Demeter HBP-1 Preamp

Here is Demeter?s description of the device:
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The H Series Bass Preamp by James Demeter uses the same all tube front end found in his classic VTBP-201 Bass pre-amplifier and combines it with the revolutionary H Series circuitry found in his professional audio H Series line. This preamp provides the best of both the tube and solid state world. It features high voltage (250V) tube front end (providing all of the preamp gain and passive tone controls), a two band solid state fully Parametric Equalizer that is tuned for, bass, a fully adjustable active effects loop with controls up front, a tuner output, a full balanced output with switchable mic or line level, both a balanced TRS line level output and an unbalanced line level output for amplifier connections and a mute switch. As with all Demeter equipment it is meticulously hand wired, using the finest components and assembled in the U.S.A.
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The features are entirely satisfactory for the rock and jazz bands I play in.

An unexpected benefit is the balanced TRS ?-in output in addition to the balanced XLR! I can send the balanced TRS output to my QSC amp while still sending the XLR to the board. When used with a balanced cable, this yields a 6 dB hotter signal with a better frequency response than the unbalanced output. The overall gain structure between preamp and amp is much better and I haven?t had to max out one channel of the amp much less bridge to mono as I was before.

I have only one critical comment about this device: the direct output does not have a pre/post-EQ option. I believe Demeter?s older bass preamp has a pre-EQ option so I?m not sure why this does not. Frankly, I thought this would manifest as more of a problem than it has. The EQ I typically use for my rig is aesthetically pleasing for recording and has yet to pose a problem for house speaker systems. It does have a mic/line switch so you can send the correct level to an amp or mixer.

It is with great pleasure that I write this review of the Demeter HBP-1 H Series bass preamp. This device is a dream come true for me. It has revealed the absolutely beautiful, pure tone of my instrument (MTD 635 six-string, Bartolini pickups, Wenge neck, satinwood body with myrtle burl top). In the 3 months since I got the preamp, I have done jazz and rock studio recording sessions, recorded live rock performances with two bands, and had several gigs with large and small sound systems. The sound has inspired me to play better and garnered positive impressions from bandmates and sound engineers. They say the sound is warmer and more articulate at a lower volume, which enables the drummer to play lower and everyone benefits.

It will be instructive if I compare the Demeter to the Aguilar DB680 tube preamp I have been using for 7 years. I want to qualify my remarks by saying the DB680 is a very well made device with every feature necessary for live/studio work, and the folks at Aguilar have been very helpful and friendly. My observations are from a personal, aesthetic perspective and not meant to denigrate Aguilar. The DB680 uses five twin triode tubes for all functions: input/output gain, EQ, crossover, effects loop. Now that I?ve heard the HBP-1, I see that even with nominal settings, the DB680 colors the sound more than I want, probably from the multiple tube stages, with audible rolloffs in both the low and high frequencies. I have tried to create the Demeter tone with liberal use of the EQ knobs and parametric filters without success.

The main improvements I?ve noticed with the Demeter HBP-1 are a much faster attack rate, even for the lowest notes, which are instantly clear and fully formed. The low notes are stronger with a more articulate fundamental. Staccato rhythms played in the low register come across more powerfully. The highs are also much more pleasing. In general, the bass plays more evenly and I am able to work on subtle timbral aspects of the bass more precisely because I can hear them all the time, even over the band. The characteristic warm tube sound is always there, even with moderate volume settings. Digging into the notes a bit harder produces a very satisfying bite that simply does not happen with a solid-state device. I can get this satisfying tone at any volume by attenuating the amp. My bass always had incredible sustain but there is a purity to the decay that I?ve never heard. This encourages playing simpler lines with long sustain, which requires being really confident in your sound.

The functions of both devices are similar except the HBP-1 does not have a crossover. However, I stopped using a crossover when I got my Epifani T-212 (Two 12-in drivers + high horn, the best all-in-one cab I have used). The HBP-1 uses solid-state circuitry for EQ and I like it much better than the DB680?s implementation. The low parametric band on the DB680 went down only to 180 Hz. Their rationale was that the deep switch and low shelf filter takes care of the region below that. I found that the DB680?s low shelf and deep switch each affected a wider area than I wanted. Aguilar?s tech talked me through how to use the internal pots to set my own amplitude of the deep switch settings (+ and ++), which was a helpful improvement but still did not provide the effect I wanted. I like to use a narrow width filter around 40 Hz to compensate for most speaker cab?s frequency response rolloff so the low B comes through evenly (32 Hz). This places the boost where it will fatten the ultra low notes without muddying the entire low frequency range. This may seem a small point but it is one of my favorite EQ settings.

The Demeter?s EQ is so clean and quiet that I have created cool new effects with frequency regions I never sought to manipulate before. Each EQ knob (treble, mid, bass, presence) creates an interesting sound with subtle boosts or cuts. Two parametric EQ bands make it easy to lower any range of high frequencies for more traditional, less bright bass tones. So, for those who think Demeter is ?too clean and bright,? it?s better to have the tonality to cut than to attempt boosting EQ to get the desired tone. The Demeter?s EQ is more subtle than some devices and is not meant to fix a deficient bass sound. On the other hand, the full range of boost and cut is useful without creating a severely unbalanced sound.

The preamp uses only one 12AX7 tube and is handwired. I expect it to be reliable and have had no issues thus far. I don't carry a backup.

I was made aware of one very small issue: they reccomend against using the XLR direct output with 48 V phantom powered mixers. They say that in rare instances, the board can put out a higher voltage and damage the preamp. I have not experienced this problem and they say a small spare chip can be carried in case this happens.

Demeter is a small, meticulous company with a reputation for making innovative, high quality equipment. It is always a pleasure to do business with a company like this and I had a great experience dealing with Adam Fifield, the ?gang of one? technical support guy at Demeter. He spoke with me at length on several occasions about where I was coming from and what I was trying to achieve and felt confident the HBP-1 was exactly what I was looking for. He arranged to send me an ?open box return? and allowed me a trial period to evaluate the device. His parting words: ?You won?t be sending this back.? I knew within 10 minutes of UPS delivery that it was a keeper. I have gotten a sustained burst of newfound creative energy from this device. Having the perfect sound motivates practicing!

I have played 25 years. Compared it to Aguilar DB680 in Sounds category.

Made in 2004.

The HBP-1 is very versatile; I intially bought it as a backup to my main rackmounted tube preamp. It has so many great sounds! It can also cut through a noisy drummer and guitarist! It's become my main preamp.

It's a single channel unit with passive and active inputs.

The only thing I would like to see Demeter offer is an optional Jensen D.I, in place of it's current internal D.I..(More on this later)

I use the HBP-1 with my Crest CA-9 power amp which powers a Bergantino HT210 & HT115 cab setup.

The HBP-1 is a 4-band tube preamp that has a defeatable solid state parametric 2 band eq; The solid state parametric section allows added control over the low end and midrange frequencies. It's parametric EQ section makes dialing in the right tone for the room a breeze.

It also has features I don't currently use: Effects Loop, etc.
For further details, check www.Demeteramps.com

My main bass is a Roscoe SKB3006 6-string bass, but I also use a Modulus Q-4 w/EMG's, and a Spector NS4CRFM w/EMG's as backups.

Depending on the style(s) of music required for the gig, I may also play a P-Bass, Jazz Bass, or a Rick 4001.

Thus far the HBP-1 is handling all the styles of music I play: Classic rock, R&B, Funk, and a bit of Country. If I were playing heavier styles I might look into a preamp with a bit more available grit.

It's very quiet.

I've found it's better suited for a clean tone. I can get some nice growl out of it, but I think the growl comes more from my hands and my bass than from my power amp, HBP-1, or my speaker cabs.

I experimented with a NOS G.E. 12AX7 tube in place of the stock Electro-Harmonix 12AX7 tube. I've found the G.E. 12AX7 has added a bit more midrange grunt and overall warmth to it's sound, but it's out-of-the-box sound is fantastic.

Thus far it's reliablility has been flawless.

I think the warranty is either 1 year or 3 years.

Andy in Demeter's Customer Service is super-nice guy, BUT there's a D.I. issue regarding mixing boards that exceed 48 volts phantom power. I made a few telephone calls and left a few emails to address this concern with James Demeter. I never received ANY reponse. As a result, I had to buy a separate direct box as a safeguard, which cost me an additional $180.00.

James Demeter: I know you're busy, and I'm no studio heavyweight or with a well-known signed act, but 10 minutes of your time would've been appreciated. Especially for the price of the HBP-1!

Wow, I've been playing for 29 years!!

If it were stolen I would certainly replace it with another one.

I love it's sound and flexibilty.

I dislike the lack of follow-up by James Demeter.

I was initally interested in the Demeter VTBP-201s preamp but I have another preamp which I think has a similar tone and features, the HBP-1 was exactly what I was looking for.

I have a pre-production Purity preamp made by Jack Read (two different "animals" with different applications). I've also owned an Alembic F1-X, an SWR IOD,and an Ampeg SVP-BSP.

If you prefer a clean tone and if you can afford buying an outboard D.I. box for gigs that require a P.A. send to a Sound Contractor, I highly recommend the HBP-1.