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As promised (looong ago), a review of the Hi-Mu combo amp.
I received my Hi-Mu 5.5 combo amp in mid-December, right on
schedule. Barry did a nice job putting it together, very professional.
Looks better in person than in the crummy GP photo. Basically, its a
Fender champ with a fancy preamp.
I asked for the combo with several options: post-transformer direct
recording output with speaker simulator, tube-driven effects loop, tone
defeat switch, and 25 W Celestian Greenback in place of the standard
Eminence speaker. I received all that plus some extras: the effects loop
usually only has a variable send, mine has variable send and receive (back
panel real estate is scarce with all the extras, so the effects return
level was placed to the side, immediately above the Hi/Lo bias switch.
Also Barry stuck a little toggle way under the amp that alters the feedback
(damping) network. In one toggle position, the circuit is in BarryÕs normal
configuration which has a small amount of negative feedback. In the other
osition, there is no negative feedback and the amp is somewhat brighter,
nosier and looser. Basically its a tight/loose damping switch. (Damping
factor is a measure of an ampÕs ability to keep the output voltage constant
regardless of load impedance.) According to Barry, he can wire the amp
either way to the customerÕs specs, or make it switchable like on my amp.
Other features of the 5.5 combo: on/off switch, polarity switch, standby
switch, 1 amp slo-blo fuse, metal film resistors and metalized caps, custom
wound power and output transformers, DC powered tube heaters, handwired
point-to-point, ceramic tube sockets, preamp out, Hi/Lo bias switch. (See
Guitar Player Feb 1994 for more details of the nuts and bolts).
The amp is solidly-built and professionally detailed. Snug black
tolex over a well-built cabinet. Solid looking chassis with white screen
printed labels over a black chassis. Black grill cloth and white
ŌmouldingĶ strip. The Hi-Mu looks like an oreo sandwich cookie. The
volume, tone and channel knobs are cool old-style chicken heads. the
effects loop and direct knobs are modern mini-knobs. The toggles are
standard mini-switches. As pointed out in the Widders-Ellis review in GP,
the back panel knobs and switches are in danger of being knocked off when
you haul the amp through doorways (IÕve knicked the door jamb once, with no
damage to the amp, but IÕm REALLY careful now). This is not a gigging amp
(a-hemh, though see below), so for most applications it wonÕt be a problem.
So far, I've gigged with it four times, took it into the studio for
two sessions, and use it daily in my home. I run a PRS custom with stock
pickups and a Strat Plus with EMG SA pickups + EMG midboost and Hi-Lo boost
(EXG and SPC modules). For effects I frequently use a TubeWorks Real Tube
Stereo Reverb (12 spring accutronix tank with 12 AX7Õs), a Roland GR-1
guitar synthesizer (driven by a GK-2 pickup on the Strat), a Lexicon JamMan
and rarely a crybaby wah-wah, E-Bow, Boss Metal Zone distortion pedal, and
Experience pedal.
The PRS pickups overdrive the amp in the clean setting with the
guitar wide open and the amp volume set to 4-5 for single note runs and set
to 3 for triad chords or greater. I was shocked at how easy it is to get
the amp to breakup at low volume. I can get the most headroom with the
tone controls in, the bias set to Lo, the amp set to 4-5 and the guitar
back down to 7-8.
The Strat doesn't overdrive the Clean channel until 4 for chords
and 5-6 for single notes. The overdrive is very sensitive to picking
transients; legato lines at higher volumes are smooth and bell-like while
picking transients snarl. I can get this with both humbucking and
single-coils, but the amp has to be tinkered with to find the sweet spots.
The Hi-Mu has two other gain stages. Gain one adds an additional
12AX7 to the preamp, gain 2 adds yet another 12AX7. Each gain stage has
its own pot (ie. Volume, Gain1, Gain2 pots). The Clean, Gain 1 and Gain 2
channels are voiced differently and all controls interact. As a consequence
a wide variety of tones are possible without monkeying with the tone
controls. Also as a consequence, switching from Clean to another channel
really changes the setup of the amp. It is often necessary to twist knobs
to get the right sound after switching channels (a pain when switching on
the fly in performance). Its a trade-off: greater tonal flexibility
well-suited for recording, but not convenient for performing. The amp is
sold as a recording/practice amp, and it is great for these purposes.
The tone defeat switch is very interesting. The tone controls
(treble, midrange, bass) are passive and don't contribute much; the treble
control is the most sensitive, mid is less sensitive and bass is basically
in or out. I leave the bass and mid almost all the way with the treble
backed off to 6 (its a bright amp). The tone defeat gives you ALOT of
extra gain. Its amazing how much the tone circuits soak up. The tone of
the amp sans tone controls is very nice...I use the tone defeat quite a
bit. The amp overdrives at lower settings with tone defeated.
The amp is quiet in the clean setting. The extra gain stages add
noise. The volume control acts as master volume for the extra gain stages
so you can get preamp distortion and muy compression at low volumes. The
amp can cover jazz, blues, country, rock, metal (sorta...), you name it.
It is a guitar amp (not good for keys or vox). The power tube distortion
is creamy and nice. The output stage is a single 6V6 and the amp is
running class A just like a Champ. The effects loop adds extra gain
(probably half of a 12AX7) and noise but is tamed by the effects
send/return pots. Without effects in the loop, the effects loop can be
used as an extra gain stage (why would you wanna? Besides, it doesn't
sound very good that way). The effects loop helps tame the noise from
pedal effects. I didn't notice any great difference when I put the reverb
before the amp input or in the loop. The pedals were MUCH noiser when
placed up front than when in the loop.
The recording out is great...really good definition without
harshness. A decent option to miking the amp in the studio. The Celestian
is delicious, though, and its a shame not to hear the speaker push back on
the transformer when goosing the clean channel with the amp cranked...mama
mia! I like it much better than the original SansAmp and preamp out from
the TubeWorks Real Tube II, and other preamps.
At home, the amp is everything I could ask for. In the studio it
is very good (I missed footswitchable channel switching at times....I
dislike overdubs...and the channels have to be tweaked after turning the
knobs). On stage, well...
The first night out I took it into a 300+ person hall. I was
hoping to mike the amp and use the PA to get the gain for the hall. The PA
amp is ok but not the best so there were some losses there. Also the
monitor mix was low (I was begging for more guitar all night) so I really
needed the gain on the amp to hear myself. Now I realize this is a 5 watt
(7 max) amp, so I shouldn't whine, and I really want to play with the stage
volumes lower (to protect my ears). Some of the problem is hall-specific,
some is because our drummer is a heavy hitter...oh well. I next tried
guitar into the Hi-Mu, split the signal at the stereo reverb, run one
signal back into the Hi-Mu and the other into a Real Tube II preamp effects
receive and from there into an 80W MosValve solid state (Mosfet) amp and 2
X 12" emminence speakers. Since the Tube Works equipment is what I hoped
to replace I was a little disappointed. (IÕve since replaced the TubeWorks
preamp, amp and cabs with a DC30 which is much better). But then again, if
I mic the Hi-Mu I get the nice tube amp sound for the house and the Tube
Works can give me the gain on stage until I can talk Kenny into playing
with a lighter touch. (Since the DC30 has a very nice tube sound, IÕve
given up on taking the Hi-Mu onstage).
So hereÕs the skinny:
5.5 Tube Combo, 1-12Ķ speaker $490
H5.5 Tube Head $440
Options:
Direct recording output $25
Tube-driven effects loop $20
Celestian G12M Greenback $92
Tone Defeat switch $15
Shipping is UPS ground, maximum $16
I paid $659.88 with shipping on December 8, 1993. This isnÕt a
cheap amp, but its very, very good for the money. IÕm satisfied and can
recommend it. The amp has a comprehensive 1 year warranty (INCLUDING the
tubes). Barry gives you two weeks to try the amp. If you arenÕt
satisfied, heÕll refund your money AND pay the freight charges.
By the bye, Barry is very nice. If you speak to him, send my
regards from Eugene, OR.
--
Rik Myers
(Zanga Zanga)
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* Earth is an asylum for angels with amnesia -- Emerson *
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