NewCastle 30 vs Scarlett 30

Since we released the Scarlett 30 shortly after the release of the NewCastle 30 I have been inundated with emails and calls asking, “what is the difference between the NewCastle 30 and the Scarlett 30?” So given the frequency that the question is being asked I thought it would be prudent to delve deeper into the subject and offer a more in depth look at the two amps and their differences.

Common questions related to these two amps:

“Which amp is cleaner?”

Hands down, the Scarlett 30 is cleaner. Everything about the Scarlett 30 was designed and tweaked to keep the tone of a ‘Top-Boost AC30’ but do it in a way that is cleaner and more flexibility and headroom.

“Which amp has more gain available?”

Believe it or not, the Scarlett 30 has more gain available at the end of Volume knob than the NewCastle 30. Here’s why. With the NewCastle 30, there is only 1 gain stage. It’s a 12AX7 that feeds into a Volume control and then into the Phase Inverter tube which again is a 12AX7. The overdrive from the NewCastle 30 comes from overloading the phase inverter and subsequently the power tubes. The overdrive characteristics of the NewCastle 30 was designed so that the amp would hold together and remain cohesive even when cranked wide open.

The Scarlet 30 however is a different beast. If you are familiar with the layout of the Top Boost AC30 preamp you’ll know that there are 3 preamp stages in the preamp itself. They are, a 12AX7 gain stage into a volume control, another 12AX7 gain stage and finally another type of 12AX7 gain stage called a Cathode Follower which is essentially a buffer that feeds the preamp into the tone controls and finally into the phase inverter etc. Because there are two actual gain stages in the Top Boost preamp (the cathode follower has a gain of unity or 1 so there’s no amplification happening there) you have a lot of potential gain on tap should you require it. I say “on tap” because in the Scarlett 30 we are very selectively tweaking the available gain down to keep as much clean headroom as possible in the amp so the amp could produce a GREAT deal more gain if we wanted it, however that would be outside the design goal of the amplifier.

The Scarlett 30 ships with (3) 12AT7 preamp tubes and that along with several other internal tweaks is what helps the preamp stay so clean. TONE HINT: If you have a Scarlett 30 and want it to be a fire breather, selectively swap some or all of the 12AT7’s for 12AX7’s and enjoy.

“Which amp would be a better bedroom amp?”

I can honestly say that either amp would work here. Because of the Power control on each amp you can vary the power from 30W down to 1/8th of a watt. So in light of this, either would do well, it’s just a matter of what tone you are after.

“Is the Scarlett 30 just a NewCastle 30 with a tone stack?”

Not at all. While both the NewCastle 30 and the Scarlett 30 both share Vox type tones, they are completely different designs. Read the next question for more clarification on the NewCastle and NewCastle 30’s beginnings.

“What is the NewCastle 30 based on?”

The NewCastle 30 is obviously a higher wattage version of our NewCastle that we released a year ago. To make the NewCastle 30 we added 2 more EL84’s, an FX loop as well as the Variable Power Supply (Power) feature to the existing NewCastle design.

When I first set out to design the NewCastle I just drew up a simple 12AX7 gain stage into a Volume control and straight into the phase inverter. It’s super simple and just about the most simple amp you can design. After it was build and functioning I spend a day dialing in the low end to make sure that even when the Volume control was cranked it would remain tight without flabbing out like a lot of amp do when you push them hard. That is really what the NewCastle is based on. It wasn’t a clone of anything; just me sitting down with a pen and paper and eventually building what I drew. Luckily it worked out and people seem to like it!


That’s all I have now on these amps. If you have any more questions, please comment below and I’ll try and answer them. Thanks guys!


  1. I live in New Hampshire so I don’t have the opportunity to play your amps in person.
    Out of the Newcastle 30 or Scarlett 30, which would you say has a more “pure” tone when the volume is turned up and it starts to distort? By pure, I mean which still has the chord articulation while retaining note bloom/sing?
    I have watched every Youtube clip that I can find and it is so hard to tell without playing the different models.
    Thanks for the help and I know you are super busy running the company so I really appreciate your time!
    I have been drooling over your amp for 4 or 5 years now.

  2. Hi,

    I own an original newcastle 30 that I absolutely love. I put a mojo hand rook in front of it for more gainy stuff. I’ll be honest though, I’m still looking for a good pedal that will give me more of a modern high gain sound when playing with band.

    Any recommendations?

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