Hello from Italy

[rendoman]

Hi! I'm Stefano, from Italy
I discovered this forum while searching info about threading tools for lathe, it looks so good!

I'm a newbie compared to you, it's little time that I practice diy, mostly self-taught, that's why i'm searching info
I got passions like: motorbikes ( still prefer 2 stroke ) , big horn speakers, tube amplifiers with handmade output transformers and guns (western, big game rifle and pistol and other tactical stuffs)
I post a couple of photos of my recents projects.
Saluti
Stefano

[Paul Jones]

Stefano,
The projects with tube amplifiers with handmade output transformers sound very interesting.
Looking forward to seeing some your projects,
Paul

[rendoman]

Thanks Paul!
Unfortunately i experienced circuit and amp many years ago (I started 15 years ago +/-), i lost the photos taken with the old phone. I got some pics of my current setup, a link below of my first hybrid amplifier with ecc83 and bu508af and my good and unlucky 2a3.

Brief introduction, i tried circuit with almost all the "audio" tube, i was fascinated by high efficency fullrange speaker and low power amp. My first diy speaker was 94db\w\m (fullrange) , the second 3 way with onken 360L enclosure 15" eminence , driver rcf and tweeter apt, the current setup is a mix between onken sub, big Fr double horn, supetweeter, i will add a driver 1" with new horn i have to built on lathe.

i tried in the past the classic el84, 6v6 el34 - kt88 and others similar.
after many test i still prefer:
-amp with no negative feedback taken from output (or very moderate in some cases), in my opinion they sound better in the range of voice
-triode connection instead of pentode

I decided to try direct heated tube like 2a3 and 45, with 6sn7 single ended driver and 83 mercury vapor rectifier with 2 chokes and good capacity enough to silence the sound of power supply. at that time i buyed a couple of output transformer (plus psupply and choke) from Novarria at Milano. "Low priced" 15w rated 16sections and double C core 20hz/20khz, in my opinion nice to look but not to listen
After this i tried the tiny Ecl 82 amp "Lo scherzo" of Chiomenti

Scherzo

100va power transformer, 2 chokes (i want to modify the ps with gas tube like 0a2, 5651 and maybe a tube regulator circuit) and for the first time i made the output xformer. 60H of primary inductance, 5k, 20hz fq min, really hand made each coil ,flat, teflon insulated. The good thing is that this little amp capable of 1,6w in triode connection sounds much better (above all in the 30\500hz) than the 2a3, much better than i sold the dht and i kept the little monster

Now i got this ecl82 as primary amp, with 110db\w\m speaker i dont need more than 0,5w in normal use, the gainclone inverted lm3886tf for sub, and a cheap chinese board (i'm testing it) with ta 2024 chip for +13khz tweeter.

next project i suppose i have to make a good enclosure for the amp, as you can see in the photo the construction is really ugly, i have to modify power supply and other stuff. I'd like to build again a dht triode with diy output, but it's only for passion, i think this setup is very good!

Amplificatore ella costruito da Stefano

schematic here :

ELLA

[Paul Jones]

Thanks Stefano and very cool. I can see you will have many projects to share and share your insight. My experience with audio tube-based amplifiers is limited to a stereo preamp and stereo amplifier kits from Lafayette Radio Electronics. I built these for my parents in 1965 while in high school. The set work very well for many years and and nothing blew if you shorted the speaker wires.
Thank you for the information, Paul

[kbalch]

Hi Stefano,

Welcome!

Very cool stuff, indeed! The details of your electronics work are entirely over my head, but it looks fascinating and very well-done. Thanks for sharing! Let's see more…

What's next on your project list?

Ken

[rendoman]

Thanks Ken!
one of my next projects is a couple of horn made on lathe from a solid 130mm ( +/- 5" ) round bar of aluminum. the drawing i made is a bit old, i want to change something in the back flange that links the horn and the driver, close to tweeter horn in the first post. (rcf 1" nd1710, titanium diaphragm).
I have to create some good threading internal tool for lathe and learn how to use properly, i was looking for some project in this forum, according to you what's the best (and easy to make) tool? i'm not a boss at grinding

[kbalch]

Have you seen these?

Internal Threading Tools

If you post a note in our Help Me Build subforum, you're sure to receive some useful input.

Please keep us apprised of your progress…

Ken