{"id":249628,"date":"2026-07-01T08:00:34","date_gmt":"2026-07-01T06:00:34","guid":{"rendered":"https:\/\/captain-guitar-lounge.com\/?p=249628&preview=true&preview_id=249628"},"modified":"2026-07-01T11:24:42","modified_gmt":"2026-07-01T09:24:42","slug":"welcome-to-dumbleland","status":"publish","type":"post","link":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/","title":{"rendered":"Welcome to Dumbleland!"},"content":{"rendered":"

[et_pb_section fb_built=”1″ fullwidth=”on” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_fullwidth_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/board-headerJPG-scaled.jpg” alt=”dumble board header” title_text=”board headerJPG” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_fullwidth_image][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”25px||15px|||” global_colors_info=”{}”][et_pb_row column_structure=”1_3,1_3,1_3″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”32px||15px|||” global_colors_info=”{}”][et_pb_column type=”1_3″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”11px|||||” global_colors_info=”{}”]<\/p>\n

Dumbleland Special #011 –
a technical analysis<\/strong><\/h1>\n

Howard Alexander Dumble<\/a> never built anything for a catalog. There was no mass production, no parts lists from the factory, and no sales department. Every amplifier that left his workshop was one-of-a-kind\u2014and most disappeared behind closed doors, into private collections, or onto the unreachable stages of great musicians. Technically, not much is known… until now! <\/p>\n

The Overdrive Special made the name legendary. But before it existed, Dumble built a series that is little more than a rumor even among connoisseurs: the Dumbleland Special<\/strong>. Depending on the source, there are between ten and twelve copies. All handmade, all from the late 1970s, all with a circuit design philosophy that Dumble later partly continued\u2014and partly discarded.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_3″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Personal Note<\/strong><\/h3>\n

The fact that an amplifier like this ends up on our workbench and we get to document it at our leisure\u2014that\u2019s not something to be taken for granted. For me personally, it’s simply unbelievable.<\/p>\n

As far as we know, there is only one other circuit diagram for a Dumbleland Special: number 009, traced by hand. However Dumbleland Special #008 has already been listed on Reverb<\/a>. Of course, there are no official documents. If you compare the two plans side by side, you’ll immediately see that they differ in several places. Presumably, Dumble himself developed the model; he reportedly customized the amplifier personally for each customer. Of course, we can never completely rule out the possibility of subsequent modifications to our specimen, but they seem rather unlikely in most places. Where there are doubts, this is noted in the plan.<\/p>\n

What follows here is a bit of amplifier history. Deluxe Amp Archaeology.
Researched to the best of my knowledge and belief\u2014enjoy reading it, Anselm.<\/p>\n

[\/et_pb_text][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/dumbleland-11-back-scaled.jpg” title_text=”dumbleland 11 back” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_3″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” link_option_url=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumble_Dumbleland-Special_DS150_011-2.pdf” link_option_url_new_window=”on” global_colors_info=”{}”]<\/p>\n

Circuit Diagram<\/strong><\/h3>\n

[\/et_pb_text][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumble_Dumbleland-Special_DS150_011-2-pdf.jpg” title_text=”Dumble_Dumbleland Special_DS150_011″ url=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumble_Dumbleland-Special_DS150_011-2.pdf” url_new_window=”on” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ fullwidth=”on” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_fullwidth_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/header_preamp-scaled.jpg” alt=”dumble board header” title_text=”header_preamp” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_fullwidth_image][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”-7px|||||” custom_padding=”6px||24px|||” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”11px||6px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Iron You Can See and Hear<\/strong><\/h2>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_4,1_4,1_2″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”18px||10px|||” global_colors_info=”{}”][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/triad-pt-square-scaled.jpg” title_text=”triad pt square” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

The first thing you notice: The transformers are huge. The power transformer is a Triad R-25A\u2014a model you’d more likely expect to find in a hi-fi power amplifier. What’s interesting here is that the 5-V winding remains unused, while one of the two 6.3-V windings powers only the pilot light. Dumble deliberately chose an oversized transformer here and used only what he needed.<\/p>\n

The output transformer is from Western Transformers in Portland, Oregon, and bears the customer number 29-1312\u2014perhaps a custom order? The choke is a Triad C-40X.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_gallery gallery_ids=”249500,249502,249504,249510,249512,249514,249516,249518,249520,249522,249524,249526″ posts_number=”2″ show_title_and_caption=”off” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” max_height=”344px” custom_padding=”||449px|||” global_colors_info=”{}”][\/et_pb_gallery][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”-7px|||||” custom_padding=”6px||24px|||” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”11px||6px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Choke Input Filtering: Dumble Thinks Differently<\/strong><\/h2>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_2,1_4,1_4″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”18px||10px|||” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_gallery gallery_ids=”249543,249539,249541″ posts_number=”2″ show_title_and_caption=”off” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” max_height=”344px” custom_padding=”||449px|||” global_colors_info=”{}”][\/et_pb_gallery][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

One detail that immediately catches the eye when reading the schematic: The choke is located before the first anode tap. That’s choke-input filtering\u2014a principle familiar from early Fender Pro models or the Orange 200. It provides a smoother, current-limited high voltage, resulting in natural sag behavior.<\/p>\n

But Dumble wouldn’t be Dumble if he had just copied it. The resistance and inductance values differ significantly from those of Fender and Orange\u2014they are set lower and more controlled. The result: Say yes, but without a sponge. Flexibility with control.<\/p>\n

The large filter capacitors are labeled with codes ranging from 7717 to 7839\u2014Week 17 of 1977 to Week 39 of 1978. This supports the idea that it was completed in 1978\u201379.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/flter_square-scaled.jpg” title_text=”flter_square” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”-7px|||||” custom_padding=”6px||24px|||” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”11px||6px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

The Prelude to Dumbleland Special #011: Familiar Pattern, Unknown Values<\/strong><\/h2>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_4,1_4,1_2″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”18px||10px|||” global_colors_info=”{}”][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/pre10_square.jpg” title_text=”pre10_square” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

The input stage follows the classic Dumble design: Rock\/Jazz switch, Deep, Bright\u2014it’s all there, just as you’d expect. Things get interesting after the second triode: Here, Dumble has incorporated an additional tone control that resembles a Baxandall circuit. Labeled “Step” \u2014 separate controls for treble and bass.<\/p>\n

This step circuit is a familiar feature of other Dumble amps. But with these component values? Extremely rarely documented.<\/strong><\/p>\n

This is followed by a classic cathode follower, and then the master volume: a 1-M\u03a9 potentiometer that already passes 30% of the signal at the midpoint. Translation: This amp is already very loud at the 12 o’clock position. There is no provision for room occupancy here.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_gallery gallery_ids=”249593,249595,249549,249551,249553,249555,249557,249559,249561,249563,249565,249567,249569,249571,249573″ posts_number=”2″ show_title_and_caption=”off” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” max_height=”344px” custom_padding=”||449px|||” global_colors_info=”{}”][\/et_pb_gallery][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”-7px|||||” custom_padding=”6px||24px|||” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”11px||6px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Phase Inverter and Power Amplifier<\/strong><\/h2>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_4,1_4,1_4,1_4″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”18px||10px|||” global_colors_info=”{}”][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Phase inversion is handled by a 12AU7 in a long-tail pair circuit\u2014reliable, proven, and unobtrusive. What\u2019s particularly noteworthy is that behind it sits a 12BH7, serving as a dedicated driver stage for the power amplifier grids. The 12BH7 can deliver significantly more current than the standard 12AX7 or 12AT7 and ensures that the power tubes operate cleanly and at full drive. Dumble has gone the extra mile here, more so than most amp builders would.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/pt3-scaled.jpg” title_text=”pt3″ _builder_version=”4.27.6″ _module_preset=”default” width=”100%” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

The power tubes are 6550s\u2014tubes that are more commonly found in hi-fi or bass amps than in guitar amps. And here’s the key point: Dumble doesn’t<\/strong> run them in ultra-linear mode<\/strong> here. Instead, the shielding grids are connected to the power supply via 550-\u03a9 resistors. That may sound like a minor detail, but it fundamentally changes the character: less tight, less linear, but with more character, more compression\u2014more amp.<\/p>\n

Fixed bias<\/strong>, as you’d expect. The bias circuit is simple\u2014it’s not rocket science.<\/p>\n

The NFB tap is switched together with the output impedance. If you change the speaker connection, the negative feedback value also changes automatically. This isn’t just a gimmick, but a deliberate adjustment: Different impedances at the output transformer alter the turns ratio and thus the damping factor\u2014Dumble compensates for this via the NFB value so that the amp sounds controlled under any load.
There’s an easier way to do this, but the master does it right!<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/nonultra-scaled.jpg” title_text=”nonultra” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”-7px|||||” custom_padding=”6px||24px|||” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”11px||6px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Clues and Mysteries<\/strong><\/h2>\n

A hand-built Dumble is always an archaeological project as well. We noticed several peculiarities with #011:<\/strong><\/p>\n

<\/strong><\/p>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=”1_5,1_5,1_5,1_5,1_5″ _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”18px||10px|||” global_colors_info=”{}”][et_pb_column type=”1_5″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/stby-light-scaled.jpg” title_text=”standby light” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”||11px|||” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Standby light:<\/strong>
Probably retrofitted\u2014perhaps even by Dumble himself? These types of resistors are not normally found in the amplifier.<\/p>\n

[\/et_pb_text][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/hole.jpeg” title_text=”get” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”-14px||10px|||” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Hole in the chassis:
<\/strong>We can’t explain this hole either.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_5″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/a-ring2_small-scaled.jpg” title_text=”a ring2_small” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”||12px|||” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||20px|||” global_colors_info=”{}”]<\/p>\n

“A” rings on cables:
<\/strong>Function unknown. Production labeling? Sorting?
It can’t stand for “A-node,” because some wires are also cathode connections.<\/p>\n

[\/et_pb_text][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/backpanelscrews_2_1-scaled.jpg” title_text=”backpanelscrews_2_1″ _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”||12px|||” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||20px|||” custom_padding=”||0px|||” global_colors_info=”{}”]<\/p>\n

Holes in the back panel:
<\/strong>There is no explanation for why there are two holes in the back panel. Nor is it clear why two different types of screws or nuts were used to secure it.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_5″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/cap-hole-scaled.jpg” title_text=”cap hole” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”||10px|||” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Closed chassis hole<\/strong>:
Earlier Dumbleland models had a capacitor here, which was moved to the circuit board in model #011\u2014the series has evolved over the course of production.<\/p>\n

[\/et_pb_text][\/et_pb_column][et_pb_column type=”1_5″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/signature1s.jpeg” title_text=”signature1s” _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”||14px|||” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”7px|||||” global_colors_info=”{}”]<\/p>\n

Handwritten inscription on a capacitor?:<\/strong> Unfortunately, it’s indecipherable\u2014perhaps the manufacturer’s autograph? Otherwise, there is no signature on the chassis.<\/p>\n

[\/et_pb_text][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/signature2.jpeg” title_text=”signature2″ _builder_version=”4.27.6″ _module_preset=”default” width=”100%” custom_margin=”||14px|||” global_colors_info=”{}”][\/et_pb_image][\/et_pb_column][et_pb_column type=”1_5″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_image src=”https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/av5mmk.gif” title_text=”av5mmk” _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Fun Fact<\/strong>:
The NFB connection on the impedance selector switch was probably never actually soldered; if it was, it was done with very little solder. It has held up well over the years, though, because Mr. Dumble wrapped the wire ends around the terminals before soldering them. As it should be: Ensure mechanical stability before applying solder.<\/p>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”-7px|||||” custom_padding=”6px||24px|||” global_colors_info=”{}”][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”11px||6px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_divider _builder_version=”4.27.6″ _module_preset=”default” custom_margin=”||4px|||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

What Remains<\/strong><\/h2>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=”4.27.6″ _module_preset=”default” custom_padding=”21px||23px|||” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.27.6″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

The Dumbleland Special #011 isn’t an Overdrive Special or a Steel String Singer\u2014it’s something earlier, rawer, and more experimental. The combination of choke-input filtering, a 6550 without ultralinear configuration, a triple-cascaded tone control, a 12BH7 driver, and switchable negative feedback reveals a designer who pushed the boundaries. Some of these ideas reappear in later Dumble designs, while others were discarded.<\/p>\n

For circuit archaeologists, this amp is a treasure trove. For everyone else: one of the rarest models from one of the rarest series in guitar amplifier manufacturing.
And it’s for sale!<\/a><\/strong><\/p>\n

[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"

Dumbleland Special #011 -a technical analysis Howard Alexander Dumble never built anything for a catalog. There was no mass production, no parts lists from the factory, and no sales department. Every amplifier that left his workshop was one-of-a-kind\u2014and most disappeared behind closed doors, into private collections, or onto the unreachable stages of great musicians. Technically, […]<\/p>\n","protected":false},"author":106,"featured_media":249720,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[50],"tags":[],"class_list":["post-249628","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"pp_statuses_selecting_workflow":false,"pp_workflow_action":"current","pp_status_selection":"publish","yoast_head":"\nWelcome to Dumbleland! - %<\/title>\n<meta name=\"description\" content=\"Dumbleland Special #011 is one of about 12 ever built. We traced the entire schematic\u2014here's what we found inside this 1978 Dumble.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Welcome to Dumbleland! - %\" \/>\n<meta property=\"og:description\" content=\"Dumbleland Special #011 is one of about 12 ever built. We traced the entire schematic\u2014here's what we found inside this 1978 Dumble.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\" \/>\n<meta property=\"og:site_name\" content=\"captain-guitar-lounge.com\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/Captain-Guitar-Lounge-140457272682315\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-07-01T06:00:34+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-01T09:24:42+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1024\" \/>\n\t<meta property=\"og:image:height\" content=\"768\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Anselm\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Anselm\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"15 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\"},\"author\":{\"name\":\"Anselm\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/#\/schema\/person\/ad51ad73b611749476de8dfd5f6f1bb8\"},\"headline\":\"Welcome to Dumbleland!\",\"datePublished\":\"2026-07-01T06:00:34+00:00\",\"dateModified\":\"2026-07-01T09:24:42+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\"},\"wordCount\":3113,\"image\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg\",\"articleSection\":[\"News & Stories\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\",\"url\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\",\"name\":\"Welcome to Dumbleland! - %\",\"isPartOf\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg\",\"datePublished\":\"2026-07-01T06:00:34+00:00\",\"dateModified\":\"2026-07-01T09:24:42+00:00\",\"author\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/#\/schema\/person\/ad51ad73b611749476de8dfd5f6f1bb8\"},\"description\":\"Dumbleland Special #011 is one of about 12 ever built. We traced the entire schematic\u2014here's what we found inside this 1978 Dumble.\",\"breadcrumb\":{\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage\",\"url\":\"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg\",\"contentUrl\":\"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg\",\"width\":1024,\"height\":768},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Startseite\",\"item\":\"https:\/\/captain-guitar-lounge.com\/en\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Welcome to Dumbleland!\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/#website\",\"url\":\"https:\/\/captain-guitar-lounge.com\/en\/\",\"name\":\"captain-guitar-lounge.com\",\"description\":\"Fine Amps and Guitars and more\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/captain-guitar-lounge.com\/en\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/captain-guitar-lounge.com\/en\/#\/schema\/person\/ad51ad73b611749476de8dfd5f6f1bb8\",\"name\":\"Anselm\",\"sameAs\":[\"https:\/\/captain-guitar-longe.de\"],\"url\":\"https:\/\/captain-guitar-lounge.com\/en\/author\/anselm\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Welcome to Dumbleland! - %","description":"Dumbleland Special #011 is one of about 12 ever built. We traced the entire schematic\u2014here's what we found inside this 1978 Dumble.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/","og_locale":"en_US","og_type":"article","og_title":"Welcome to Dumbleland! - %","og_description":"Dumbleland Special #011 is one of about 12 ever built. We traced the entire schematic\u2014here's what we found inside this 1978 Dumble.","og_url":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/","og_site_name":"captain-guitar-lounge.com","article_publisher":"https:\/\/www.facebook.com\/Captain-Guitar-Lounge-140457272682315\/","article_published_time":"2026-07-01T06:00:34+00:00","article_modified_time":"2026-07-01T09:24:42+00:00","og_image":[{"width":1024,"height":768,"url":"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg","type":"image\/jpeg"}],"author":"Anselm","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Anselm","Est. reading time":"15 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#article","isPartOf":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/"},"author":{"name":"Anselm","@id":"https:\/\/captain-guitar-lounge.com\/en\/#\/schema\/person\/ad51ad73b611749476de8dfd5f6f1bb8"},"headline":"Welcome to Dumbleland!","datePublished":"2026-07-01T06:00:34+00:00","dateModified":"2026-07-01T09:24:42+00:00","mainEntityOfPage":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/"},"wordCount":3113,"image":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage"},"thumbnailUrl":"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg","articleSection":["News & Stories"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/","url":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/","name":"Welcome to Dumbleland! - %","isPartOf":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/#website"},"primaryImageOfPage":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage"},"image":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage"},"thumbnailUrl":"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg","datePublished":"2026-07-01T06:00:34+00:00","dateModified":"2026-07-01T09:24:42+00:00","author":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/#\/schema\/person\/ad51ad73b611749476de8dfd5f6f1bb8"},"description":"Dumbleland Special #011 is one of about 12 ever built. We traced the entire schematic\u2014here's what we found inside this 1978 Dumble.","breadcrumb":{"@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#primaryimage","url":"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg","contentUrl":"https:\/\/captain-guitar-lounge.com\/wp-content\/uploads\/2026\/06\/Dumbel-Dumbleland-Special.jpg","width":1024,"height":768},{"@type":"BreadcrumbList","@id":"https:\/\/captain-guitar-lounge.com\/en\/2026\/07\/01\/welcome-to-dumbleland\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Startseite","item":"https:\/\/captain-guitar-lounge.com\/en\/"},{"@type":"ListItem","position":2,"name":"Welcome to Dumbleland!"}]},{"@type":"WebSite","@id":"https:\/\/captain-guitar-lounge.com\/en\/#website","url":"https:\/\/captain-guitar-lounge.com\/en\/","name":"captain-guitar-lounge.com","description":"Fine Amps and Guitars and more","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/captain-guitar-lounge.com\/en\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/captain-guitar-lounge.com\/en\/#\/schema\/person\/ad51ad73b611749476de8dfd5f6f1bb8","name":"Anselm","sameAs":["https:\/\/captain-guitar-longe.de"],"url":"https:\/\/captain-guitar-lounge.com\/en\/author\/anselm\/"}]}},"_links":{"self":[{"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/posts\/249628","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/users\/106"}],"replies":[{"embeddable":true,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/comments?post=249628"}],"version-history":[{"count":27,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/posts\/249628\/revisions"}],"predecessor-version":[{"id":251300,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/posts\/249628\/revisions\/251300"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/media\/249720"}],"wp:attachment":[{"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/media?parent=249628"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/categories?post=249628"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/captain-guitar-lounge.com\/en\/wp-json\/wp\/v2\/tags?post=249628"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}