plotting out deluxe rvb with some dumble bits

[martin manning]

-The 47k in "clean" tonestack. Is this to mitigate the PAB jump? Isn't it just similar to having a big mid pot in there? 72k to ground? So it would be a mid boost of sorts, as opposed to a full bypass of tone controls?

Correct. You can adjust that to taste. above 100k is pretty much a full lift.

-They seem to both work, but is there a reason you changed the wipers on the clean/OD switch? My wipers were "in" and "out" . It seems that they are all doing the same thing, but perhaps there is a functional reason you routed them this way?

Same thing.

-I'm a bit confused by how you are doing the "OD master". Is ground coming from wiper of 100k trim, high coming from wiper of "drive" and the wiper going to the connection of C12 and the high side of the treble pot?

Sorry those little flags (OD1g and OD2) are just there so I can plot the signal traces by name. Ignore them. ODOut is the one that goes to the OD relay. There is only one master, which controls the preamp output regardless of whether it comes from the clean or OD. OD Drive is the only other distortion control, but you can set the OD entrance trimmer to set the range of distortion you want.

-the 10u is similar to what I've done in other amps, though I split it to a couple of small(4.7uf) early and then standard 22uF later in circuit.

You can play with the cathode cap values of course, I just went with the Bluesmaster OD values.

On the bias, the circuit in the snip and in your schematic are the same, fail-safe type.

[imo1]

-The 47k in "clean" tonestack. Is this to mitigate the PAB jump? Isn't it just similar to having a big mid pot in there? 72k to ground? So it would be a mid boost of sorts, as opposed to a full bypass of tone controls?

Correct. You can adjust that to taste. above 100k is pretty much a full lift.

-They seem to both work, but is there a reason you changed the wipers on the clean/OD switch? My wipers were "in" and "out" . It seems that they are all doing the same thing, but perhaps there is a functional reason you routed them this way?

Same thing.

-I'm a bit confused by how you are doing the "OD master". Is ground coming from wiper of 100k trim, high coming from wiper of "drive" and the wiper going to the connection of C12 and the high side of the treble pot?

Sorry those little flags (OD1g and OD2) are just there so I can plot the signal traces by name. Ignore them. ODOut is the one that goes to the OD relay. There is only one master, which controls the preamp output regardless of whether it comes from the clean or OD. OD Drive is the only other distortion control, but you can set the OD entrance trimmer to set the range of distortion you want.

-the 10u is similar to what I've done in other amps, though I split it to a couple of small(4.7uf) early and then standard 22uF later in circuit.

You can play with the cathode cap values of course, I just went with the Bluesmaster OD values.

On the bias, the circuit in the snip and in your schematic are the same, fail-safe type.

Im unsure of how to break up the quotes..Sorry!
-That is cool on the PAB. I could do a 100k pot and figure out how best to implement it with my circuit. Noted!

-My only question on the "master" implementation is: wouldn't it be better to put it at the end of the OD section? I am assuming that the clean channel will be set as I need it and then I could use "drive" and level" of OD in a similar manner to a pedal, and that would have an effect on how the gain works. Since its a single channel amp with a switchable gain stage, I don't see the reason for the master there. I tend to like how Fender amps balance out naturally in terms of pre amp and power amp gain. I'm imagining that I find a really nice base sound that is "the sound" of the amp" and then work on making the OD section bring that out more of that sound, where it naturally sculpts the eq and the eq of the gain, I can find the best of it.

I'm feeling pretty close, at least in theory to what I want to build. I really appreciate you(and Ian) taking the time to share your thoughts and knowledge!

[imo1]

Out of curiosity, are the last components of the preamp you sent meant to emulate the tremolo section of the amp?

I'm also curious, is there a way to hear what the "master" would do there and also hear what the circuit would sound like without it?

The original deluxe schematic only has that 220k in line with the PI tube. What do those components do to the signal pre PI? Is it meant to dump some signal?

I know I'm dancing ahead a bit, but I am imagining an amp that does all the stuff I like about a Deluxe, but with a bit more low end clarity and power. I want to keep as much of that quality, as least as a starting point. There is a thing that Fenders do that I love around 6-7 on many of them where they get a really unique bite. I have noticed that many of the players that play Dumble style amps have a little bit of a different take on "cleans" that is a much cleaner sound but doesn't work for the rhythm/lead playing as well.

[martin manning]

-That is cool on the PAB. I could do a 100k pot and figure out how best to implement it with my circuit. Noted!

Some people have installed a trimmer hanging off the Mid pot to do just that, preserving the ability to adjust it in the future.

Out of curiosity, are the last components of the preamp you sent meant to emulate the tremolo section of the amp?

Yes, the resistor R32 labeled LDR is the trem's light dependent resistor.

I'm also curious, is there a way to hear what the "master" would do there and also hear what the circuit would sound like without it?

Circuit simulators generally show frequency response and waveforms, which is in a way hearing (by seeing) what is happening. It is possible to generate a large output file, convert it to WAV, and actually listen to it, but I have not tried that. The arrangement I'm showing is like the second gen ODS. The next iteration was to keep the master at the PI input, but add an OD output level control. I can try moving the master to the OD output and see how that works with different clean volume and OD drive settings. As you can imagine, the number of cases to look at starts to get big.

The original deluxe schematic only has that 220k in line with the PI tube. What do those components do to the signal pre PI? Is it meant to dump some signal?

The two 220k's following are a level adjustment going into the PI. They are placeholders to some degree, but the idea is you don't want to overdrive the PI.

I know I'm dancing ahead a bit, but I am imagining an amp that does all the stuff I like about a Deluxe, but with a bit more low end clarity and power. I want to keep as much of that quality, as least as a starting point. There is a thing that Fenders do that I love around 6-7 on many of them where they get a really unique bite. I have noticed that many of the players that play Dumble style amps have a little bit of a different take on "cleans" that is a much cleaner sound but doesn't work for the rhythm/lead playing as well.

Keeping the clean preamp and reverb true to the Deluxe, with the power supply changes you mention should get you what you are wanting. The OD section and cascading is all Dumble, and should produce something similar to the ODS HRM sound, with the difference being that the clean preamp is Fender DR.

[imo1]

The original deluxe schematic only has that 220k in line with the PI tube. What do those components do to the signal pre PI? Is it meant to dump some signal?

The two 220k's following are a level adjustment going into the PI. They are placeholders to some degree, but the idea is you don't want to overdrive the PI.

In theory though, shouldn't the clean deluxe side, without the OD engaged, be hitting the PI with the correct level(at least what Fender plotted in design) with just the 220k mixing resistor? If I don't do the master, instead putting it in OD section as I drew it, it would simply be the mixing resistor into PI? I probably will mess with dumping some signal there, and understand why it is there as a placeholder. I just want to do everything I can to preserve as much of the Deluxe circuit in terms of pre/power gain balance as I can. I was thinking that the level control in the OD section would allow me to find a sweet spot that drives PI in a good way but can attenuate as well, avoiding more of the blocking distortion

[martin manning]

In theory though, shouldn't the clean deluxe side, without the OD engaged, be hitting the PI with the correct level(at least what Fender plotted in design) with just the 220k mixing resistor?

To replicate the DR, it should actually be going through a 220k with a 320k going to ground, since in the DR the other 220k mixing resistor is a path to AC ground (B+) via the 100k plate resistor of the other channel's second stage.

[imo1]

In theory though, shouldn't the clean deluxe side, without the OD engaged, be hitting the PI with the correct level(at least what Fender plotted in design) with just the 220k mixing resistor?

To replicate the DR, it should actually be going through a 220k with a 320k going to ground, since in the DR the other 220k mixing resistor is a path to AC ground (B+) via the 100k plate resistor of the other channel's second stage.

Ah! Thanks for explaining that! I know that intellectually, but i never see it when I look at a circuit. That makes sense.

I don't know if you remember, but you were advising me on a similar issue a couple of years ago when I built my kid a single channel DR. I figured out that the PI was getting hammered, but mainly put it down to not having the additional channel resistance and pull on the circuit. I didn't clearly see that as I initially had it, there wasn't the same circuit dump pre PI as there typically was in a DR

[BarryW]

just wanted to chime in - consider grabbing an individual chassis from zachmdhunter on eBay if you haven't already ordered from mojo. That allows you to get your other pieces individually. I sent you a PM. Great discussion, thanks for the input from everybody, especially Martin and the other Ian. Amazing resources here on TAG that I've learned so much from! thank you all.

[martin manning]

Looks like zachmdhunter a selling a Mojo chassis and faceplates. A way to get the Mojo kit without the transformers would be to buy the chassis and small parts kit from them, but everything is a compromise. I would have no use for the carbon comp resistors, for example.

[imo1]

I actually am returning the transformers for future credit. I get a discount on their stuff, and for what I’m needing to do, it’s a no brainer. Wood and metal work take up so much time and I need to get this up and running(and great sounding!) in just a couple of weeks.

And yes, I totally agree! There are so many amazing folks here so willing to share their knowledge and experience!

[imo1]

In the name of trying to be more thorough with my process, I jumped in gallantly to creating a layout.
I used DIYLC rarely, so I'm pretty clunky with it.

Anyway, it took me forever, but I finally got something..Was gonna submit it and it was too big! My intention was to plot out the deluxe layout and see what I needed to add to the board, so I was using the full dimensions, which go beyond the printable, and shareable bounds.

So. I can see it, but unless I shrink it down, can't share it.

I have a question regarding the relays. I'm using the hoffman boards. 5v relay, which i'll be powering off of the unused 5v rails.
Hoffman suggests using the negative line from the relay to switch them on and off. I'm wanting to run both 'PAB' and 'OD' to switches and then a dual footswitch, though a 5 pin DIN connector. He says not to ground the relay negative to chassis, but if I switch that way, on my PAB, the circuit works by attaching to ground. If i use the power rails unconnected, but one of the signals grounds, would this affect the power rails, or am I getting confused?

Honestly, the relays, and their integration always confuse me!

[imo1]

I would like to share the layout once I get it up and working, as I think it will be a good, usable design that would work for a lot of players due to volume and accessibility of parts

[martin manning]

I would wire the relays exactly as shown in the Dumble ODS layouts. The only difference is that you will be running an unregulated DC supply.

[imo1]

OK. I figured out how to shrink it. I couldn't find the preference for a couple of days. It is really hard doing this while touring! Apologize for the lack of clarity on my part.
Here is where I am. The power is a bit unfinished, but I was mainly trying to figure out how to use the existing deluxe board and where I needed to add.
I couldn't figure out a way to make a DIN connector so I just used a switch for the layout.

deluxe_blues.png

Let me know if any obvious errors pop out. I know its probably not the best layout, but I'm just glad to have a reference!

[imo1]

@martinmanning
I am going to implement your grounding scheme on this Deluxe. I was re-reading that thread, and you mentioned testing power supply before hooking up the component board. Do you do this with approx resistors to emulate tube load? Ive typically checked PT and power cap/resistor network for proper voltages, but they are obviously quite a bit higher without the load. I tried to ballpark them by estimating current consumption of circuit, and I anticipate some switching of resistors to get me where I need to be, but hoping to be efficient with this process and would love any suggestions on best practice here.