"Red Star Drive"

[svstee]

It worked out!
Hardly heats up the resistors at all. played hard for 45 minutes and both the tube and the resistors were barely warm. I am running it off 9V, so that may be a factor. Hooked it up to a DIP diode switching array and found out the best combo really is one GE and one Si, although decent, lower gain asymmetrical clipping can be produced with 2 Si on one side and a single Ge on the other. I'll box it up tonight and have it on me board tomorrow!
Thanks for the help and the great circuit!

[frequencycentral]

Hey well done - glad it worked for you!

Check this out:

Also, if anyone plans to build Version 2 for a 9 volt supply, the 220 ohm / 1 watt resistor should be changed to 150 ohm / 1watt. With only 50 ma current draw it's quite feasible to run this circuit from a 9 volt battery

So you are starving the heater a little - shouldn't be a problem, but worth checking the voltage at pin 3 of the 5672. You may want to change to voltage drop resistor. It would be interesting to see if what you've done has any effect on the sound?

.........and post some photos when you're done boxing it up.

[svstee]

Actually, I accidentally used two 220 ohm resistors instead of two 440's... so I'm running at 110 ohms. sounded good, so I didn't bother to fix it.
I'll probably do what i do to 99.9% of my pedals, put it in an unpainted 2$ RACO box.

Less money spent on enclosures=more money for parts=more pedals!

[svstee]

Here come the pics, all mounted to the lid of a RACO box. Easy to wire, but I gave myself way to much extra wire because I wasn't sure it would fit...



I actually boxed her up last night, but I left my camera in my shop and was too lazy to go back and get it.
As for the enclosure, when I first started making pedals, I went to Lowes to look for things that might work as boxes, and found all those awesome RACO boxes. I thought I was the most original thinker ever, built like 10 pedals before I saw how many people had done it before me oh well, there really is nothing new under the sun.
Couple questions though:
1: how did you chose 1 watt for the resistor? I have two 1/2 watts running (still onny 1/2 watt I think, but I figured it would dissipate heat better) and it barely gets warm.
2: In your other versions you use an LM317. What advantages does it have that the resistor does not? Dealing with the heat sinks semms like a pain to me.
3: Where did you get those heat sinks?

[frequencycentral]

1: how did you chose 1 watt for the resistor? I have two 1/2 watts running (still onny 1/2 watt I think, but I figured it would dissipate heat better) and it barely gets warm.

I chose that resistor based on this equation:

5672 > 1.25 volts / 50 ma heater requirement. Voltage drop from 12 volts required: 10.75 volts.

10.75 volts / 50 ma =  215 (ohms)
10.75 volts x 50 ma = 0.5375 (watts)

So I guess I'm being conservative on the watts.

2: In your other versions you use an LM317. What advantages does it have that the resistor does not? Dealing with the heat sinks semms like a pain to me.

My first build using 5672 was the pentadriver, which uses two of them. I was pretty green about how to drop voltages, and the LM317 seemed the logical way at the time.

3: Where did you get those heat sinks?

Maplin in the UK.

Here's my Pentadriver with two 5672 and the heatsink:



Your photos are awful by the way! No offence meant! 

[svstee]

I took all of them with "Bat. Low" blinking at me. I'll get some decent ones later.
Any idea were I could find heatsinks like that one in the U.S.?

[frequencycentral]

The only advantage of the LM317 really is that whatever voltage you feed into it you get the same voltage out. With a voltage drop resistor out output is (maybe?) proportional to the input voltage.

No idea where to get those heatsinks in the US, sorry!

[svstee]

Cool, thanks!
Looking forward to building your Murder One sometime soon!

[frequencycentral]

Looking forward to building your Murder One sometime soon!

Me too - I think the design stage is finished - I've just got to decide on the enclosure. I would like to build it without it looking like a Zvex ripoff, but that layout is so logical. I'll see what I come up with.

[svstee]

Would running this at 18v be a good experiment? I'm thinking about building a voltage doubler/A-B Box so I can give my tube pedals good headroom without giving me multiple power supply problems and not having a separate unit for A-B switching (for a tuner).

[frequencycentral]

Would running this at 18v be a good experiment? I'm thinking about building a voltage doubler/A-B Box so I can give my tube pedals good headroom without giving me multiple power supply problems and not having a separate unit for A-B switching (for a tuner).

Yeah - that would definately be worth doing! I've tried 5672s with a MAX1044 to increase the voltage - sounds great.



EDIT: Though have a look at the MkII version that Jasper designed - it occurs to me that a higher plate voltage will mean that you will need to change the diode clippers, maybe double them up like Jasper did. The signal will be too high for the MkI diodes to clip otherwise.

[frequencycentral]

I have no doubt that you guys are now sick to the teeth of me and my submini tube obsession! Anyway, I recorded a couple of new soundclips of my Red Star Drive, nothing special playing wise, just trying to show what the pedal can do.

Signal path:

Squier Telecaster Custom (HB) > Red Star Drive > Roland Bolt 60 watt tube combo > Shure SM58 > Event Echo Gina 24 soundcard > Wavelab

The effect is bypassed in the first half of this clip, then the Red Star Drive is stomped set up for (maximum) clean boost: http://www.aronnelson.com/DIYFiles/up/Red_Star_Drive_Boost.mp3

This clip has two parts, with the clip pot set at half and then full: http://www.aronnelson.com/DIYFiles/up/Red_Star_Drive_Clipping.mp3

[svstee]

Man, that sounds exactly like mine, and I'm running it at 9v. I wonder how much difference those 3 watts make. Also wanted to share my thoughs on this pedal, I'm not a huge fan of its clipping for lead work, I think it sounds too compressed. Great for rhythm stuff though, and works great as a booster of other FX.
My .02$.

[criszou]

hi...where can I find 1N67A, mouser doen't have one? 
or what is substitute for 1N67A?

Thank you

[frequencycentral]

hi...where can I find 1N67A, mouser doen't have one? 
or what is substitute for 1N67A?

Thank you

Try any Ge diode, In34a should work too.

[Stinger]

Just finished to build the MK I of the project and now i understand why there's MKII out there... It doesn't have hard clipping...
Is there any vero version for the MKII?
Thanks

[Stinger]

anyone?