Wrecking Ball help - loud hum

P

punchy712

Member
I decided to try out some tube-based pedals and so I started with 4 C2C projects that I just finished up. Three of them fired up perfectly, but the Wrecking Ball has a massive constant hum as soon as I bring up the volume (gain and all other settings can be at minimum). I'm hoping to get some pointers on how to start troubleshooting this issue as it might be a bit different than the standard pedals I've done in the past. With an audio probe right at the input, the hum was there, so I'm guessing there's a problem in the power section.

If anything obvious looks off or if you have some tips, it would be very appreciated.

I forgot to mention that the pedal seems to work otherwise.
 

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Audandash said:
What are you using for your power supply? The wrecking ball will pull significantly more power than the other projects.
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That's a good call and hadn't considered that as a source of hum. I was just using my pedal power which gives out 200-250mA, which after typing out is likely nowhere near enough. I think I assumed that if it worked for the 2-tube Black Eye then it would be fine for this too. I can double up on the current, but even then I'm not sure it'll be sufficient. Looks like I'd need to go buy a 1 Spot as that seems to be the best/easiest option for high current 9V output.
 
punchy712 said:
That's a good call and hadn't considered that as a source of hum. I was just using my pedal power which gives out 200-250mA, which after typing out is likely nowhere near enough. I think I assumed that if it worked for the 2-tube Black Eye then it would be fine for this too. I can double up on the current, but even then I'm not sure it'll be sufficient. Looks like I'd need to go buy a 1 Spot as that seems to be the best/easiest option for high current 9V output.
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Yeah man, 250mA isn't even enough for a single-tube pedal, I typically recommend 500mA for a single tube and add 200 mA for every additional tube. Insufficient current will absolutely give you some noise because the tubes aren't able to heat up enough to pass signal properly.
 
punchy712 said:
That's a good call and hadn't considered that as a source of hum. I was just using my pedal power which gives out 200-250mA, which after typing out is likely nowhere near enough. I think I assumed that if it worked for the 2-tube Black Eye then it would be fine for this too. I can double up on the current, but even then I'm not sure it'll be sufficient. Looks like I'd need to go buy a 1 Spot as that seems to be the best/easiest option for high current 9V output.
Click to expand...
I think the best option is to buy a power supply from the C2CE shop now that there are power supplies available.
I am going to buy several power supplies with my next PCB order so I can have a power supply available every time someone borrows a Sushi or C2CE pedal from me.
I think for $13 each power supply at 1000mA you can not get better value for money.
c2celectronics.com

9V 1000mA Power Supply

This is a generic high-current 9V power supply for use with tube pedals and other effects that require more juice than the typical adapter can supply. Voltage (nominal): +9V DC Current: 1000mA Pola…
c2celectronics.com c2celectronics.com
 
Audandash said:
You might want to consider one of the current meter kits to measure ma’s in the future. It’s especially helpful for the tube pedals. To be honest I’m surprised it worked at all with such a small amount of power.

www.pedalpcb.com

DC Current Meter Kit - PedalPCB.com

DC Current Meter
www.pedalpcb.com www.pedalpcb.com
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I've been wanting to build a DC current meter for a long time, this might finally push me to do it.

I'm really surprised that the 1 and 2 tube pedals worked, which is why I didn't even think of the power supply as a cause. I picked up a 1 spot power supply and with 1.7A available it should be fine to even run two of these pedals if needed. The hum is gone now, so thank you for all the help.
 
punchy712 said:
I've been wanting to build a DC current meter for a long time, this might finally push me to do it.

I'm really surprised that the 1 and 2 tube pedals worked, which is why I didn't even think of the power supply as a cause. I picked up a 1 spot power supply and with 1.7A available it should be fine to even run two of these pedals if needed. The hum is gone now, so thank you for all the help.
Click to expand...
In the future if you decide to run multiple tube pedals from c2c the Cioks dc7 or dc5 power supplies are tough to beat. They are pricey but each outlet is isolated and can power up to 600ma each which is plenty for “MOST” of the c2c projects. The one spots are a great buy and I am sure the power adapters Nathan has now are roughly equivalent in quality (1 amp max I think vs 1.7). They are all power hungry but thats what makes them sound so good!
 
Audandash said:
In the future if you decide to run multiple tube pedals from c2c the Cioks dc7 or dc5 power supplies are tough to beat. They are pricey but each outlet is isolated and can power up to 600ma each which is plenty for “MOST” of the c2c projects. The one spots are a great buy and I am sure the power adapters Nathan has now are roughly equivalent in quality (1 amp max I think vs 1.7). They are all power hungry but thats what makes them sound so good!
Click to expand...
I'm definitely impressed with the sound of these tube pedals, so thanks to Nathan for making these available. I had plans to build a Soldano XP77 preamp, but the Black Eye may do for now.
 
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