HRW Mystique

[MartyGrass]

I have always liked HRWs sometimes!  The right guitar and amp settings can bring out a very pleasant brightness and sparkle.  The secret about making these pickups, as best I can guess, is a cryo treatment of the magnets.  I've asked Ren Wall a couple of times over the years about cryo treatment.  He just smiled and wouldn't comment further.

I'd like to put this to rest.  What's the truth?

 

[DetroitBlues]

The truth lies with Ren.  Just like the secret sauce of the 357, so does the HRW mystique will go down in history as a great unknown.

Only way is for someone to sacrifice the HRW and see what is different about them.

They pop up here every now and then, but no one has ever dissected one of them.

[MartyGrass]

We've gone down this path.

 

 

[ElNumero]

My 2004 555 has HRW’s. I even got a black dot on my pickup selector switch!!  

[Steiner]

24 minutes ago, ElNumero said:

My 2004 555 has HRW’s. I even got a black dot on my pickup selector switch!!  

Me too!
It’s a black switch though…

[Heritage1970]

46 minutes ago, ElNumero said:

My 2004 555 has HRW’s. I even got a black dot on my pickup selector switch!!  

They put those on all guitars that left the factory with HRWs. It's a side fretboard marker dot. Ren told me that was Marv Lamb's idea, so any time someone would see a Heritage with that marker, on TV, live, etc, they would know it had HRWs in it. 

[MartyGrass]

You're right about the dot.  I've put HRWs in my guitars a couple of times and did this. Clever guys!

Edited February 12 by MartyGrass

[ironmike]

unbalance the  coils by unwinding one a handfull , and slide in an alinco 2 magnet.

[MartyGrass]

47 minutes ago, ironmike said:

unbalance the  coils by unwinding one a handfull , and slide in an alinco 2 magnet.

Where did this idea come from?  

[TalismanRich]

16 hours ago, ironmike said:

unbalance the  coils by unwinding one a handfull , and slide in an alinco 2 magnet.

But I thought Schaller glued the magnets in, so they aren't so easy to replace.

[Heritage1970]

8 minutes ago, TalismanRich said:

But I thought Schaller glued the magnets in, so they aren't so easy to replace.

Yep. Pretty sure they do (or did) 

[MartyGrass]

To be candid about this, around a decade ago I really didn't like HRWs, at least in the bridge position in solid bodies.  The high frequency output was too sharp to my ears.  Eventually I sorted it out.  The neck position was always fine.  It's odd to me because I've never had an issue with Schallers.

I'm pretty sure HRWs were cryo treated.  I asked Ren once.  He just smiled.  In that particular context it would have been easy for him to say something like there's more to the story.  He didn't.  This conversation occured when I brought in a Johnny Smith with a Floating #3 pickup and asked about getting a tone control added.  He did the work while I was there, which took maybe 15-20 minutes.  He charged very little, no more than $50.

  

[nuke]

I’ve taken apart and repaired many Schaller humbuckers and there’s nothing special in them. The parts are all metric, and specific to Schaller, so you can’t swap bobbins and magnets, keeper bars and screws and baseplates with US made pickups or parts. They also come with different pole spacing depending on whether they are bridge or neck position. Many other brands are the same spacing for any position even if marked neck and bridge. 
 

Even many Chinese manufacturers use the standard US measure components. 
 

It isn’t so much you can’t take the magnet out and swap it, it is just you probably won’t be able to get another magnet of the exact same dimensions to fit in the Schaller humbucker. 
 

Anything is possible as to what’s in the HRW’s. It is entirely possible they were cryogenically treated. It is also possible that the baseplates, covers, bobbins and magnets were supplied to Heritage unassembled and they wound and assembled them at Heritage. 
 

Im happy with the HRW in my 2001 H535. Don’t want to take them apart. 

Edited February 26 by nuke

[MartyGrass]

Highly unlikely that bobbins were wound at Heritage.  Ren is a clever person.  I'd bet on the cryo treatment.  If not that, it's something that can change the sound but doesn't require a lot of labor.

 

Is It Cool or Not? Cryogenically Frozen Gear Explained | Ultimate Guitar

[ironmike]

On 2/22/2026 at 6:55 PM, MartyGrass said:

Where did this idea come from?  

REN

[nuke]

My Gibson R0 with CustomBucker 3 humbuckers have unbalanced coils (per Gibson) and they have a noticeable amount of hum pickup that other Gibson p'ups do not.  (and just for fun, I recently yanked out the alnico 3 magnets and replaced them with alnico 2 magnets, which so far I'm happier with)

 

My 2001 H535 with HRW's exhibits no hum, so I don't think the coils are unbalanced. 

I pulled out the Gauss meter and measured the magnetic field strength and polarization. One of the unusual things about Schaller pickups is the screws are "north" and the slugs are "south" which is the opposite of Gibson and most other humbuckers. The bridge and neck read about the same in terms of strength, and I'd estimate they are alnico 5 and strongly charged, with excellent field strength. Not the highest I've ever seen, but a bit more than most I've measured. 

The HRW's are definitely made from Schaller components, from the base plates to the covers and bobbin spacing, even the screw threads. But, Schaller could have simply supplied Heritage with the raw components, right down to empty bobbins for Heritage to wind themselves, and loose parts for them to assemble as they see fit.  Or they may have supplied them wound or in any other state of partial assembly.  I did check the electrical characteristics, the bridge is pretty hot, much higher wind than the neck. I wrote down the inductance and capacitance of the coils and 

If I didn't like the HRW's so much, I'd open them up. 

Schaller pickups are very well made. I'm working on several at the moment for a friend doing some restorations on 80's and 90's pointy shredder guitars. I just had one apart to replace the wire with a 5-conductor cable. I had them completely disassembled to clean up the baseplate and solder the ground shield. One characteristic that I've found is they are consistently wound, with very little variance pickup to pickup, and usually have low capacitance windings, so even hotter winds are nice and bright. I tend to wonder if Schaller built their own winders. They were certainly capable of that. 

If curious, maybe I can snap a picture of a Schaller pickup disassembled for repair. 

Edited 8 hours ago by nuke

[MartyGrass]

Ren wouldn't divulge his secret on HRWs.  But I have talked about it with him and with his long-time co-workers.  He would only smile when asked about what he did to Schallers.  My guess is that they took a bath in liquid nitrogen.  I highly doubt he did a partial uncoiling for several reasons.  The first is the lack of any hum.  The second is that a cryo treatment is an established way to modify a pickup.  The third is that cryo treating is clean and relatively easy.

Why did Heritage promote the HRW?  The best answer I can come up with is because they could, especially is the process is secret.

Here is what I got from AI.

 

Cryogenic treatment for guitar pickups involves deep-freezing the components (typically to around 

 or 

) to permanently improve their molecular grain structure. Proponents claim this process relieves internal stresses in the metal parts, such as magnets and copper wire, resulting in enhanced clarity, smoother frequency response, and increased output. 

ProjectGuitar.com +4

 

Claimed Benefits

While controversial in the guitar community, those who offer cryo-treated pickups cite several specific tonal and physical improvements: 

• Enhanced Clarity & Definition: Treating materials like copper and silver is said to improve string definition and provide "faster" transients.
• Smoother Overtones: The process aims to align the molecular structure to be more uniform, which some makers claim makes overdriven tones smoother and more "in tune" by reducing dissonant overtones.
• Increased Output: Some manufacturers report measurable increases in output (up to 18%) because the treatment potentially lowers electrical resistance and improves conductivity.
• "Turbo-Aging": For hardware and magnets, cryo-treatment is often marketed as a way to replicate the "relaxed" feel of vintage parts that have naturally settled over decades. 

 

Brands & Services

Several high-end and boutique brands incorporate cryogenic treatment into their products: 

• Seymour Duncan: Offers the Zephyr Silver series, which uses cryogenically treated silver wire and magnets for maximum expression and detail.
• Lindy Fralin / Callaham: Features the Callaham Cryogenic Fralin pickups. Callaham has also been known to offer treatment services for customer-supplied parts.
• V.I.P. Pickups: Uses a "cryo-tuning" process for their LOVERS PAF-style humbuckers to achieve a more transparent, vintage sound.
• Faber Guitar: Provides cryogenic treatment for various guitar hardware and components to minimize "bad" overtones.
• Nitrofreeze: An industrial service provider often used by boutique builders to treat electronic and musical components. 

 

Scientific & Practical Considerations

• Skepticism: Critics often point to a lack of peer-reviewed data supporting tonal claims, suggesting that perceived improvements may be due to psychological factors or "marketing hype".
• Risk of Damage: Extreme cooling can sometimes cause plastic parts (like bobbins) or adhesives to crack if the process isn't carefully controlled.
• Metal vs. Wood: While the effect on ferrous metals (steel) is well-documented in industrial settings for hardening, its effect on non-ferrous metals like copper is more debated in the audio world.