increased knowledge.
The original column—at least as original as I know it—was called “Ask Mikey" and was written by Mike Soldano of Soldano Custom Amplification. At some point, Mike became too busy to author the column, so the magazine needed to find a knowledgeable replacement in the tube-amp world. They wound up calling another one of the top boutique amp companies, Budda, and spoke with my partner Scot Sier. Since the questions were of a technical nature, Scot asked me if I would like to write the column. Upon accepting the challenge, the column in Musicians Hotline became Ask Budda. Once Hotline became Premier Guitar, the name of the column also changed to Ask Amp Man, and the tradition of answering readers' questions continued.
First, let me say that it's been an honor to have authored this column for so many years and to have been associated with Premier Guitar. The publication is well respected by its readers, as are the authors and columnists within. I know, because I'm told this all the time. I have been in the business of repairing and modifying, as well as designing and building, guitar amps for about 35 years now, and am probably as well known for writing this column as I am for the amp business.
The hands that have been inside of countless amps have also been on the necks of many, many guitars. Here, Jeff Bober lays into a favorite Strat. Photo by Robert Jordan
I was recently reminded of an instance when I was attending one of the big guitar manufacturers' “experience" parties. There was a gentleman performing onstage with the likes of Davy Knowles and David Grissom, and I really enjoyed his performance. (No disrespect to those other two players. Ha-ha!) I spoke to him after his set, later in the evening, and told him I really enjoyed his playing and his tone. At the time, I guess I looked similar to the frontman of a very successful band (dyed blond, coiffed hair with a bit of a beard and moustache), so he engaged in conversation with me. After a minute or two he noticed the name on my badge and said something to the effect of: “Man, I was just being nice to you because I thought you were Chad. You're the guy who writes the Ask Amp Man column! Now I'm really happy to meet you." That's not the first or the last time I've been acknowledged and thanked for being the author of this column—and I am very appreciative of that.
I've always looked at the column as a way to help people: be it someone who lives nowhere near anyone with the ability to diagnose or repair an amp, or someone with a desire to improve an amplifier and make it better suited to his or her needs. Although some have said it would be a great platform for self- or brand promotion, I never thought that appropriate for the column, so I tried never to use it in such a manner. It was always fun to read the questions and think about the possible causes of a problem or symptom, or a way I could help owners tweak or modify an amp to achieve a better result for them. It was also interesting to find someone whose need or application was outside the box, which prompts one to look at things with a different perspective. This is all part of the learning process, which makes everyone better at what they do. Of course, there are times where you just have to say, “No, you can't do that!" Ha-ha!
I also really enjoyed bringing you, as of late, interesting amps that have crossed my bench. For all the years I've been in this business, I still occasionally come across something I haven't seen before or seen only a few of because there simply aren't many of them around.
Putting his own amps, and a Gibson Les Paul, to use, Jeff rocks on the big stage with Johnny Chill, a side project of John Palumbo of Crack the Sky. Photo by Ellen Wiley
And then there are amps that were manufactured by relatively small companies—well known in their day, but after not being manufactured for decades and initially built in small numbers, they slowly fall off the radar. I have done columns on amps such as West and Sundown, where, after the columns were published, the likes of Dave West or Dennis Kager have contacted me and thanked me for writing a column on their amps. Something as simple as that brings one such joy, and for that I'm grateful.
I hope I've been able to bring at least a few of you a little bit of joy, or a sense of accomplishment—or, at the very least, increased knowledge. That said, there's only so much one can write in a column for more than 13 years without repeating one's self, so I've decided to bring it to an end. I'll still be designing, building, and repairing amps (which I really love to do), and if the folks at Premier Guitar are so inclined, maybe bringing you a feature story now and then. Or maybe something entirely different. Who knows! And if you'd like to hear what others in this wonderful world of music are up to, you know you can also hear me, as well as my co-host Mick Marcellino, on our weekly Amps & Axes podcast.
To bring this to a close, I'd like to leave you all with just a little bit of my philosophy: Live in the moment and be practical. We are all (at least most of us) guitarists. And that can come with the search for the ultimate tone, but don't let it get to the point of obsession. We live in an imperfect world—there is no perfection! If you keep lusting after every new guitar, amplifier, cable, capacitor, tube, speaker, pedal, pick, or battery, you will never be satisfied. If you have the opportunity to try or experience any or all of those … great. But it's not going to make or break you. Some of the best music in the world has been made on the most basic collection of materials, so do the best with what you have and improve or upgrade when it's practical. After all, music is supposed to be fun and good for the soul, so don't ruin that with obsessions. Life is too short. Take time to smell the roses. Or coffee. Coffee is good, too! Learn, have fun, respect other musicians, and, just as Frank Zappa said, “Play yer guitar!"
All the best, Jeff.
Except for the gain issue reader Rick Patterson describes, this month's amp is in remarkably good condition for
its half-century lifespan.
Dear Amp Man,
I have a '60s amp sold by Fender. It's a Regal R-1160 dual 6V6 with tremolo. Seems to be the same as a Lectrolab R600B. This amp does not saturate before almost full volume, and it's very subtle at that. I read your column on modifying negative feedback loops and I'm wondering if you could look at the schematic and show me where I would make this modification and what value caps you would recommend? I'm new to this sort of modification and would like to improve the tone without destroying the amp. If you need any pics, I can provide whatever you like.
All components and controls on this Regal R-1160 seem original, except this replacement speaker:
a Ted Weber Legacy Series.
Hi Rick,
Thanks for reading Ask Amp Man and thank you for your question. But even more, thank you for bringing this amp to my attention. I don't believe I was aware of Fender selling any amp that didn't have their name on it, but it does say right on the control panel “Distributed exclusively by Fender Sales Inc., Santa Ana, Calif.," so it's a very cool little piece of history, for sure. And to top it off, sans replacement speaker, it's in great shape!
Regarding your desire to modify the feedback loop in this amp to enable it to break up sooner: That's a good idea and a good place to start with many amps, but unfortunately not here. The first thing I noticed on the schematic you sent along with your question was that this amp doesn't even have a negative feedback loop! Not really unusual, but most amps without this tend to break up a bit more, so I was surprised that you say this does not.
to your expectations.
I would first suggest making sure the preamp tubes are not a contributing factor, and then possibly have a qualified tech give the amp a quick check to see if all seems well. Pay attention to the bypass capacitor across the output stage cathode resistor (Photo 1). While this doesn't control the amount of front-end gain in the amp, a bad or weak one can sure make an amp sound anemic.
If the tubes and bypass capacitor seem good but the amp doesn't have a lot of inherent gain, this could actually be an asset to some musicians. There are a couple of scenarios where lower gain is preferred—one being in a harp amp, but the other, more near and dear to guitar players, is if the amp is to be used as a pedal platform. In this case, the lower gain and higher headroom of an amp can really let the pedals shine. Some refer to such an amp as “pedal friendly."
Photo 1
That said, your desire is to get more crunch from this '60s jewel, so I do have a suggestion. Since both channels on this amp are virtually identical, why don't we leave channel 2 stock and modify channel 1 to bring it closer to your expectations? Sound good? Okay, let's go.
Photo 2
Hot modding. First, locate R7 in the amplifier (Photo 2). This is a cathode resistor for the first gain stage of channel 1. It is un-bypassed, so let's add a bypass cap across it to get more signal gain from this stage. I would use anything between a 4.7 µF to 10 µF, 25V DC. Plenty of amps use a 25 µF on up to a 250 µF cap, but anything that big may yield too much gain in the lower frequencies and that's something that would just muddy up the sound in a low-power, open-back amp such as this. Be sure to connect the positive side to the tube end of the resistor. If access to the resistor is too prohibited, connect the + side to pin 8 on the tube socket and connect the – side to the ground lug of the terminal strip.
Photo 3
Next, locate R15 (Photo 3). This will be one of the mixing resistors supplying the signal from channel 1. According to the schematic/parts list for your amp, this should be a 220k resistor. In your amp, however, both mixing resistors are 470k. This could also be a contributing factor in the lack of gain you say the amp has, but, regardless, let's leave channel 2 alone. I would suggest attaching a 220k resistor in parallel across the 470k resistor from channel 1. This will give you a stronger signal from channel 1.
There are a few other tricks that can be done, but some require the actual removal of components from the amp. The complete unsoldering and removal of components from tube sockets and terminal strips is often best left to someone with a considerable amount of experience in such matters. Other mods can require a bit of trial and error before a final component value decision is reached. I believe the modifications done above should give you an amp that you can push into overdrive much more easily, while leaving one channel cleaner for other uses. You could even get creative and use an A/B box to switch between the two channels for a lead/rhythm setup.
There you have it. I hope your Regal can now generate some royal sounds!
A rear view displays the EV 12L speaker and array of 6L6 power tubes and three 12AX7s. The reverb is solid-state, driven by a pair of discreet transistors.
Solid-state of the union. The first thing you notice when looking at the tube compliment is that the amp only has three preamp tubes. While this is certainly enough to achieve the typical amount of gain for the era, it’s not enough to support the onboard reverb. That’s because this amp is a hybrid: a mix of tube and solid-state circuitry. A pair of discrete transistors drive the reverb tank, which I think may be more reliable than driving the tank with IC chips, as is pretty typical today.
While all the overdrive in the amp is developed strictly with tubes, there are a few parts of the audio path that involve solid-state design. The first is the tone controls. Traditional tone controls can only attenuate (cut) their respective frequencies. The bass, middle, and treble controls in this Carvin amp are IC driven and are active controls, which means they can boost, as well as cut, frequencies.
Photo 1 — Amp Man suggests lifting one end of the wire coming from the push-pull pot on the master volume so the sound of the amp opens up—restoring its high frequencies.
Pretty cool, but setting them can be a bit more critical than your typical tube amp. The other part of the signal path that utilizes solid-state circuitry is, of course, the EQ, which also can be used to cut or boost frequencies. The EQ is assignable to either the rhythm or lead channel, but not both. This is not atypical, but if you think about it, it is a bit strange, as you cannot use the EQ to establish the signature tone of the amp. It can only be used for making substantial tonal changes to either channel, which can be nice—and, with the “M” amps of this era, necessary for the overdrive channel, in my opinion—but is not really necessary in this amp. Lastly, the presence control in this Carvin works in the feedback loop, as in most traditional tube amps, but is changed in the later X series amps to be included as part of the active tone controls. So far, this is a cool amp, but let’s get into it and make a few tweaks so it becomes even cooler and more usable.
Ins and outs. The first thing you hear about this amp is that it has its own sound. This is immediately noticeable in the rhythm channel. It has a very full bottom end and a nice top end, but doesn’t sound like a traditional F-style clean. That’s not to say it can’t, as that’s where the EQ can come in handy, and I think the clean sound is very unique and useable—especially with the bright function engaged. Now let’s switch over to the lead channel, as this is where the amp can stand some improvement. The lead mode master volume control is a push-pull pot and has two options: normal (in) and pull for “Hi Lead.” In Hi Lead mode, the drive channel is very useable and matches relatively well with the rhythm channel, but in the in-position normal mode, it is, in my opinion, unusable. It’s extremely dark and sounds like someone threw a few moving blankets over the amp. Here’s where we can do a few changes to make this amp sound better.
Photo 2 — Wanna match the tone on both channels? Our columnist suggests removing the 22 µF capacitor and replacing it with a 4.7k resistor with a 0.022 µF capacitor in parallel.
If we follow the schematic, or better and easier yet, the wires coming from the push-pull switch on the rear of the master volume pot, we see that they connect to two different capacitors. One shunts most of the high frequencies to ground. This one needs to go! Simply lift one end of the capacitor from the circuit board and you’re good to go (Photo 1). If you follow the other wire, you’ll see that it connects to a 22 µF capacitor whose other end is attached to pin 3 of V1. When this cap is connected via the switch to ground, it adds a considerable amount of gain to this stage—especially to the bottom end.
The problem is, there is so much gain that the bottom end starts to choke at higher gain settings, and it especially does so when the output power switch is set to 60 percent. To alleviate this, remove this cap and replace it with a 4.7k resistor with a 0.022 µF capacitor in parallel (Photo 2). Now, with the master volume on the lead channel pulled out in the Hi Lead mode, the tone of both channels matches very well. Pushing the Hi Lead pot in actually increases the gain in a very balanced way and gives the amp even more drive and sustain.
And there you have it: an amp whose boogie gives the competition a serious run for its money. Enjoy!