JJS designed Submini Amp

DeanM · Post by **DeanM** » 22 Apr 2010, 17:26

frequencycentral wrote:....but don't you guys yearn for more features? MOSFET boost, tremolo section, pre amp output, dummy load.....

haha....nice!!

frequencycentral · Post by **frequencycentral** » 22 Apr 2010, 20:27

Wilco wrote:Hey Rick,

Would you mind telling us some more about this latest creation of yours (not to mention post some gut shots)?

It's basically a heavily modified Murder One that I built for a guy who already bought a stock Murder One a year or so ago. It's really flexible! I wish I still had it to make soundclips, but but's gone to it's new owner. Great as a standalone practice amp, with built in effects - the boost is insane - instant massive compression and feedback at the highest setting. It's even more fun as a preamp into another amp, with a lot of control over the sound using the gain and volume in combination, the boost and trem just add to the fun. The MOSFET boost section is a SHO variant, the tremolo section is from my Vibracaster tube tremolo design, the tonestack is BM based. The preamp out just takes a feed from lug 2 of the volume control. The dummy load resistor is on a switched socket, so the OT sees a load when there's no speaker plugged in. The guts are not my best, as it was a 'work in progress'. I'm planning to do something similar for myself, but using a Superfly as the amp section instead of Murder One.

daz · Post by **daz** » 25 Apr 2010, 05:37

A short rough clip with two 6021:

Have to try it with a 6111..

Wilco · Post by **Wilco** » 25 Apr 2010, 10:00

Sounds great (and LOUD)! Lots of drive. Doesn't seem the gain controle is very usable (for the kind of music you're playing) beyond 10 or 11 o'clock, although you might disagree.
I had the same thing and indeed found a 6111 much more usable, be it less LOUD.
I guess dialing in a higher B+ can get you more clean headroom as well. Just be carefull the SMPS doesn't get too hot when you do that.

daz · Post by **daz** » 25 Apr 2010, 10:54

Thanks Wilco! The video was a get together with some guitar mates and they had a good play though. they were impressed.
Yeah it has alot of gain. The first part with the les paul jr sounded sound ballsy and marshally in person as opposed to what was captured on camera.

Definitely want more headroom so I'll try it with 6111.

I found the tone control range works in the first 1/3 of the pot range. Think that needs some tweaking too...

Once again thanks again for your help wilco!

rasta_maleek · Post by **rasta_maleek** » 22 Aug 2010, 08:29

hey boys, i have one of this monsters, i run it with a 6021 in preamp section and 6021w in power section, i suprimed one of the stages, and i get two preamp stages and one power stage.
And one mod is implemented, fenderished, marshallized and insane.
Look this photos and video.

rasta_maleek · Post by **rasta_maleek** » 22 Aug 2010, 08:33

and some video,

moisho · Post by **moisho** » 15 Sep 2010, 17:09

I love this amp!!!

borislavgajic · Post by **borislavgajic** » 16 Sep 2010, 15:23

.I think soon to do something simmilar....

really nice builds....thanks people

Boris

rasta_maleek · Post by **rasta_maleek** » 20 Sep 2010, 21:01

I'm the owner of two Rick Holt models too. Murder one and super fly.

thereminator · Post by **thereminator** » 11 Oct 2010, 12:48

Hi.
rasta_maleek - Great job.
But I think PCB needs a little improvement.
Subminiature tube has 8 Pins with 40 radius degree for each pins except 80 radius degree between pins 1 & 8. It's not good idea to bend tube pins to match to PCB.

moisho · Post by **moisho** » 03 Nov 2010, 15:49

Hi guys.

If you take a deeper look at JJS pictures, you will see there are a couple of blue leds under the subminis. This will do a great effect!! Could someone help me with the led conections??

thereminator · Post by **thereminator** » 04 Nov 2010, 13:14

I hate blue LEDs in tube amp. It looks disgusting. Tube heater glowing looks much better.

moisho · Post by **moisho** » 05 Nov 2010, 19:04

I can understand it. I will try it. If I don't like it I will take them out.

bluestomp · Post by **bluestomp** » 21 Nov 2010, 08:27

I build this amp with PCB layout in pdf file, and after complete build I only hear litle hum but no sound when I set volume in middle or top.
Anybody can give me guide for this problem? like voltage value in several critical point.

Thanks for your help.

best regards

rasta_maleek · Post by **rasta_maleek** » 03 Feb 2011, 19:01

thereminator wrote:Hi.
rasta_maleek - Great job.
But I think PCB needs a little improvement.
Subminiature tube has 8 Pins with 40 radius degree for each pins except 80 radius degree between pins 1 & 8. It's not good idea to bend tube pins to match to PCB.

thanks for the advice, but i can not blend this pins on diylayout, BTW submini tube has flexible leads, maybe i could do a immprovement with corel draw, let my know if you need a new layout and pcb artwork.
cheers

Dr.Maligno

rasta_maleek · Post by **rasta_maleek** » 05 Mar 2011, 20:24

other subminiamp by my hand, single ended, cathode follower, tone stack complete, all in the hand.

cheers

mrkaploca · Post by **mrkaploca** » 27 Sep 2011, 17:42

It would be great if somebody would draw JJ board with nixie supply instead of the original one!

mrkaploca · Post by **mrkaploca** » 05 Oct 2011, 23:35

ok,as nobody did it,I took few minutes to combine Nixie SMPS with JJS layout(including rasta maleek's mod->never replyed so I did it as I figured out -out of his layout...I will post wiring image tommorow,it's way to late now...bzzzzzzzzz

bluestomp · Post by **bluestomp** » 07 Oct 2011, 02:24

bluestomp wrote:I build this amp with PCB layout in pdf file, and after complete build I only hear litle hum but no sound when I set volume in middle or top.
Anybody can give me guide for this problem? like voltage value in several critical point.

Thanks for your help.

best regards

any suggestion for this please?