Pettyjohn Rare - First Impressions.

[László]

IF they are doubling any input voltages from 7-18, then they have in fact added a full voltage doubling circuit. That would be a lot of circuitry to add in a pedal.

Inside their Pettydrive 3. Seems they're not afraid to put a lot of circuitry in a pedal.

Quoting their website re: how they do it:

"36 Volts of High-Headroom Power

All CORE Series pedals feature an inverting charge pump, usually reserved for studio rack gear, that first inverts and then doubles your power source, allowing for up to 36v of power. That's 4X the headroom of most standard guitar pedals!

This means you can plug in a a 9v power adapter and get 18v of headroom, or plugin a 18v power adapter for 36v of headroom.

Higher headroom empowers a pedal's op amps to operate at their theoretical maximum, providing the cleanest, least distorted signal possible. By doing so, tone can be dialed in further down the circuit providing unprecedented control when you want to push a signal into overdrive, distortion and fuzz.

The higher headroom in Pettyjohn pedals also allows you to stack them in your pedal chain with little-to-no tone suck."

I figure this is why their pedals are expensive, though not much worse than other high end pedals that look a lot simpler inside, and less than pedals like the Origin effects stuff. So to me, these are an excellent value.

On a personal note, I've usually driven their pedals with 18V, though I havre enough pedals on the board running that way that my power supply is really challenged. So now I run a few with only 9V. I need to up my power supply game to take full advantage of the headroom in all their pedals.

Hopefully the above info helps you wrap your head around what they're doing.

 

[Prina]

All CORE Series pedals feature an inverting charge pump, usually reserved for studio rack gear, that first inverts and then doubles your power source, allowing for up to 36v of power. That's 4X the headroom of most standard guitar pedals!

What a cute little transformer.

Had to think abut the 'inverting' part though. Transformers only transmit the AC component of the primary input, and none of the DC component, to the secondary output and AC inverts every cycle anyway. So what they're probably talking about is using an inverter circuit to turn the DC to AC before stepping up the voltage via the transformer, similar to the 12V DC to 110V AC units for cars. Then they'd rectify & filter that stepped-up current back to DC.

 

[László]

What a cute little transformer.

A thing of merriment and joy! They use very small transformers in lots of high end microphones and mic preamps as well, like the Neumann U87, U89, Neve 1073, etc.

Had to think abut the 'inverting' part though. Transformers only transmit the AC component of the primary input, and none of the DC component, to the secondary output and AC inverts every cycle anyway. So what they're probably talking about is using an inverter circuit to turn the DC to AC before stepping up the voltage via the transformer, similar to the 12V DC to 110V AC units for cars. Then they'd rectify & filter that stepped-up current back to DC.

I'm on a 'need to know' basis here.

I don't 'need to know' how these gadgets work. I just need to know whether they work, and how to operate them.

For me, end of story. The pedals work. They sound great.

Stephen Pettyjohn is a mastering engineer who has designed mic preamps as well as the line of pedals. He's pretty good at electricity.

 

[DreamTheaterRules]

Hopefully the above info helps you wrap your head around what they're doing.

Yes, and my apology again for thinking you didn't get it. Clearly they are going way beyond what anyone has done in pedals before. And part of my misunderstanding of the marketing jargon would have been clearly answered if I had read this before replying.

And, part of it didn't even make sense at first... That is A LOT of stuff to add inside a pedal just for the specific purpose of doubling the supplied voltage. You could always just use a higher voltage supply. But they are clearly pushing the boundaries of what you can do inside a pedal.

 

[DreamTheaterRules]

What a cute little transformer.

Had to think abut the 'inverting' part though. Transformers only transmit the AC component of the primary input, and none of the DC component, to the secondary output and AC inverts every cycle anyway. So what they're probably talking about is using an inverter circuit to turn the DC to AC before stepping up the voltage via the transformer, similar to the 12V DC to 110V AC units for cars. Then they'd rectify & filter that stepped-up current back to DC.

That's why I didn't "get" this at first. It's like "surely they aren't doing inversion and step up just to increase the voltage! They could just do that with a bigger power supply!" But... here we are. LOL

 

[László]

Yes, and my apology again for thinking you didn't get it. Clearly they are going way beyond what anyone has done in pedals before. And part of my misunderstanding of the marketing jargon would have been clearly answered if I had read this before replying.

And, part of it didn't even make sense at first... That is A LOT of stuff to add inside a pedal just for the specific purpose of doubling the supplied voltage. You could always just use a higher voltage supply. But they are clearly pushing the boundaries of what you can do inside a pedal.

No need to apologize. I don't understand this stuff very well, and it's often just as likely I don't get it, as I do get it.

But I was kinda sure I got it right tis time.

 

[DreamTheaterRules]

He's pretty good at electricity.

Clearly, and I'm just some dude on the internet, so don't pay any attention to me. LOL

 

[László]

That's why I didn't "get" this at first. It's like "surely they aren't doing inversion and step up just to increase the voltage! They could just do that with a bigger power supply!" But... here we are. LOL

The Pettydrive 3 is a different pedal than the Core pedals. So was the Pettydrive 2. So maybe it's different. I was just looking for a gut shot on their site to show how they build their gear.

 

[DreamTheaterRules]

No need to apologize. I don't understand this stuff very well, and it's often just as likely I don't get it, as I do get it.

Well, I do, and didn't mean to come off like a know it all. This guy is pushing the limits... my "traditional wisdom" doesn't apply here. LOL But if you ARE someone who has delved in this, this stuff is REALLY interesting!

 

[László]

Well, I do, and didn't mean to come off like a know it all. This guy is pushing the limits... my "traditional wisdom" doesn't apply here. LOL But if you ARE someone who has delved in this, this stuff is REALLY interesting!

The only Pettyjohn pedal I opened up was the Pettydrive 2 I gave my son, because it offered a choice of diodes or something, and I wanted to see how it worked - they literally had a different unused part in a holder that you could swap out one of the circuit board parts with (!).

When I opened it, I thought, "This looks really different from my other pedals". I only open pedals to remove the batteries since I use DC power with them, and lately, batteries leak, so I don't want that to happen. But yeah, they look different inside, that's for sure.

The PJ pedals don't come with batteries so I generally don't open them.

 

[László]

I forgot to mention that I ordered more of the Grimm TPR cables from Revelation with the small connectors to put the PJ Edge pedal back on the board, so I will have a dozen on the board (including the tuner). That's more pedals than I've ever run on one pedalboard at the same time.

I think I may be developing a little pedal acquisition syndrome...

I'm still not sure where I'll locate it. I may just take the easy way out and put it where there happens to be a spot already. Otherwise I have to move a bunch of stuff and I don't know if I have that kind of energy.