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Hi,
I have seen some cheaper boost converters too based on MC34063, but I still have some Max1771 for new builds. The last one I build was based on FrequencyCentral's Obsession amp:



For the JCM combo I choose the output transformer based on information from other projects, like the superfly, and I adjusted the SMPS voltage for less noise and better tone. Recently I changed the mosfet for a better one with less internal resistance,and put some 10uF 400V low ESR capacitors and reduced that value to 200 V. 

I made a document for Magnus, if you're interested it's here:
https://www.dropbox.com/s/4hcgkkefek6znqg/submini%20JCM800.pdf
It still needs some tweaking to reduce a bit of hiss at max. setting and to control gain, I always play with the gain at half, more than that and It's too much for that small speakers, they sound too distorted and have some fuzziness. With a bigger speaker it's ok.

Finished a 1590b layout, take a look:

it only has 73.4x44mm, but I'm still thinking if mounted jack's are a good approach for this build...layout was still NOT TESTED, so feel free to ask for it if You want, but there will be noise.

Cheers

Really nice amp!!
What high voltages are you using?
Regards

The Max1771 SMPS delivers 240 v from a 12v 1A supply.

The board and schematic are here:
https://dl.dropboxusercontent.com/u/10420127/Superfly%20Project.pdf

Hope you enjoy!

yes,
it is really loud to play at night. I only play full gain when the volume is at 1/4 of the pot.

Unfortunately there is not much distortion at this volume level, even with gain maxed.

It works nice with pedals, but most of my pedals are bigger than the amp...

Hi, here comes the sound sample!

Cheers, Thomas

I think Frequency Central was interested in making some PCB's to sell.
this is a smaller version, and the build is a bit more difficult, to make all the components fit in such a little space.

If you're interested i can send you my layout, or the normal version.

Well, another one!
now a superfly in a 1590a!





Greetings
Thomas

Yes, it is an all-tube amp, the output transformer is a Hammond 125a, and i guess the full distorted volume has aprox. 1W

Some gut shots!




it's a small turret board build

and Schematic!

https://dl.dropboxusercontent.com/u/10420127/submini%20JCM800.pdf
Thomas

Finally made some better pictures!





cheers

Well, after murder one I tried to build my own tube amp combo...
based on jcm800 amplifier, using russian submini tubes, with PP triodes and LTP PI.
I used Dmitry's power amp schematic, and made a PTP layout using nails as turrets.
The speakers are old oval computer speakers, and I used a big muff tonestack instead of the TMB.
The power supply is the max1771 SMPS, from frequency central projects, and a 12V, 2A wall wart.
I made some videos with my crappy phone cam:

Clean sound

High gain

I think removing the 470pF caps across the grid stoppers would help with a little more low end.
Thomas