Guitarking Overdrive Special - Introduction

No two Overdrive Specials were ever built exactly the same, but the basic circuit topology is what gives the Dumble amps their special qualities, and all Overdrive Special amps share this basic topology.  The warm sustaining cleans, and of course that saxophone-like midrange and sing that these amps are famous for,  all come from the cascaded four gain stage preamp and unique "tone stack". The power amps are more common and extension of the classic Fender designs.

The earliest versions in the 70s are characterized by their slightly lower gain overdrive resulting in a more “raw” overdriven tone, and not quite as much of that classic lower midrange frequency content.  The 70’s clean channel is very much like a “fat” Fender Blackface Twin, very warm with that classic 6L6 sparkle but much rounder and fatter by comparison.  Players that made this generation of amps famous include Lowell George, David Lindley (primarily playing slide guitar with Jackson Browne), and Carlos Santana. This version is a long-time favourite here at Guitarking.

Most of the Overdrive Special amps built in the 80’s amps are known as “non-HRM” Skyliner amps.  The “non-HRM” refers to the extra tone-stack that HRM amps have after the second OverDrive stages.  The non-HRM amps don’t have this tone stack and as a result the overdrive is bit more open and full sounding.  The Skyliner tone stack is very balanced for both the clean and overdrive channels.  There are quite a few variations on the 80’s circuit, some more appropriate for jazz/fusion playing and some more for country or blues playing.  The most reknown amp of the era is the voicing of  Robben Ford’s Dumble #102 with it’s unique character in the mids. Also available at Guitarking. Build from the ground up with EU and US parts and fully handwired.

The HRM amps that were built in the 80’s and 90’s incorporate an extra tone-stack after the second overdrive stage. HRM stands for Hot Rodded Marshall or Hot Rubber Monkey (whatever is historically correct) and include this 2nd, internal EQ that only applies to the gain channel. These amps are often referred to as the Bluesmasters and in the overall ODS line-up these are the amps with most gain and compression while still preserving those impressive cleans if the 2nd tube is left out of the circuit. Also this amp is a shop favourite at Guitarking and defintely one you should try if you also need to step in heavier territories now and then.

All of the above 3 voicings (and others upon request) are available at Guitarking in practically any look you want. Color and pattern of the tolex and grillcloth, Combo or Head, style of the knobs etc. All at your fingertips.

Heads start at E2795 and Combo’s at E3295 for the 50W versions. 100W versions start at resp. 2995 and 3495.

Standard the ODS comes with a passive loop. A Dumbleator, which turns the passive loop into a tube buffered loop, can be build in to the main chassis at an additional cost of E275. Once you become a more avid Dumble user, this is definitely a value-add.

Each ODS comes with a standard input and an input that first passes a FET based, neutral boost. For a 50^E surcharge this FET boost can be switched with your footswitch and gain level selected with a knob that replaces the FET input jack.

All of these amps are handwired in the Netherlands. Chassis and Transformers are made in EU and components are true to what Dumble used in his days. This means that all crucial resistors in the circuit are NOS. Capacitors are all brandnew and the best we can source today. For tubes we have our own favourites that are used by default but also this is subject to your imagination. Want all NOS tubes in your ODS ? Possible.

Guitarking Overdrive Special Standard

If there is one voicing we had to pick as our favourite ODS voicing here at Guitarking, it would be this one. We love it so much that we like to call it our ‘standard’. And the one we would recommend to anyone  that hasn’t made up their mind yet on what Dumble flavor to pick.

In fact this amp is the 2nd generation of the ODS circuit dating back to end 70’s. If compared to the late 80’s voicing  this one could be described as more aggressive, upfront and dynamic. Less compressed than later generations and as such, closer to the classic Fender circuits where it all started.

As with each Guitarking Overdrive Special, this amp can be customized in terms of looks as well as  adding sound features. Build-in Dumbleator ? Footswitchable FET boost ? NOS tubes ? 50W or 100W ? You name it.

Guitarking Overdrive Special #102

Robben Ford’s life-long companion is the 102^nd take on the Overdrive Special circuit. And what a special amp this turned out to be ! In the evolution of the Overdrive Special, this amp is referred to as a High Plate Skyliner. Without diving into technicalities this results in a more polished and open sounding drive compared to the more “raw” overdriven voice of the 1st generation ODS. When it comes to the cleans it results in a more compressed feel in the amp.

What makes it stand out is it’s unqiue mid-voicing. And you don’t have to Robben or like his music style, to fall in love with this amp. Paired with a strat bridge pickup for example, this amp sustains in a way you probably never considered possible. Single notes sing as if you were plugging a humbucker into a Marshall stack. Chords remain transparent and unlike attempts to mimick this with pedals, the string seperation and transparency is just unrivalled. With a Humbucker and the FET engaged you can easily dial in a saxophone like drive that is such a great fun !

And as with each ODS, with a push on the button you return to it’s marvellous clean channel. A Fat & Sparkly Fender is probably the best word to describe those cleans.

As with each Guitarking Overdrive Special, this amp can be customized in terms of looks as well as  adding sound features. Build-in Dumbleator ? Footswitchable FET boost ? NOS tubes ? 50W or 100W ? You name it.

Guitarking Overdrive Special Bluesmaster

The Bluesmaster is one of the latest ODS versions that were built before Dumble stopped building them in series. It’s most remarkable feature is a second, internal EQ (Treble-Middle-Bass) after the 2nd gain stage. With this EQ it’s possible to have both the clean and the overdrive channels voiced in it’s own way. It enables you to better dial in your own unique tone; one that fits your fingers and your gear best.

It’s also the ODS with most gain on tap. More polished and smooth than earlier versions and therefore highly sought after in the guild of Blues(rock) players. Having said this, the cleans out of this thing remain fat and sparkly and there is plenty of headroom left to perform your love ballads in an undistorted fashion. This is definitely one of the most versatile versions of the ODS. One that would sit perfectly in a modern day pop/rock band…..

As with each Guitarking Overdrive Special, this amp can be customized in terms of looks as well as  sound features. Build-in Dumbleator ? Footswitchable FET boost ? NOS tubes ? 50W or 100W ? You name it.

Historic replica of Steel String Singer No 2

Steel String Singers are probably the most iconic (and expensive) guitar amps ever build. There are 12 amps accounted for and the original SSS#002, started it’s life with Jackson Browne and is currently in the possession of John Mayer. He used it to record his early and most renowned albums and created a huge following of young guitar players that are all in search of that particular tone.
It’s in the hands of SRV though, where the Steel String Singer first reached it’s mythical status. It is known to deliver lower lows and higher highs than anything out there. Not to speak about it’s deep and lush reverb surpassing that of the best Twin Reverbs. With a tubescreamer in front and your guitar loaded with a manly set of strings, this thing is simply Stratocaster Nirvana.
This particular amp is a near identical replica of the original schematic. It’s build up with NOS resistors and only uses A-grade capacitors. The transformers are made in EU and the thick, silk-screened aluminum chassis is made in The Netherlands.
The 7 (!) pre-amp tubes and 4 power amp tubes are Tung-Sol reissues made in the Reflektor factory in Russia. These are amongst the best new production tubes available.
Final disclaimer: this amp is not for bedroom players. Although it does deliver great tones at lower volumes, it’s magic needs a stage.

Guitarking FD-50-Head