What’s on *YOUR* workbench?

kerryfine said:
Found nothing on this forum about the Tortenmann TA-100 germanium overdrive so wanted to share this great circuit! Breadboarded it this week and it’s going to be my next build now. It thickens up my Boogie Mark V90 3rd channel into Rectifier territory! But also has really nice lower gain drive sounds on tap if that’s your thing.

Uses 3 PNP germanium transistors in a negative ground format. Sounds excellent, good amount of crunchy gain on tap and adds nice girth to already overdriven channels.

Tested some different diode combinations (not extensively yet, just what was on my little diode DIP switch board) and my favorite was asymmetric clipping with MOSFET (2N7000) + Ge (1N34) on one side and 1N4148 on the other.

Used Toshiba 2SA478 with hfe in the 70-100 range with low leakage <120. But also didn’t mess around with leakage very much.

Give this one a go if you have some spare PNP Germs!
Some sound demos below:
1. Clean channel: bypassed then engaged with 75% gain
2. Dirty channel: bypassed then engaged, adds girth to the chugs

Click to expand...
Im soo gonna do a board for this! I love the demos and i have tons of PNPs that i havent used yet. I like that its a negative ground circuit using PNPs! Thank you for bringing this to the forums attention!
 
Last edited:
steviejr92 said:
Im soo gonna do a board for this! I love the demos and i have tons of PNPs that i havent used yet. I like that its a negative ground circuit using PNPs! Thank you for bringing this to the forums attention!
Click to expand...
Sweet! Enjoy, there is a perf board layout out there if you google search the circuit.
 
steviejr92 said:
Im soo gonna do a board for this! I love the demos and i have tons of PNPs that i havent used yet. I like that its a negative ground circuit using PNPs! Thank you for bringing this to the forums attention!
Click to expand...
I would definitely be interested in a board! I did find a veroboard layout here http://dirtboxlayouts.blogspot.com/2023/10/tortenmann-ta-100.html but I do prefer PCB's.

Edit: That layout is pretty nice though, and quite a bit less offboard wiring than most pedals.
 
Here’s the perf layout I found from Effectslayouts
effectslayouts.blogspot.com

Tortenmann TA-100

Came across the schematic for this and thought it would be a good addition. It's a unique germanium overdrive using PNP AC128s, though the e...
effectslayouts.blogspot.com effectslayouts.blogspot.com
 

Attachments

  • IMG_2089.png
    IMG_2089.png
    1.2 MB · Views: 5
kerryfine said:
Comeonnnn have some fun with perf board! Haha 😂 it makes the build take a little longer than 10 minutes to prolong the enjoyment!
Click to expand...
Ahh, but you see, I don't have any perf board! Maybe I should get some, I think you can just solder the pots into it directly? Which is a plus for me.
 
Cool! TA-100!
Good to see some interest in the Torte!

I've got the ELS "Hundo" PCB sitting on ice, long awaiting its turn under the solder iron.

On my computer I've got the ELS drill-template and the schematic for it, but not the build doc.
The Wayback Machine doesn't have a record of the Hundo either. 🤔

[rummaging ensues…]

I'd think I was imagining it, if it weren't for the fact that I'm holding it in my hand...

71234A44-652D-484B-B10B-B6C5A710B186.jpeg
 
Paradox916 said:
confirmed the Klein Bottle pcb and components.. just need to order the enclosure nowView attachment 79243
Click to expand...
May The Force Be With You |Team-Building Star Wars Game | The Go Game
 
I finally got around to fixing the intermittent LCD screen on this MOTU interface that I traded a rarely used DIY bass cab for:

Motu 828X.jpg

Just needed some solder reflow on one side of the display, but it took a while to find the magic button.

And then I decided to play with using it as a standalone mixer for home practice with a mic. It has separate seven band PEQs on every input and output channel, plus an OK reverb and really good per-channel compressors and limiters. The menu driven faders would be a bit wonky for live use, but it sounds great and could function fine for solo or duo coffeehouse gigs and the like. Since it's in a 3RU EFX rack I next patched in my ancient Lexicon MPX550, which somehow works much better with the MOTU than it ever did with my very nice Crest mixer. Much better than the onboard verb in the MOTU too. I was ready to give away the Lexicon before I tried this, but nope.

And then the rabbit hole of MOTU stuff running on Windows. So many horror stories, and I don't want to get too cocky just yet, but last night I had it running happily at 2.7ms latency with a couple of very resource hungry plugins. Not all that easy to get there, but I'm stubborn and totally up to hacking the registry and doing whatever else it takes if it keeps me from having to buy new hardware. :cool:
 
Last edited:
Silver Blues said:
The MOTU stuff is great IME, especially hardware wise - I run one on Windows and thankfully haven't had any issues. 🤞
Click to expand...
The 828x design is a decade old and it definitely took some determined tweaking to get it working right on my new Win11 PC, but as I said I'm OK with that and it does sound really great. I'll probably pick up one of the M series units for my iPad sooner than later too, which was my plan for the PC before this rack mount one fell into my lap. Way more features than I actually need, but WTH.
 
I’d like to get a Motu. A lot of their ad/da interfaces have DC-coupled outputs, and at a decent price compared to other options. Then I can automate CV signals and send them directly to my modular synth.
Passinwind said:
doing whatever else it takes if it keeps me from having to buy new hardware.
Click to expand...
Annd that’s why I don’t have one yet. My 2010 mac mini and 2008 Apogee Duet just won’t kick the bucket!

I say that, but also “please continue working for the duration of this album project.” :D
 
You must log in or register to reply here.
Back
Top