1977 Princeton Reverb Repair Part 2

Part 2

The missing bypass cap may have been intentional. The work was not subpar, it may have been a “fix” for the washed out reverb that happens on Fender amps above 4, generally speaking. I had never thought of that one, so there again, someone knew what they were doing, electronically speaking. I brought the entire pre amp section of the amp back to vintage specs.

I then moved on to the power supply cap which was in proper working order, so on to the power and rectifier tubes:

The Rectifier tube was an old Chinese made tube, that honestly, I was shocked it still functioned…The power tubes were generic Russian made and were WAY out of range from each other, like one was reading 28mA and the other was over 50mA…This would explain the “after it is on for an hour, it loses power and dynamics” issue. Fortunately, I had just received a new order of TAD 6V6 tubes…a box of 50, all matched within 3mA! The new Red Base TAD products are really impressive…The quality control going on over there is top shelf, and the tones are very vintage to my ears. Once those new tube were installed, everything came back to life on the old ’77.

Most of the pre amp tubes were older Sovtek short plates tubes, not the best tones I’ve heard from a new pre amp, but very reliable and they all tested good and were quiet, so no changes there. The fiberboard was warped (they all are basically) and had a big hump in it and only one screw “holding” it in the chassis, so I added a screw and locking nut to the other end of the board to secure it better.

After some de-oxit on the jacks and tube sockets, I hit all the pots with lubricant to assure a nice quiet sweep in those. She was just about ready to fire up, but I always use my current limiter to fire amps up, new, used or recently repaired, just in case there is an issue, it is at half voltage. This is also how I “form” the caps of a new amp, bringing up the voltage slowly so as not to hit a new unloaded cap with 400VDC right off the bat. All checked out in that department as well!

Once at full voltage, I checked the bias…I had swapped out the resistor in the bias supply as the old PR’s did not come with a Bias adjustment pot. This is one small change I made with the Lil King Amp, added a bias pot so it is much easier to dial in where you want to be on current, while not changing the tone or dynamics of the original design. Having noticed the current and DC voltage was so much higher on this amp when I fired it up originally, I changed the bias supply resistor from what is usually a 22k resistor to a 27k…I knew that the bias would be way too hot with a 22k. I was also hoping the DC voltage would come down a tad as well with the new rectifier, and it did. It was originally reading 440 VDC, which is what Deluxe Reverb amps usually read, whereas a Princeton Reverb is usually in the 400-425 VDC range. Bias is always a sticky talking point for many techs. If you go by the old manuals a set of 6V6 tubes in this amp should be set in the low 20’s…I prefer the upper 20’s and closer to 30mA per tube. This amp was pulling 32mA per tube at 420 volts so the change of the bias resistor and rectifier tube helped! Definitely on the hot side of things, but these TAD tubes can take a beating, almost the same way a JJ can. The JJ tubes are like tanks and you can basically run them at 440 VDC with few issues…I would say the TAD tubes are close to that, minus the filament rattle. I love the JJ tubes, but they rattle pretty badly on low notes. I use dampening rings to help with this on the JJ GZ34 rectifier I used. The TAD 6V6 were dead quiet and no rattle at all. I burned in the amp on the bench for a solid 24 hours to assure all was stable. When I do this, I will randomly plug in a guitar throughout the day to test the amp a few times, I also measured voltage and current several times.

The next day when I sat down at the bench, I found the amp to be set exactly where it was the evening before! All was ready to load back into the cabinet.

A word about these late 70’s Fender amps…the cabs are not great! In the old days you had the baffles made from higher quality plywood and you could remove them aka “floating baffles” These later versions still had pine shells in most cases, but the baffles and back panels where made from plain old particle board and the grill cloth was mounted on a thin frame and held to the baffled by Velcro. NOT my favorite design, but it works. They are also heavier…And honestly, a little stiff as the baffle doesn’t seem to have the same throw as an older plywood baffle. We use void free baltic birch for the Lil King and all other cabinets, in the period correct floating baffle style. To me this is a BIG part of the old tones, cab size and material plays a big role in the tone of an amp, and the weight!

Once I loaded it all in, I had a chance to try the amp out next to a recently completed Lil King with the stock 12” Alessandro Eminence speaker I use. I ran a speaker cable to both amps so I could run the ’77 into the Lil King’s speaker and the LK into the ’77’s vintage 10” speaker. I put some video below for you to discern the differences. I am pleased with how the LK sounded and very pleased with how much better the ’77 sounded.

This is NOT a competition, tone to me, is as subjective as looking at a painting or a sunset. It is what speaks to you as a player or listener. To my ears the PR is a little bright for my taste, but to others, that is what they love about a Silver-face! What do you think?

I met the customer to drop off the amp, and this rare repair job was complete! All reports back are that the amp sounded better than he had heard it and it was ready for some work on a new PBS soundtrack!

Thanks for reading this and please tell your friends about the blog if you think this will be of interest!

Wayne

What are the differences between the Lil King and Lil King S?

…and what’s this I hear about a Lil King X?

First let’s start with the Lil King…first built in 2004, at that time, there were NO Princeton Reverb Chassis available in the boutique amp supply chain, and I know this because the few big companies that were around back then did not have one yet…I am sure someone, some where probably had a few made or bent and welded one themselves, but for someone looking to produce a replica on the fledgling boutique amp market like myself, there was nothing out there. I had an old silver face PR and had a company blueprint the metal work and produce them for me. Several LONG months later it was done and by late 2004 I had the FIRST Lil King built and ready to send to David Wilson (RIP) of The Tonequest Report for review. Back then I had to build and sell these things so I could pay for the parts to build more. (I have a story about how I got the very first Lil King back…YES, I sold the first one to buy the parts for more!!) One of the great things about replicating after years of playing these old Fenders was that prototyping was not nearly as important as when you build something that is tweaked or completely NEW in design. That, as you know, is not something I do, I build replicas, “flaws” and all! I did not borrow ANY money to start Headstrong, it was literally amp to amp back then.

The Lil King is a faithful reproduction of the AA1164 Black Panel Princeton Reverb, and at that time, trust me there was NO ONE building these for the commercial market. I did not tweak anything in the circuit to change the bass response or clean it up etc. Just built this thing as close as I could to an old one. Side note, I did side by side tests of a few GOOD vintage examples that I had access to, as you know there can be a huge variance in these old amps…Some sound good or great while others are just off for a variety of reasons.

The Lil King Reverb is built around one of the GOOD vintage examples and after nearly 20 years and 700 ( I am building chassis no. 700 this week for Deke Dickerson) of the stock Lil King amps of which I have personally wired EVERY ONE, I am confident that its as close as it gets…Not saying it is better than anyone else’s take, just as close as it gets!

The idea for the Lil King-S (the S stands for “Souped up” or “Stage” ) came in 2009 after several years of building the Lil King and people asking me about beefing the amp up or tightening the bottom end. There are a few popular Princeton Reverb Mods out there as you know, but I wanted to take it further…This is one of the few times in the 20 years I have been building amps that I even considered doing this. To me one of the main reasons Princeton Reverb’s sound the way they do is the Phase Inverter (read the Blog, “why do the Princeton Reverb and Deluxe Reverb amps sound so different” for more on this) I wanted to keep that, otherwise I am building a single channel Deluxe Reverb basically. I wanted all that sag to happen like a Princeton, but much louder and cleaner on the way to that point. I boosted the PI voltages by using the untapped leg of the Filter cap can, bumped some voltages in other places, but mainly…I had a HUGE Princeton Sized Power transformer built AND a 35 watt Output transformer built with a special primary impedance so that it would handle a variety of power tubes. It was my thought that is I beefed up all of this, but kept the PI the same, the amp would land at about 25 watts with 6L6 tubes. SO the main difference in the stock Lil King (black panel Princeton reverb AA1164) and the Lil King S is the transformer set and higher voltages across the board…The effect of this has also been explained in previous Blog posts, so please check those out if you are so inclined!

Lil King S (left) and stock Lil King (right) power transformers built to my spec by Heyboer

The Lil King-X…Well that is what I call a “flex” model between the two amps. There is a significant amount of room between the Lil King and at the Lil King-S, so over the years I have talked to so many people about what they wanted out of the amp I was building for them, that the X took shape. Charlie Hunter was one of the first to have one built. He had several Lil King and Lil King S amps, but sometimes there was too big of a gap between them for certain rooms. The X can be many things…The one I just built for JD Simo, is Lil King S power transformer, Deluxe reverb output transformer, it will run 6V6 or 6L6s, for 18-22 watts. PI voltages were raised, but pre amp voltages were kept close to the stock AA1164 readings. I have done so many different versions of this to achieve what someone wants…stock LK power transformer with a Deluxe reverb output to juice it just a little, Lil King S power transformer with stock Princeton Output and 6V6s…a ton of voltage mods to clean or brighten…It is virtually endless.

I personally prefer the stock versions of both, but there have been some cool variations. Rest assured, this is not nearly as complex or vast as it seems, these are finite incremental changes, some of which are so subtle, only guys like JD and Charlie Hunter can really tell the difference…subtle changes to mids, volume, headroom, and compression…these are guys that are TRUE MASTERS of what they do and have done it for so long, they can hear these little 1-5% changes….Not to discourage anyone from exploring this, but lets not over think this thing…Call me and I can walk you through some of this…it is not something that you should obsess over, I can get you where you need to be based on the information you provide.

Lil King-S (left) and Lil King (right) Output transformers built to my specs by Heyboer

Between the Lil King, the Lil King-X and the Lil King-S, I have built almost 1000 chassis, so I have heard most if not all of it at this point…There is a reason guys call me about this circuit…And I am not one to brag, but I do think I have earned the right to consider myself a bit of an authority on the Princeton Reverb and what makes them sound so good!

I hope you enjoyed this latest 5 AM rant! Time to get to work on Lil King No.700!!

Thanks for reading!!

As always, you can call or email me ANY time with questions and feel free to comment below!

Wayne

Why would I get a Lil King over a vintage Princeton Reverb

That is a great question!

Let’s first start with why do you want this size amp? Are you a collector or vintage enthusiast? A gigging musician who needs tone AND reliability?

First let’s make sure the Lil King or Princeton Reverb is the amp you need:

What is the primary use or need for the amp? Rehearsals and gigs? Recording and home based playing? Coffee shops or bars? All of these things need to be considered before making a large purchase like this…that is how I approach every call or email that comes in and we will cover more about my approach to making sure you’re looking for what I build in a future post. Now on to the topic at hand as we will assume this sized amp is what you’re looking for.

To the collector I say, buy the old one! While the Headstrong holds its value very well relative to other boutique amps (mainly due to VERY low production numbers and high demand), it will not appreciate in the same way as a good vintage piece of gear. So to the collector I can offer a wealth of knowledge about this particular model (as I have personally built almost 1000 LK/LK-S chassis), and will be able to possibly answer some tone, tech type issues as well as a hearty congratulations on your recent acquisition! There is nothing quite like getting that old amp and having it live up to expectations! I remember it well, this is why I wanted to build amps…knowing that it will be increasingly harder to find those pristine examples, much less affording them. The days of me getting a 1961 Brown Vibrolux (player grade) for $300 ($50 bucks at a time from gig money btw, 6 gigs later I officially owned my first vintage Fender) are LONG GONE. …Or the old Sears amp in case I found for $5 at a Goodwill in Ashland OR. Or a friend who found a ’62 Bassman Head for $6 at a yard sale in Hawaii, you get the point…

BUT, if you are in a position to afford an amp like that now…Please, call me anytime to talk about it, brag, ask questions, I share your passion and would love to hear all about it!

Opposing view points and why I build:

To the player and even the vintage enthusiast, on a budget, I can offer guidance on deciding between a players grade PR or a new or used LK. I offer the same level of customer service to you regardless of where you bought it, new or USED. Over the years I extended the warranty on the entire line for LIFE! This means that while some parts in the amp will fail over time and not be “covered” by the warranty, when you send in the amp, I will replace the majority of these parts at my cost. Also, labor charges on out of warranty work, is half of my normal hourly rate for repair work. This can be an invaluable asset to the weekly gigging musician or the home hobbyist. Generally speaking the main issue with Headstrong Amps is and will always be tube life and reliability. Over the last 20 years I have tried virtually every tube brand out there of any quality and as long as I can get them, I will always use what has worked best in these amps for so long. Occasionally a speaker will blow, and even less common is a transformer. I can count on two hands the number of power transformers I have seen blown…Not bad for well over 1000 amps out the door. To give you an example of what it would cost to replace a PT, which is basically the most catastrophic thing that can happen to the amp…Out of warranty repair on this is less than $200 on most amps! That is tough to beat on any repair, much less something that major. My point is, DO NOT panic, I have you covered…Give me a ring or email and we will get you straight on this. Remember though, about 1% or less have ever had this issue…

So BUY WITH CONFIDENCE!

To me, I prefer to have an amp that if it has any issues, I can call the guy that built it whether or not I bought it new or used…And if it was ever stolen, it is completely replaceable. Piece of mind is often overlooked in the artists tool bag. If you are able to focus only on creative variables, and not, “what is my gear going to do to me tonight?”, it more easily allows you to reach further into your creative process, letting go of mental blocks and restrictions. I know…psycho babble, but we are a finicky bunch! Guitar players are some of the most unique personalities I’ve ever had the pleasure of dealing with…Musicians in general, but we guitar players are definitely a different breed.

These are just a few thought I have on this, as every player is unique in some way, please feel free to give me a ring any time to discuss this question in more detail! I hope to connect with you this year, and in the years to come, to help you along on your tone quest!

Please like and subscribe to this if you are so inclined, I plan on having more of these gear ramblings this year!

All the best to you all,

and thanks so much for 20 years of support!

Wayne