Help with Hot Rod Deluxe to Mayer-esque Dumble

[jinx1499]

Hey all,
I have recently acquired a Fender Hot Rod Deluxe that I would like to re-purpose to a Mayer type Dumble. I've heard the two rock but actually prefer the Ceriatone Joyful Music more; it seems more open and dynamic. I've seen a few JM 20 "Lunchbox" style heads floating around, so I know it can be done with pretty solid results. I guess my real question is: How can I take the preamp section of the Joyful Music and tweak it to work with my OT, PT, etc of the Hot Rod Deluxe. I'm not sure if the transformers will make a huge difference compared to the original iron but I'm not necessarily looking for a 1:1 clone. Something in the ballpark is fine with me. Just pretend John needed a duplicate of his amp and all you have is the transformers from the Hot Rod Deluxe

Thanks in advance for the help.

[xtian]

How can I take the preamp section of the Joyful Music and tweak it to work with my OT, PT, etc of the Hot Rod Deluxe

Start by posting a schematic, please. Otherwise, we have nothing to comment on! The preamp likely won't need any modification. You just need to be concerned with the rectifier, reservoir caps, bias circuit, etc.

Aren't you going to use the PCB you bought from me?

[jinx1499]

I absolutely am going to use that PCB, I just want to use it for a #183 style amp (still trying to work that out). I bought a 2nd HRD so I could do this project. Here are the resources I have for the JM style amps

This schematic was posted by M Fowler about 4 posts down
https://ampgarage.com/forum/viewtopic.p ... 4&start=15

And this is a layout of the Ceriatone Joyful Music 50
http://www.ceriatone.com/ceriatone/wp-c ... t-2015.jpg

[jinx1499]

Also, this one: the "Wunderbar 50" PDF that Sonny ReVerb posted here:

https://ampgarage.com/forum/viewtopic.p ... &start=105

[pompeiisneaks]

I'm sure xtian will be very helpful on this but basically you've got almost identical topologies between many of the dumble amps, just different component values. You'll need to just assess which components need to be different from the basic one that xtian sold you so you can swap out components etc.

~Phil

[norburybrook]

personally speaking , the reason the JM/SSS amps work is because they are 100w amps....loud clean platforms that take pedals well. a 20w amp just isn't the same thing.



MC

[donvan]

I don't know all of the Hot Rod Deluxe variants but I've seen both 40 and 80 watts. How many watts is yours?

[donvan]

I don't know all of the Hot Rod Deluxe variants but I've seen both 40 and 80 watts. How many watts is yours?

I take that back. It looks like the 80 watt variant is just an extension cabinet.

[pompeiisneaks]

I don't know all of the Hot Rod Deluxe variants but I've seen both 40 and 80 watts. How many watts is yours?

I take that back. It looks like the 80 watt variant is just an extension cabinet.

There is a Hot Rod Deville that is I think 60 watts, and a either a 2x12 or 4x12 cab like a bassman style, that would still be basically the same thing but for the output section.

(real time tangent follows as I googled schematics:)

I'm not really sure why the deluxe is 40W with 2x6l6gc and the deville is 60W with 2x6l6gc? Do they just bias them colder? the schematics show both at +60mV at the cathode resistor (1 ohm) so they're biased at what seems to me to be the same rate?

some googling later:

Oh I see now 485VDC on the deville vs 431 on the deluxe so yeah biasing them hotter by upping the voltage.

I know 6L6's can do 60 watts, but just didn't realize what they were doing...

So yeah, you still only have 2x6l6 and 60 watts, and a bit louder, but probably not "TONS" louder like a 4x6l6 100w amp.

~Phil