Carl's Custom Amps is high demand please allow 10 to 14 weeks for your amp to be built, tested and shipped.

This is for the 20W version but I also offer a 45W and 45W+ version. For most players 20W is more than enough power. 

You can choose your tolex and piping colors!

Description:

Early Marshall amps were incredible—-rich, thick, bluesy and mean! There just something about a KT-66 loaded early 60’s JTM. Jimi Hendrix, Eric Clapton, Angus Young, Joe Perry and countless others have used them. However they too loud to be used by most players. They are great pedal amps but the real magic is getting the amp to sweet spot. The British Bluesmaster delivers all those early Marshall sounds but is fitted with London Power so you can get real power tube overdrive at low volumes. The volume can be controlled as transparently as possible from full power down 1/10W.

The channels are internally jumpered so you don’t need a patch cable. Also we’ve added a bright boost switch to the amp (not pictured) so the amp is more useful darker guitars or if you want little more bite. The SAG (the tube rectifier effect) is completely variable so you can go from solid-state rectifier sounds to tube rectifier sounds and beyond!

London Power’s Power Scaling:

The 60s and 70's Plexi are incredibly  loud amps and were designed for big stages.  They too loud for most players to use even in a club setting.  The British Overdrive series features variable power which solves this issue. Power Scaling allows the player to dial in anything from full power down to 1/10W. So these amp are capable of playing anything form a bedroom to a stadium.  Many amps have  "wattage" and "power" controls that sound unnatural. London Power’s Power Scaling  is different from most of these and very transparent.  Plus in any setting below full power it extends the life of the power tubes.  

Other Features:

Linked Input:  

The amp has a linked input so there no need to use a patch cable to jumper channels. This allows you to blend the sounds of normal and bright channels.

SAG Control:

One of the cool things about JTMs was the bloom of notes that comes from the use of tube rectifier. The one trouble is that the sag is set meaning you cannot get more or less and that the sag changes with volume changes. Instead of the tube we’ve added SAG control. It allows the user to adjust the sag/compression and makes the amp more reliable!

Tube Swapping:  

The 20W, 45W and 45W+ Watt versions all come with KT66 power tubes but can use any of the following power tube types with re-baising: EL-34, KT77, 5881, 6L6WGC, 6L6GC, 6V6 or 6550s. Bias ports and externally accessed bias pots allows the user to swap tubes. The 20W and 45W version uses two power tubes and the 45W+ version uses four power tubes for the bigger “100W Marshall” feel without the extra volume. Two of the power tubes in 45W+ version can be pulled for the two tube power section sound with no affect on power output.

Spec/Features:

All tube,  Bright and Normal volume controls, boost switch, Crisp/Stock Switch, Vibe Switch (Negative Feedback)  treble, mids, bass, and presence, power and limit controls,  ON/ OFF Switch,  hand wired for great sound and reliability with a method that shortens the signal path, super quiet grounding for low noise, special resistor selection for low noise and great tone, adjustable fixed bias, solid state rectifier.

Parts:
Malory 150 and Panasonic Tone Caps,  Ultra Long Life Filter caps, Heyboer Hammond Output transformer, custom made toroidal power transformer, Cliff or Switchcraft jacks,  aluminum chassis, 12 ft power cord.

Don’t waste your time or blow out you ear drums—get awesome tone!

Customer Comments:

“My background

I am a bedroom player with severe G.A.S. My guitar heroes are hendrix, clapton, gales, sayce, bonamassa, josh smith, keith richards, simo, 3 kings, duane, and SRV. As relatively varied tones from my guitar heroes are, I get into these periods of time when I am addicted to a particular tone--and I have to have it. As a result, I have owned vintage (brown and blackface) fenders, Ac30s, boutique dumble clones, marshalls, and the list goes on and on. I had Carl build me a one off vibro-princeton with built in global negative feedback cathode biased monster and it was amazing ( his customer service and patience and expertise was incredible and if you're thinking about working with him---just do it). Out of all of the amps that I have or have owned, my vibro-princeton is the one I plug into the most: what sets his builds apart is that his amps sound so NATURAL. I plug straight in and there is the sound...kew the goose bumps. 

On to the bluesmaster. First, the amp is beautiful. It is not a kit amp. I ordered the 45W+ because I like to play dual mono and I have another amp I would like for this one to keep up with. With the power scaling, you can bring the volume down but maintain that big amp feel.   You know the heros. You know the tones.  The tone I will try to describe is one that is just a little past the edge of breakup. I typically ride my guitar volume (no treble bleed). I want all of the dynamics to be in my hands -- clean when I am playing softly and roar when I dig in. I do not play with a pick, so when I play a note I want the note to have an immediate clarity, and then depending on how hard I play the note, to roll over into a round warm  sound. The amp is very versatile and I have not gotten a tone out of it that I have not liked thus far. Some switches/ knob change the feel; some change the sound; some change both feel and sound. The updated amp comes with a '62 and a '65 setting on the back. With my strat, I like to have the amp in the '62 setting and the "crisp" setting. Being internally jumpered, I just set my normal and bright volume, set my TMB and presence. The sag control is amazing. This allows me to start off with that clear crunch tone and then kind of roll over into that warm round sound--kind of like the first chord in the opening of " Bold as Love." The power and limit pots are the last thing that I touch. In my opinion/experience, the power and limit help me get out a rut---going to the extremes make me play differently and think of new stuff. Right now, I have the amp in a 2x12 wired 16 ohm with 2 alnico speakers. I have the amp in "safe mismatch" output @ 8 ohms and put the power knob all the way up. I then use my limit knob like a volume knob. Heaven: clear, round, some squish, warm, ballsy, dynamic, bloomy, harmonic, and again Natural-- I don't need to put 1000k worth of pedals between my Bluesmaster and my guitar to get what I want. Carl and crew know what they're doing.” 

R.J Eric

 “I reached out to Carl a few months back, and explained to him what I was looking for in an guitar amplifier. I was looking for the that gritty, bluesy, dirty, sweet tones of the yesteryear. He recommended his British Bluesmaster with the London Power Scaling Design. I had never heard of London Power Scaling, but it sounded pretty intriguing. An amplifier that could get that heavenly cranked JTM-like tone, even down to a whisper volume, if needed. This amp sounded like it was just what I was looking for. So I said "lets do this", Carl said 'will do".

 So fast forward a little bit. I now have the Bluesmaster in my possession, I'm chomping at the bit to hook it up and hear her sing! Now here'e thing, it took me a solid week to learn to dial in the overdrive, not because it was difficult, but because the clean tones on this amp are some of the best that I've ever heard! No kidding, maybe the best. I just kept wanting to hear it clean. So sweet, full, dynamic and responsive, even without reverb. And I'm a certified reverb junkie.Now add a little bit of reverb to it and it's like a walk in the clouds!

But enough about the clean tones, it's the dirt and grime that people want to hear about, and this circuit does dirt very well! And it will get this great overdrive from bedroom volume, to noise ordinance violation summons volume! Just some small adjustments to the power and limit knobs will take you from the edge of breakup, to head long over that edge! It's hard to explain to someone what great tone is, but you know it when you hear it! I dig this amp, a lot. “

 Josh C.

“After a delightful evening tweaking my Bluesmaster, I can put my perceptions into a review. You may comment as you see fit. Here we go.

I received my Carl’s Custom Bluesmaster 20 watt a couple of days ago and find it to be the best amp I have ever come across. I’ve spent a fortune trying countless tube and solid state amps, all high end, and while they each have their own great sound, none produced what I heard in my head, but I got by with the gain just high enough to “put hair on it,” without sounding like a 14-year-old who doesn’t know how to use his new distortion pedal. Not to mention the fact that most of my practicing is at home, where I could never really let the amp move the speaker, and the sound was ultimately never satisfying, often frustrating to the point of blunting my interest in playing.

Not so with the Bluesmaster. Right out or the box I recognized that basic tone, flowing, creamy and singing, and all your recalled tones from the early 1970’s come rushing back. The guitar sounds “true” with the Bluesmaster driving humbuckers though the old 212 Celestion cab. The London power scaling (“Variable Power”) takes a bit of experimenting with (like with that exotic seasoning that was missing from your favorite dish), but after a few hours practice, I use the Limit control as a volume knob (employing the actual wattage knob as a sort of gain governor). True to Carl’s instructions, keep the “Limit” level lower than the wattage level, and the creamy overdrive stays genuine (as opposed to reminiscent of a gain pedal, never quite there), just as you remember from those priceless LPs. What you hear out of a Bluesmaster is almost like some  fundamental timbre that separates this from all the modelling amps (and many tube amps) out there, ever closer, but still hopelessly far away from what those of us who know that sound from “back in the day” are seeking. Open chords sound like a roar, but with a tight, smooth character, no circuit-generated gravelly candy sounds here.

It’s difficult avoiding the use of wine-tasting jargon, but Carl’s new Bluesmaster amp is enough to satisfy even the most frustrated jaded cork sniffer. My only concern is that I can’t stop playing it. If vintage Marshall is what you’re hearing in your head but never through your ears, give a Carl’s Custom Bluesmaster a listen in a real live setting, and you’ll feel right at home.

Bravo. “

Dennis O.