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Sub-mini tube amps

Started by madbean, July 04, 2010, 11:55:27 PM

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thomasha

#120
Well,
finally started the build, found a lot of noise in the preamp,
but PI and power are nice and quiet, now I will build it inside a 1590b to verify if the proximity with the grounded enclosure reduces the noises.


Cheers, Thomas

mishagolin

thomas, a beautiful build you've got there.

i had read about Dana's sub mini plexi. thats how i found out about his submini power pentode.

still really excited to see and hear some of these builds

thomasha

#122
Hi,
unfortunately I had some problem during the build, and with the amplifier in the enclosure there is a lot of noise and blocking distortion.

Recently I found some new sub-miniature tube amp ideas:

http://lucythesoloist.blog33.fc2.com/blog-category-50.html

http://lucythesoloist.blog33.fc2.com/blog-category-58.html

http://lucythesoloist.blog33.fc2.com/blog-category-55.html

http://lucythesoloist.blog33.fc2.com/blog-category-64.html

Time to learn japanese!

I still have the heat issue, the 1590b is getting really hot, and with temperature the SMPS voltage is also dropping.
The fan could be an improvement, or relocating the fet to the exterior, drilling some holes in the chassis...change to a bigger box.

Well, I'm still working on it.

I'm hoping to see what Madbean has done with all that sub-miniature tube layouts he posted.

Thomas

PS. Just another video from my first small combo, I'm thinking of making one more!


thomasha

#123
Hi you all!
let's start with the vacation builds!
I finished a small (3" speaker) subminiature amplifier, based on frequency central's vibratone.

It's just a murder one with a tremolo at the first cathode.

I tried to build a antique radio style cab, similar to a gibson.

I also tried a power transformer as output. It's a 220v to 6v transformer, but I rearranged the laminations to create a small gap. It still sounds nice though.

Well here are the pictures: there will be a video soon!






Cheers,
Thomas

copachino

Affiliations: madbeanpedals fan and pedal porn lover....

Leevibe

Looks and sounds awesome! I'm jealous. :)

thomasha

#126
Hi,
this time another video, but with a comparison between the small PC speakers and a Celestion greenback 12".

It's the same amplifier that was introduced before, it's kind of noise, and there is still a lot of gain in this amp.
The output stage is very sensitive but I use the guitar volume to tame the highs.



Made one for the Vibratone too!


And the preamp tubes amplifier:


Next one will be the superfly!
Cheers
Thomas

HamSandwich


Scruffie

So I took Tomasha's ball and ran with it, a full sub-mini JCM800 to fit a 1590BB with everything but the jacks board mounted. The layout was tighter than I thought it was going to be so i'm not holding out too much hope of it working without a couple of noise or oscillation issues but you never know! So if anyone wants to try it...
Works at Lectric-FX

Leevibe

Quote from: Scruffie on October 03, 2016, 11:50:27 AM
So I took Tomasha's ball and ran with it, a full sub-mini JCM800 to fit a 1590BB with everything but the jacks board mounted. The layout was tighter than I thought it was going to be so i'm not holding out too much hope of it working without a couple of noise or oscillation issues but you never know! So if anyone wants to try it...

Holy smokes!! :o :o :o

pickdropper

I don't know when I'd have time to build it, but I kind of want to.
Function f(x)
Follow me on Instagram as pickdropper

selfdestroyer

Quote from: pickdropper on October 03, 2016, 10:52:28 PM
I don't know when I'd have time to build it, but I kind of want to.

Took the words out of my mouth. lol

Cody

sturgeo

I've had one of these: http://www.ampmaker.com/store/190-0-190V-5W-power-transformer.html lying around since I finished my JTM45 build with the intention of making a low watt Plexi or JCM similar to the Marshall offerings, its a pity ampgarage has been compromised as that was a valuable resource.
That Mini Amp 2.0 is exactly what I'm after  :)

Scruffie

Haha, thanks guys, hopefully i'll have built it up by the end of the year and can post how it works out at least.

I'm also going to do a layout for a Selmer Treble 'n' Bass 50 (the Syd Barrett amp) bass side preamp in to a self split power amp with 12A'7 tubes like I did with my mini AC30 clone if that might be less daunting, hoping with its lowish gain fuller frequency preamp and the lower power amp distortion from self split that it'll make for a low wattage stoner rock kinda amp.

Quote from: sturgeo on October 04, 2016, 08:26:11 AM
I've had one of these: http://www.ampmaker.com/store/190-0-190V-5W-power-transformer.html lying around since I finished my JTM45 build with the intention of making a low watt Plexi or JCM similar to the Marshall offerings, its a pity ampgarage has been compromised as that was a valuable resource.
That Mini Amp 2.0 is exactly what I'm after  :)
Wait, are you talking about the amp I just posted or is there an amp in this thread called the Mini Amp 2.0? The one i've posted is set up to run off a 2A 12V Power supply, has the tube heaters in series and a SMPS on board so it's not ideal for that transformer really.
Works at Lectric-FX

sturgeo

Quote from: Scruffie on October 04, 2016, 01:32:58 PM
Wait, are you talking about the amp I just posted or is there an amp in this thread called the Mini Amp 2.0? The one i've posted is set up to run off a 2A 12V Power supply, has the tube heaters in series and a SMPS on board so it's not ideal for that transformer really.

Sorry should've made it clearer, this one: https://diyguitarfreak.wordpress.com/2010/09/15/the-miniamp-2-0/