100W SSS Build with Amplified Nation Chassis

[Krinkle]

I joined here years ago and built an Express and never really thought much about the Dumbles until I was poking around earlier this year and realized the difference between the ODS and the SSS. So I modified my 50W SF Fender Bassman, got some good help from the fine people here, and was blown away with the tone I got. My brother took a listen and immediately begged me to build him an amp. I posted asking for the dimensions of the SSS chassis and Taylor from AN was nice enough to sell me the last 2 of his initial chassis design run.

So here goes. Based on what I've picked up from schematics and people here at TAG, the first build will be full 100W build for my brother, the second will hopefully be a full blown 150W build, but if I find that the 100W is perfectly fine for me, I may change my mind. I'll be deviating from the SSS002 schematic that I used to mod my Bassman. The AN chassis has a few extra features due to the fact that Taylor builds a EJ version in them. Off the top of my head the differences will be;

1. Dual bias pots. The holes are there so I'm going to use them. I will be doing a full wave bias as well. I have an idea how to do it. I don't expect Taylor or Funk or anybody who builds for a living to give away the goods but I figure there's tons of people here who probably already know how to do this and can probably correct any mistakes I may have made.

2. Presence control. As of now I have 4k7/390/1uF/2kL pot.

3. Half power. I think I have this one figured out based on a schematic floating around here.

4. CF voltage change. I was about to play around with the voltage on the plates of the CF in the SFBM and see if I could lower it to a "safe" level and see if the tone changed. I say "safe" because I'm not sure that more than 300V on a 12AX7 is really an issue. I know the data sheet says so but there seems to be a lot of people who've had a lot more voltage on there without any issues (so far).

5. DIN connector for footswitch. I want to be able to switch the FET, Reverb and PAB, like the big boys do.

I would also like to clarify some errors on SSS002, and answer some other questions that I have, like the Deep Switch and PAB.

Thankfully the schematics are here in .sch format so I'm working up a complete set before I start building. I've attached some pics of the beautiful chassis Taylor sold me and the schematic of the power amp. The other schematics are almost done, but I don't want to post them until I clean them up some more. Please take a look at the portion of my bias circuit in the schematic and let me know if you see anything wrong. As a matter of fact, if anybody has time please take a look at the whole schematic and let me know what you think.

I'm not going to edit anything, I find that it's confusing for anybody late to the party when things are being discussed and you can't see what the issue was. Please give me a hand along the way here so I can build a killer SSS and share the experience. My hope is this will somehow help anybody coming behind me, just like other people's previous builds help me.

[mhartman]

Sounds like a great plan! Not to be a stickler, but that's actually not an Amplified Nation chassis. That's a chassis that I designed and had fabricated a few years ago. I did sell 5 or 6 of them to Taylor at AN. Good luck with the build!

Mike

[Krinkle]

Sounds like a great plan! Not to be a stickler, but that's actually not an Amplified Nation chassis. That's a chassis that I designed and had fabricated a few years ago. I did sell 5 or 6 of them to Taylor at AN. Good luck with the build!

Mike

Oops, sorry Mike! It's funny because during my search of the internet for pictures to try and help with my build, I found some pictures of a build that I think you did and I thought the chassis looked the same. I just figured Taylor sold one to you like he did me. Thanks for letting me know, I'm sure Taylor just never thought to mention it.

Great job on the chassis, it is fantastic. I'm really looking forward to this build. I just have a few schematic things to sort out as I want to have one that is as accurate as possible before I do the mechanical/electrical layout. I really want to take advantage of some of the improvements that I see like full wave dual bias, etc. Plus I am going to use my modded Bassman as a test bed to try out things that I am not 100% sure on. That way I can give myself the best chance of building and doing minor tweaking as opposed to having a bunch of unknowns and tearing everything apart multiple times.

We have a CNC machine at work that I can sneak time on every blue moon and I plan on drawing the PCBs in AutoCAD, hence my desire to get the topology right the 1st time. I will try to make allowances for tweaking regarding component size and connection. The good thing is that it there are multiple PCBs so I hope to get lucky and get most of them right the 1st time. I'm not worried about the PCB design, I've done that at work many times so I should have a good shot at it regarding human error.

Thanks for the encouragement, I'm pretty excited about it. I'm trying to balance between getting as good and accurate a build as possible, bugging people for info, and sharing info. I hope I can do this without ruffling any feathers. Just to let everybody know, if anybody shares something with me just for the sake of helping me out on this build that they don't want put out into the real world, I feel that I will have to respect that request. All I can commit to is that I will 100% share what I figure out. I think that's fair.

I really appreciate what each and every TAG member has shared so far, I never thought in a million years I would be doing this build. Hopefully this build will generate lots of discussion and great tone.

[mhartman]

No problem man. It will make for a killer build! I'm looking forward to seeing and hearing it!

[Krinkle]

Happy Easter everybody!

Anybody want to talk Dumble grounding, or grounding in general?

Here are my latest schematics, with power supply nodes and grounds included - the letters in circles, big ones for voltages, small ones for grounds. I'm adding as much detail to the schematic as I can think of. I'd like to end up with one that leaves nothing to guessing. I'm getting pretty close to the point where I start laying this out and with the noise I'm getting from my Bassman mod I want to give myself the best chance at a quiet build.

1. Is there a known Dumble grounding style or should I just go with Aiken/traditional grounding, or Larry (Novosibir) grounding? I'm thinking of just building to Aiken's "rules" which make sense to me, but maybe HAD had some genius/diabolical ground scheme as amazing as the rest of his circuitry.

2. The Japanese schematic looks like mostly one big star ground to me a lot of A's and more A-B's. Am I missing something?

3. Are Dumbles inherently quiet (or noisy)? I'm sure the ODS/Humbucker combination is well known but what about SSS/Strat? I've heard some clips on YT and it's hard to tell because of the typical single coil noise.

Anyways, here are my schematics, please give me some input and help me make this an awesome build.

[Krinkle]

I almost forgot, thanks to Martin Manning for the Filter Section idea, I've included it in my schematic and I'll change my Bassman mod soon to see how it sounds. I'm sure it will be great.