GearDump

Bitmo Modded Valve Junior

The Epiphone Valve Junior is one example of an amplifier with a rabid modification community. Players typically modify the circuit, speakers, and even the output transformers to get what some call boutique tone on the cheap.

When I came into possession of my Fender Hot Rod Deluxe I had no idea the difference the custom baffle and two 10″ Eminence Legend Speakers would have. I had never been that big a fan of the stock Hot Rod Deluxe sound but wanted one for the fender clean tones. The thing was monstrous, it could roar with overdrive or sing with a fuzz. I couldn’t help but wonder why the original owner parted with it.

Anyway, I’ve owned my fair share of modifiable amps–particularly the Valve Junior. I have been less then happy with most of those amps with basic circuit mods but I think if you have some major amplifier surgery done you could probably see a noticeable increase in performance. (continue reading…)

For many guitar players Dumble’s name is legendary. He has crafted amplifiers for SRV, Larry Carlton, Robben Ford, and some of his other amps have ended up in the hands of many others, particularly John  Mayer who reportedly has several of them. Dumble amplifiers are notoriously expensive because of their rarity. Alexander Dumble can only produce two or three of them per year. On the used market their prices are in the tens of thousands. When most people think of Dumble amplifiers they refer to the ODS or Overdrive Special but their are other models he has produced as well.

Since I have never had the good fortune to play through or near a Dumble most of my opinions are based on the accounts of others. As I understand it, Dumbles are extremely touch sensitive. Many players who have used them call them unforgiving. When picking lightly the amp barely distorts. If picked roughly the amp (again based on clips) has a glorious overdrive devoid of icepicking but with just enough presence to cut through the mix. Perhaps that is the reason so many great blues and jazz artists covet these amps as the tonal holy grail. Adding to the confusion is the fact that each Dumble is built to suit a player. That means the Dumble that Santana has will not sound exactly the same as Larry Carlton or Robben Ford’s.

Dumble’s have become so appreciated that attempts have been made to clone the ODS. Two-Rock & Fuchs are two well known company’s doing just that. Dumble himself has attempted to stop these cloning attempts through the use of resin or epoxy coatings covering all the components on the amp internals. Nevertheless Two-Rock and Fuchs have at least come close since their amps are so popular. It is well known that John Mayer often pairs his Dumble with a Two-Rock as well. Frankly, even these boutique clones are far to expensive for me to investigate on my limited budget but perhaps someday I will. Nevertheless, I believe it only a matter of time before a manufacturer like Fender, Peavey, Marshall, or even Bugera release an amp sounding very similar to one. Until that time we will all sit and drool.

Special Thanks to youtube user peterguitlerche for allowing me to use his dumble clip.

The video above was posted by Johnhguitar on youtube. He does a reasonable job of demonstrating it’s tones so I’m borrowing it. Thanks John!

The Rivera R30 or Thirty-Twelve is a tone machine plain and simple. As with all Rivera offerings it is heavily dependent on tubes with a proper bias setting. These amps can be found on Ebay for reasonable prices. The R30 is a bit like a Fender amp with EL34’s in the power amp. The amp features two channels with totally seperate volume and tone controls. The clean channel has a notch switch that takes the amp from bassman to blackface in an instant by shifting the mid range of the amp. Both channels also feature a footswitchable boost control.

The remarkable thing about this amp is it’s versatility. With the clean channel pre-amp volume at a reasonably low level it has a warm clean sound. With the pre-amp volume boosted the amp easily gets into vintage overdriven lead sounds that are not far from SRV. The notch switch adds a little personal dimension to the amp. Unfortunately the Notch switch is not footswitchable though, that would have been a nice addition. The boost switch adds a bit more punch and volume to the amp. Some players have mentioned that it actually adds more preamp volume without 12ax7 saturation thus adjusting the amount of powertube saturation we here. Whatever the case may be the “ninja” boost is a welcome addition to this amp’s tonal arsenal.

The Gain channel is pure unadulterated British raunch. I don’t own a Marshall and with this in my closet I certainly don’t need one. At higher Gain’s it sounds very JCM-800 like. With the gain switch it gives me a quick lead boost when needed. Honestly, I don’t use the gain as much on this side since I have a lot of overdrives and fuzzes that I enjoy using but when I have, I have not been dissappointed.

The only place where this amp falls short is in it’s cabinet dimensions. Even Rivera has acknowledged this since the new Chubster is virtually the same amplifier in a different cabinet.  If you are looking for boutique tones and great build quality with a tiny price tag I highly suggest a used Rivera.

Paul Rivera is an Amp legend. He designed many amps for Fender, participated in construction at Mesa Boogie before they became mass produced and even designed some of the popular and successful Yamaha solid state amps in the late 70’s and early 80’s. Paul is a nice guy to talk to, and if you call Rivera you might actually end up on the phone with him. During Paul’s tenure at Fender he designed the last set of Amplifiers that were hand made. That period was just before the Red Knob era and the sale of Fender back to it’s workers. Many of those amps are highly soughtafter, particularly the Fender Superchamp (Champ II) and Deluxe Reverb II among others.

I have tried to avoid buying Tubes at major chain stores simply because I have never had good luck with groove tubes. GC normally only carries Groove Tubes or Mesa in store. Sam Ash has only ever had Groove Tubes as long as I have shopped there as well. The other day I was in Sam Ash and saw that they actually carried tubes from JJ electronics. I have never really used JJ tubes save for in my old Classic 30, and frankly I wasn’t impressed but I figure I would give them a try.

When I purchased my Rivera it came with some joker’s idea of good tone, two horribly mismatched Groove Tubes with the number 5 written on the label. They were so bad that after the amp had been used for a few hours, one would only get mildly hot while the other would blaze.

When I installed the JJ’s I didn’t bother to do a Bias check since I assumed that any tubes would be better. These did the trick marvelously. The fender side of the amp exuded those sweet cleans whilst the British side ranged from JTM-45 snarl to JCM-800 crunch. Ironically I had never enjoyed turning this amp up since on the Brittish side it just seemed to get louder with less saturation. The moment I got the master volume to 8 I realized what I had been missing. This amp can really saturate and sound fantastic. Those Rivera clips on youtube simply don’t do them justice.

I was really impressed that the matching of these tubes was fairly close as well. I’ll update after I do a Bias!