1590A Boneyard

[papasaurus84]

I love boneyard so much and i love 1590A also. So i decided to relayout this babe so she could stay in a warm 1590A. For the last couple day i learn and working with eagleCAD from gaussmarkov. I feel that 9 volt is not good enough for boneyard. 12volt makes her scream lot sexier. But i want this pedal run with 9volt adaptor. I dont want 12V adaptor. What im doing here is doubling the 9 volt to 18, then cut that to 12 volt. Since i'm a newbie, i don't excactly know what i'm doing here, but it works well in my previous boneyard. There's a suggestion from my friends to use a voltage divider so i get 6v, and doubling that to 12 volt, but i haven't tried it yet. Here's the sketch of the layout. I need suggestions and comments from all of you that experienced more in 1590A or babyboarding.

Thanks and regards,

Desta. 

[alanp]

How well does the Boneyard work on 18volts or 15volts? That could make life easier.

You can use a 7812 regulator to kick 18 volts down to 12 volts, you will just get a lot more heat to dissipate due to the greater voltage difference if I'm understanding things rightly.

[papasaurus84]

How well does the Boneyard work on 18volts or 15volts? That could make life easier.

You can use a 7812 regulator to kick 18 volts down to 12 volts, you will just get a lot more heat to dissipate due to the greater voltage difference if I'm understanding things rightly.

CMIIW, LF347 couldn't handle more than 12 volt. Yes, i use 7812 here to feed up this beast, and you're right, it produce significant heat. now i'm workin on it.

[Thomas_H]

The suggestions with bringing the initial voltage down to 6V and doubling it is a good one.
But dont use a voltage divider, use a 6V zener diode to bring it down or a 7806 voltage regulator if you dont want to calc the correct current resistor for the zener.
How much does the boneyard consume (in mA) ? you might get away with a 78L06 if is below 60mA.

[shawnee]

THANK YOU! This will be a great pedal. I was just about to build another Boneyard in a 1590B but I am going to wait for this one. I agree that the +/- 12 volts sounds better. You notice it more if you are playing with lower gain like an AC/DC type crunch than when using this pedal as an 80"s rock box.

[papasaurus84]

update: inverter changed from 9volt to 18 volt.

thanks for the reply guys...

i was wrong alanp, you're right. i've changed the 7660 section from 9volt inverter to an 18volt inverter. LF347 have an ability to handle up to 40volt. so yes, this is a good fact.

@thomas, now we don't need a regulator or zener anymore, because the inverter is automatically produce 18volts.

@shawnee, i hope this could be a good news for you. can you imagine how 18 volt affect this beast? oooh, it's gonna be sexy tone...

ps: should i make a new thread for a documentation?

thanks, regards,

Desta

[selfdestroyer]

I am VERY interested in this also. I have been having a blast with my Boneyard II but if I can get a 1590A I can save some board room.

[shawnee]

I have run mine at +/-12v, 15v, and 18v. It gets cleaner and quieter (less compressed) the more voltage you use. At some point for high gain it seems to sound better a little compressed to "sing". If using for med/low gain 18v is awesome. For high gain 12v worked very well. I built one with sockets for voltage regulators and settled on 15v. Of course this is just my opinion and sound is subjective.

[papasaurus84]

I have run mine at +/-12v, 15v, and 18v. It gets cleaner and quieter (less compressed) the more voltage you use. At some point for high gain it seems to sound better a little compressed to "sing". If using for med/low gain 18v is awesome. For high gain 12v worked very well. I built one with sockets for voltage regulators and settled on 15v. Of course this is just my opinion and sound is subjective.

whoa...you did it? i have to re-check my schematics then.... . thanks for the input, shawn. i'm gonna post a schem for 18v today.

[shawnee]

Yeah it will work at +/- 18v but I wouldn't use a MAX1044 in it for the charge pump. I think I used a TC1044SCPA or even safer bet is a LT1054 (with pin 1 not connected to anything). I used sockets for voltage regulators so I can change the voltage if I want to so the charge pump is giving +/- 18v all of the time and then the circuit is getting fed the output of what ever voltage regulators I put in.

I never thought about it (but it's a much better idea) to use the zener diodes before the charge pump to drop the voltage before you double it. Less voltage going to the charge pump, cheaper, and you don't have to incorporate ground one leg of the voltage regulators, you could use any charge pump you want. I will do it this way from now on and socket the zeners so I can try different voltages. If you want the full voltage, just use a jumper in the socket (or use a 9.1v zener so that any input voltage will be ok and not fry your circuit if you accidentally plugged in a 12v power supply).

[shawnee]

The suggestions with bringing the initial voltage down to 6V and doubling it is a good one.
But dont use a voltage divider, use a 6V zener diode to bring it down or a 7806 voltage regulator if you dont want to calc the correct current resistor for the zener.
How much does the boneyard consume (in mA) ? you might get away with a 78L06 if is below 60mA.

Can you explain how to calculate the current resistor for the zener diode Thomas? I didn't realize that you had to do anything other than put the zener in between +9 and the IC.

[RobA]

The Evil Mad Scientist link gives the basics of why you need the resistor and how you would calculate it. The second link has a calculator as well as an explanation.

http://www.evilmadscientist.com/2012/basics-introduction-to-zener-diodes/
http://www.reuk.co.uk/Zener-Diode-Voltage-Regulator.htm

The main thing is that a Zener diodes current goes pretty much asymptotic in breakdown without a current limiting resistor. There are two points to computing the current requirements. The first is you need enough to keep the Zener conducting and that is specified in the product sheet. The second is to have enough current to supply the load. The load current will probably determine the resistor value mostly in this case (depending on the diode you use).

One thing to consider though is that this really isn't all that efficient of a way to set the voltage. I'd use a voltage regulator. Also the charge pumps aren't specified at 18V input. The LT1054, for example, is at max at 15V input voltage. So, getting +/- 18V would need another path.

[RobA]

Another thing you could do on the voltage would be to put in an LM317 and a trimmer to dial in the voltage. You could set it up to give you the voltage sweep that want.

[shawnee]

Thank you Rob! On the LT1054, I am only putting 9v in but getting +/-18 volts out. I have done the same thing with a TC1044scpa with no problems.

[shawnee]

ATTN: papasaurus84- I must have gone brain dead and didn't realize that I was telling you that you could put 18v into a charge pump until I re-read my post. I built a separate little power supply that takes +9v in and turns it into +/-18v out. DO NOT put 18v into your circuit.  I don't see any way that the pcb and a power supply pcb would fit into a 1590A. You could use a 12V supply into the pedal to get +/-12v if you use a TC1044scpa or maybe even 15v in if you use the LT1054 but it will be pushing the limit. Probably will work for a long time but the charge pump could give at some point.