New Amplifier Design - "Murder One" - Submini Pentode, Low Voltage

[Ripthorn]

_SUBZERO me up! 

The "other" designs sound pretty bloody tempting too though!   

If I were you, I might wait around to see his Promiscuous Girlfriend , that sounds like it should a great little amp. (In case you missed it, his next amp is a little dirt machine that he is tentatively calling Promiscuous Girlfriend, I just like to mess with the title)

[sweetwilly]

Combine a Promiscuous Girlfriend with a Murder One and you've got life with no chance of parole my friend!

It's the "Ted Bundy" of low-watt amps I'm looking forward to in particular, but will have to wait for Rick to go public with that one!

[stereovoid]

rock and roll dudes!!

[stereovoid]

hi all, recieved my murder one this morning hot off the bench from rick! it has blown me away! its a beast...and a beautiful one at that! i'll do a bit of a write up once i've had more time to play! did do a little recording though! www.myspace.com/mybandisclub27  The song is reflecting frequency, you have to excuse the bad vocals and mixing...it was a quick job! i used a ten inch 16 ohm blackstar speaker cab. added some reverb from my boss recorder and compressed overall. the guitar is straight into the amp. no bass on it...i don't own one! and the drum machine is very boring! see what ya think! peace, steve.

[frequencycentral]

hi all, recieved my murder one this morning hot off the bench from rick! it has blown me away! its a beast...and a beautiful one at that! i'll do a bit of a write up once i've had more time to play! did do a little recording though! www.myspace.com/mybandisclub27  The song is reflecting frequency, you have to excuse the bad vocals and mixing...it was a quick job! i used a ten inch 16 ohm blackstar speaker cab. added some reverb from my boss recorder and compressed overall. the guitar is straight into the amp. no bass on it...i don't own one! and the drum machine is very boring! see what ya think! peace, steve.

Sounds Like it's in good hands Steve, and I'm glad you're enjoying it. I'm glowing with pride!

[stereovoid]

and i'm glowing at the fact the tube glows! doh to me but i thought they would both be non glowers like the pentaboost! this amp is great, loving the fact that i can record an all on ten true tube sound at eleven at night! going to be posting some more demoish clips rather than song stuff soon! hats off to you rick!

[spudulike]

@Rick,
Where do you get your tubes from ?
UK supplier ?

[frequencycentral]

@Rick,
Where do you get your tubes from ?
UK supplier ?

I don't know of any UK suppliers for these tubes, though you will find suppliers in Europe and the USA on Ebay.

[stereovoid]

was yust trying the murder one through a 12 inch 4 ohm cab and it sounds killer, also finding that a combination of gain and guitar volume tweaking is making this much more versitle than i first thought, full out heavy rock back to crunchy blues, sweet! loving it!

[frequencycentral]

Gut shot of the pre-PCB prototype, for those who are interested:



......and a cheesecake shot:

[Ripthorn]

I've never seen such a clean piece of perfboard wiring as that...

[frequencycentral]

I've never seen such a clean piece of perfboard wiring as that...

Thanks Brian. I've had practice...........there are eight 100mm x 160mm totally stuffed perfboards in my DIY modular synth. After that little amps and effects are a doddle. The key is a very fine soldering iron tip:

[svstee]

Gut shot of the pre-PCB prototype, for those who are interested:

Man, I know you would be shooting yourself in the foot a bit here, but if you sold PCBs for this I would buy a couple for sure!

[Ripthorn]

I actually have a 1/64" tip, but have just never put it on the iron, the current tip works so well, I think I will go till it dies and then use the fine one.  Good to know my joints might actually clean up...

[Berger]

Ok after doing some of your other projects, and am really having fun with submini tubes again.

I have the parts on order, but I'm wondering if you could explain what is going on in the Murder One design.

I'm guessing the 6111 is the "preamp" section. Or at least the part that "colors" the sound. And that the 5672 is a clean boost acting as the "power" amp section feeding the transformer? So I could replace the 5672 with a clean boost of my choosing? Is it possible to place a tone stack in here, if so where?

Thanks for all your help!
-Berger

[frequencycentral]

Ok after doing some of your other projects, and am really having fun with submini tubes again.

I have the parts on order, but I'm wondering if you could explain what is going on in the Murder One design.

I'm guessing the 6111 is the "preamp" section. Or at least the part that "colors" the sound. And that the 5672 is a clean boost acting as the "power" amp section feeding the transformer? So I could replace the 5672 with a clean boost of my choosing? Is it possible to place a tone stack in here, if so where?

Thanks for all your help!
-Berger

Hi Berger, glad you're having fun!

Yeah, the 6111 is a two stage preamp, the 5672 is the power amp section. The 5672 could be replaced by the 5639 you used in your Pentaboost with a bit of thought. I've breadboarded similar amps using different submini pentodes instead of the 5672, such as 6397 and 5902. If you do use a 5639, you could conside higher plate voltages, at the 5639 handles up to 165 volts, so you could add more stages to the MAX charge pump(if the works, I blew a MAX by adding two extra stages) or consider using the SMPS I used in my Sub Zero amp. TBH, I wouldn't add a tonestack to this, as you'll lose a lot of gain and volume by doing so. However, if you replace the 6111 (gain of 20) with a 6112 (gain of 70), you'll be able to add a tonestack without losing out, as the extra gain of the 6112 makes up for tonestack losses. If it were me, I would add the tonestack after the first triode, before the gain control.

Rick

[Berger]

Thanks for all the info. I have some 5672s coming in, hopefully today, but I'll breadboard it and compare the 5639s as well. I also may play around using some different tubes for the preamp section. Sounds like I understand what you're doing with the setup, which is great....I love learning about this stuff.

I got a couple LT1054CP so I'll use those for the power supply...at least for now.

Thanks for the response!

-Berger

[Berger]

Another quick question, do you need to use higher voltage capacitors for the other caps in the circuit? 100v? Also cause I still use the usual 1/4 watt resistors?
Just wondering since the voltage is getting pumped higher than the usual 12volts.

thanks!
Berger

[frequencycentral]

Another quick question, do you need to use higher voltage capacitors for the other caps in the circuit? 100v? Also cause I still use the usual 1/4 watt resistors?
Just wondering since the voltage is getting pumped higher than the usual 12volts.

thanks!
Berger

I don't think there's any need to use high voltage caps or anything other than 1/4 watt resistors except for those specified. I've build half a dozen of these, which are all in use, and they all appear to be functioning just fine!

[Berger]

Thanks, I've been having fun looking at different "preamp" designs and am really looking to bread boarding this thing up and playing around and seeing what sounds I can get from it.

Berger