The Amp Garage

I built an ODS preamp in a 1590XX enclosure using sub-mini tubes about two years ago and it was well worth the effort. Here's the build thread. . https://i.postimg.cc/sxY35x0G/Mac-Guffin-Pic.jpg A few months later I found a builder in Canada who makes something similar for sale. Here's his site. htt...

Thanks, guys! The sweet spot I've found with this is with the B+ at 210V and about 140V on the plates. That's with a 9V True Tone 1-spot plug. I've got a lead on a 12V plug that I need to order and try. It really needs some stress testing and updates before I'd put any PCBs out into the wild. I wasn...

Way, way beyond my best expectations. Works perfectly. Sounds incredible. No noise. No pops. No heat issues. Running about 140V at the plates. It even works well as a boost/OD pedal into another amp. I've mostly been using it into a Two Notes CAB M cab sim for headphone playing and it sings. Been us...

No personal experience, but Trinity offers a 22W ODS kit with 6V6s.

https://www.trinityamps.com/product/trinity-osd-kit/

There are signs of life. Still waiting for pots, but tubes are working and I'm able to get 170V on plates with 9V one-spot.

alkuz1961 wrote: ↑Sat Jan 30, 2021 8:56 am I am a little surprised by the size of the capacitors. What is their voltage range?

The HV electrolytics are 400V. HV film caps are 250V. The others are at least 50V.

Just waiting for Pots now. Everything else is mounted. Got some heat reflective tape to put between the tubes and PCB. Hope that helps a bit. Also added some pads so I could run bus wire to tie down the tubes to secure them mechanically. https://i.postimg.cc/yd8H3Ct1/Mac-Guffin-Top.jpg https://i.pos...

Ordered some PCBs today. Fingers crossed.

Never really understood the point of that. Running two devices in parallel should reduce noise by 3db, so why not parallel the input triode?

Got a first draft for the PCB layout. The SMPS is together on the tab between the footswitches.

Hello - The T-T Pepper construction looks well thought out. Relatively low operating point for 12AX7, given their power supply outputs 60V. Quite likely tweakable. Here is gutshot of a Kingsley Jester scrapped from TGP. It's presumably a recent one as the power supply is a 555-based pump. Similar i...

Something more like this? That's better ;^) A couple of people have asked about this concept recently, so there will be interest in how it works out. Looking at the data sheet, 6N17P are similar to 12AX7's (mu is lower, though, ~65 where you are operating them), and in my experience the boost conve...

I was going to use .4w MELF SMD resistors for everything, but I'm going to use through-hole resistors for the plates and cathodes so I can use sockets and tweak them as needed. I saw a Marshall conversion on 18Watt where the builder ended up using higher values, going from 100K/1K5 to 220K/3K9. Also...

martin manning wrote: ↑Thu Jan 07, 2021 12:17 pm

jubal81 wrote: ↑Thu Jan 07, 2021 4:04 amI've made a couple tube pedals in the past...

Have you successfully run four cascaded stages plus a buffer without any decoupling?

Ah, good catch!

Something more like this?

cool idea. Personally I'd go with the high plate values or Bluesmaster. #102 for example, a great well balanced amp. Looking forward to following this project. M Still learning about the different versions, so I'll definitely check those out. I'm thinking I'd prefer something on the cleaner side, w...