Well, I gone and done it! in Austria when you have a child, you get four weeks off as a father to stay home and help out.
Since our new son came into the world at the beginning of November, I’ve had some time off, and decided to finally throw together a 45 amp, without all the bells and whistles that I normally would use. There’s no Coleman regulators, no fancy, expensive output transformers, no solid state help.
It’s relatively simple, AC heating, a 6SL7, and only parts that I had in the junk box. I think it turned out great, I’m really impressed, I had never actually tried AC heating in all my years of building….
I was going for that 1950s industrial look.😎🤞🏻
Since our new son came into the world at the beginning of November, I’ve had some time off, and decided to finally throw together a 45 amp, without all the bells and whistles that I normally would use. There’s no Coleman regulators, no fancy, expensive output transformers, no solid state help.
It’s relatively simple, AC heating, a 6SL7, and only parts that I had in the junk box. I think it turned out great, I’m really impressed, I had never actually tried AC heating in all my years of building….
I was going for that 1950s industrial look.😎🤞🏻
Attachments
I got lucky and scored a box of 150 original cinch tag strips on eprey…. So I used them generously. I normally only use the ceramic tag strips from Techtronics, but I didn’t want to waste them on a scrap box build.
I want to thank kmaier for inspiration, and for his budget 45 schematic, even though I didn’t use a 12at7, I did use his hum pot method.
So far, I’m really impressed with this little amp, it always seems that sometimes even the cheapest parts can come together to form something greater than the sum of its individual parts🙌🏻
I want to thank kmaier for inspiration, and for his budget 45 schematic, even though I didn’t use a 12at7, I did use his hum pot method.
So far, I’m really impressed with this little amp, it always seems that sometimes even the cheapest parts can come together to form something greater than the sum of its individual parts🙌🏻
Very Tidy build! So much space in that chassis - a luxury indeed. Hope you also spent quality time with your partner and baby! 😉
Oh, I only work on amps after around 9:30 in the evening when the kids are in bed, and the wife is comfortably on the sofa. But not every night, some nights are reserved for adult time watching some of our favorite shows together. It’s important to still take time Together, especially with young children at home, adult conversation and just time alone together is worth it weight in gold !
I’m always amazed how much space you really need in a chassis. I have a rule of thumb, decide how big you need it to be, and then buy the next size larger.😂
I find it so much easier to avoid problems with hum and other things, if you have a bit of extra space. Plus those poly caps aren’t exactly small.
I find it so much easier to avoid problems with hum and other things, if you have a bit of extra space. Plus those poly caps aren’t exactly small.
Nice build!
I’m jealous of the parts you had sitting around in a box 🙂
Just finishing up a 45 build as well. Notice you are using the Tamradio iron from a Sony TC500A. Supposed to be well regarded output transformers.
I picked up a Sony specifically for the Coral Holey Basket drivers. Wanted to see what they sounded like. I hadn’t considered the iron the the unit. They were a bonus which I too am using in my build.
Having space in a chassis is indeed a nice thing to have. Mine is a bit on the small side, and real estate is limited. Made for some challenges positioning the iron in such a way as to minimise their interactions with each other.
I’m using a 6SN7 as a driver, and a 5U4G as a rectifier.
Wondering if you might post the schematic? Curious to see what the differences is between the one you are using and the Craigtone/Korneff I’m using.
Enjoy the amp, and the new addition to your family!!!
I’m jealous of the parts you had sitting around in a box 🙂
Just finishing up a 45 build as well. Notice you are using the Tamradio iron from a Sony TC500A. Supposed to be well regarded output transformers.
I picked up a Sony specifically for the Coral Holey Basket drivers. Wanted to see what they sounded like. I hadn’t considered the iron the the unit. They were a bonus which I too am using in my build.
Having space in a chassis is indeed a nice thing to have. Mine is a bit on the small side, and real estate is limited. Made for some challenges positioning the iron in such a way as to minimise their interactions with each other.
I’m using a 6SN7 as a driver, and a 5U4G as a rectifier.
Wondering if you might post the schematic? Curious to see what the differences is between the one you are using and the Craigtone/Korneff I’m using.
Enjoy the amp, and the new addition to your family!!!
Thank you very much, yes I’m very happy with it. Those transformers are OK, that’s about it. They’re not exactly hi-fi. But if you can get them cheap, they’re definitely nice for a budget. I had a look at that schematic you referenced, not really a winner there. There’s not enough gain in the circuit, and all those fancy audio file resistors, and capacitors labeled, yeah, that’s not for me.
I used a 6SL7 running at 2 mA per side, the 45 tubes are running from a B+ of 345, from a 6CA4 rectifier .the B+ for the driver comes from a pair of UF 4007, for a B+ of 400 V. Driver needs a higher B+ to provide enough swing to drive the 45.
I’ll drop a schematic tonight, and post it. I saw your thread with the amp you are building, it looks great so far, but I would definitely recommend something different than the driver that it uses, you just need more gain.
I used a 6SL7 running at 2 mA per side, the 45 tubes are running from a B+ of 345, from a 6CA4 rectifier .the B+ for the driver comes from a pair of UF 4007, for a B+ of 400 V. Driver needs a higher B+ to provide enough swing to drive the 45.
I’ll drop a schematic tonight, and post it. I saw your thread with the amp you are building, it looks great so far, but I would definitely recommend something different than the driver that it uses, you just need more gain.
That power transformer only has 300 V available, with a 5U4, your B+ is going to be pretty low……
I actually have too much B+. Had to drop it down from 455V
I did a fair bit of research on schematics, and this was the one I found that seemed to get some good reviews. The Korneff is well regarded.
Contemplated doing the Yamamoto A08, but wanted a simpler circuit.
Look forward to seeing what you based yours on.
I did a fair bit of research on schematics, and this was the one I found that seemed to get some good reviews. The Korneff is well regarded.
Contemplated doing the Yamamoto A08, but wanted a simpler circuit.
Look forward to seeing what you based yours on.
How in the world are you getting 455V B+ from a 300V winding with a 5u4gb?
Is that unloaded?