The Disposable Amp

I get quite a few questions that usually take the form of something below:

Why would I buy a Headstrong over a re-issue or hand-wired version?

What is the difference between your amp and “Company X”?

Over the years I have made it a policy to not talk bad about any amp company, regardless of what quality they put out or level of service they may or may not provide. I also do not compare my work any other company other than the one I am trying to emulate, mid 50’s-Mid 60’s era Fender amplifiers, that is the bar!

But if pressed for an answer, one of the main differences, is that the amps I make are built to last a lifetime and if you decide to come back and buy another amp from me, it is because you loved the last one so much and want another or you need something else I build to fill a gap in your amp line and you appreciate the level of customer service I provide.

NOT because of this:

Maybe it is the 5th or 6th time to the repair shop one year and you have to make a decision on to pour more money into the same problems, or in most cases, just buy another. I call this the disposable amp model. That is what MANY companies do, more common on the import and mass production level, but also in some other boutique type models as well. I am sure you are familiar with Fender’s re-issue lines and the Hot Rod line, or the Pro Jr. line. These amps, when dialed in can sound really nice and there is a reason most guys request them for back line set ups when on the road without band gear…You can dial in a sound that “works” for the gig, you know what you’re getting, and they do provide the essence of that vintage tone.

The real problems fall to the owners and come in the form consistency, reliability, and long term life span. This is probably not a mistake or oversight, this is a business model. You will inevitably go right back to that amp on the same sales floor multiple times over the life of your guitar playing career…You know the amp, it sounds pretty good, you know how to get your sound out of it…And you dumped a bunch of money into the last one, so really that’s all you either want to or can afford spending on “another” amp. My Dad used to tell me, “pay me now or pay me later” is how life works. You can spend it all on something of quality, or you can buy something decent that probably won't last and you will be spending the same amount (or more) than just buying the one built right the first time. This is not exclusive to amps or gear…I have found this with everyday purchases as well. Just buy the right tool for the job at the requisite quality level to get the job done!

If you have read my other blogs, you know that I am not trying to sell you an amp, but rather, build you an amp you want or need. After we have established that I build something you can use. I am stating the above so that if you are in a position to buy quality over quantity, this is something to seriously consider. Some of us are in no position to spend the money on a new $2000-$4000 dollar hand-wired blah blah blah…And for you, the Re-issue or similar is a KILLER way to go! If you get a good one, they are actually damn nice! I worked with a backline company near Greensboro NC that had all the familiar characters set up on stage, but the speakers in the Re-issue’s had been changed to AlNico Weber’s! The guy playing it was a monster so that helped, but the guys working for the backline company said the owner buys the amps and sends them all to his tech to go through them and upgrade the speakers and tubes….It made a noticeable difference to my ears!

So there are ways to make marked improvements…If you don’t want to learn how to do basic (and a bit more in most cases) maintenance on these amps, make sure you develop a friendly relationship with a tech in your area…They are not always adversarial…In fact, you may want to consider them your lifeline to decent reliable tone…This may improve the dynamic between you and your tech. Regardless of what you buy at this level of quality, just remember that the idea is to get you to buy several of these over the life span of your hobby, or career! This is obviously a viable way to go based on the fact that most people go this route!

I am positive that $4000 Custom Shop guitar with the $1000 pedal board and high end cables will sound great through that $1500 Re-issue…

The other option is to buy something on the higher end market…First figure out what it is you need: wattage, speakers (size and number), what gigs you need it for and more importantly, don’t need it for. Also, do you need just one amp? Is that even possible for one amp to do all of that. My belief is the one amp that sounds like many is a bit of a “jack of all trades, master of none” situation. I will save that for another blog…It is important to know what you can afford, but also what you actually need for your gig. There is the element of what you deserve as well, that gig could be sitting in your music room alone, or with some friends, if you work hard and have the means, you probably deserve to treat yourself! Also this may be for relaxation and fun…It is not very fun taking your not that old “disposable amp” to the tech again!

It is all something to think about and if at some point you call me to ask about a build or just some advice in general, you can rest assured, I will do what I can to get you what you need or point you in the best direction if it is not something I build!

Hope this made some sense and thanks again for reading!

Wayne

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

The 1977 Princeton Reverb Repair Part 1

Part 1

A couple weeks back a local customer emailed me regarding a Lil King S he had acquired on the used market in the Asheville area. It was an easy fix, but it had a changed cab and a few other things done to it. NO matter, I got that thing fixed right up for his next session! I will cover that one in a future post. He mentioned that he had a 1977 Princeton Reverb that had been acting up and when I met him to pick up his S he brought the PR with, so I could have a look. I was hoping from the description, it would be an easy tube swap or solder joint touch up, “Sounds great for an hour then drops volume and or reverb fades”, you know, boilerplate, my old amp isn’t working right stuff.

I don’t normally do repairs, but if it is a vintage Fender, especially a Princeton Reverb (PR), I will do the work…mainly because I have all the parts on hand to build a new one, so a repair is usually pretty straight forward. Also, I love to hear the old ones as they are usually all a bit different. Some of this is obviously based on the work that has been done to them over the decades, and also, the production process back then was not the most consistent, supplies could change, multiple people building the amps, etc.

I was also thinking I could test this amp out against Lil King (LK) #700 that I had just finished up for Deke Dickerson. Once I got it in the shop, I turned it on to burn it in and see if I could replicate the issues. Sometimes these intermittent issues can be the hardest things to track down. I’d rather have an amp that won’t turn on or has a smoked resistor…Intermittent usually means you’ll hear something along the lines of “it’s working fine here on my bench” back from your amp guy…Then maybe a bench fee, and you take it home, with a emotional cocktail of hope and skepticism…To turn that damn thing on, and then almost immediately, it does the thing again!!!

Back to the tech, repeat and so on…it is NO fun for anyone involved. I know what both sides feel like…in my other posts I have referenced this, take it to a tech and not know what it will sound like when it comes back…Even when it is just some new tubes…it’s agonizing as a player…and as a consumer!

I, of course didn’t hear any of the volume drop or cutting in and out. Jacks seemed fine, tubes seemed fine…I had not even opened the amp up yet, just plugged in and listened. I always try to approach it as a player first…Play the thing and LISTEN. Well I a/b’d it briefly with #700, using a long speaker cable from my bench, I plugged the LK into the PR cab with the (seemingly) original 10” speaker as well as into the bench LK Cab that has a well broken in Alessandro GA-SC64 speaker. First thing I noticed…man the PR was really bright and edgy on the top end and upper-mids…through both speakers. The reverb was also way off…cranked to 6 it wasn’t as present as the LK on 3…There was definitely something off. The LK was way warmer and more responsive…I am confident in the job I do replicating these old Fender’s and that the 70s ones are generally considered “close” to “ok but a little bright” but this was a ways off…This was not a fair way to compare…and Deke was ready for his amp. I decided the a/b test at least in terms of playing would need to wait so I could inspect the 77 and ship Lil King #700 out west.

Opening up the chassis really filled me in on what was going on

There was obvious work done inside, some good, some not so good, the reverb issue was because someone omitted the bypass cap on the reverb driver tube (v2 12AT7)…this was why it didn’t have the lush wash out of a normal Fender reverb. Also, there were quite a few metal film resistors (very stable voltage wise) in key spots, and honestly, in completely random spots as well

The Plate resistors on the pre-amp tubes are the ones you may have heard or heard about, the term, popping, cracking, sizzling or a combination of any of those when they go bad…seeing these replaced is pretty common. I have my beliefs on this, and there are MANY more, most, by guys that probably know more than me about electronics and very likely, everything else…But I do know that in the pre-amp plates, that is where this carbon composition resistors shine for tone, you want the voltages to drift…that is what the old amps did…SO that was the first order.

I assume they didn’t have some of the common values for Fender amps…btw, if a tech tells you he doesn’t stock say a 100k 1/2 watt resistor, he probably doesn’t work on many Fender amps. You may need to seek a second opinion for the repair. To remedy not having the a few 100k’s, and a couple 56K’s he just wired two resistors together to attain the value needed. I replaced all of that with the 1/2 Carbon Composition type to get it as close as I could back to stock

Stay tuned for part 2 and maybe 3 if it is needed…Next we get to the power tubes, rectifier tube and check out the differences between the 64-67 and this 1977 Princeton Reverb

NEXT WEEK:

“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…. “