Voodoo Amps Mesa/Boogie Heartbreaker Head Mod

I purchased this Mesa Heartbreaker on E-Bay and had it shipped directly to Trace at Voodoo Amps for his Deluxe Mod including a new Mercury Transformer. After receiving the amp after a few weeks it had a couple of problems. I sent the amp back and the issues were quickly sorted out and I'm finally able to give the amp a fair review.
Having 2 channels which are co-dependent on each other limits the amps flexibility somewhat, but the Voodoo mod makes up for this by increasing the character and response of each individual channel. The Fender side sounds more Fendery and the Marshall side more Marshally, if that makes sense.
I play and write mostly rock and classic rock. If I had a preference it would be toward the English bands rather than the American ones. Although I do love the Eagles.

After the initial hiccup, the amp is now functioning perfectly. The issue the first time was a lack of control over the second (Lust) channel with the gain being full up when the volume knob (which sets the gain level) was all the way off. It was also blowing fuses. the first channel worked perfectly.
Now however, the amp is truly amazing. I've owned several amps (Vox, Mesa, Soldano, Matchless, Marshall, and Fender) and this modified Mesa cops elements of all those amps and manages to be distinctive on it's own. I've always had trouble with Mesa Boogies. They sound great initially but for some reason they change over time. Especially annoying is having them sound different from gig to gig.
This the modded version still manages to capture that thick Boogie midrange but on Channel One (the Love ch.) it produces one of the best blackface Fender tones I've ever heard. It sounds like an enormous 100w Deluxe. The EQ is much improved and responsive as well. So much so in fact that care must be taken especially with Fenders that the treble control is not set to high.
I use Fenders, Gibsons, and Hamers so the versatility in an amp is very important to me and the Heartbreaker works with all my guitars very very well.

Aside from the initial problems all has been great so far.

Trace was very helpful and stayed in contact with me through the whole process. When they say they will work until they get it right, they actually mean it! The customer service at Voodoo is top notch.

I have been singing, playing guitar, bass and drums pretty much my whole life. I have a fully equipped studio in my home and write, record, and mix my own music. I am also the Front-of House engineer for a show on the Las Vegas strip called Le Reve at the Wynn hotel and I've also mixed Cirque du Soleil's "O" at the Bellagio.
I was also the guitarist for the "Classics IV" (they were famous for "Spooky", recording the original before the Atlanta Rhythm Section) for the last tour they did in 1989 and '90.

For those of you unfamiliar with this amplifier I will list a few of it's many features: 100 Watt (or 60 Watt switchable) two channel head powered by either four 6L6 or EL-34 tubes; switchable 5AR4 tube or solid state rectifier circuit; five 12AX-7 preamp tubes; switchable variac control; monoaural effects loop; footswitchable reverb and channel switching; switchable power section voicing control; slave (line livel) output; fixed tube biasing. Each channel has a typical layout of knobs (volume(gain), treble, middle, bass, master, presence, reverb) as well as a seperate low/high gain and trim/fat switch per channel. There is also a level knob to control the amp's overall volume. Because this amplifier has so many options it took awhile to dial in the sounds that I wanted. I play a wide variety of music ranging from jazz, blues, latin, ska, experimental, rock, thrash, grindcore, ambient and electronic generes. I have been able to achieve some very nice clean tones with this amplifier both on stage and in the studio, but I never found a mid to high gain distortion sound that I was happy with. After investigating my options for a new amplifier I decided to have the Heartbreaker modified by Voodoo Amps. They have a very good reputation, and most importantly the capabilities to work on a wide variety of amplifiers. I listened to soundclips of their amplifiers, talked with owners of Voodoo-modified amps on Harmony-Central and spoke with Trace numerous times about the sound that I wanted to achieve out of the Heartbreaker. The Voodoo Amplifier Hex preamp circuit was installed, as well as their Global, Bottom and Cream circuits. Because of the available space constraint inside the amplifier chassis, external controls could not be added for the extra three circuits. They were instead optimized for the overall sound that I was looking for. The results are posted below. Voodoo Amps also supplied a certificate of authenticity as well as a label for the amp verifying the work performed.

In addition to the Voodoo/Heartbreaker I use an ES-335 style guitar fitted with Joe Barden pickups for articulation and clarity. They are switchable from single-coil to humbucking as well as in/out of phase. I often change pickup configurations within songs to coax different tones out of the amplifier. I also have a Stratocaster fitted with three Joe Barden pickups for alternate tones when I need them. I use mainly Electro-Harmonix and Lexicon effects with the amp, and for speakers I have a Mesa/Boogie 4 X 12" Rectifier Standard cabinet. I also use a Roland VG-88 for extra sounds which I mix in using footpedals.

Before the modifications I found that channel one was an incredibly versatile and great sounding clean and 'pushed' channel. Some people have complained about 'flabby' bass response, but I have not experienced this. Perhaps it is due to the particular pickups I am using. I could never find a sound I was satisfied with in channel two though. I did not like it set to clean because I though that it lacked dynamics. The mildly overdriven sounds seemed pretty nice, but I only need those occasionally. The high gain sounds were very loose and unarticulate, and I did not care much for the character of the midrange frequencies. I tried using EL-34 power tubes in the output section, but the second channel turned a bit brittle to my ears. The bass response was tighter, but the undesirable midrange was still there and the high end was too piercing. After trying out many diferent ways of setting the amp up I decided to have it modified.

After the Voodoo modifications:

Channel 1 - As Trace had explained to me both channels on the amplifier share some of the same circuitry, so adjusting the sound on one channel will have an impact on the other channel's sound. I was very happy with the stock version of channel one, but I think that the modifications have made it even better. The main difference is in the midrange. With the stock channel the amp sounded great when I was playing alone, but with the band sometimes my sound would get lost (and we are only a trio). The modified channel now has a very pronounced midrange presence, which adds a subtle vowel-like effect to the sound. This has been a very pleasing experience for me, because as I play chords and single notes with varying technique-the sound coming out of the amplifier changes in a much more immediate and drastic way than before. There seems to be more articulation as well. I feel that the changes that were made now allow the amplifier to be better equipped as a tool for expression. The new clean voice sits very well with the percussion and the bass, and I can hear each note much more clearly than before. This channel is much better than the clean tones I have been able to get from each of the following amps I have owned: Carvin Quad-X, Roland JC-120, Fender Twin, Mesa/Boogie Triaxis and Mark IV.

Channel Two - Distortion characteristics seem to be the main reason why people go to Voodoo Amplifiers for service. I know that tone is subjective so I am trying to make this as straighforward as possible. I have decided to keep the 6L6s in the power section, although the EL-34s did sound very nice as well. The character of the modified channel two does not even remotely resemble the stock channel two. One dramatic difference is the character of the distortion. It has a 'finer', more pleasing grain to it. It is very intelligable across the strings, so it does not garble up with different chords such as suspended, diminished, etc. There is alot more gain on hand, yet the channel is intensly dynamic, sort of like a Marshall JCM-800. With the gain on full I can achieve a more-saturated tone than I know what to do with, but if I bring down my guitar volume the amp yields a nice purring overdrive. Within the context of a phrase no matter where the gain is set at; by varying pick attack the dynamics of the amp respond quickly and accurately. There is a tremendous amount of low bass

The reliability of this amplifier falls upon Mesa/Boogie, Voodoo Amplifiers and myself. First, I think that Mesa/Boogie has designed and built a fine amplifier that will last a very long time without major servicing. I have never had any problems with it beyond the normal care of periodically retubing it. When I was originally shopping for a Heartbreaker both Guitar Centers near me had a broken floor model. This did put me off a bit, but consider the source. Secondly, the work performed by Voodoo Amplifiers is top notch. I am an Electrical Engineer so of course I took a peek at at the craftsmanship. The soldering was very neat and orderly as well as the component placement. I know that reworking an existing printed circuit board layout to accomodate a redesign can be a tedious process, and Trace has done a fine job. Lastly, I always carry spare tubes and fuses with the amp just as a precaution. I carry the amp in an anvil-style foam-lined flightcase, which I highly recommend. For those of you having trouble finding an affordable case for your Heartbreaker head; I am actually using a Tremoverb case with a couple extra peices of foam. These are frequently on E-bay for decent prices. The stock dimensions are a bit different, but it does work. I also use a Furman AR-1215 voltage regulator to protect the amp from surges and provide a constant voltage for it to operate. Taking these extra precautions is the least I can do to protect my investment. I can not afford to gig with backups, so I take extra care with my equipment.

Trace was very good at getting back to me and discussing what I wanted out of the amplifier. I sent him clips of songs that I felt had tones similar to what I wanted, and I made a list of all of the amplifier sounds that I have had in the past and what I liked and disliked about each. I greatly appreciate his patience and enthusiasm toward the project.

I feel that Voodoo Amplifiers has brought a fine amplifier to the next level. I have spent years finding out what I want out of an amp, and I am very happy to finally have an amplifier that has it. I highly recommend their services to anyone considering a modification or a new amplifier. My band will begin recording our third album in September 2002, and this amplifier will be my main choice throughout. You can check us out at:
www.jjflux.net