Sunday, May 8, 2016

The Fender Princeton Amplifer

The Evolution of the Fender Princeton Amplifier

The Fender Princeton was introduced in 1947 and discontinued in 1979. It was one of the first amplifiers Fender offered, and in the line-up even before Fender’s smallest amplifier, the Champ, which was introduced in the 1948.

Fender Princetons and Princeton Reverbs are highly valued particularly as great recording amplifiers. Jazz artists liked them two, since they were small, yet loud enough to be heard in a combo and had great headroom. Blues and rock guitarists like the early breakup of the 6V6 tubes. This is all sort of funny since Leo Fender considered this to be a student amp, hence the name Princeton. In his original line-up he also offered the bigger and slightly louder Harvard amplifier.

1947 Princeton "Woody"
The original 1946 Woody Princeton had no covering, just a wooden housing with a choice of natural finish or stained mahogany or walnut. This 4 watt cathode based amplifier came with an 8” field coil speaker. By 1947 this was changed to an 8” magnetic Jensen model. The amplifier used a 5Y3 rectifier tube, while the preamp section was made up of a single metal envelope 6SL7 or a 6SJ7.

The power tube was a single 6V6. It had an instrument volume control, a mic volume control and a tone control, along with 3 inputs. This amp was produced through 1948 when it was replaced in by the TV front Princeton. Fender usually put their badge on the lower corner of the Woody amplifier.


1949 Fender TV Front
The TV front Princeton was covered with tweed fabric made of lacquered linen cloth. and It came with a brown mohair grill covering. It pumped 4 watts of power into an 8” Jensen P8R speaker. This amp came with a 5Y3 rectifier tube, a metal envelope 6SJ7 preamp tube and a single 6V6 power tube. The amps controls were on the top of the chasis instead of the back panel.

Again the came with an instrument volume control, a mic volume control and a tone control along with 3 input jacks. This amp continued through production from 1948 through 1953 when the Wide Panel Princeton replaced it.


The badge was placed on the top front side of this amp, and would remain in this position on subsequent amps until Fender came along with their front panel line.

1953 Wide Panel Princeton
The Wide Panel Princeton came with some changes. The covering was still tweed, but the chasis’ shape was different. The grill cover was made of brown linen. Inside the amp housed an 8” Jensen P8T speaker. However some came with Oxford EV8’s and some came with 8” Cleveland speakers.

The tube configuration was a little different as well. Fender used either the 6SL7, or a 5B2/5C2/5D2 or a 12AX7; whatever was available. The Power tube could be a 5B2, 5C2, 5D2, a 6V6 or a 6V6GT.


Once again the rectifier tube was a 5Y3, but it could also be a 5B2, 5C2, 5D2 or a 5Y3GT. The changes caused a slight increase in wattage to 4.5 watts. The amp controls and fuse were now on the amps top control panel. This amp had an instrument volume control, a mic volume control and as on/off throw switch. This amp was in production until 1955 when Fender redesigned it to the become the Narrow Panel Princeton.

1955 Narrow Panel Princeton
On the narrow panel Princeton the chasis was redesigned. The covering was still tweed suitcase material with a dark brown grill cloth cover with a diagonal pattern. The control panel and two input jacks were on the top, with similar controls and fuse placement. The speaker was usually a Jensen P8T, but it could be an Oxford EV8 or an 8” Cleveland speaker.

By this time Fender had settled on a 5Y3 rectifier, 6V6GT power tube and a 12AX7 preamp tube. It is interesting that the initial models utilized a “choke”, which was a small transformer attached to the speaker to act as a filter usually to minimize bass response so the speaker wouldn’t rattle.




Speaker with a choke transformer
Later Fender removed the choke from the circuit. These amps were in production from 1955 through 1960. They were replaced by the Brown Princeton amp.

The Brown Princeton amp was the first step Fender took in modernizing its design. The control panel was on the front of the amp. The wooden chasis was covered in brown tolex. The speaker grill material was a color usually described as wheat.

The Brown Princeton amplifers power rating was dramatically increased to 12 watts, which powered a 10” Jensen C10R or an Oxford 10J4 speaker. The front facing control panel was painted brown and the knobs were also brown. The amp feature hi and low gain input jacks, a volume control, a tone control as well as speed and intensity controls for the built-in tremolo circuit.

This amp was no longer cathode based, but non-adjustable fixed bias. The rectifier tube was a 5Y3, two 6V6 power tubes worked as class AB, two 12AX7 tubes acted in differing ways. Half of the first tube acted as a phase inverter, while the other half was for preamplification. Half of the second tube worked the tremolo, while the other half was utilized for preamplification. These amps were only manufactured from 1961 to 1963.

1963 Princeton amp
In 1963 Fender once again modified its design to the blackface model Princeton amplifier, which in my opinion one of the finest amps ever made. Originally the black tolex cover chasis had grey grill cloth.

In late 1964 this was switch to silver sparkle grill cloth. Once again this was a class AB fixed, non-adjustable bias amplifier. It was powered by two 6V6GT tubes operating in push-pull mode. The rectifier was a 5Y3 tube.

The main preamp tube was a 7025. And two 12AX7 tubes split the load between phase inversion, preamplification and the tremolo circuit. The first model had the same control panel as the Brown version, although the control plate on this amp was black with white lettering. The knobs on it were white.

1964 Princeton amp
By 1964 the controls were modified to Volume, Treble, Bass, Speed and Intensity. This amp came with the familiar Fender black skirted knobs with chrome insert. Neither of these amps had a Fender badge.



Perhaps it was the lack of a reverb driver, that provided this amp with exceptional headroom. The Blackface Princeton amp could be cranked up to 7 or 8 on the volume and still produce a clean sound.

1964 Princeton Reverb
Later in 1964 Fender designed the Princeton Reverb amplifier. This was in my opinion a spectacular amplifier and great for recording. The chasis design was similar to the previous model, with the addition of a reverb potentiometer. The circuit was obviously different.

The rectifier was usually a 5Y3 tube, but substitutions were used, so it could be a GZ34 or a AA763 or a AA964. The twin power tubes were once again 6V6GT’s. The phase inverter was half of a 12AX7 and the other half was used for preamplification.

1964 Fender Princeton Reverb
The main preamp tube was a 7025. Another half of a 12AX7 was used for the tremolo, while a 12AT7 was used as the reverb driver. The amps 10” speakers ould vary in brand. It was generally a Jensen C10R or C10N. However Oxford 10L5’s and 10J4’s were also utilized.

Hammond Reverb tank
The wattage on these amps varies from 12 to 15 watts. The Hammond reverb unit was tucked in a leatherette pouch on the bottom of the chasis. The send and receive wires came out of this pouch. This amp featured the Fender badge with the long tail.

Note the Ground Switch on the left
I might point out that as far back as on the Fender brownface model a ground switch was included on the amps back mainly to reduce noise.





Back in the days where buildings only had two prong receptacles and amps had two prong plugs, if you got a shock from touching a microphone or another anything else the way to solve it was pulling the electrical cord from the wall receptacle, reversing the plug a half turn and placing it back in the receptacle.

BF Princeton with AC plug
When the blackface Fender amps came along the included a “courtesy” plug on the amps backside. You could plug in your buddy’s amp or if you had an electronic effect, say an Ecco-plex you could plug its power cord in the back of your amp. Perhaps the biggest courtesy was, since the polarity was the same, so you wouldn't get shocked.

The back panel of these amps had a 1/4” plug for the speaker and another input for an external speaker. They were also equipped with inputs for the reverb/tremolo pedal and the reverb out/send.


The Black face Princeton Reverb was produced from 1964 through 1967.

1966 Princeton Reverb
CBS purchased Fender in 1965. By the opinion of most the quality of Fender amplifiers did not diminish for a few years. The chassis were still made of pine and finger jointed and the electronics were still superb. There did come a point it seems that CBS/Fender designers were under the gun from accountants with cost analysis and things changed.

CBS/Fender’s first major change was to change the control panel from black with white script to silver with blue (or in some cases red) lettering.

1968 Princeton amp
In 1968 Fender introduced the silverface Princeton amp. This was a staple in their line-up through 1979. This is the Princeton amp sans reverb. The circuitry changed somewhat. The tube complement included a GZ34 for the first couple years, but by 1970 this was changed to a 5U4GB. I am betting this had to do with cost.

The power tubes remained dual 6V6GT’s, always a Fender favorite. A 7025 was used for the preamp and half of a 12AY7 served double duty for the preamp circuit, with the other half used as a phase inverter for the power tubes. Another half of a 12AY7 was used for the tremolo circuit. This amp pumped 12 watts into a 10” Oxford 10J4.

Initially in 1968 this amp had a blue sparkle grill cloth with an aluminum frame. The grill cloth remained, but the aluminum frame was gone on 1970 models. From 1976 to the end of the run the grill cloth was orange and silver.



The Fender badge with the “tail” was mounted on the side of the amp from 1968 through 1974. Mid 1974 and after the badge was changed so the the tail was removed.

The control panel featured hi and low gain inputs, volume, treble, bass, speed and intensity potentiometers topped with Fender skirted knobs. The initial rear panel featured the courtesy plug, the fuse, a “ground” switch, an on/off switch, the speaker input, an external speaker input, and the vibrato jack for a footswitch.

Later in the run the ground switch was replaced with a 3 position throw switch.

1968 PR with aluminum frame
The Silver face Princeton Reverb was much more popular than the Princeton amp, so it remained in Fendera lineup from 1968 through 1981.

The tube complement was similar to the reverb(less) model. The GZ34 was the rectifier until 1970 when it was replaced with the 5U4GB. Once again the power tubes were twin 6V6GT’s. A 7025 acted as the preamp tube. One half of a 12AY7 was used as the other part of the preamp circuit, while the remaining half served as the amp’s phase inverter.

Another half of a 12AY7 was used for the tremolo, and one 12AY7 was used as a reverb driver, with a half of a 12AY7 being used for reverb recovery.

This amp pumped 12 to 15 watts into either a 10” Oxford 10J4 or a CTS (Chicago Telephone Supply) 10” speaker. The grill cloth material used on the Princeton Reverb was the same as used on the Princeton amp and was changed in the same time frames listed above. The control panel was comprised of a hi and low gain input jack, volume, treble, bass, reverb, speed and intensity potentiometers and a pilot light.

The rear panel included the courtesy plug, a “ground” switch, a fuse, the on/off switch, the speaker jack, an external speaker jack, inputs for the vibrato and reverb footswitch, the reverb send and reverb receive jack. The reverb unit was also in a pouch on the floor of the chassis. This amp was available through 1981.

Princeton Reverb II
By the next year Fender was looking to the future and dramatically redesigned this little amplifier. The last tube amp in the Fender Princeton collection is the Fender Princeton Reverb II. This was Fender’s entry into modern amplification.

This amplifier and the circuitry were designed by the legendary Paul Rivera. And it was a much different amp than all of the previous models. In fact Rivera created a whole new line-up of Fender tube amplifiers.

For one thing the rectifier was solid-state. Two 6V6GTA tubes provided power for this amplifier. The preamp tube section included a 7025 as a phase inverter, with half of it used for the preamp. One12AX7 tubes completed the preamp section and one more 12AX7 was used to drive the reverb and for lead distortion.

Another 12AX7 was used as a reverb pickup and the final preamp section. However these tubes could be 12AY7’s or ECC83’s or ECC81’s The speaker was beefed up to a Fender Special Design 8 ohm 12” model to accomodate this amps 20 watt output.


The chasis was still black tolex, but the silver control panel section was once again black with white script.

The potentiomer knobs were the Fender skirted style with chrome centers. One thing that made this amp so special was the channel switching capability. The front facing control panel included a single input for guitar, a volume control that you could pull forward for lead. Next in line was the treble control. When pulled forward it acted as a bright control.


Then the Mid control, which was also a push-pull knob that when pulled forward added midrange boost. Then the bass control, which was followed by the reverb control. Next was a potentiometer for lead level, followed by a master volume controll and finally a presence potentiometer. The on/off switch was front mounted as was the pilot light.


The rear panel included a fuse, a grounded electrical cord, a 3 way ground switch (A/Off/B), the 1/4” speaker input jack, a 1/4” line recording jack, two pedal jacks, two RCA jacks for reverb output and input and a hum balance control. The Princeton Reverb II was offered from 1982 through 1986.

In 2006, Fender revived the Princeton name for a tube amplifier creating a rather unusual amplifier called the Princeton Recording-Amp in their Pro-tube series. This was essentially a blackface Princeton Reverb with an additional section of chassis which housed a built-in overdrive, compressor and a power attenator.

That same year they issued the Princeton 650 in the Dyna-touch III series. This was a solid-state amp with lots of bells and whistles.

In 2008 Fender reissued an updated version of the '65 blackface Princeton Reverb.

Fender has also offered an updated version of the '68 silverface Princeton Reverb. These amps are still offered in the Fender line-up

It is interesting that the Princeton amp was the basis for Randall Smith’s creation, the Mesa Boogie Mark 1.






Smith's original modified Princeton
Smith was running a small amplifier repair business when he borrowed a Princeton amp and modified the preamp section, then added a Bassman transformer, installed a 12” speaker that allowed this little amp to pump out 60 watts. That was the start of his business and a story for another day.






This is Kenny Vaughn and his SF Princeton Reverb

Saturday, April 23, 2016

Lonnie Mack - Dead at age 74 - Rock's First Guitar Heroes

Lonnie Mack
Lonnie McIntosh known to all as Lonnie Mack died yesterday at the age of 74 of natural causes. He was one of the first “guitar heroes” and an influence on countless players including me.

The Wham of that Memphis Man
As a kid I’d put his LP, The Wham of that Memphis Man, on the record player and turn the speed down to 16 2/3’s to slow down his licks so I could copy them on the guitar.

Lonnie remained active in the music business, mostly playing clubs and touring with band members that had remained with him for year until 2004 when he retired.

In 1963 he went into a recording studio in Cincinnati, Ohio called Fraternity Records. After a session had finished, Lonnie and some other players stuck around and laid down a few tracks which included his own instrumental version of Chuck Berry’s Memphis and another instrumental song called he called Wham. What emerged was one of the greatest instrumental guitar albums of all time.

Lonnie with his unmodified Vee
Lonnie's biting guitar style, use of a Bigsby vibrato and trademark sound became legend and were copied by musicians worldwide including Stevie Ray Vaughn, Jeff Beck, Duane Allman, Mike Bloomfield, Ted Nugent and so many others.

In the mid 1950’s Lonnie started playing in clubs all over the Midwestern United States; mostly in Ohio, Kentucky and his home state of Indiana. That first LP that I have mentioned went on to be rated one of the 100 Best Rock n’ Roll records of all time.

Mack released his final LP in 1990; Lonnie Mack Live - The Attack of the Killer V.

Throughout his career Lonnie played his 1958 Gibson Flying Vee. The serial number on it was 007 as it was one of the first made by the company.




1957 Flying V prototype
Gibson had  manufactured prototypes of the Flying V in 1957, under the direction of Gibson president Ted McCarty. This was during an era when America was entering the race for outer space. Cars had fins. There were TV shows about rocket ships and even Walt Disney had hired scientist Wernher von Braun to pique America's interest in space exploration. Gibson decided to get in on this action with some modernistic guitar designs that had an almost aerodynamic look by offering 3 futuristic guitar designs. Lonnie Mack played the Flying Vee.

1958 Flying Vee
The original 1957 prototype had a rounded bottom. It was made of mahogany and was a very heavy instrument. McCarty ordered that a large wedge be cut be made in the bottom end of the guitar’s body to alleviate some of the weight. This cut gave the guitar it’s Flying V appearance and it’s name.

Because blond colored furniture (and blond women) were all the rage during this era, light colored Korina wood was used instead of mahogany.

The guitar was introduced in 1958 along with the Moderne and the Futura (aka The Explorer). It was a dismal failure. The design was too much for the guitarists that wanted their guitars to look…well,like guitars. Due to slow sales, only 98 guitars, production only continued until 1959. Some left over units were sold up through 1963.

Lonnie with his unmodified V
Lonnie McIntosh was a country boy who grew up in Harrison, Indiana which was only 20 miles west of Cincinnati. At 13 years of age he had a quarrel with a teacher and was promptly dismissed from school. All Lonnie wanted to do was play guitar. He hung out at a store in Norwood, Ohio, called Hughes Music. Norwood is mid-sized blue-collar town just outside of Cincinnati and used to be home to a GM plant.

Lonnie Mack in the mid 1960's
The owner Glen Hughes would talk to Lonnie and discovered that Lonnie was interested bow and arrow hunting. Mr. Hughes pulled out the latest Gibson catalog that he had received and showed Lonnie the arrow shaped guitar. Lonnie was in awe. He had to have that guitar.


Hughes put in an order to Gibson and he drove from Cincinnati to Kalamazoo, Michican to pick it up. Lonnie got one with the serial numbers 007.


The story goes on that Lonnie wanted a vibrato put on his V, but due to the guitars design there was no place to mount the unit. The best vibrato unit in those days were the ones made by Bigsby.


Glen Hughes had a stainless steel bar cut and bent so part of the unit was mounted on the guitars body and the end of the unit was attached to the crossbar that ran between the sides of the V.

Most everyone named McIntosh is knick-named Mack and Lonnie McIntosh soon became Lonnie Mack.

On March 12, 1963, Mack had played guitar on a recording session for a girls group called The Charmaines at Fraternity’s recording studio. The allotted studio rental time had twenty minutes remaining, the group invited Mack to take advantage.

Lonnie and the other session players put down two songs on tape that evening and one was a rocking, uptempo guitar version of the Chuck Berry song called Memphis Tennessee.

At that time Mack's job was performing behind another Fraternity artist named Troy Seals. Seal went on to become a well known Nashville song writer.

Mack had forgotten about the session, however someone at Fraternity did not. They liked it well enough to issue it as a single. Seals had just heard from a friend that Lonnie’s song was climbing the charts. By the summer of 1963 Memphis charted in at number 4.

Lonnie Mack
Mack released a follow up called Wham, that became one of his signature tunes. Wham reached number 24 on the Billboard charts. In an interview Mack states he put it together from two songs he had been writing. Lonnie followed up with an LP called The Wham of that Memphis Man.

The album cover shows Lonnie leaning on the bottom of his upside down Flying V. This was before the Bigsby unit was installed.



Magnatone 260
Mack also was fond of his Magnatone amplifier. Just about everyone else was using Fender amplifiers, but Mack loved the True Vibrato effect of the Magnatone. This was engineered using circuitry similar to what was found on electronic organs that caused the pitch to continuously alter. Fender’s vibrato was actually tremolo since it caused the sound to be turned off and on.

Mack said that he was going after the Hammond organ sound that was prevalent in Gospel and Blues.

When Lonnie Mack was playing at clubs in the mid 1960's. He originally used a Magnatone 260 to get his signature sound. This amp had the true FM vibrato, but no reverb.

Gene Lawson
Lonnie later ran his Flying V into an old blonde Fender Reverb Unit then into the Magnatone amplifier. For the road this was a Magnatone M-9 that was modified by a fellow named Gene Lawson.

Lawson removed the amplifiers speaker and put in a step down preamp. The signal from the Magnatone was then sent to a blonde Fender Bandmaster head which powered two blonde Fender Bandmaster 2 x 12” cabinets. I am told that all of the Fender equipment had the “wheat grill cloth on them.”

And that is how Lonnie got his unique sound back in the day.

Later on as Lonnie began to play larger venues he used a Boss chorus pedal through a large amplifier,

Eventually Lonnie settled on a using a Roland JC 120 amplifier that he placed on top of two matching speaker enclosures.







2003 Concert
Lonnie Mack attempted to paint his Flying Vee red, which wound up with a pink hue after it dried out. He eventually got the red colour on the guitar.

Lonnie playing #007
Lonnie loved that guitar and once said he dropped it out of the rear end of his van while driving and the guitar remained in tune.

One time after a bad show, Lonnie told the story the he got mad and threw the Vee in a trash can. A fan fished it out and returned it to him five minutes later.

That guitar is now worth at least six figures, not just due to the fact it is an original 1958 Gibson Flying Vee, but the fact it is Lonnie Mack's Flying Vee.

Mack said that he has played the heck out his Flying V; the back of the neck is scarred up. The guitar has been re-fretted and new pickups were installed back in the late 1960’s.

The back side of the Wham LP

There are couple of interesting facts that have resulted from Mack’s career in the mid 1960’s.

First of all Memphis was the highest rated guitar song. Much of its popularity is due to the popularity of the electric guitar at that time.



Throughout his career Lonnie had recorded with The Doors, as a bass player and played on concert bills with them.


He also recorded with James Brown (who also record most of his hit records in Cincinnati, Ohio at another company), Ronnie Hawkins and Doby Gray.





Lonnie with Keith and Ron

He played concerts with Roy Buchanan, Albert Collins, Ron Wood, Keith Richards and Stevie Ray Vaughn.














This is a recent video featuring Gene Lawson, Mack's original drummer