Author Topic: Classic amp topologies made with submini tubes  (Read 15668 times)

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thomasha

Re: Classic amp topologies made with submini tubes
« Reply #20 on: August 04, 2014, 03:50:19 PM »
Hi,
yes, they similar, but Z-vex uses the american versions. The socket is a problem indeed, I'm using IC's sockets so far.
The clean headroom in the nanohead is very reduced, as it only uses one triode in SE, it will only output 1/4W or so.
These one has two triodes in PP and a real Pi, not self-split like the Superfly. It's louder, something like 1W, like the load line shows. I'm redesigning the amp to obtain more headroom, and max. power from these tubes and the SMPS
The 12ax7/12au7/ecc99 amplifier is better, and the JTM1 clone will be one of my next projects, but i'm kind of a miniaturizing maniac, addicted to sub-miniature tubes.  ;D

mrsmash23

Re: Classic amp topologies made with submini tubes
« Reply #21 on: September 30, 2014, 02:18:55 PM »
@thomasha

Hello, any updates on your JCM800 project? Or even any news about JTM1 project?  :) Thanks in advance!

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #22 on: October 27, 2014, 07:03:34 PM »
Hi,
after some soldering I finished the board, take a look:



After some testing, there was a lot of noise in the preamp, using only the PI and power stage it was nice and clean.

I'm drilling an old enclosure to test how the circuit behaves.
If it works like the first build, the proximity with the enclosure removes the SMPS noises.
Cheers,
Thomas

frequencycentral

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Re: Classic amp topologies made with submini tubes
« Reply #23 on: October 27, 2014, 08:09:54 PM »
Wow Thomas! That's a lot on a small PCB...hope it works out.

Rick

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #24 on: December 15, 2014, 07:02:29 AM »
Hi!
unfortunately that board was very noise... back to project....

The SMPS near the first stage was a horrible layout idea. I'm thinking of reducing it to 3 tubes, same as the little 1W marshalls and use a cathodyne PI. (more space, less heat)

And make a separate board for the SMPS, with a cooler, or heatsink the fet. The best fet I could find was the IRF644, but it still gets really hot after one hour playing...a better low ESR capacitor and inductor are in to buy list.

Just thinking of it's worth dropping the electrolytic capacitor for 2 film capacitors...easier to find at least.

Well, I made another video of the first build:

I salvage this same kind of speakers yesterday, I think this amp needs a brother, I just need to find a nice wood piece for it...

Thomas

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #25 on: March 11, 2015, 10:02:49 PM »
Hi all,
new video, this time with a real speaker!


Cheers
Thomas

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #26 on: June 10, 2015, 10:03:21 PM »
Hi,
I made another prototype, this time using 3 tubes. The PI is now a cathodyne, and the B+ is 234V.



This should fit in a 1590b box.

Cheers,
Thomas

Taylor

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Re: Classic amp topologies made with submini tubes
« Reply #27 on: June 10, 2015, 10:48:36 PM »
I'm enjoying your submini tube odyssey! Cool build. I started this thread but never got my Superfly working back then. Maybe I'll try to resurrect it one of these days, as my building skills have improved somewhat in 6 years.   :icon_lol:

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #28 on: July 22, 2015, 06:45:53 PM »
Hi,
this was already posted elsewhere, but for completeness, here is the final version of that amplifier in the video above!







and I made a small doc. if someone is interested.
https://dl.dropboxusercontent.com/u/10420127/RussianJTM.pdf

cheers,
Thomas

Digger1770

Re: Classic amp topologies made with submini tubes
« Reply #29 on: July 22, 2015, 07:06:37 PM »
That is one of the coolest things I have ever seen! :icon_biggrin:

ASchmalex

Re: Classic amp topologies made with submini tubes
« Reply #30 on: July 22, 2015, 09:35:24 PM »


Hi,
this was already posted elsewhere, but for completeness, here is the final version of that amplifier in the video above!



cheers,
Thomas

That is very cool, sounds nice too!
Wonderful and inspiring build!

deadastronaut

Re: Classic amp topologies made with submini tubes
« Reply #31 on: July 23, 2015, 04:09:53 AM »
cute-ist amp ever...sounds cool too.  8)
http://www.youtube.com/user/100roberthenry
http://deadastronaut.wix.com/index
https://deadastronaut.wixsite.com/effects

^ SPACE PATROL FUZZ/ NANO-8 MIDI DRUMS /CHASM REVERB / TREMSHIFTER / FAZE FILTER/ABDUCTOR II DELAY pcb's + WAH LIGHT PLATES. and sausa

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #32 on: September 22, 2015, 08:17:46 PM »
Hi,
made a new video of this amplifier:



and this:


cheers,
Thomas
« Last Edit: September 22, 2015, 09:07:33 PM by thomasha »

deadastronaut

Re: Classic amp topologies made with submini tubes
« Reply #33 on: September 23, 2015, 04:29:08 AM »
ha ha i just saw that on youtube.. ;)

cool.. 8)
http://www.youtube.com/user/100roberthenry
http://deadastronaut.wix.com/index
https://deadastronaut.wixsite.com/effects

^ SPACE PATROL FUZZ/ NANO-8 MIDI DRUMS /CHASM REVERB / TREMSHIFTER / FAZE FILTER/ABDUCTOR II DELAY pcb's + WAH LIGHT PLATES. and sausa

Jarno

Re: Classic amp topologies made with submini tubes
« Reply #34 on: September 25, 2015, 03:56:56 AM »
Fantastic build!

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #35 on: December 15, 2016, 03:27:45 PM »
Another one to the list:







same schematic as the previous one, but using the 6111 and 6112 tubes, that required some changes.
I used a prototyping board this time.
Cheers

tonyharker

Re: Classic amp topologies made with submini tubes
« Reply #36 on: December 15, 2016, 04:14:47 PM »
Did you change the bias on the tubes or use the same as the Russian ones?

thomasha

Re: Classic amp topologies made with submini tubes
« Reply #37 on: December 15, 2016, 04:25:49 PM »
changed the cathode resistor to 1k.
Current for both output triodes is 8mA at 220v, roughly the 1.8W max. dissipation.

Cozybuilder

Re: Classic amp topologies made with submini tubes
« Reply #38 on: December 15, 2016, 07:08:58 PM »
Wow, that is one great looking sub-mini tube build Thomas!  8)
Some people drink from the fountain of knowledge, others just gargle.

runmikeyrun

Re: Classic amp topologies made with submini tubes
« Reply #39 on: December 16, 2016, 01:26:28 AM »
Awesome!!!


Ham fisting my way through one build to the next since 2003. 
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