Alnus Rubra
Loving nature’s wonders
That’s killer Doug! That Dallas looks so good atop your great work.
New head amp help
- Thread starter DougUSMC
- Start date
Ok, I guess I wasn't clear, apologies!
I "thought" I had 2 each of Blues, Greenback, and V30s, but my math (or memory) was bad. What I had was 2 each Blues and V30s, but only one Greenback. I decided the plan was to put 2 V30s and 2 Greenbacks in this cab, and change the Orange 2x12 clone to 2x Blues.
BUT
I guess I only have one Greenback, b/c that's all I could find today! So, temporarily (until the 2nd Greenback gets here), I'm going with this setup, but I'll swap out the Blue soon:
So, here are the before and after looks at the setup:
OK, that just looks killer in my (ahem) inestimable opinion.
D
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THAT looks great, and the speaker combo is interesting.
Just be careful to remember that you have a 15 watt speaker in there.
D
Deleted member 5962
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Also, didn't see the ratings on the speakers, but assuming you are wiring it series/parallel?
dmatthews
Dave's not here
Bloody LOVELY!
DougUSMC
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That's what I was thinking of last night. At first I was leaning towards a CNC or Laser etching machine, but now I'm thinking about a 3D printer. A friend has one, but I haven't even started looking at what the design software looks like.
Thanks! TBH, the main reason I decided on a V30 / Greenback pairing was so that I could NOT be 15w limited. Amazon says the 2nd Greenback will be here tomorrow.
Yup, with the change they'll all be 25 & 30w, so I'll stick to the standard 1960A wiring plan.
D
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V30s are 60 watts, so you're still limited by the greenbacks, just not to 15 watts. I'm not sure what the standard 1960A wiring is, or what ohms your speakers are.That's what I was thinking of last night. At first I was leaning towards a CNC or Laser etching machine, but now I'm thinking about a 3D printer. A friend has one, but I haven't even started looking at what the design software looks like.
Thanks! TBH, the main reason I decided on a V30 / Greenback pairing was so that I could NOT be 15w limited. Amazon says the 2nd Greenback will be here tomorrow.
Yup, with the change they'll all be 25 & 30w, so I'll stick to the standard 1960A wiring plan.
I’ve seen 16 ohm speakers (parallel-series) but 4 ohm (series-series) can be used too for a final cab impedance of 16 ohms, which is normal for Marshall.
D
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OK, I knew the standard Marshall 4x was 16 ohm. Obviously there are two ways it could end up there, so I didn’t know which. And that’s why I mentioned what ohm rating the speakers were, which I never did see an answer for.
Sorry...
They're typically 16 ohm to my knowledge. I’ve torn apart a few and that’s what I saw. It doesn’t mean that there could be other configs, but that’s my experience. Marshall wasn’t known for inconsistency in their cabs.
D
Deleted member 5962
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No, I'm sorry, I meant I didn't ever see an answer to what all of Doug's speakers were rated, so I didn't know which way he'd need to wire them.Sorry...
They're typically 16 ohm to my knowledge. I’ve torn apart a few and that’s what I saw. It doesn’t mean that there could be other configs, but that’s my experience. Marshall wasn’t known for inconsistency in their cabs.
If I'm buying individuals, I usually buy 8 ohm. For 2x's, usually 16 ohm. I've never had a 4x. But When discussing this above, I was wondering what his speakers were rated and never saw an answer to that.
DougUSMC
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Yup, all of mine are usually 16Ohm too. From everything I read, that's the standard setup for Marshall 4x12s, so I stuck to that and their OEM wiring plans too. That allows for a 4, 8, or 16 Ohm switching option w/their Stereo/Mono switch module.
You’re a young guy! My ears are the ones that’re old!
DougUSMC
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Lol, it's all relative!
I still have the two different hearing tests I did, entering the military (20 y/o) and exiting (32). I can see HUGE differences in them, and that was > 15 yrs ago!
That being said: I have a ton of hum/buzz that just isn't going away. I tried a couple of different heads, and it seems that the common denominator is the Dallas.
Anyone have any ideas on where to start to quiet it back down? I've heard they're normally super quiet...
Gorgeous! I wasn’t fortunate enough to find a paisley head like you, so glitz up! A little tip/ Dallas is a beast with bass and at gig volume, you will rattle the tubes and make filament noise. Setting head on the floor will isolate it enough to prevent that problem.
They are normally quiet. The place to begin is to disconnect everything from the head except the speaker, and see if it’s noisy on its own, no guitar, no pedals, no switching system, etc.
If it’s not noisy on its own, the culprit is a ground loop somewhere. If noisy on its own, the most common issue would be a tube.
It’s a process of elimination.
DougUSMC
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Ok, thanks, I'll try that tonight.
If it's a tube, is there somewhere that I can figure out the OEM tubes of a Dallas?
Also, I was doing some research and came across "Bias". Don't fully understand that yet...
You really need to inspect your existing tubes. If they are all stock, it’s probably a tube cocktail that struck the fancy of the PRS employee at the time. Mine has different power tubes from yours, but the exact make and model will tell you what they pursued, tone-wise. I took pictures of mine when I pulled them out to help me maintain the great vibe. Each tube was specifically chosen for its influence in the chain. It was very deliberate.
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Bias is the control that is adjusted to make sure the power tubes receive the voltage that the manufacturer thinks will sound best with the amp. On the back of PRS amps are three jacks for testing the bias, one black (common) and two red (one for each tube). This is a VERY easy thing to adjust if you have a multimeter that reads millivolts (every one I’m aware of reads millivolts).
Set the multimeter to millivolts.
You stick the black probe into the common jack, and the red probe into one red jack, adjust the bias for that tube, then do the other tube.
There’s a hole in the chassis for the screw that adjusts bias; you’ll need a small screwdriver for the purpose.
No two tubes are perfectly matched, but with the screw adjustment, you bias the tubes to an average that’s close to the manufacturer’s spec.
I don’t know PRS’ bias recommendation for the Dallas, because I don’t have one. Ask Customer Service.
Here’s a video on the process.
Ta da! Done.
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