After over a year with no updates, I am pleased to release to you, sound clips of my latest model!

But first, I must reveal the name and sound clips of my first model…

The Labrador

This is the amp that started it all.  It’s a compact 12-18 watt (depending on configuration) head.  It’s designed to have a simple, yet flexible, control scheme, and a wide range of tones.  The clean tone is vintage inspired with very low headroom.  It won’t stay clean all the way up to 10.  Quite the opposite, it will begin to compress and break up fairly low on the volume control.  It’s designed for a thick tone that gives excellent touch sensitivity.  As the gain is increased, the tone starts to break up, but it retains a vintage sound.  Flip the gain switch to high and the character changes considerably.  The tone takes on a fuzz characteristic that sustains for days.  This is all done using 2 12AX7s and absolutely no distorting diodes in the pre-amp.  The amplifier is available with three different output configurations.  A classic American 6V6 output stage for 12 watts of power, a strong and powerful bass and shiny highs, a classic British EL84 output stage for 18 watts of power with a midrange that melts like butter, or combined output stage that allows pairing 1 EL84 with 1 6V6.  To my knowledge, JDP Amplifiers is the only company to market this option.  In addition to a gain switch, the controls include a gain knob, bass, treble, and master volume.  The amplifier has a 6CA4/EZ81 rectifier tube with a switchable solid state option.

Clean

Mild Crunch

Blues

Rock

High Gain

Thanks to Patrick of Kindred Coffee Roasters for playing and recording the sound clips.

Now onto the reason for my post.  Introducing…

The Pitbull

I am keeping with my 4 knob layout, high gain/low gain switch and 12-18 watt power level.  But this time, I pushed the sound into a different direction.  I wanted something that had more clean headroom so I could enjoy a bit more volume before breakup began.  I cleaned up the clean and gave it some sparkle.  It still retains a smooth transition into distortion as you dig into the strings.  The high gain, I went back to the drawing board with this one.  I wanted to get even more gain than before, without the fuzz characteristic.  I added another 12AX7 to the pre-amp to push the gain into metal territory.  Overall, I modified the tone controls to give a bit of a midrange scoop, imparting a meatier tone to both the clean and the high gain settings.  The tone controls still retain a very wide range of adjustment found in the Labrador.  This amplifier is also available with the three different output configurations.  The amplifier has a 5Y3 rectifier tube with a switchable solid state option.

Guitar is run directly into amplifier, with exception of “Rock”, where an Electro-Harmonix Holy Grail Reverb is used between the guitar and amplifier.
Amplifier is running Tung-Sol Re-issue 12AX7s and JJ EL84s.
All recordings are through a 2×12 cab with a pair of mid 1960s Jensen C12-R speakers.

Clean – Tube Rectified, Telecaster Bridge PU

Blues – Tube Rectified, Stratocaster Neck PU

Mild Crunch – Tube Rectified, Telecaster Neck PU,
Mild Crunch – Solid State Rectified, Telecaster Neck PU
Mild Crunch Solo – Tube Rectified, Telecaster Neck PU

Rock – riff 1 – Tube Rectified, Stratocaster Neck PU
Rock – riff 2 – Tube Rectified, Stratocaster Neck PU

High Gain – SS Rectified, Jaguar Bridge PU

ALL MAX – riff – SS Rectified, Jaguar Bridge PU
ALL MAX – solo – SS Rectified, Jaguar Bridge PU

Again, thanks to Patrick of Kindred Coffee Roasters for playing and recording the sound clips.

–The art of simplicity, the science of versatility, and the magic of music
JDP

It’s been almost a year since I have posted on here.  However, it has not been an idle year for me!  I have been doing a lot of preparation work for the production of my amplifiers.  I have finalized a cabinet design for my amplifiers,  I have decided on a naming convention for my amplifiers and I am on my final draft of the owner’s manuals.

I have begun the design process for another 12-18 watt model that digs further into the high gain territory without sacrificing the clean tones.  The first prototype is functional and sounding promising, but it still needs some refinement.

I am a firm believer in the philosophy that if you aren’t doing it right, it’s not worth doing.  This is part of the reason I have taken my time, so that I can stand fully behind what I make.

–The art of simplicity, the science of versatility, and the magic of music
JDP

Jim Marshall dies at 88

May he rest in piece…

I officially have a builder for my amplifier chassis!  I’m supposed to have the first one in two weeks.  I will be posting pictures once they come in.

I always wanted to find out how my amplifiers would respond to a drop test.  Little did I know that I would be given such an opportunity.

I was bringing the amplifier back from a friend’s house and I set it on top of what I thought was a full cardboard box.  The box was sitting on the ledge shown in the first picture.  I left to grab another load from the car and when I came back, I found the amplifier laying flat on the ground!

I soon realized the cardboard box collapsed under the weight and the amp slid off and landed on the concrete floor, about 36″ down.  The amplifier was not in any sort of chassis.  It was (other than damage) just as pictured.  I picked it up and inspected it for damage.   I feared the worst….

The gain knob had come off completely, the bass knob was pushed in which broke off part of the knob, the green lens had a scratch and the power switch was broken.  Looking at it from the side, the front panel was bent inward significantly!  Fortunately, none of the tubes were broken in the fall.

I replaced the power switch and powered it up.  The light bulb was burnt out, but everything else worked.  The knob shafts were intact and all the controls turned smoothly like nothing had happened.  I closely inspected the circuit and there was no internal damage.  Had it been mounted in a chassis, I am convinced that the amplifier would have suffered no damage at all.

I put a new knob on the gain control, leaving the broken bass knob as is, and put it to use as my personal amplifier.

*Please note: damage resulting from falling is not covered under warranty.

I have completed the prototype 50 watt amplifier!

It has all of the tonal range of my smaller amplifiers, with much more headroom and very powerful bass.  The bass is very clear and never muddy, while the highs have a nice sparkle to them that’s always lively and never overpowering.  The tone controls still allow you to greatly dial back the bass and highs for a “lo-fi” sound.

The increased headroom and strong, clear bass with a dialed down treble allows authoritative jazz tones that weren’t possible on the smaller amplifiers.  The sparkle in the highs make your guitar sing, whether it’s clean or crunchy or fuzz*.  The rectifier sag adds a touch of compression to give that sustain, or switch over to solid state for greater punch and attack.

With 6L6s, the amplifier has greater headroom and stronger bass.
With EL34s, the gain is increased and the midrange can be driven into a nice crunch.
†No adjustment/biasing needed to switch tube types!

This amplifier has the tonal range of 4 amplifiers, and it does this with only 4 knobs!

Tube count: 6
Transistor count: 0

The art of simplicity, the science of versatility, and the magic of music.

–JDP–

*The High Gain option will be standard in the 50w model.
†The option to mix output tubes on the 50w model is still under development and is not available at this time.

I’ve been tweaking the 50 watt amplifier.  It’s sounding very promising!

Some of the highlights:
50 watts of power
6L6 or EL34 power tubes
3 12AX7 pre-amp tubes
5U4 or solid state rectified
Sound signature borrowed from it’s little brother
Still just 4 knobs (Gain, Bass, Treble, Volume)
4/8/16 ohm output

I’ve modified the tone controls to beef up the sound a bit to match the greater output power.  I’ve also added a small amount of negative feedback to increase the headroom.  I’m still in the process of tuning this by ear.  I expect to have the prototype done by the end of the year.

JDP Amplifiers will be a vendor at the September 25th vintage guitar show in Elgin, IL!

Come try our amplifiers first hand!  We will have on hand for demonstration: a Fender Telecaster, a Penco Les-Paul copy, a 2×12 open-back cab loaded with Weber 12A125A’s and a 4×12 closed back cab loaded with Celestion G12T-75’s.

Feel free to bring your own equipment as well to see how our amplifiers sound with your axe, pedals, cab etc.

Also for sale will be new tubes by JJ and Tung-Sol and a variety of NOS tubes.

Date & Time:
Sunday, September 25th
10:00am to 4:00pm

Location:
Holiday Inn
495 Airport Road
Elgin, IL

For more information call:
R & B Production 847-931-0707

See also the Facebook event page.