Fender Hot Rod Deluxe/DeVille/Blues Deluxe rescue plan: HRD-to-ODS

[sonicmojo]

I almost want to do it just to do it but I don't even have a donor.....

What Dumble gen is this based on or is it flexible?

[xtian]

I almost want to do it just to do it but I don't even have a donor.....

What Dumble gen is this based on or is it flexible?

Bluesmaster! https://ampgarage.com/forum/viewtopic.php?f=5&t=12875

There is a bit of flexibility: high or low plates, HRM or not, 50 or 100 watts (depending on PT/OT!). Master Volume on the BluesMaster, strangely, precedes the OD. It was an easy mod to move the MV after the OD, like in most ODS amps.

[xtian]

Faceplate arrived, from indcom.graphics:

face1.jpg

face2.jpg

[Guy77]

Awesome face plate! The guys at Indcom are great !
Do you go with the acrylic material that they laser engrave? If so what is that finish it looks shinier than the flat black I usually get?

Thanks

Guy

[xtian]

Yes, this is GravPoly (brand name), and I specify the "brushed" finish, versus the matte one. Cheers!

[sirbergs]

Faceplate arrived, from indcom.graphics:

I didn’t realize you were in Chico. My wife pretty much grew up there. We visit every few years. Great town. Love swimming in Salmon and other holes in the upper park.
She has many Pleasant Valley High stories.


Sent from my iPhone using Tapatalk

[xtian]

UPDATES ON BUILD
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Please see post #1 for BOM, scream-attic, and build notes!

[jinx1499]

Hi All!
Just wondering if anybody had some insight as to how to set up a switch to take the HRM out of the circuit. Also, I'd like to set up the OD EQ for external use. What type of shielded wire should I use to keep noise to a minimum?

Thanks in advance and special thanks to Aaron for helping design the board and for all the answers to my questions so far!!

[xtian]

Jason, you have the schematic from post #1? See relay K4, which is set up to lift the HRM tone stack when energized.

[jinx1499]

Awesome...now how do I add an external switch to toggle that?

[xtian]

In this version of the PCB, The HRM tone stack was designed to "lift" in unison with the preamp tone stack, IFF P9 (the PAB_ALT swtich) is shorted.

To answer your question, if you want to add a SPST switch that lifts the HRM tone stack only, that's easy. Omit relay K4, replace D11 with a 10K resistor. Finally, remove R75, and the two solder pads for R75 become your switching points for the SPST switch: open means tone stack is lifted, closed means tone stack is in-line.

[jinx1499]

Perfect, thanks for that! Any thoughts on the 3 core shielded wire I should pick up for the trim pots?

[xtian]

Perfect, thanks for that! Any thoughts on the 3 core shielded wire I should pick up for the trim pots?

Well, you might use star-quad cable, like this:

https://www.markertek.com/product/l-4e6 ... foot-black

but the tricky thing is, your wire from the plate of the preceding triode is going to have ~200vDC on it, presuming you have the whole HRM tone stack removed to a remote board. Maybe no issue.

[jinx1499]

Yikes. I was just planning on running wire as basically an "extension" from the PCB. Guess it's not that easy, huh?

[xtian]

Yikes. I was just planning on running wire as basically an "extension" from the PCB. Guess it's not that easy, huh?

It may turn out to be just that easy, three wires: input, output, ground. Just be aware you've got ~200vDC on the input wire.