Need bias info on splawn quickrod

Hey guys. I was wondering if anyone could help that knows approx where to bias a new quickrod at. I’ve read in the area of 60-65 % percent and around 32-34 ma..
I’m getting a lot of hum and noise , I’m very suspectful it’s the guitar doing it. But I figuired I’d get new tubes or at least get them check d to be safe. It’s a 2015 model. Anyone who has done it or had it done and knows. I appreciate the info.
Thanks. Pat

The numbers you posted are in the right ball park.

So you have a used QR, not a new one I see.

My QR is super quiet when sitting idle so hum and noise seem indicative of another problem, as you've indicated.

I, or someone on this board, can probably help you troubleshoot.

Attached is a biasing tutorial that might help

http://splawnfans.proboards.com/thread/ ... g-tutorial


Plug guitar straight into amp and put the gain on 12 noon and volume on 10am. Then play.

Then plug your guitar into the FX return and let us know. Where did you buy the amp from? Where the tubes in the amp or packaged separately? I'd swap some preamp tubes around - that is more likely the suspect.

Need the plate voltage, number one.. And, the bias sweep on these is extremely minimal. You get a cold set, there's not enough range to get them up to snuff, get a hot set, you can't get them cool enough.

KT77's RIP in these amps!

FWIW, my Competition 50 watt's PV was 435. 60% put it just under 35mA, 65% 37mA, 70%, 40mA. I was told by Scott that 40 was acceptable (and "just fine"), I opted for 38.

311splawndude":28q7d61w said:

The numbers you posted are in the right ball park.

So you have a used QR, not a new one I see.

My QR is super quiet when sitting idle so hum and noise seem indicative of another problem, as you've indicated.

I, or someone on this board, can probably help you troubleshoot.

Attached is a biasing tutorial that might help

http://splawnfans.proboards.com/thread/ ... g-tutorial


Plug guitar straight into amp and put the gain on 12 noon and volume on 10am. Then plug your guitar into the FX return and let us know. Where did you buy the amp from? Where the tubes in the amp or packaged separately? I'd swap some preamp tubes around - that is more likely the suspect.

Click to expand...

Thank you. Great info there. Yup there’s a good bit of him sitting idle while the gainnstag scare used. But I think it’s a grounding issue with the guitarcas the pits are suspect. After speaking with Scott. He says the hymn is normal. I was just being cautious with the tubes. Bi did replace all the preamp. Just haven’t done the power tubes. I absolutely love the amp. For the record !!

Could be a bad guitar cable! I almost went insane one time with an amp, and it turned out to be a bad patch cable, but, it applies to regular cables too, (including speaker cables). Sounds silly, but, they can cause all kinds of havoc!

I would highly suggest cleaning all the tube sockets, spray all the jacks, pop a cable in and out a few tubes, rinse, and repeat. I just got a Yeti that had some noise problems, and after a good cleaning of tube sockets, pots and jacks, its as quiet as a church mouse, (aside from minimal normal hum). Sounds better too, so something dirty was holding it back!

Also, could be a wiring issue in your house!

napalmdeath":3ifnvmy1 said:

Could be a bad guitar cable! I almost went insane one time with an amp, and it turned out to be a bad patch cable, but, it applies to regular cables too, (including speaker cables). Sounds silly, but, they can cause all kinds of havoc!

I would highly suggest cleaning all the tube sockets, spray all the jacks, pop a cable in and out a few tubes, rinse, and repeat. I just got a Yeti that had some noise problems, and after a good cleaning of tube sockets, pots and jacks, its as quiet as a church mouse, (aside from minimal normal hum). Sounds better too, so something dirty was holding it back!

Also, could be a wiring issue in your house!

Click to expand...

Thank you. I’ll try that I think it’s a combination, I’m going to replace the cables Fix the guitar pots with new and I think that will help. It’s definitely a grounding issue that’s causing the hum. It’s quieter when I hold the strings. It’s a old house with 2 wire as well lol

32 mA is where Scott told me to bias mine when I inquired. It was a 2013 dropB+, and I put KT77s in it, biased to 32 mA, and it FRIGGIN RIPPED!!!!!!

If it's getting quieter when you're holding the strings, it could be EMI/RFI in the environment, in addition to a grounding problem. Does the amount of hum get better or worse depending on how the guitar is oriented in the room (e.g. north/south vs east/west)? If you can, try it out at another location and see if it's better or worse. Also, be careful with that ungrounded house current. That can easily contribute to hum/noise problems, not to mention that it can be dangerous.

FWIW, I don't remember the exact numbers, and IIRC the plate voltage in my Splawn Competition (single channel 50w QuickRod) runs closer to 500vdc, I biased it to about 67%. I'm using KT77s, too, and it sounds amazing!!

Thanks for the replies fellas. I took he amp over to get all the tubes checked and biased. Ordereda electronics upgrade kit from RS guitar works. The old pots were suspect and their was a cap that was cut in there. A doddgy tone pot and I was getting bleed thru with the volume all the way off. I think we should be good now Lol

Man, those RS kits are really good! Been using them in all my guitars for years. The bias and tube checkup should help, too!

I have a 2005 model that I run at 32mA. I get some hiss out of the amp, but nothing that a good noise gate can't get rid of.