yek
Legend!
* EDIT: Up-to-date information is available in Yek's Guide to the Fractal Audio Amplifier Models *
ODS-100: based on Dumble ODS-100
These models are based on a Dumble Overdrive Special (ODS) amp.
A Dumble is THE most expensive amplifier available, no.1 of Vintage Guitar’s list of most valuable guitar amps. They were built by Howard "Alexander" Dumble, in L.A. Every Dumble is unique because they were built on special order, specifically designed for the buyer. He retired in the 90s. They say there are less than 300 Dumble amps. More info about Dumble. Dumble (and Trainwreck) discussion forum.
Famous Dumble players include Robben Ford, Larry Carlton, John Mayer, Carlos Santana, Keith Urban, SRV, Eric Johnson, Joe Bonamassa.
We’ve got several models of Dumblesque amps in our Fractal devices, such as the Bludojai and Fox models.
Cliff owns an actual Dumble, serial #213, with EL34 tubes. It has a HRM circuit. The “ODS-100 HRM” models are based on this amp. Cliff:
The “ODS-100 Ford” models are based on on schematics which supposedly represent Robben Ford’s Tan Dumble, serial #102. Cliff:
Pictures of Ford’s settings:
The amp has two inputs: FET and Normal. The FET input has a different impedance. The models are based on the Normal input.
The amp has a Preamp section and an Overdrive section.
The controls on the original amp are: preamp Volume (model: Input Drive), Treble/Middle/Bass (shared preamp tone controls), Overdrive Level and Ratio, Master/Presence (power amp). The clean channel has a bright cap on the Master Volume. This causes the tone to get brighter as the MV is reduced and vice-versa.
There are three switches: "Bright" (adds spark). "Mid" (boosts the mids), "Rock/Jazz". Cliff:
There’s also a footswitchable Preamp Bypass (PAB) which bypasses the input tone stack.
The “Ford 1” model is based on the PAB engaged. “Ford 2” model is based on the PAB bypassed. “Ford Md” is based on PAB engaged and Mid-switch engaged. “HRM Mid” is based on the Mid-switch engaged.
The OD’s gain is set through Volume and OD Level, modeled in Input Drive and Overdrive. On all amps like this the first control sets the “sensitivity” and the second one sets the amount of distortion. Cliff:
Models with Input Drive and Overdrive controls always feel “elastic” and spongy, a real joy to play.
It’s a Master Volume amp. This means that the amp’s distortion is created in particular by the preamp tubes, not the power amp. The Master Volume, which works in the power amp section, is still very important to the tone and feel. You have to decide for yourself what setting in the model works for you best. The default setting is a good point to start of course.
The Zendrive is one of the pedals that tries to recreate the Dumble tone. Rooben Ford uses it himself through Fender amps. We’ve got a model of this pedal: Zendrive.
Cliff’s Dumble cabinet with EV speakers has been captured in IRs. Look up the 4x12 Rumble stock cabs.
ODS-100: based on Dumble ODS-100
These models are based on a Dumble Overdrive Special (ODS) amp.
A Dumble is THE most expensive amplifier available, no.1 of Vintage Guitar’s list of most valuable guitar amps. They were built by Howard "Alexander" Dumble, in L.A. Every Dumble is unique because they were built on special order, specifically designed for the buyer. He retired in the 90s. They say there are less than 300 Dumble amps. More info about Dumble. Dumble (and Trainwreck) discussion forum.
Famous Dumble players include Robben Ford, Larry Carlton, John Mayer, Carlos Santana, Keith Urban, SRV, Eric Johnson, Joe Bonamassa.
There’s always a lot of talk on the forums about Robben Ford's Dumble tone. It’s an elusive tone, worshipped by a lot of jazz / blues / fusion players. It's a thick, mid-heavy, smooth lead tone, very touch-sensitive. The “note flip” is a certain tonal characteristic attributed to the Dumble and some of its clones. So what’s the note flip? Quote: “It sounds KIND of like its starting to feed back, but its not. It flips the note up so that a different harmonic order is heard, or something like that”.
That trademark tone is not for everybody: hit a power chord and it may terrible to your ears.
But there’s more to Dumble than the Robben Ford sound.
That trademark tone is not for everybody: hit a power chord and it may terrible to your ears.
But there’s more to Dumble than the Robben Ford sound.
We’ve got several models of Dumblesque amps in our Fractal devices, such as the Bludojai and Fox models.
Cliff owns an actual Dumble, serial #213, with EL34 tubes. It has a HRM circuit. The “ODS-100 HRM” models are based on this amp. Cliff:
“They call HRM "Hot Rubber Monkey" but what it really means is "Hot Rod Marshall". The HRM Dumbles have a fixed Marshall tone stack at the output of the lead channel. This gives a little scoop to the mids."
The “ODS-100 Ford” models are based on on schematics which supposedly represent Robben Ford’s Tan Dumble, serial #102. Cliff:
“The ODS-100 Ford 2 model is not based on the HRM model with the HRM tonestack removed. Whether or not the model matches any particular Dumble is unknown as we have not been able to procure a non-HRM Dumble yet. The model is based on schematics that were given to us that supposedly accurately represent Robben Ford's Dumble. Whether or not the schematics are accurate I do not know. The voltage divider at the output of V1B is set to 0.078 which is based on the values that are indicated on the schematic for the set-point of the trimmer. As no two Dumbles are identical it stands to reason that one person's interpretation of the ideal Dumble voicing may not agree with another's. Since V1 is running clean you can get more gain by simply increasing Input Trim. It will have basically the same effect as increasing the trimmer."
Pictures of Ford’s settings:
The amp has two inputs: FET and Normal. The FET input has a different impedance. The models are based on the Normal input.
The amp has a Preamp section and an Overdrive section.
The controls on the original amp are: preamp Volume (model: Input Drive), Treble/Middle/Bass (shared preamp tone controls), Overdrive Level and Ratio, Master/Presence (power amp). The clean channel has a bright cap on the Master Volume. This causes the tone to get brighter as the MV is reduced and vice-versa.
There are three switches: "Bright" (adds spark). "Mid" (boosts the mids), "Rock/Jazz". Cliff:
"The Mid switch, sometimes labeled "Deep", shorts out the 390 pF cap in the tone stack (which is in series with a 2 nF cap). All that is left then is the 2 nF cap. With PAB active this lowers the lowcut frequency."
There’s also a footswitchable Preamp Bypass (PAB) which bypasses the input tone stack.
The “Ford 1” model is based on the PAB engaged. “Ford 2” model is based on the PAB bypassed. “Ford Md” is based on PAB engaged and Mid-switch engaged. “HRM Mid” is based on the Mid-switch engaged.
The OD’s gain is set through Volume and OD Level, modeled in Input Drive and Overdrive. On all amps like this the first control sets the “sensitivity” and the second one sets the amount of distortion. Cliff:
“Input Drive increases the gain amount as you rotate the knob clockwise. As the gain increases the tone is shifted from a treble and upper mid emphasis, which produces an up front sparkling tone, to a lower mid and bass emphasis, which produces a thick meaty tone.
Overdrive increases the gain amount as you rotate the knob clockwise but with no alteration of the tonal balance.
Different combinations of Input Drive and Overdrive settings will have a dramatic effect on the response of the amplifier and the personality of your instrument. It is easy to get familiar with the action of these controls and you’ll be amazed with your ability to make any guitar sound mellow, fat, soulful or aggressive.”
Models with Input Drive and Overdrive controls always feel “elastic” and spongy, a real joy to play.
It’s a Master Volume amp. This means that the amp’s distortion is created in particular by the preamp tubes, not the power amp. The Master Volume, which works in the power amp section, is still very important to the tone and feel. You have to decide for yourself what setting in the model works for you best. The default setting is a good point to start of course.
The Zendrive is one of the pedals that tries to recreate the Dumble tone. Rooben Ford uses it himself through Fender amps. We’ve got a model of this pedal: Zendrive.
Cliff’s Dumble cabinet with EV speakers has been captured in IRs. Look up the 4x12 Rumble stock cabs.
Cab Pack 17 provides more IRs of this cabinet.
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