Coming soon to runoffgroove.com: Thunderbird

[Frank_NH]

I have a question about the power section of the design.  What is the reason for specifying tantalum capacitors - is there some advantage in terms of noise reduction?  Would normal electrolytics work OK?  Thanks.

[~arph]

I have a question about the power section of the design.  What is the reason for specifying tantalum capacitors - is there some advantage in terms of noise reduction?  Would normal electrolytics work OK?  Thanks.

See page 3: http://www.diystompboxes.com/smfforum/index.php?topic=109465.msg1003234#msg1003234

[Frank_NH]

Thanks (that one slipped by me).  Here is the explanation:

c. Some capacitors involved in the voltage tripler are specified to be solid tantalum for low ESR (as explained above).  These capacitors must be rated for 35V minimum to avoid trouble.

[peterc]

Hi all

I was looking at the DIY PCB layout and was wondering about adding in the extra pads and using 16mm pots.....

There will be space as is, and if necessary, the PCB could be extended as well by a few mm and still fit into a 1590bb.

Anyone see any other issues with doing this?

Peter

[B Tremblay]

You can use 16mm pots and flying leads to the pads. That's what I did with my first prototype build of the circuit. It was a different PCB layout, but that doesn't matter.

[Bucksears]

What size/type is the enclosure in the completed/labeled Thunderbird pic on the Runoffgroove site?

[B Tremblay]

1590BB from BLMS

[gtr2]

I think the top second side art has been left off the build document PDF?  Unless they made 2 different layouts.  Commercial and home etch single side?

The etch layout is the last page of the build document.

Josh

[Buzz]

I just received my board from 1776. Top notch, thanks !

It's going to be a nice tight build.

In order to keep it a neat build some of the caps are going to have to be physically smaller than the ones I have on hand. ( nothing looks worse than a huge electro hanging over the top of a pcb ! )

So what would be the minimum voltage rating for the film and electro caps?

Would it be 35v as applies to the tantalums or could I go lower?

[B Tremblay]

35V across the board (no pun intended) is the safest bet. Good luck with the build!

[Frank_NH]

Here's is my 1776 Effects board (sorry for the grainy image).  Yes, 35V rated caps, including those tantalums.  The only issue I had with fitting components was with some of my 470nF box caps - I get them from Smallbear as his are physically smaller and fit the board better than others I've gotten elsewhere.  I really love the 9mm pots - very easy to mount to the PCB and they work great!

[Buzz]

Cheers Guys.

Yep, my 470nfs are too fat ( wide? ) for this build.

Thanks for the heads up, I'll check out smallbear if I can't source them locally.

Small bear have unmatched price, product range and service for pedal components. The US postal fees can be prohibitive for small orders when you live in Oz.

Great looking board Frank. Neat as a pin.

[aion]

Yep, my 470nfs are too fat ( wide? ) for this build.

In a pinch, you could the 470n's on the bottom side of the board. Since the PCB mounted hardware is all along the top, you won't run into anything.

[agung]

whats the best replacement for 1n5711?thank you

[stm]

You can use BAT46 or the like as well.  Smallbear carries them.

[K Zustang]

Hey Guys,

just finished my build last night. Sounds very good and dynamic with a lot of sweet spots even at lower gain settings which I really love.

One thing I am curious about is why there such a strong HISS at volume levels above 9 o'clock. It seems that the hiss is always there even at lower gain settings and without pushing the TONE or TOP to high levels.

Any suggestions? My build is pretty neat without long wires or anything but I also didn't use the coax cables on the input and output. Could that be it?
Did anybody here get strong HISS also?

Thanks a million,
D

[Frank_NH]

My build does have some background hiss (though it's relatively low level), but it's a loud effect and I rarely need to turn up the volume past noon.  Rolling back the treble will diminish the hiss somewhat.

Since there are a lot of amplification stages in this design, some noise is inevitable.  Using standard noise reducing building practices should help (i.e. metal film resistors, shielded cable for input/output, etc.).

Then again, no complains about tube amp hiss...  

[K Zustang]

The HISS is on the LEVEL pot mainly. No matter what the GAIN settings are. At high GAIN the volume is so loud that the hiss is practically negligible.
At low GAIN, which is my favorite sweet spot, around 10-11 o'clock, the volume is lower so I crank the LEVEL knob a bit closer to noon. Around these volumes the HISS is pretty audible.
I always use the metal film resistors which are excellent.
I will replace the input, output and level wires with shielded wires hooked to the ground on one side and see how this helps.

Thanks,

btw, just compared the Thunderbird with the Thor and the Thunderbird does sound better and has much more versatility. I still love the Thor.
Next mission is to compare them both with Wampler's Plexi-Drive and Pinnacle.

Doron 

[Buzz]

I proved my own ignorance on this pedal. I did a really neat job, I was careful and neat with all my soldering. I tested all my components. It sounded GREAT! Best guitar distortion pedal ever. My bandmates eyes nearly popped out of their heads when they heard my Squire parts-caster - Thunderbird - ratty old Marshall 800 combo.

It did, however have a slight hiss. Not as much hiss as an off the shelf DS-1. I could roll it off with either the tone or volume controls.

So I went back in and re-touched any solder points that looked even slightly suss. Now it is dead. I cooked something. De-bugging here I come. The more I learn the less I know. 

[K Zustang]

Check your voltages.
It might be the charge pump which is a little sensitive if you do soldering work while the chip is mounted.

btw,

The HISS is around 4kHz and it's very hard to get rid of.
Shielded wiring did help a little but not that much.
Still sounds great.
Volume knob on guitar doesn't clean up the pedal like I expected.

Best sound I got was with the pedal in front of a Catalinbread WIIO. These two together sound amazing.