Ampeg Reverberocket R-12-R DIY project (installment 2)

chas.wahl

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I've posted this continuation of the discussion begun awhile back in these two threads
as a separate thread, in hopes of not confusing anyone.

Here is my first stab at a layout:

1659548773447.png


and the schematic, in current state:

1659548932063.png


It would have been really hard to develop the schematic without the guiding light of EL34 denizen Sonny Reverb's own DIY layout done a few years ago:

1659549182694.png


The PDFs for the above images are uploaded below.
I have diverged from Sonny Reverb's layout in several ways:
• All filter caps are on the board (no cap can)
• In order to make that work, I've extended the board over the bottom of the laydown PT
• I rotated the circuitry to the right of the power tubes' cathodes resistor 90 degrees, to fit things better and to put the power tube leads on the left, and the PI tube leads on the right.
• I have run all the B+ stuff and its dropping resistors on the lower edge of the board

Along the way, I have added some things to the circuit that are cataloged on the upper right of the schematic. I tried to arrange things to eliminate long under-board runs to the extent possible (despite its being a circuit with some springing ahead and going backwards).

I haven't yet gotten to wiring up all the leads from board to pots, switches, jacks and other panel items; that fun is yet to come. I have drawn all components to true size based on a BOM that I've developed alongside the layout.

I'd be grateful for any recommendations for improvement, warnings and so forth.
 

Attachments

  • Reverberocket-R12R-2022-08-02-layout.pdf
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  • Reverberocket-R12R-2022-08-02-schem.pdf
    429.1 KB · Views: 15
  • Verberwaffe_brd-CWmarkup-reduced.pdf
    2.3 MB · Views: 14
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chas.wahl

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OK, 120-something views and no replies; that's gotta mean something, but I can't figure out what, unless it's disinterest. Undeterred, I have completed a draft with all the off-board circuiting:
Reverberocket-R12R-2022-08-14-layout.jpg


I have, as might be expected, made a few changes/corrections to the schematic and previous layout above, in the course of making this progress. There is a lot of cross-board wiring, and I've dealt with that, in some measure, by taking many of those leads through a hole in the board (connections & soldering being done above the board), with most of the run being run under-board, shown dashed. My plan is to have a head with the chassis on the bottom, board with top side down, the inverse of something like a Fender Blackface era combo. That means that "under-board" wires will actually be laying on the upper side of the board.

Here's a section through the head, to help explain the above graphically:
Reverberocket-R12R-2022-08-14-section.jpg


You may notice that the board is split into two parts, one over the PT bell, mounted higher (actually, lower) with several filter caps on it (left side of the layout), and the other, longer one that contains the bulk of the circuitry and components on the right. The latter is mounted with 3/4" clearance beneath it, and the smaller board has an additional 5/8" to allow the wires from the PT to be routed between the bell and underside of board.

I would appreciate feedback concerning whether the design decisions I've made and described seem reasonable, or not.

I've attached PDFs of the graphics above, plus the current schematic, because the resolution of the JPGs is not great if you try to zoom and read text. The PDFs are much clearer.

In terms of dimensions, the head cab (sides included in layout) is 20" wide and 8-1/4" deep at the bottom. It fits on the top of a Tweed Deluxe size cabinet.
 

Attachments

  • Reverberocket-R12R-2022-08-02-layout.pdf
    100.3 KB · Views: 11
  • Reverberocket-R12R-2022-08-14-section.pdf
    24.6 KB · Views: 7
  • Reverberocket-R12R-2022-08-14-schematic.pdf
    442.1 KB · Views: 9
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solfege

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I'm following with interest (partly b/c this is a dream amp for me) but it's also way beyond my pay grade to comment on. I like the latest complete layout, which I understand better than the earlier ones.
 

chas.wahl

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Thanks for the advice, but I'm inclined to be "old school" where filter caps are concerned. Thought about using a cap can, as Ampeg did BITD, but decided against that too. I like the filter caps lying supine, and situated with the circuit components they serve, to the extent possible.
 

Kevin Wolfe

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I don’t know how I missed this after watching your other threads.
Awesome work. I’m rootin’ for ya, always loved those amps.
 

mk_716

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I watched the last threads and I'm watching this one, please carry on! Came close to building it a couple times...
m.
 

chas.wahl

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I won't be getting to this for a while; sorry if that's a disappointment. I have several projects in the queue ahead of this one (including a major health thing very soon), and need to develop my building skills more before tackling it. I may start gathering parts and the chassis (which will be custom, one-off) though. If I make further revisions to the schematic and layout, I will post them. When I start the actual build, I'll probably start a new thread, including "in previous episodes" info.
 




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