1948 Regal / Oahu / Bronson – Style 50K Squareneck Hawaiian

This guitar was given to me by a very good friend. I really didn’t get around to playing it because the intonation was a bit off… but this turned out the be only caused by the nut raiser.  There are no brand indications whatsoever, but the might have worn off or may have been painted over.

It was imported straight from the US together with its little sister:

Hawaiian music hype

It is not a blues-guitar. It is an Hawaiian guitar and a response to early 20th century hype of Hawaiian music. It was the very same hype that put the ukulele in our collective memory. Remember that during depression days of the late 30s, even the Martin guitar factory only survived thanks to ukes.

Following the 1915 Panama Pacific International Exposition in San Francisco, Hawaiian music became very fashionable in the United States, leading to two predominant Hawaiian-music correspondence schools in the ’20s and ’30s: Oahu and Bronson. Oahu was headquartered in Cleveland, Ohio, while Bronson’s office was in Detroit, Michigan. (It is unlikely that either city was a hotbed of Hawaiian culture at the time.) Each of these outfits sold lessons by mail (often attempting to enlist advanced students as teachers and representatives) and featured its own line of guitars.

Oahu-labeled guitars were made for the Oahu Publishing Co. of Cleveland, which called itself “The World’s Largest Guitar Dealer” in 1935.

The Honolulu Conservatory of Music was established in Flint, Michigan in the late ’20s by Harry Stanley and his half-brother, George Bronson. Stanley founded Oahu in 1933; Bronson started the Bronson Music & Sales Co. in Detroit about the same time.

Harry Stanley around 1938.

Oahu offered a variety of squareneck and roundneck acoustic guitars — most were made in Chicago by Kay and Harmony. The most common are inexpensive ($22.50 in 1935) birch guitars with a dark brown finish. More expensive models were available; I used to own an all-mahogany small-bodied squareneck with black-and-white “rope” style binding ($65 in 1935). The top of the line was a rosewood/spruce jumbo with “pearl” inlay, soundhole ring and top trim. These were $158 in 1935 — more than $2100 in 2004 dollars.

But is it an Oahu guitar?

Oahu did not manufacture these guitars themselves. In fact they were mainly a publishing company focusing on sheet music and instruction books. They branched out into instruments, but had them build by other companies.

In the 30’s the company name was consistently stamped inside the sound hole. Our guitar does not have that however, although it looks very similar. As stated earlier, Oahu did not build guitars, they were built by either Kay or Harmony.

The Harmony company, founded at the end of the 19th century, was bought by mail order company Sears-Roebuck & Co in 1916, simply to corner the ukulele market. In the late 1930s, Harmony “also bought brand names from the bankrupt Oscar Schmidt Co.—La Scala, Stella, and Sovereign. They sold not only Harmony products, but instruments under the Sears name, Silvertone, and a variety of trade names—Vogue, Valencia, Johnny Marvin, Monterey, Stella, and others.”

Note the rounded off headstock, which is almost never found on Oahu-branded guitars:

1948 Oahu slotted headstock

But then again, have a look at this one:










And here’s a headstock from the Bronson Guitar Company: not very different, but note the upside-down tuners. Which are actually the correct way around when playing lap slide.

There seem to be Oahu’s without the brand stamped in the soundhole. On Jake Wildwood’s blog I found this very similar 50k model without the Oahu brand stamp. It does have the logo on the headstock:

It has the fake binding painted on the soundhole like mine, but also around the edges of the guitar. The most surprising thing, which is why it caught my eye, is that this guitar has the exact same bridge as mine. Jake writes:






The standard metal bridge is very recognizable because it has pyramid ornamentation. I was suprised to find this Youtube video of another squareneck Oahu with that same Regal/Oscar Schmidt bridge:

But it has more:

  • painted binding only around the soundhole
  • only light in the sunburst is around the bridge

Oahu guitars usually came with a very strange metal molded bridge, which was bolted down as you cannot glue metal to wood. So maybe the bridge was replaced. The original looks like this:

Original Oahu metal casted bolt-on bridge — source: youtube

Most distinctive feature of our guitar are the diamond fret markers:

All the material I could find is pointing to the the 1940s:

Stamp on the back

There is no manufacturer or company referenced inside the guitar. There is only this:

Then I found this Oahu for sale: http://www.thunderroadguitars.com/1948-oahu-square-neck/

Inside the guitar, there is this:

If this is really a ’48 Oahu, then the quest has ended. By 1948, they seem to have give up stamping the name inside the guitar.

Tube Radio Guitar Amp: Part 3 Making Plans – Vox Pacemaker 1965

Yes, there is a very nice and decent guitar amp hidden inside this scruffy old Philips radio, all the components except a suitable output transformer and speaker are present to solder up this nice gem:

Huh? Why? How?

Power rectifier EZ81 — If you are in Europe and hunting for tube radio with any value in the guitar amp field, check for this rectifier tube. If you see it, buy the radio!  This tube is used is the early Vox amp, up to the AC15 as power rectifier.  Most vintage American amp you will be looking at require at least 3 different voltage from the transformers: a high voltage, 6.3V for the tube filaments and 5V for the rectifier. The EZ81 does not require the special 5V, just feeds off the high voltage.

phillipspowersectionIn this way, it is just like a Vox Pacemaker — although below schematic is from a Cambridge Reverb (the same amp + reverb):cambridgereverbpower

Or an AC-15, also using an EZ81:


And all of these are unlike any 50’s Fender amp, which require three voltages on the transformer 6.3V, HV and 5V especially for the rectifier:

Transformer and rectifier tube in a Fender 5E3 Tweed Deluxe amplifier.

2 Power tubes EL84 & 1 Preamp tube ECC83 — if the transformer can power this in our radio, we need only one extra ECC83 tube to make a Vox Pacemaker. It uses 2 x EL84, 2 x ECC83 and an EZ81.  The Philips radio powers and additional 5 tubes for RF purposes, so it is certain that this transformer from a piece of €10 junk can function as the heart of a Vox Pacemaker, Vox AC-15 or Marshall 18W…. value: $75. My calculation seems to indicate this transformer could pull 5.4A on the high voltage.  I don’t believe you could find one that would feed anything more than a 25W amp.


The only thing that is missing, is the output transformer, which will cost around €50. Chassis, resistors (after measuring), 6.3V pilot light and mounting screw can all be salvage from the zombie corpse.

I really think you could use a lot of the power transformers in old radios, but the output transformers from household radio sets will never be strong enough.

Tube Radio Guitar Amp: Part 2 Plugging in…

After thoroughly checking the internet ressources and mostly figuring out which buttons do what, it was time to fire it up.  First I had to dig out some speakers to at least have some load connected to the output transformers to avoid them burning up.  IMG_5065

Well, incredible enough: the zombie came alive…. and it’s name is Steve Tyler.

Not all bands are working, but that’s not the part we care about anyway: we want to plug in our guitar.  For that we use the PU/phone/GRAM input on the radio.  In my case is was a sort of three prong plug: left signal, ground, right signal.  I salvage a two prong from another radio, had to snap it in two, then soldered one to the tip, another to the lug of an input jack.  Guitar is mono, this radio is from 1965 and a stereo unit, so we only use either left or right channel. You always have to connect to the middle, that’s ground.

IMG_5066Of course, you will also have to switch the radio to activate the phone channel.


Well, the sound when playing through a Epiphone Les Paul is mostly a kind of dog fart like fuzz tone that makes the cat up and hit for the garage, the real buy celexa prices lofi dirty gritty overdriven sound. And the volume is also lacking…

Speakers: I think these are 4 ohm speaker, while the output transformers like to see 8 ohm on each speaker. I am overdriving the speaker and overheating the output transfo’s.  I need to address that issue tomorrow.

Settings: The best tone and most volume is with all tone button disengaged. Mono turned on, but even in that mode, the Stereo Exp. function seems to do something (good).

Power Filter capacitors

These suckers are dead as Zed, after 55 years…no doubt about it.  I didn’t have immediate replacements for the big canned 50uF caps, but a third 8uF cap was much more in reach and obviously in need of replacement:

IMG_5076Here it is located in the schematic as C3:

powersectionI rolled up a home made 8µF/900V cap made up of two 4µF 450V’s in parallel:

IMG_5077And mounted them like this:


This gave me a tad more volume.

Input Resistance

The factory schematic shows 100k resistance in series with the phone jack on both channels. Decreasing the value to 68k (standard input resistance on most Fender amps) also will increase the volume a bit.  You may jumper it altogether, but if you start picking up Russian RF signals, it’s not the radio.




Sigma 000M-1ST Acoustic Guitar

000A terrific second hand find for €130, the Sigma 000M-1ST lists new for $355.    Originally the Sigma brand was set up by Martin in 1970 to respond to growing demands and the guitars were built in Japan.  It was sold by Martin to the German company AMI Music Instruments, GmbH in 2007, but by then Martin has even lost the rights to the name Sigma in the US.

Hence, Sigma guitars were marketed from 2014 onwards under the name of Kindred Guitars, and there seems some current battle about the ownership of the brand.

Golden Guitar Gallery in Nazareth, Pa. seem to have lost the right on the use of the name to Six Strings Brokerage.

000M-1ST specs

Among the earliest Sigmas built from 1970-1979 there is quite a bit of solid wood, but by the turn of decade they had depleted their stock. From 1980 onwards, almost all Sigma (unless explicitly indicated) are non-solid tops, backs and sides. The new line of Sigma/Kindred however, are all feature solid spruce tops. If we read the orientation chart, we can read the specs of this guitar:

Sigma model chart
Auditorium size (000) solid top, laminated mahogany (M) back & sides, with gloss finish (1ST)

I expected this guitar to be short-scale, but it isn’t – as a matter of fact, Martin 000’s are not consistently short scale to begin with. Scale length and nut width match the 15-series Martin 000. But strange is the nut width difference between 000-18 and 000-28.  In the end, this Sigma’s specs are most like the OM-18 Authentic, with its solid spruce top, long scale and smaller nut width.

  Sigma 000-1ST Martin 000-18 Martin 000-28 Martin OM-18 Authentic Martin 000-15M
back&sides laminated mahogany solid mahogany solid rosewood solid mahogany solid mahogany
top solid spruce solid spruce solid sitka spruce solid adirondac spruce solid mahogany
body size 000 000 000 000 000
scale 25.4 24.9 24.9 25.4 25.4
nut width 1-11/16 1-3/4 1-11/16 1-11/16 1-11/16

So this trusted Martin muppet is wrong: not all 000’s are short scale, not all OM’s have wider nuts, etc… Luckily there is a community out there to correct her:


Truss rod

As Dave constantly warns us: before you buy a guitar, make sure the truss rod works. Suprisingly, neither the 5mm allen wrench which came with my Simon & Patrick Pro Mahogany was too small and a 6mm wrench too big for the Sigma. I called the big store selling Sigma in Belgium, they told me to come round, but couldn’t tell me what type and size of wrench would fit this guitar. Also sent a mail to Sigma, as yet got no reply.  In fact the neck relief is quite ok, but it could use a nudge and I just want to check whether it is working.

Sigma 000M-1ST sound hole truss rod
Sigma 000M-1ST sound hole truss rod












Update! Today I got a reply from Sigma Guitars:


it is a 4mm hex wrench, usually there is one in the box.

Kind regards


There was no box and no wrench with the guitar, but it’s a standard 4mm allen wrench.  It was strange, because I had discovered this at the same time as the mail buying celexa online arrived, while I was trying to set up another guitar: The Gretsch Jim Dandy parlor guitar I had bought my daughter. Saddle on that was already pretty low from the factory, and putting some tension on the truss rod straightened it out.

Just like on Martins, the Sigma truss rod is quite a way back in the neck, so I had to use the long end and twist it with a pair of pliers.  In fact, it needed little adjustment, just a little nudge extra was good.

Sigma truss rod adjustment with 4mm wrench
Sigma truss rod adjustment with 4mm wrench


The neck consists of three pieces of mahogany: heel, neck proper and the headstock.

Neck - heel joint
Neck – heel joint
Neck-headstock joint
Neck-headstock joint

Action, Saddle & Bridge

I had been watching the listing of this sale for a few weeks, hesitating to buy it, when the listing suddenly dissapeared.  I thought it had been sold.  A week later it was relisted, and I didn’t hesistate then.  The day after the sale was concluded I learned what had happened.  People had come to see and try the guitar, but were turned off by the extremely high action on the guitar.  The seller took the listing off line and went to see the store where he had bought the guitar 2 years previously.  The ‘tech’ there told him he didn’t have the proper truss rod wrench nor knew where to get one.  He advised the owner to sand down the saddle to proper string height, which he did.  When I took out the saddle, this was what I saw:000-saddlepre01


The bottom of the saddle (top of the picture) was sanded straight; this was obvious as the saddle wouldn’t even stand up by itself on a flat surface.  I sanded the saddle off straight and took off some more material.  I kept the strings caught in a capo, so I could quickly re-install a string to check the action in between sanding sessions.


One problem that popped up was that the saddle didn’t fit snugly in to the slot.  I will be ordering a new saddle one of these days, so I put in a very small piece of thick paper to make for a tight fit as temporary solution.


I ended up with a little over 2mm on the bass side, just a little less on the treble side.  Time to get me some proper measuring tools.


Even more importantly, the intonation turned out spot on, except for the G string (just slightly sharp).

Edit: after adjusting the truss rod, the action improved a little more.


On the basis of the information of the original owner, this guitar was bought in 2013, so presumably, the first two numbers in the serial refer to the build year: (20)12. 0304 might be date code as well… 4th of March? Would this be the 519th guitar built by Sigma?  We will have to look at more serials.