Vacuum Tube (Thermionic Valve) Fun!

[MarioMaster]

Thanks for the info on that -- I wonder if I could put in some kind of time delay on the amp design.

Use these for authenticity

2 ea Ampertite Time Delay Relay 115N105 | eBay

 

[Sigurthr]

Hehe, only the fancy items had built in time delay relays! The rest of us had to flick the heater switch and wait before flipping the anode switch!

 

[DashApple]

Not sure if I posted this before ,

I made a headphone hybrid Tube / Semiconductor amp along with my own PCB layout and board .

IMG_0402[1] by TwirlyWhirly555, on Flickr

IMG_0400[1] by TwirlyWhirly555, on Flickr

Runs from 12V , tube provides voltage gain and a mosfet and regulator in CC provide the current gain .

 

[Sigurthr]

I remember you mentioning it but not a photo, nice work! Is that a dual pentode?

 

[DashApple]

I remember you mentioning it but not a photo, nice work! Is that a dual pentode?

Tube is a dual triode used in preamps , 12AU7

 

[DashApple]

Made another one in a metal case this time , supply is 12V from 3 LiPo's

IMG_0821[1] by TwirlyWhirly555, on Flickr

IMG_0812[1] by TwirlyWhirly555, on Flickr

IMG_0814[1] by TwirlyWhirly555, on Flickr

 

[DashApple]

Hybrid headphone amp V3 - New case , Resistance logo , Orange / black .

IMG_0829[1] by TwirlyWhirly555, on Flickr

IMG_0826[1] by TwirlyWhirly555, on Flickr

 

[Sigurthr]

Looks sweet!

 

[aryntha]

Hybrid headphone amp V3 - New case , Resistance logo , Orange / black .

ionlaser555, would you be interested in doing a 12AX7 or even more useful-like, a 6BQ7 headphone amp build for someone? I'd be freakin' interested, I-tell-you-what.

Is that one mono-in though? no stereo?

 

[DashApple]

Looks sweet!

Thanks : D

ionlaser555, would you be interested in doing a 12AX7 or even more useful-like, a 6BQ7 headphone amp build for someone? I'd be freakin' interested, I-tell-you-what.

Is that one mono-in though? no stereo?

Thanks for the offer : ) but Honestly I wouldn't know where to start , The amp I built was from a circuit I copied down a while back , im not that good at doing the valve circuits on my own , I get the most part but im still getting there .

Its a dual triode ( 12AU7 ) to give voltage gain and then a class A Mosfet / LM317 stage for current gain .

The audio is stereo in / stereo out , there are two 3.5mm stereo jacks under the large gold phono jack ( I use that as the 12V supply input )

 

[The Lightning Stalker]

A triode is a triode. There are minor
differences, but one tube can generally be
substituted for another. Of course the
audio characteristics will be a bit
different and the tube has to be able to
handle the power.

 

[Sigurthr]

Yep, as my experiments with the 1927 triodes showed, they're pretty easy to fudge into whatever you want them to do. Pentodes though... there's some witchcraft.

 

[DashApple]

Well I don't mind trying : ) ,

Random thing I made , Astable 12AU7 multivibrator driving neon tubes and EM87 magic eye tubes : D

https://www.youtube.com/watch?v=flNM0Q8rS-E

https://www.youtube.com/watch?v=eXGulijHwnE

IMG_0831[1] by TwirlyWhirly555, on Flickr

 

[djQUAN]

So I installed a new charge controller for my home off grid setup and wanted to test it's capability.

I went and built a tube preamp with the whole workshop running off of wind and solar

Here is the tube pre just completed, doing a quick test before plugging it into my amp.

Here is my bedroom setup. I'm using a laptop with foobar and FLAC files, Schiit Bifrost dac, async USB connection, the tube pre, my DIY lateral mosfet amp pushing 300w/ch into 4ohms, B&W 686 speakers. Silver interconnects and DIY braided speaker cables.

The tube pre on the amp for testing.

Nice glow on the toobs

Sounds pretty sweet. Unfortunately, this build was for a friend. Now I want to build one for myself too.

 

[Sigurthr]

Beautiful build, very sleek! Reminds me of the builds I saw being done during the heyday. I always admired the physical construction skills it takes to mount things so nicely to a DIY chassis.

 

[djQUAN]

Thanks. Took a few more pics. My friend picked and bought all the parts needed and made the chassis. I simply did the assembly and wiring.

The volume control is a stepped ladder attenuator. I forgot what switch was used for the input selector but remember it was an NOS unit. Signal wiring is solid silver wire, ground wire is solid PCOCC copper. IEC connector has solid copper pins

Internal shot of the preamp.

Source selector and volume control

Input and output connectors

Used the extra wires to make short interconnects using WBT tips.