I build these one at a time for $1699 Shipped (U.S. 48 states)
The Rachelle 2204 Model point-to-point hand wired amp is inspired by the very famous 50 watt Marshall
JCM800 2204 circuit. After a great deal of modifying, testing, and retesting, I have come up
with what I consider an amazing version of this
Marshall classic. The design is actually more of a Plexi 50 watt and a JCM800 hybrid , as the transformers
used are of Plexi specification. It's also housed in a Plexi style chassis with a drop through transformer.
I can't call it a clone because there are many modifications to different areas of the amp that separate
it from a standard clone. Read this page for more of the unique
special features!
I will describe in detail in the following paragraphs what makes this 2204 circuit different from the rest.
Please note: I can modify this design with different capacitors and resistors if need. The price is the same if you desire
carbon composition or carbon film resistors.
Expensive? Yes, I know you can get a bunch of different amps at this price,
but I make them one at a time and use the highest quality components.
Here are some shots of the outside of the amp. It differs from a
JCM800 in that I house the amp in a Plexi style small head box.
This is in my opinion the best looking Marshall head cabinet ever made.
The cabinet is made by Mojo and is of the highest quality.
It is covered in black levant and is trimmed with gold piping.
The back of the amp has a gold tone grill. I replaced stock Mojo chrome screws
with brass ones that have trim rings - looks a lot nicer!
Here is Jeanie with her back off. All tubes are purchased from
Doug's Tubes and this guy knows his stuff!
The power tubes are a matched set of JJ KT77.
The KT77 has a more articulate sound and better highs and lows than an EL34. In my opinion, they make the crunch sound less mushy.
The preamp tubes are Tung-Sol 12AX7 Reissue in V1, and
Electro-Harmonix 12AX7 in V2 and V3.
All preamp tubes have balanced triodes. I chose the Tung-Sol for the gain characteristics.
It really adds a beautiful break up compared to the other 12AX7s I have tried.
The Electro-Harmonix 12AX7 is known for being very durable with low microphonics.
I chose them in V2 and V3 to bring reliability to the amp. They sound great in these positions as well.
A close up of the back of the amp. There is a voltage selector and an impedance selector for flexible
connectivity. There are also 2 speaker jacks and easy access to the amps 2 fuses.
A close up of the logo. It is laser cut white Plexiglas and attached with three brass screws.
A close up of the front panel. Notice the Fender Style pilot light.
It makes it easy to change lamps and jewels (the glass lens).
The face plate is gold plexiglas and the indicator numbers go up to 11!
An extreme close up of the Carling long bat toggle switches. I also use the expensive Plexi style chrome trim rings on the switches.
A beauty shot of the completed chassis. The transformers are actually Plexi 50 watt specification from the finest
transformer maker in the world - Mercury Magnetics of California.
The power transformer is a Mercury Magnetics ToneClone P4550JT-G2, the output transformer is a Mercury Magnetics
ToneClone O50JM, and the choke is a Mercury Magnetics ToneClone MC10H.
A beauty shot of the completed chassis from the back. High quality Belton Micalex tube sockets are used for all tube positions.
A shot of the steel chassis with extremely beefed up hardware. I use all stainless steel hardware everywhere on the amp.
I also incorporate stainless Nylok nuts wherever possible. OT and Choke are mounted with 1/4" bolts and all
4-40 hardware has been increased in size to 6-32 where possible. This makes the amp very sturdy and resistant to shock damage.
The stainless hardware means no rusty hardware ever! Notice the heater wires that are carefully twisted to reduce hum.
The turret board is hand drilled and turrets set by hand. There are also no extraneous turrets doing nothing.
A chassis shot with all premium components. Capacitors (yellow components) are
Sozo Mustard Cap Premium Line
and are only available from Sozo directly. Don't confuse these with the common standard line - these are the best made!
The resistors (brownish-orange components) are Vishay Dale metal film
military spec and have the tightest tolerances in the business.
The amp will sound good for a long time as these maintain there value over a longer period.
The black components are the famous Sprague Atoms electrolytic caps and are considered the finest in this position.
The two gray resistors in the bottom of the shot are 2 watt metal oxide. Instead of connecting to wires
that usually flop around under the turret board, I have installed 2 extra turrets to provide stability and reliability.
CGE Potentiometers are used. These pots are considered the closest to the coveted CTS type found in Marshalls from late '67 on.
You can also see the incorporation
of a ground buss bar that provides a very consistent ground source. It is routed to a single point
on a transformer bolt eliminating the possibility or ground loops.
F&T Cap Cans are used. These are the best made!
The soldering throughout is top notch. I am not bragging but I have been soldering for over 20 years
and I hand wire studios for a living. No cold solders on this baby!
The power section has been beefed to industrial strength. Instead of the standard 1 watt resistor it has a 3 watt!
The standard 1 amp rectifier diodes have also been upped to the 1N5809 fast recovery 3amp variety. The power
section is 3 times as robust as stock.
Some close ups of the turret board from left to right.
The cathode resistor (farthest to the right) has been lowered to 8.2k to slightly increase gain.
A close up of the presence pot wiring.
Power transformer and power switch wiring detail.
Shielded wire is used from the inputs all the way to V1 tube socket. The 68K resistors have been
mounted on the turret board instead of hanging off of the input jack for a sturdier design. You can also see in
this picture that the treble peaking circuit has been eliminated. This is a common modification to make
the amp sound better at lower volumes. It also unclutters the signal path from the guitar to the first gain stage.
Rachelle 2204 Model - Parts Summary
Modifications over a standard JCM800 kit
Premium Components
Cabinet
Chassis
Turret Board
Tubes
Here is the recording rig. Read more below!
Recordings:
It is a very versatile amp and it can even to a pretty good clean. If you reduce the volume know on your guitar the
amp cleans up very nicely as well. I find by using the volume knob I don't require channel switching.
So you can see how this amp really sounds I kept the recording set up simple. I used a Digidesign
Mbox with Pro Tools 7.3.1 cs4 software and a Shure Beta 57. No effects or pedals of any kind were used!
The guitar is a Fender
California Series Telecaster
with a single Dimarzio
Virtual Hot PAF DP214 F spaced pickup in the bridge. The guitar volume control is a
push-pull type to make the pickup a single coil. The strings
are Ernie Ball Power Slinkys.
The cabinet is a
StoneAge Custom Cabinets 2X12"B"with a closed back.
The speakers are Southbay Ampworks Scumback.
The left speaker in the 2x12 is actually a Scumback H55 bas cone and the right speaker is a Scumback H75. I mic'ed the right cone
for all recordings. The speakers are 8 ohms each and are wired to provide the amp a 16 ohm load.
My name is Joe Popp and I have been playing guitar for 30 years.
I have been searching my whole life for the killer crunch tone. I tried so many
amps but was unable to get the crunch tone like the old JMPs and JCM800s had so I decided to build my own.
Final Check Items
* Double check of all solder connections for continuity
* All voltages checked to be within spec
* Turret board and chassis thoroughly cleaned of rosin and stray Solder
* Amp burned in for 8 hours
* Amp precisely biased
* Elimination of treble peaking circuit
* Cathode resistor slightly lowered from 10K to 8.2K
* Power supply overbuilt by 3 times of specification
* Hand drilled turret board with hand pressed turrets - no unneeded turrets
* No effects loop or reverb to keep the signal path as pure as possible
* Mercury Magnetics transformers and choke
* SoZo Premium Line Mustard capacitors (not to be confused with the standard line)
* CGE Potentiometers - closest to original CTS Marshall pots
* F&T multi-section cap cans
* Sprague Atom electrolytic capacitors
* Vishay Dale metal film resistors (Can also be built with carbon comp or carbon film)
* PTFE Wire Through out 18 Gauge on heaters 20 Gauge elsewhere
* Fender style 6.3 volt pilot light with glass jewel
* Carling long bat switches with plexi trim rings
* Belton Micalex tube sockets
* Cliff 1/4" jacks
* Built by Mojo Musical Supply to original small box Plexi specs
* Finger jointed Baltic Birch - very strong
* Black levant covering with gold piping
* Rear cover chrome screws replaced with brass and brass trim rings
* High quality steel Plexi style chassis
* All hardware oversized stainless steel
* Use of stainless Nylok nuts wherever possible
* 1/8" black fiberglass
* Hand drilled and turrets hand set
* V1 Tung-Sol 12AX7 Reissue with matched triodes
* V2 and V3 Electro-Harmonix 12AX7 with matched triodes
* V4 and V5 JJ KT77 matched pair
This amp was built for crunch! The clips provide many different examples of the crunch sound that
the amp specializes in creating.
Other Builds:
Rachelle
Rachelle Prototype
Questions or comments? Contact: Click here to email Joe Popp
Visit: Joe Popp.net
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