The earliest Hiwatts were built during the period 1963 – 1965.  They are top-mounted with a white front grill and have a black-on-gold “cursive” plexi logo, see Picture #1.  In 1966 – 1968 Reeves shifted to a front-loaded design with a “script” plexi or traffolyte logo, as shown at Picture #2.  As with Marshall, there are transition models, which vary in some characteristics, such as the bottom two heads in Picture #1.  Reeves also subcontracted assembly to smaller companies when the workload became heavy, which may account for the cosmetic changes that took place at various points in Hiwatt’s early history.

Picture # 1

Picture #2

During this period Reeves also manufactured various prototypes and supplied amplifiers directly to musicians.  All of these probably were different, as they were designed and built for specific customers.  Examples of these are shown in Pictures #3 – #6.  Some models made during 1968 – 1969 had metal badges, as shown at the bottom of Picture #6.  Reeves also sold some heads under his own name, as shown at Picture #5.  This may have been due to a restrictive distribution deal, as was the case with Park and Marshall.

Picture #3

Picture #4

Picture #5

Picture #6

Starting in 1970 most models have a white-on-black traffolyte block logo, which is the “classic” Hiwatt look, as shown at Picture #7.  Reeves entered into a manufacturing relationship with Harry Joyce, whose company put the heads into production.  The two models for which Hiwatt best is known are the DR103 and the DR504 (“DR” being the initials of the company’s founder).  The DR103 is a 100 watt class A/B valve head using an EL34 power tub output stage (it is a popular misconception that Hiwatts are pure class A).  The DR504 is a 50W version.  Both types were made individually with hand-laced wiring looms and point-to-point construction on tag-strips.  This time-consuming method of construction gives remarkable dynamics, clarity to the sound and a sonic signature that is unavailable from any other amplifier.  In addition to innovative circuit design with its radical tone-shaping capabilities, and meticulous wiring technique, other contributors to the characteristic Hiwatt sound are the output transformers supplied by Partridge, the most prestigious of British manufacturers; and the Mullard output tubes.

Picture #7

Reeves died in March 1981.  Joyce died in January 2002.  In April 1985 the UK company Music Ground bought the Hiwatt name and makes extremely accurate reproductions.  Music Ground does not own rights outside of the UK and Europe.  In North America and Asia it is owned by Fernandez, which has marketed an unfortunate line of pedals and accessories.  In the early 2000s Fernandez sued Music Ground on account of Music Ground’s importing amplifiers into the US, allegedly in violation of its rights.  Music Ground settled the case by agreeing not to do so in the future.  Below is an interesting document that details the dispute in further detail.  In April 2010 Music Ground evidently shut down and its future prospects are unknown.  Vintage Hiwatts appear regularly on EB and elsewhere and if you’re looking for one those most likely are your best option.

Hiwatt UK Patent Dispute

Illustration of the problem – how to control the modules on the right with the Voyager

]]> http://kronemyer.com/2010/07/25/songs/using-a-moog-voyager-as-a-master-midi-controller/feed/ 0 http://kronemyer.com/2010/05/10/songs/a-critique-of-eurorack-modular-synth-enclosures/ http://kronemyer.com/2010/05/10/songs/a-critique-of-eurorack-modular-synth-enclosures/#comments Tue, 11 May 2010 01:22:58 +0000 David Kronemyer http://kronemyer.com/?p=508 DAVID KRONEMYER: There’s a semi-not-obvious issue with the now-popular Eurorack format, which is that while the modules may be economically-priced, the racks are expensive. And while they are amazing, many of the newer modules no longer are so economically priced. Doepfer’s dealer in the U.S. is Analogue Haven/Shawn Cleary. Shawn sells Doepfer Euroracks for $530 + shipping (approximately $35) + California’s confiscatory 9.75% sales tax (if you live in California, at least). This pushes to $620 per rack. If one has 10 modules in a rack (which seems to be about the average width), this adds an extra $62 to the cost of each module. Compare: a set of MOTM rails, which will accommodate 10 single-width modules, is $54 + shipping; a set of synthesizers.com rails, which will accommodate eight single-width modules, is $65 + shipping; and a set of Blacet (frac rack) rails, which will accommodate five double-width modules, is $79 + shipping. Even if you double these to reach the same average module density as a Eurorack, you’re still at about 25% of the cost.

Please understand I’m not bagging on Shawn or saying the Eurorack isn’t worth it. In fact we have about a dozen of them! It’s a highly specialized business and I’m sure Shawn’s margins are really thin. I’m just making an observation about relative cost. Also, there are less expensive alternatives. For example, Monorocket (also available through Analogue Haven) makes a portable case for $350 (though it’s not a rack mount).

There’s another problem with Euroracks, which is the power supply. While the buss board offers +5 VDC, all Doepfer power supplies now are +12/–12 VDC. If you want +5 VDC – a necessity for many modules from Analogue Solutions, for example – you’re out of luck. Doepfer makes a little thingy that converts +12VDC to +5VDC. While we’ve never tried it, the picture on Doepfer’s site makes it look not all that sturdy, capable of handling one or two modules at most. On top of that the Doepfer power supply is 1200 mA, which leaves little head-room. Doepfer used to make a power supply with only half that much! As a general principle, the more head-room, the better the sound.

We are very careful with module count, correct polarity, etc. However, mysteriously, the –12 VDC on one of our Doepfer power supplies recently disappeared. The +12 VDC was just fine, as were the buss boards. We realized we were exhausted by this tomfoolery and decided to install our own power supply, which also would provide +5 VDC. Power One makes a high-quality linear power supply, sold by DigiKey (Part No. 179-2317-ND). It gives +12 VDC, –12 VDC and +5 VDC, all in one convenient unit. So we removed the now-deceased Doepfer power supply and installed this one instead.

This power supply is way overkill for the rack. As you can see the Alcatel connectors also are ludicrously huge for this application. The only reason why we used them, and the heavy-gauge wire, is because we had them lying around from a previous project. It was a happy moment to see all of the LEDs on the Doepfer buss rail light up. We are eyeing our other Doepfer racks guardedly.

WARNING – do not try this at home unless you know what you’re doing!

The transformer

The Alcatel connectors

All lights illuminated!

Here is the solution we have implemented (see picture).  We have six separate 20-amp AC lines coming into the studio from the main power service.  First they go to Tripplite power conditioner-line stabilizers.  These maintain the incoming voltage at a steady 120 V and also filter out noise, spikes and other undesirable artifacts.  Then they go through a metering panel, which shows amperes – volts – watts.  This gives a ready indication of each circuit’s capacity and status.  Then they go to balancing transformers manufactured by Equi=Tech.  Usually AC line voltage is 0 V on one leg and 120 V on the other.  What balanced power does is change this to 60 V on both legs.  This promotes common-mode rejection (analogous to balanced audio cabling) and lowers the noise floor by at least 10dB.  It also eliminates ground loops (audible as 60 Hz hum) and complex star-grounding schemes.  We can turn our main mixing system all the way up without audible hiss or noise.  Oversized cabling is used throughout to reduce impedance and promote headroom.  We also have uninterruptible power supplies for computers (not depicted).

Here are a few other observations:

1.  Most studios have at least three separate cabling systems (AC, audio, MIDI).  Power cabling should be physically separated from audio and MIDI.  If they run parallel, there should be space between them; if they cross, they should do so at right angles.  These same principles apply to digital cabling, computer cabling and time-code cabling.

2.  Power to anything but sound-producing keyboards or modules must be on a completely separate AC circuit.  Lighting and computers, for example, always should be on their own lines (as seen in the picture, four circuits are devoted to audio and two circuits to non-audio).  It is difficult to over-emphasize the importance of this step.  Back in the days of 24-track analog tape recorders, we even went so far as to rewire them, segregating power to the electronics from power to the motors.  This considerably improved the sound of the electronics, because they did not have to deal with motor factors such as torque and slew.  It also improved the performance of the motors, because now they could have a consistent power source without also worrying about powering electronic components.

3.  Multiple wall-warts of the same power type (e.g. 12 VAC) easily can be replaced with a single, larger AC transformer.  This provides consistent power to all of them and results in significantly improved sound quality.  Many modules are 9 or 12 VDC.  We have two large transformers (made by Acopian) to make these conversions, then distribute the power along separate lines, to the same effect.

In conclusion, studios typically spend thousands of dollars on gear while at the same time ignoring basic principles of how to make it sound good.  This doesn’t make a lot of sense because the way things sound is constrained by the least-satisfactory variable.  It’s important to optimize every step of the process in order to achieve a desirable outcome.

Publison Infernal Machine – Manual

Publison Infernal Machine

I recorded this track to demonstrate their capabilities in three passes, 1:30 long with minimal processing.  It includes sounds from the dreaded “Super Space Drum” (left), the “Electronic Crash Drum” (right) and the “Clap Track” (towards the end).  The Mini-Synthesizer on the left sounded better with bass and the one on the right sounded better with lead, so there you have it.

ElectroHarmonix

DAVID KRONEMYER: Over the years the studio where I produce many records has accumulated a variety of MIDI sound modules (“ROMplers,” so called because their sounds typically are stored on a single ROM chip) and samplers. The MIDI sound modules include older ones made by Roland, E-Mu, Yamaha and Alesis, together with others. The newer ones are made by Access Virus, Nord, Novation, Waldorf and others. The samplers are Akai, Kurzweil, E-Mu and Roland. At one point this studio probably had 200 sound modules and samplers in a dozen floor-to-ceiling racks. All of them were/are MIDI-controlled and stereo out.

The last generation of sound modules made right before the advent of VST instruments have SPDIF digital outs. These are intriguing because they suggest the possibility of by-passing a stage of digital-to-analog (“DA”) conversion before introjecting the sound into ProTools or Logic. Most digital converters (such as the Apogee Ensemble and all of the other Apogee converters) have a SPDIF digital in. The problem is there is only one of them, which creates a challenge to mix all of these separate digital sources.

Surprisingly there are not a lot of SPDIF digital mixers. Almost every mixer now made claims to be a “digital mixer” and they are in the sense that they take analog signals, mix them and then convert them to SPDIF or AES-EBU digital. None of them however mix signals in the digital domain, which is what one might think a “digital mixer” does. After exhaustive research we concluded that the best (and possibly the only) solution to mixing actual digital signals is the Roland M-1000. It accepts four (stereo) SPDIF ins and also a (stereo) analog input.

We took 24 modules and connected them to six M-1000s as depicted in the accompanying photo (one M-1000 not shown). We established a limit of 24 modules for this exercise because we devised a way to address each of them separately in Logic (which will be the subject of a separate post). The problem with this set-up was that the Ensemble (like all other Apogee converters) only has one SPDIF in. Thus it was only possible for one M-1000 at a time to address Logic. The other ones had to go through a DA conversion phase out of the M-1000 and then another analog-to-digital (“AD”) conversion phase through the Ensemble. Although these were high-quality conversions it still basically defeated the purpose of remaining exclusively in the digital domain.

We experimented with ganging four M-1000s into one M-1000 as a kind of digital summing mixer however this lead to audible jitter and other undesirable digital artifacts. To stay exclusively digital we ended up disconnecting and reconnecting M-1000s so as to address that elusive but desirable single SPDIF port.

After a while we decided that this system was a lot of trouble. So we decided to utilize the on-board DA converters on each of the modules and mix straight into Rane SM82 mixers. These are analog but then went straight into the AD conversion phase of the Ensemble. The results are depicted at the second photo. We also retained one M-1000 so we could continue to use the Ensemble’s sole SPDIF port. The Ranes are stackable and in principle we could have tripled the inputs for this revised system. We retained the 24 module limit however for further interface with Logic’s MIDI control system.

We were not able to discern any sonic difference between this set-up and the initial one using the M-1000s. We also were able to stay with a single AD-DA conversion cycle. From this we concluded that the DA converters on the last generation of ROMplers and samplers are as good as (or at least indistinguishable from) their respective SPDIF outs through a digital mixer and then into Logic through Apogee converters.

A post on addressing 24 MIDI channels in Logic simultaneously will follow shortly.

DAVID KRONEMYER: The studio where I do a lot of work has a variety of synths and synth modules. As a matter of performance ethic we decided we wanted to keep all of them on, all of the time, and accessible via a master stereo buss. Over a period of time we attempted to devise a variety of ways to accomplish this result. For different reasons the solutions we implemented were unsatisfactory. Our Solid State Logic console lacked sufficient inputs. The new SSL XLogic SuperAnalogue X-Rack has an XR624 eight channel input module going to a summing mixer, which allows for 28 stereo inputs in four rack spaces (60 stereo inputs with two racks). To be sure this is a high density count however all of the inputs come up at unity gain (none of them have variable gain controls). Furthermore the on-board computer (which adds considerably to the cost) doesn’t do anything for this module configuration. The Speck Ultramix is an elegant solution however even with its high input count it taps out and was unable to put enough inputs on a single buss.

We therefore determined to use the Rane SM26 for the mono synths and the SM82 for the stereo synths and modules. We acquired 24 of the SM26 and 24 of the SM82. We rechipped several of the older units. A few of them did not function properly and in lieu of trying to fix them ourselves we sent them off to Rane for repair. We would like to complement Rane’s product support department, which restored them to pristine working condition quickly and inexpensively.

The SM26 has six input channels and the SM82 has eight stereo channels (actually nine if you use the stereo return as an input channel, which we did). Both have a feature where you can chain several modules together on a single buss, which we did in combinations of two or three. We evaluated several master buss modules, including the attractive and desirable Neve 8816 summing mixer. We ended up selecting the TubeTech SSA 2A, which has eight stereo pairs and four mono channels. I have the feeling these master buss summing mixers are marketed as a tool for digital audio workstations such as Logic and ProTools, so one can take separate stems from the DAW and mix them down “outside of the box.” Although our purpose might not be the one initially intended, it works great.

All of the modules terminate at the back of the racks on EDAC/ELCO 90-pin connectors. The snakes then lead to (a) stage boxes throughout the studio for the keyboard synths, or (b) EDAC/ELCO 90-pin connectors on the back of the racks for the samplers ROMpler modules. This was a considerable wiring project, as one might imagine. Here’s a photo of the front of the racks:

This supplied us with a total of 576 channels. The stereo buss is whisper-quiet, even when pushed to higher gains. We attribute this primarily to (a) plenty of AC headroom (900 amps coming into the studio); (b) use of Equi=Tech balancing transformers, reducing the noise floor by about 10db; (c) we tied all of the power supplies together to a single transformer; (d) careful wiring practices such as separating all power from all audio; (e) progressive optimization of the chips inside of the mixers; and (f) over-all component excellence.  We sincerely appreciate the great modules from Rane and Tube-Tech which made this project possible.

BTW we still need some more channels.