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

[criszou]

Hi, I go to my local store looking for sub tube 6111, but the store only have JAN-6111W. Is this tube 6111W is same as 6111? I ask to store's owner, but he doesn't know.

Wow, you can get 6111 at your local store - lucky you! I have to get my 6111 shipped across the Atlantic!

JAN-6111W is just fine. In fact better. JAN = Joint Army Navy, higher quality.

but only 6111 and 6021, but if I want to build your tube bonanza schematic, some part, not only tube, I have to shipped them across Pasific  
Thank you Rick...I'll try JAN-6111W.

[Plan B]

Hey Rick, I was getting ready to build v5 with slight modifications to the perf layout you provided for v3, and noticed the 100uf cap, but it isn't on either schematic.  Should that 100uf cap be there, and does the voltage rating need to be 100v like the 10uf caps?  I'm assuming so because of it's proximity to the PS (and Im also assuming that it is a part of the PS).  Also, what is it's purpose?  I want to say power filtering, but since I know nothing about this stuff, that's just a guess.

[frequencycentral]

That cap is just for stability of the 12v input. It only needs to be rated somewhere above 12v, so 16v would do. I tend to just use 10uF 100v cos I buy them in bulk, but any large value will do.

[Plan B]

Very cool--can't wait to fire this up!  I'm assembling the board right now.  Still a little confused about the transformer wiring, but i guess we'll see what happens

[frequencycentral]

I use Hammond 1750A transformers, wired up thus:

• Blue to B+
• Red to 5672 pin 1
• Black to speaker socket tip
• Green to speaker socket sleeve, with a jumper to common ground

The red and blue I just solder onto the copper side of the perf thus:

[Plan B]

Thanks again Rick!  I saw that earlier, but my trouble lies with the tranny I ordered and how the wires are oriented--unless of course there is a uniform color code, in which case I guess I should be fine.  That, and although I think I sort of know what to do with the offboard stuff, admittedly I can't say I do with complete certainty.

Perhaps to save you a bit of time, I think I have the changes for the v5 from the perf layout posted earlier.  Unfortunately, I don't have access to DIYLayout ATM, so it is in text-form.  Please let me know if I made a mistake, but if I'm right, it would look like:

Trace from pin4 of IC1 to perf hole d2, from d2 to d4, d4 to c4, c4 to c5 which is the negative end of the new 10uf cap, positive of that cap being b5; then from c5 to c6, then jumpering from c6 to f6.
The two new bias resistors could go on j6 and k6, and k7 and l7, respectively.  With either an additional row to the perfboard, or via jumpers, go from pin5 of IC1 to the end of the 100k resistor and the 1m resistor could be jumpered anywhere along the ground wire (say, f23 for example).  Then those remaining leads would be wired to the outside lugs of the switch.
The new .1uf would then sit at m22 to m-whatever, which would then connect to the center lug of the switch.

Sorry if that was a total mindbender and/or totally wrong.  Figured other first-timers might benefit from a fellow noob's observations while also getting another pair of eyes to look over what I think might be going on. Or at least get a good laugh. 

[frequencycentral]

Trace from pin4 of IC1 to perf hole d2, from d2 to d4, d4 to c4, c4 to c5 which is the negative end of the new 10uf cap, positive of that cap being b5; then from c5 to c6, then jumpering from c6 to f6.
The two new bias resistors could go on j6 and k6, and k7 and l7, respectively.  With either an additional row to the perfboard, or via jumpers, go from pin5 of IC1 to the end of the 100k resistor and the 1m resistor could be jumpered anywhere along the ground wire (say, f23 for example).  Then those remaining leads would be wired to the outside lugs of the switch.
The new .1uf would then sit at m22 to m-whatever, which would then connect to the center lug of the switch.

Checkmate in 5 moves - amazing! 

[Plan B]

Trace from pin4 of IC1 to perf hole d2, from d2 to d4, d4 to c4, c4 to c5 which is the negative end of the new 10uf cap, positive of that cap being b5; then from c5 to c6, then jumpering from c6 to f6.
The two new bias resistors could go on j6 and k6, and k7 and l7, respectively.  With either an additional row to the perfboard, or via jumpers, go from pin5 of IC1 to the end of the 100k resistor and the 1m resistor could be jumpered anywhere along the ground wire (say, f23 for example).  Then those remaining leads would be wired to the outside lugs of the switch.
The new .1uf would then sit at m22 to m-whatever, which would then connect to the center lug of the switch.

Checkmate in 5 moves - amazing! 

Thanks Rick!  I learned more than I thought from this project, and I thought I was going to learn a lot in the first place, and now I'm completely addicted to these little monsters, and can't wait to see if I can make some designs myself!  This taught me an absolute boatload about both amp and stompbox design, building, and theory--all while in a safe context and with an awesome result for my efforts--assuming I don't fudge up the offboard and tranny.

Thanks again mate! You're the champ!

[frequencycentral]

^^^

Ah, no, I meant that it totally confused me (being a visual learner) and reminded me of chess moves, or battleships.

Anyway, here's a layout for the Version 5 schematic, it adds the bias switch as well as a 1N4007 across the power rails for a bit of polarity protection. It's one row and one column larger than the original layout. If anyone wants to make some up and send them to me for 'evalualtion' I'd be pleased as punch!

[Plan B]

^^^

Ah, no, I meant that it totally confused me (being a visual learner) and reminded me of chess moves, or battleships.

Anyway, here's a layout for the Version 5 schematic, it adds the bias switch as well as a 1N4007 across the power rails for a bit of polarity protection.

Oh...well, the good news is that mine doesn't look that far off from yours--just sloppier soldering and peculiar placement on my end.

For the polarity protection diode, would a 1n4001 suffice?

Regardless, I still stand by my "you're the champ" comment. 

[frequencycentral]

For the polarity protection diode, would a 1n4001 suffice?

Should be fine. You may not need it if you don't make dumb mistake. But as I sell these I figure it's best to have some protection.

[Plan B]

For the polarity protection diode, would a 1n4001 suffice?

Should be fine. You may not need it if you don't make dumb mistake. But as I sell these I figure it's best to have some protection.

Meh--better safe than sorry I suppose.  Should have this whipped together later today--I'll let ya know how it turns out. 

[dellamorte]

would it be possible to use a murder one to drive a reverb tank rather than a speaker like a fender outboard reverb?

[frequencycentral]

would it be possible to use a murder one to drive a reverb tank rather than a speaker like a fender outboard reverb?

Maybe - try it! You'd want a gain recovery stage after the reverb tank. Maybe you could screw around with the basic circuit but use the first triode stage of MO for that instead of using it to drive the second triode, so the topology would be triode > pentode > OT > reverb tank > triode. Tell us if it works.

[Plan B]

Would a 12v 1A regulated wallwarr work to power it?  I seem to remember from somewhere that they could be rated higher than necessary, but not lower?  Also it is what the dude at one of the local shops suggested since they didn't have a 500ma.  I just want to double check to make sure nothing is going to explode or anything before I try using it.

Thanks!

[frequencycentral]

Yup 12v / 1A regulated is fine, the circuit will just draw as much as it needs. I'd steer clear of switch mode though, never tried one but they may cause heterodyning (whining) in conjuction with the charge pump's HFO.

[Plan B]

Yup 12v / 1A regulated is fine, the circuit will just draw as much as it needs. I'd steer clear of switch mode though, never tried one but they may cause heterodyning (whining) in conjuction with the charge pump's HFO.

Well, guess I'm really gonna have to bank on that "may" part.

What is the name of a kind that wouldn't have that problem?  Or a type you would suggest?

[frequencycentral]

Yup 12v / 1A regulated is fine, the circuit will just draw as much as it needs. I'd steer clear of switch mode though, never tried one but they may cause heterodyning (whining) in conjuction with the charge pump's HFO.

Well, guess I'm really gonna have to bank on that "may" part.

What is the name of a kind that wouldn't have that problem?  Or a type you would suggest?

I'm in the UK, dunno where you are? FWIW I find these are perfect: http://www.maplin.co.uk/Module.aspx?ModuleNo=32746 ie not switch mode, just a transformer, a few caps and a voltage regulator inside.

Hmm, maybe I do recall someone somewhere using a MO with a switch mode without issues. I really should buy one to find out for sure...

[dimi3]

V5 layout yees thanks Rick, I will put this together, I have a few questions before I start.

I will be ordering parts at banzai, except the tubes that I have.

What is the correct spacing of electrolytic caps? 2,5mm should be ok for latest PCB posted in layout?
What kind of metalfilm caps are u using? the 0,1mf ones?
Banzai doesent have Hammond OT but this: http://www.banzaimusic.com/3.5-Watt-Output-Transformer.html, did you use this one on your first builds? or I should go for Hammond?

I have the power tubes already and preamp tubes, but 6112 not 6111, it has bigger mu (70) compared to 6111 (20) will this work or I will lose all clean headroom becouse of more gain?

Thanks for the help.

[frequencycentral]

That transformer is good for this build. Banzai also sell the electro caps: http://www.banzaimusic.com/10uF-100V-Radial.html It's a tight squeeze fitting them, you'll work it out! They stock the two voltage drop resistors too.

The 0.1uF I use are: http://www.rapidonline.com/sku.aspx?tier1=Electronic+Components&tier2=Capacitors&tier3=Ceramic&tier4=Radial+multilayer+ceramic+capacitors&moduleno62498&catref=08-0270

I've used 6112 a couple of times in Murder Ones, they work fine and give more crunch. The Most fun you can have is to use SIL strip as sockets and try 6111, 6021 and 6112.