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Is That A Stock Photo?

I have a couple more amps up for sale on Reverb. And, as it happens every time I post photos on Reverb, I get messaged by someone asking me if these are the “real” photos of the amp or if are they stock photos.

Reverb won’t upload stock images if the listing is for a used item. They check the EXIF data of the images. Amongst other things, the EXIF data of an image includes information that can determine whether a photo is stock or not.

What do I do to take a great product photo?

Simple.

A sheet of white paper.

The paper was taped to a wall and rolled out. The amp was placed on the sheet of paper. I used my Olympus EM1 camera mounted on a tripod. I shot the image at 1/60th of a second, f2.8 with a 50mm equivalent lens (25mm f1.8) and ISO 1600. I did not use any studio lighting for the shot. I used the existing halogen lighting that was in the room.

Brought the image into Lightroom. A little bit of colour correction. Boosted the whites. Exported it out to Pixelmator where I brushed out the remaining shadows and then I cropped out the background clutter.

And?

This is a stock photo from the Mesa Boogie website.

And my front-facing shot again:

Maybe I take too good care of my gear? My Lone Star Special is over 12 years old and still looks like new. Perhaps that is why I get people asking me if the photos of the amp are real or not. I need to rough things up a bit. Rip out some tolex. Throw some dirt on the grill cloth. Smear the control panel with grease.

Rock ‘n roll!

Mesa Boogie Tube Problems

I had posted about retubing my Mesa Boogie Lone Star Special amp here and here.

4 JJ EL84 power tubes, 5 JAN-Philips 12AX7 preamp tubes and 1 Sovtek 5Y3GT rectifier tube. At first, everything seemed fine. As the tubes burned in, the sonic character of the amp changed noticeably. Where I had kept channel 2 as a higher gain channel — clean with some dirt if driven hard from the guitar — I engaged the Drive to push more of an overdriven sound. The distortion sound was rich in harmonics and sounded awesome. Far sweeter than the old tubes. But, during rehearsals a few weeks back, and ever since, the volume of the amp randomly drops. Dramatically. It’s almost as if the amp loses headroom.

Obviously, tubes might be an issue. Or perhaps a transformer.

Searching the web, I found some folks had experienced the same issue. And specifically highlighted the Cathode Follower Tube as suspect.

From Mesa Boogie:

SOUND “DROP-OUTS”? / INTERMITTENT SIGNAL

One Possible Cause

Most (but not all) Mesa/Boogie amplifiers have one or two “cathode follower”? tube stages in their preamps. Tube selection is CRITICAL in these stages.

Specifically, in a 12AX7 tube used as a “cathode follower”?, the voltage difference between that present at the cathode, as compared with the heater voltage, can be withstood or tolerated by certain types of tubes, whereas other tubes will fail. The failure of a “cathode follower“ tube will cause sound dropouts or signal loss.

For the past few years, Mesa has been using two types of 12AX7 tubes: ones originating in Russia (Sovtek EH), and ones originating in China. The Russian (Sovtek) tube is NOT reliable as a cathode follower. Of the tubes we are using today (March 2008), ONLY THE CHINESE 12AX7 IS RELIABLE AS A CATHODE FOLLOWER.

In conclusion, if you are troubleshooting for signal dropout in a Mesa/Boogie amp, suspect a cathode follower tube, and try replacing it with a Mesa 12AX7 that is marked as “CHINESE”? (silk-screened on the tube itself).

Below is a partial list of Mesa amps and cathode follower tube locations:

GUITAR AMPS BASS AMPS

Lone Star & LS Special: V3
M-Pulse: V2
Stiletto: V3 & V4
Venture: V2
Road King I: V3 & V4
Big Block 750: V4
Road King II: V3 & V5
Titan: V4
Roadster: V3 & V5
M2000: V2
Dual & Triple (2ch or 3ch): V3 & V4
Bass 400+: V2
Tremoverb: V3 & V4

ANOTHER POSSIBLE SCENARIO may occur in the “SPONGY”? (or on some models, “TWEED”?) power setting: the reduced filament voltage may cause very low output from a RUSSIAN preamp tube. Again, the recommended fix is to replace the “sagging”? tube with the CHINESE type of Mesa 12AX7 – which are more immune to this type of failure.

I will try to source a Chinese tube today. The JAN-Philips tubes are US but I do have quite a few Russian tubes. And it looks like I will have to make a trip to Toronto to find some Mesa tubes if I can’t get this resolved. Lots of playing ahead over the next two months and the Lonestar Special has my tone. But not with random sagging.

Tubes

I purchased my Mesa Boogie Lone Star Special 1×12 combo amp back in 2005. Wonderful sounding tube amp. A few weeks ago, one or more of the tubes became microphonic. I was able to trace the noise back to one set of power tubes — they operate in pairs — although it looks like I need to retube the whole amp. It has been four years after all.

Although I do pay some attention to the tone wars on tubes, I’m not sure that I have the time or money to audition dozens of them. I ordered a full set of tubes from thetubestore.com, a Canadian source for such products. I purchased 4 JJ EL84s, 5 JAN-Philips 12AX7s and 1 Sovtek 5Y3GT.

I still used the amp over the past two week-ends and it held up fairly well although I did have to put it to standby when I was not playing.

Some players believe that retubing opens up the sound of an amp. That even after six months or so, the tubes can become “tired” with frequent play and the sound does not bloom as it should.

Not sure I believe that but I do know that when tubes start to go microphonic, it is time to replace them. Funny, the tubes on my 1984 Fender Super Champ were replaced only once after 20 years. I replaced the tubes with some highly recommended NOS tubes. I did not notice a major change in sound. Did the amp sound different or better than before? I guess spending a couple of hundred dollars on tubes might influence the answer to that question.

Disconnected

I was playing last week and something odd happened to my rig. I generally work through a Mesa Boogie Lone Star Special. This is a wonderful sounding amplifier with a lot of great features including one that I use a lot: solo mode. Solo mode is engaged through a two-button foot switch. One of the buttons triggers the first and second channels of the amp and the other button adds a boost to output of the currently selected channel. Very handy in live sound situations where you want the solo to cut through. I trust sound engineers but sometimes they do not always react in time for the start of a solo line.

Last week the solo mode would not engage. Of course I followed the usual routine: press button, no solo mode, press button, no solo mode, press button, no solo mode. I lost count of the number of times I repeatedly pressed the button. What could be wrong?

Troubleshooting on stage is not very productive so I waited until I got the amp home. I have found over the years that the best way to troubleshoot is to deal with the basics first. And so I focused on the foot switch and the cable that connects the footswitch to the amp. Fortunately, I began with the cable. A very basic Tip-Ring-Sleeve cable. The continuity meter showed green on Tip and Sleeve but no joy on Ring.

I removed the jacket to take a closer look and sure enough the contact to Ring had separated. Likely due to a cold solder. I stripped the wire and resoldered the contact.

Everything works. I can solo again.