Pictures!

[vigilante397]

Well I promised I would do this a while ago, and I finally got it boxed up: Mesa Boogie Dual Rectifier preamp with three 6N21B tubes in a 1590B enclosure. It took some tweaking to get it to stop overheating, but I finally got it going reliably and it sounds soooooooo gooooooood





And super messy gutshots:

[bloxstompboxes]

Well I promised I would do this a while ago, and I finally got it boxed up: Mesa Boogie Dual Rectifier preamp with three 6N21B tubes in a 1590B enclosure. It took some tweaking to get it to stop overheating, but I finally got it going reliably and it sounds soooooooo gooooooood





And super messy gutshots:

Hey Nate, where did those knobs come from? I am looking for some replacement aluminum knobs for a vintage 70s stereo receiver. They want like $20 a piece on ebay for the originals. Yeah.. right. They would have to be pretty big though, and have one even bigger for the tuner knob.

Cool pedal by the way!

[vigilante397]

Hey Nate, where did those knobs come from? I am looking for some replacement aluminum knobs for a vintage 70s stereo receiver. They want like $20 a piece on ebay for the originals. Yeah.. right. They would have to be pretty big though, and have one even bigger for the tuner knob.

Cool pedal by the way!

Thanks! The knobs came from Bitches Love My Switches, he calls them "The Skinny." They're a little pricey as pedal knobs go ($1.50 or so) but I love them. Solid aluminum, fit in tight spaces, and available in silver or black I think Smallbear has a bigger selection of aluminum knobs, but BLMS has a pretty good spread, and they're significantly closer to me georgraphically.

[temol]

Hey Nathan,

you know you have to post some noise from the preamp...

T.

[vigilante397]

Hey Nathan,

you know you have to post some noise from the preamp...

T.

I know I finished it after my kids were in bed last night, I'm planning on throwing together a quick demo when I get home from work today.

[rankot]

Well I promised I would do this a while ago, and I finally got it boxed up: Mesa Boogie Dual Rectifier preamp with three 6N21B tubes in a 1590B enclosure. It took some tweaking to get it to stop overheating, but I finally got it going reliably and it sounds soooooooo gooooooood

Is it some kind of pre-made dc booster? I've recently bough few from China, 24 and ±15V, they work fine and are really cheap!

[vigilante397]

Is it some kind of pre-made dc booster?

Nope, I designed it myself I was looking for a more efficient way to get 6.3V to the heaters, so I designed a little buck circuit using the Linear ADP2300. I designed it the day after this board went to fab, so I made a little daughter board and had a couple made at OSHPark, but now that I've confirmed it works I've just been designing it into my new builds Unfortunately it can only handle heaters for two tubes, so the third is heated with a 7806 mounted to the box next to the footswitch.

[thomasha]

WOw another awesome tube pedal, now you can start with the tiny amps...

I'm working on a mesa boogie too, but it only uses battery tubes (5678, 5672). Almost no tube glow, but no heat at all.

How high is your B+? I built a JCM clone a long time ago with four of these russian tubes and it gets pretty hot.

[Marcos - Munky]

And super messy gutshots:

Still didn't found the "messy" part

[vigilante397]

How high is your B+? I built a JCM clone a long time ago with four of these russian tubes and it gets pretty hot.

For subminis I usually use a B+ of 200V. Before I consider a new design "finished" I like to run it for three hours straight to make sure it will last the duration of a reasonable gig. After three hours this one was warm for sure, but still handleable. The new design will use an additional switcher instead of a linear for the third tube heater, so that should help even more with the heat.

[vigilante397]

Just finished throwing together a quick demo for the preamp, featuring a guest appearance by my daughter.

[rankot]

Is it some kind of pre-made dc booster?

Nope, I designed it myself I was looking for a more efficient way to get 6.3V to the heaters, so I designed a little buck circuit using the Linear ADP2300. I designed it the day after this board went to fab, so I made a little daughter board and had a couple made at OSHPark, but now that I've confirmed it works I've just been designing it into my new builds Unfortunately it can only handle heaters for two tubes, so the third is heated with a 7806 mounted to the box next to the footswitch.

Why not using simple voltage drop resistors for heaters?

[vigilante397]

Why not using simple voltage drop resistors for heaters?

Efficiency Using resistors means you have a large, hot resistor. Using a linear supply means you have a large, hot linear regulator. Using a 92% efficient heater means that if your load takes 300mA at 6.3V, instead of pulling 300mA from your 9V, you're only pulling 228mA from your 9V supply. So with this setup, instead of losing 3W to heat, I'm losing 1.2W to heat, and as soon as I get the redesigned boards back that number will drop to 0.3W 

[DaveLT]

So I want to make ROG's Big daddy but I feel their perfboard layout is a bit too wasteful and my perfboard works best not trying to bridge solder so... very tiny board once I cut off the excess 

[ElectricDruid]

Just finished throwing together a quick demo for the preamp, featuring a guest appearance by my daughter.

Love it. It's like a mini-moshpit round at your house, isn't it?!

[bean]

My eyes were a bit bigger than my stomach on this one. It's a DM-2 with modulation using one of the smallbear dual-concentric pots for the rate and depth controls. I intended for it to go in a 1590B but I only had bare 1550B for etching. But, they're almost the same size. The modulation board is tucked under the main one. I haven't checked for LFO ticking yet so I may need to put some kind of shield between it and the audio board.

[bluebunny]

Here's a couple more from the Bunnylab production line, both runoffgroove.com designs.  First is the Britannia overdrive (1776 board), followed by the Tri-Vibe (TH Custom).

[vigilante397]

So a few years ago I saw a demo for the Matchless Hotbox and I knew I had to have one. I tried to build one a couple years ago and failed miserably (and expensively). Now that I have more of a grasp of what I'm doing I gave it another go, and succeeded It sounds every bit like it should, and it's going straight on my board as my new go-to dirt box.



When I was doing the layout I couldn't find a good place for the LEDs so I tried mounting them behind the tubes, and I kind of dig the look it gives. Blue LEDs are for clean channel, red LEDs are for drive channel.



And here's a gutshot for anyone that was curious. I wasn't sure if I wanted the Channel switch to be a toggle or a footswitch, so as you can see I left provision for either

[deadastronaut]

^ awesome....love it, especially the red....

[diffeq]

both runoffgroove.com designs.  First is the Britannia overdrive (1776 board), followed by the Tri-Vibe (TH Custom).

Groovy. 
Nice builds!.