Lexicon Studio Core 2 & MP100

The MP100 daughterboard makes Lexicon's MPX100 multi‑effects unit available as a plug‑in within your MIDI + Audio sequencer.

Lexicon's reverbs are highly regarded by many musicians, and their new Core 2 combines them with multi‑channel analogue and digital I/O to create an affordable computer recording system. Martin Walker tries it out.

Lexicon launched their PC‑based Studio hard disk recording system back in 1998. This was a recording environment based around the Core 32 PCI card, a professional‑quality breakout box, and software compatibility with MIDI + Audio sequencers such as Cubase VST. A daughterboard, the PC90, could be attached to the Core 32; as the name suggested, this contained the same DSP chips used in Lexicon's high‑quality PCM90 reverb.

This was all well and good, but the Core 32‑based Studio system cost over £2500 on its launch (see SOS July '98). However, Lexicon have now revisited the Studio concept and produced the Core 2 PCI card, which is altogether more affordable at £599. The Core 2 is also supplied with a breakout box, this time with four analogue inputs and eight analogue outputs (all with 24‑bit capability), as well as S/PDIF In and Out. It also features two Toslink optical connectors that can be configured as either ADAT or S/PDIF In and Out. An unusual feature is the provision of selectable Dbx Type IV soft‑knee limiting on every analogue input, to simulate tape compression and increase headroom. Lexicon's UK distributors, Pure Distribution, claim that any PC audio‑recording application with ASIO support will work with the Core 2; Syntrillium's Cool Edit LE is bundled with the card, but I suspect that most users will want more advanced software than this. The original Core 32‑based Studio offered close integration with Steinberg's Cubase VST and I elected to stick with that for my tests. While I was carrying out my review, news reached me that not all ASIO applications were working equally well — more on this later.

As with a Core 32‑based Studio system, you can add a reverb daughterboard to the Core 2, although this time the board you can use, the MP100, is derived not from the PCM90, but from Lexicon's less expensive dual‑channel MPX100 hardware reverb. Those of you wondering whether you might be able to buy the Core 2 but run it with the PC90 daughterboard instead of the MP100 will be disappointed, as the Core 2 apparently does not support the PC90. But even with the Core 2/MP100 setup, you still have access (from inside your computer, remember) to true‑stereo processing and good‑quality reverb, as well as tremolo, rotary speaker emulation, chorus, flange, pitch‑shifting, delays of up to 5.7 seconds, and echo. All of which easily merits further investigation...

Installation & Setup

The Lexicon Core 2 card (foreground), shown connected to the I/O breakout box. The optional MP100 reverb daughterboard can be seen to the rear

The Core 2 card isn't particularly long (eight inches) but it is crammed with far more discrete components than you normally see on soundcards. There are three connectors on its backplate: a 25‑way 'D'‑type socket to attach the breakout box, and a pair of Toslink optical sockets for ADAT or S/DPIF‑format digital I/O.

There are four jumper connectors on the Core 2, which allow you to enable and disable the Dbx Type IV limiting for each of the four analogue inputs. I decided to disable it on two inputs before installation for comparison purposes (more on this later), but most users will probably leave all four jumpers in their default 'enabled' position.

The Core 2 breakout box is a free‑standing unit about eight inches wide, three inches deep, and 1.75 inches high. It's painted black, and looks similar to that of the Echo Gina. I did feel that it looked a little anonymous for a £600 package (see picture). On the back is another 25‑way 'D'‑type socket, and a specially shielded cable is supplied to attach this to the soundcard. This is only one metre long, and no longer cable is available, but of course you could make the standard audio cables attaching to the breakout box longer to compensate.

The front panel of the box houses four unbalanced quarter‑inch jack sockets for the analogue inputs, eight for the analogue outputs, and a pair of phono sockets for co‑axial S/PDIF In (and word clock) and Out. Opening up the breakout box confirmed that it contained only sockets and no converters (the D‑A converters are on the card), but this technique has been used with success in several other designs such as the Echo Gina and Midiman Dman 2044, and it seems to have no effect on the quality of recordings made with the Lexicon (more on this later). A quick scout around showed that the Core 2 card uses two stereo AKM AK5383 A‑D converter chips for its four analogue inputs, and four stereo AKM AK4324 D‑A converter chips for the eight analogue outputs, along with a pair of Crystal CS3310 stereo digital volume‑control chips for level control.

The card must be installed in a PCI slot with buss master capability — if you're in any doubt refer to your motherboard manual. I had no problems fitting the Core 2 card, and on subsequent bootup it was correctly detected. The installation CD‑ROM was automatically requested, and the drivers were installed when I placed it in my CD‑ROM drive. I was back on the desktop within a couple of minutes, the only annoyance being that a new 'LXSTUDIO' folder had been created in my root directory, and I wasn't given the option of moving it elsewhere.

Drivers & Control Software

The Core 2 page of the LexPanel utility lets you set up inputs and outputs to suit the rest of your gear, as well as input gains. The status of the Dbx Type IV compression for each input (set by jumpers on the card) is also displayed.

Although the drivers are automatically detected and installed, you need to run the Setup.exe program on the CD‑ROM to install the Lexicon Control Panel utility. After doing this and rebooting, I found the new Lexicon Studio icon on my Taskbar. Unfortunately, double‑clicking on this produced a quick flash on my screen but no Control Panel, and exactly the same happened when I attempted to launch it from within Cubase VST. Thankfully I had already done some Internet research on the Core 2, and remembered another user having this specific problem, so went straight to the Lexicon web site and browsed through their Knowledge Base (www.lexicon.com/kbase/kbase.asp). Sure enough, this specific problem was mentioned, and the cure was to download the version 1.21 drivers to replace the 1.20 ones supplied on my CD‑ROM.

After I had downloaded the 2Mb file, I updated the drivers. First you need to remove the old software (using Control Panel's 'Add/Remove programs' option), run the 'Update Driver' option inside Device Manager, and then re‑run the new Setup.exe file. Thankfully the version 1.21 drivers did indeed cure the problem I was having, but unfortunately I had subsequent problems with audio glitches during playback and recording which couldn't be overcome. Lexicon subsequently sent me Beta versions of some even newer drivers labelled version 2.10 Beta 32 that completely cured this problem on my PC [As this review was going to press, the finished drivers were ready for download from the Lexicon site, with further upgrades promised — Ed]. However, since it is far easier to install new files, rather than updating existing ones, I recommend that new Core 2 users visit the Lexicon web site before they install their soundcard, and download the very latest drivers in the first place.

Once you have finished installing the drivers and control panel, you will find new devices to use in both multimedia (MME) applications and ASIO ones (see the screenshot on page 75). Unusually, the entries don't mention the make or model of the soundcard at all, and the entries that appear when using the ASIO drivers inside Cubase VST (for instance) are even blander — the inputs simply appear as A/D 1 to 4, and the outputs as D/A 1, 3, 5 and 7.

Staying In Control

The full range of inputs and outputs available to MME applications are shown highlighted here.

All controls for the Core 2 are accessed through its own LexPanel (there are no entries in the normal Windows Volume Control applet). You can launch this quickly by double‑clicking on the new LexPanel icon on your PC Taskbar, or directly from within any ASIO‑aware application, such as Cubase VST.

The LexPanel has three tabbed pages, or four if the optional MP100 board is installed — see later. The one you will visit most often is labelled 'Core2'. Its Hardware Configuration box contains buttons to enable/disable specific inputs and outputs — by default all four inputs are enabled, along with four of the available eight outputs. You can enable the remainder if your PCI buss can cope with the extra traffic — I reckon most PCs will be able to manage this. On the digital side you can enable S/PDIF In and/or S/PDIF Out. This pair make use of the co‑axial phono sockets on the breakout box, but by clicking in the Optical tick box you can instead route them to the pair of Toslink sockets on the Core 2 backplate. If you need multi‑channel digital I/O, you can instead enable the ADAT In as long as the S/PDIF In isn't already enabled, or the ADAT Out as long as the S/PDIF Out is disabled. Enabling either ADAT In or Out automatically disables the S/PDIF optical options. Two additional options labelled 'Aux Send' and 'Aux Return' are for the optional MP100 effects board, although their function is not mentioned at all in the Core 2 User Guide.

When you change any option, the Apply button starts flashing, and you must either click on this or the main OK button to save the routing changes. If you are using ASIO drivers you must then quit the ASIO application and relaunch it before the changes 'take'. However, if using the MME drivers, you have to reboot Windows completely before the changes take effect. These restrictions seem reasonable given that the drivers must be reinitialised in each case, and a dialogue box explaining this is displayed to warn you when you finally click on the OK button.

The input level control sliders are also on this page, with a dB readout beneath. Here you can adjust full‑scale input sensitivity between –18dBV and +14dBV. A pair of link buttons lets you gang the two sliders of each stereo pair together. Beneath these sliders is a tick box for the 'Low Latency option'. This makes no difference when using MME drivers, but reduces the ASIO latency from its default 47mS at a sample rate of 44.1kHz (43mS at 48kHz) down to a rather more useful 6mS (at both sample rates). Unfortunately you have to reboot Windows for the new setting to take effect — this seems rather extreme, since most other soundcards I've reviewed over the last year or more let you change it from within the application, and the RME Hammerfall lets you change it without even stopping playback!

Lastly, this page also features four indicators that show the current status of the Dbx Type IV compression option for each input — these reflect the position of the jumpers on the Core 2 card, but there is no way to adjust the settings using software control.

Punch Drunk

The Core 2's Punch function provides 'zero' hardware latency. When running ASIO drivers (with Cubase VST for instance) only those busses already activated in the ASIO application are available for punch routing, as shown here.

The Punch page allows you to set up hardware 'zero' latency monitoring. First you need to click in the tick box marked 'Enable Punch', and then select any combination of inputs and outputs in the Source and Destination windows (multiple selections can be made using the shift or control keys). A mono mix of the selected inputs will then be sent to all of the outputs selected. Given that the combined monitor signal may exceed the digital ceiling, a Mix Level fader is also provided to reduce its level to avoid distortion.

When using an ASIO application like Cubase VST, the only available Punch sources and destinations are those specifically enabled within Cubase when the LexPanel is launched. If you change any Cubase setting (such as activating another output buss, or enabling a different input) you have to close the LexPanel and open it again before these changes are flagged. Once you have everything set up to your liking (and monitoring set to 'Global Disable' inside Cubase) the Punch feature works well, and although you can only monitor your inputs in mono this won't cause many people problems, since the remainder of the track is still heard in stereo.

When using the MME drivers, you need to click on the LexPanel Monitor button to enable the Punch feature. This enables every possible source and destination, but only while the LexPanel is 'on top'. Once you switch to another application such as Wavelab, this takes over control, and the punch feature is disabled. I am used to using the Echo Console supplied with my Gina soundcard, which lets you send any combination of inputs directly to any combination of outputs, whatever other applications are running, so I found this very limiting. I also found the User Guide confusing on this subject, although it did make sense after I'd tried out all the options.

The third LexPanel page is System, and this lets you select the clock source. This page is available when you launch the utility in isolation, and when another application is already using the MME drivers, but if Cubase VST is running a small dialogue appears asking you to select an MME or ASIO panel. Normally you will choose ASIO, since clock‑source selection should be made within VST; in this case the System page doesn't appear. Clock choices vary depending on which inputs are enabled — Internal should be used when the Core 2 is the master, S/PDIF if either the optical or co‑axial S/PDIF inputs are enabled, ADAT data when the ADAT interface is enabled, and word clock RCA if you want to use the co‑axial S/PDIF connector as a word clock input.

Finally, there are two graphic LED displays not mentioned in the manual. The one above the clock‑source selection shows that a valid clock‑source is being received, and a similar LED graphic shows that the sample rate used by the current application is valid. Both have tick boxes that launch 'notification' windows if the validity of clock or sample rate changes. Unusually, only 44.1kHz and 48kHz sample rates are available, even though both A‑D and D‑A converters being capable of 24‑bit/96kHz operation. However, changing from 48kHz to 96kHz not only doubles the amount of hard‑disk space needed for recordings, but also doubles the amount of processing power needed to run software or hardware effects. For this reason I can understand why Lexicon have decided not to offer a 96kHz sampling rate, since the MP100 daughterboard would not be able to run at this rate.

In Use

When using the MP100 with non‑VST compatible applications you launch its front panel using the Edit button on the Effects page.

My initial audio auditions using a wide range of music types were very encouraging, with 16‑bit playback quality noticeably better than that of the 20‑bit Crystal converters of my Echo Gina. In particular the high end was sweeter and more detailed, with subtleties in the mix appearing that I'd not noticed before. RMS background noise in Wavelab measured –93dB for 16‑bit recordings, and a very good –109dB for 24‑bit ones. I got exactly the same figures in my review of M Audio's Delta 1010, which uses very similar AKM converters mounted in its rack case. This shows that you don't necessarily have to place the converters outside the computer to obtain low‑noise performance, even with 24‑bit designs.

Unfortunately I had a system crash every time I tried to record at 48kHz using Wavelab v3, although Sound Forge v4.5 worked perfectly at this sample rate. Lexicon also advise that Cakewalk Pro Audio v9 will lock up unless you disable its WavePipe acceleration, which unfortunately means that your latency will increase.

During my initial listening tests, my other soundcards seemed relatively happy alongside the Core 2 once I had the beta version 1.21 drivers, although I did experience occasional random glitches, as mentioned previously. These disappeared after I installed the Beta version 2.10 drivers, but then I started getting random system crashes. I soon discovered my Echo Gina card to be the culprit, and disabling it cured my hardware problems with the Core 2 once and for all.

I had no problems using the drivers with either the 'High' latency setting or the lower 6mS setting, but I do feel that a few other intermediate settings ought to be provided, like 12mS and 23mS, for those whose PCs aren't quite so speedy. There are no DirectSound drivers, so I carried out some tests with a few soft synths to see what sort of performance you can expect using the MME ones. VAZ Modular (reviewed in SOS March 2000) managed a healthy 24mS, but I didn't manage to get Cubase VST running at the same time. Seer Systems' Reality also had a low latency figure, and was very responsive for real‑time performances, but Native Instruments' Reaktor needed 130mS to avoid glitching.

All the analogue recordings I made were very clean, but I was particularly interested to try out the Dbx Type IV Conversion System. This works by introducing a logarithmic compression in the final 4dB below clipping, so that even if you overdrive the A‑D converters you still don't overload. I carefully set up the level of a complete mix to peak just below digital clipping, and then recorded it with and without the Dbx enabled. On playback I could identify the Dbx version blindfold — it provided subtle improvements in ambience and warmth, and when I compared subsequent recordings made at higher input levels, the digital edginess due to clipped transients was fairly obvious compared to the smoothness of the Dbx‑enabled version.

Of course there's a limit to how much you can squash your peaks, and for complete tracks I wouldn't recommend more than a couple of dBs. However, for individual instruments such as drums you could probably extend this to around 12dB to add 'analogue tape' warmth without clipping, and this makes it very useful. I'm surprised that changing the settings of the Dbx Type IV Conversion System isn't possible from software, but having spent several hours comparing recordings made with and without, I would happily leave it permanently enabled.

MP100 Installation & Routing

It only takes seconds to attach the optional six by four‑inch MP100 reverb card to the Core 2 via three metal stand‑offs and a 12‑pin connector, and once it has been installed, its effects can be accessed from music applications using either the MME or ASIO drivers. Unfortunately, although the detailed instructions headed 'Inserting MP100 within an ASIO Application' do work, the system suffers from a major flaw: the effects emerge delayed by the current latency value of the card. This is because Cubase VST Tape‑Type monitoring has to be enabled — a totally unworkable situation for most musicians trying to record a performance with effects. Thankfully I managed to discover another routing method that doesn't suffer from this problem, and representatives of Lexicon agreed with me that the manual should be updated to include it. Here it is:

Firstly, you need to enable the additional Aux Send buss using the Lexicon Control Panel, and then either restart your music application if you are using the ASIO drivers, or reboot the PC if using the MME ones. With the MP100 active, a fourth tab appears in the Control Panel marked 'Effects'. From here you can select which signals are sent to the inputs of the effects engine via drop‑down menus, and where its outputs are routed. My recommended routing is to connect the 'Aux Send L (ASIO)' and 'Aux Send R (ASIO)' to the Left and Right effect inputs respectively, and its L and R outputs to D/A 1 and D/A 2. Inside ASIO applications like Cubase VST, the Aux Sends appear as an extra stereo output buss, and this needs to be enabled inside Cubase. Then, to route the effects Send from any track to the MP100 you select this new Aux Send buss as its destination, and you will then hear the effects mixed into the main Core 2 output signal.

During the installation, an MP100.DLL file is installed in your Vstplugins folder, so that the MP100 simply appears as another plug‑in inside VST for editing purposes, although its Effects Master Volume control should be ignored. Normally you would have the MP100 Wet/Dry mix setting at 100% so that the effects are fully wet, and control individual effect levels for each track using their send controls. However, effects like flange and chorus are still best used by enabling the VST pre‑fade button, pulling down the VST channel fader, and then relying on the MP100 Wet/Dry mix control for the best sound.

You should be able to use this technique in most applications that support multiple audio busses. Its only disadvantage is that unlike the method described in the manual, the hardware effects are not incorporated into the final mix if you use the VST Export Audio function. However, to overcome this you can either re‑record your entire mix through the analogue inputs to a new stereo pair, or revert to Lexicon's own documented method, since the effect latency problem only occurs in real time — not when the effects have been recorded to a new stereo track.

MME‑based applications that can access multiple audio busses can use similar routing, while for those with a single output you can add effects globally by choosing D‑A (MMIO) for the source and D‑A for the destination for the MP100 in the LexPanel. This effectively places the MP100 between the MME drivers and the D‑A converters, or you can also place it between the A‑D converters and the driver inputs for real‑time monitoring with added effects.

Editing MP100 Effects

Inside Cubase VST you launch the MP100 front panel by clicking on the Edit button on the VST effects rack, but when using it with MME applications, you click on the edit button on the Effects page of Control Panel to launch an almost identical front panel.

There are 240 programs in the MP100, arranged in 21 banks which each contain a different effect type. These are exactly the same as those listed in the SOS review of the MPX100 (August '98). Each program provides control over Mix Level, Effect Level (or Effect Balance in the dual‑program banks such as Chorus‑Delay or Pitch‑Reverb), as well as a special parameter for each type of effect. For instance, the Hall programs feature Decay, the Tremolos have a Rate control, while the Flange programs have Resonance. In the dual programs a further delay time parameter appears, along witha Tap tempo button — two clicks on this set the delay time to the spacing between the clicks. Parameter controls can either be adjusted by clicking and dragging them with the mouse, or by highlighting them and then using the rotary knob or Inc/Dec buttons. A Bypass button is also provided.

There are no user presets as such when using the ASIO drivers, but every one of the 240 programs can be edited and saved using the standard Cubase VST Load/Save Effect and Bank commands. You can also type in new program names, but I couldn't find a way to save them with the drivers I was using! However, you can automate all of the controls inside Cubase. When you use the MME front panel an extra bank named User Presets is available. Here you can store up to 16 of your own effects using its dedicated Store and Delete buttons, as well as naming them: however, you cannot change the 240 presets. The actual effects sound just as good as you'd expect, with smooth reverbs, rich chorus and flanging effects, and easy‑to‑use delays. Refer back to the original SOS review of the MPX100 for a fuller picture.

Final Thoughts

Reaching definite conclusions about the Core 2 is not easy, for several reasons. Firstly, there are no other products with quite its complement of features at around the same price point for comparison purposes. Its complement of four inputs and eight outputs is unusual. It sells at a similar price to both the M Audio Delta 1010 and Aardvark Direct Pro 24/96, and the recording quality offered by both of these seems on a par with that of the Lexicon, but they all have very different feature sets. The Delta 1010 has double the number of inputs, balanced inputs and outputs, MIDI In and Out, and a more impressive‑looking rackmount case containing external converters. The Direct Pro has four balanced ins for mic or line use, along with four compressors, four EQs, and a monitoring reverb (not comparable with that of the Lexicon), but only four outs, although again it features an impressive desktop interface with external converters. However, neither of them include the Core 2's support for ADAT and optical S/PDIF I/O — but whether you need this support is something only you can determine.

This leads me on to my second major point — the opinion you will form of the Core 2‑based Studio depends very much on the way you prefer to work and your existing equipment. Many of its plus points will be of no interest to some people, but equally some of what I consider to be its operational oddities will not affect many users. For example, I thought the Dbx Type IV soft‑knee limiting on its inputs was an excellent idea, especially for musicians who do a lot of live recording — but I found it frustrating not to be able to switch this in and out while listening to audio, nor to be able to change my mind about the settings without physically removing the card. However, if you either don't like the Dbx limiting, or like it so much that you leave it on all the time, you should not find this a problem.

The option to add a Lexicon reverb for an extra £149, in the form of the MP100 daughterboard, is another unique aspect of the Core 2. However, whether you will find this attractive depends entirely on how highly you rate the reverb from the MPX100, whether you will find the effects latency and/or workaround a problem (it won't affect you if you only ever add effects after recording) and, in the final analysis, how much you are prepared to pay for the privilege of having access to a Lexicon from inside your PC. After all, if the 'within a PC' aspect is not so important to you, you can now buy the hardware MPX100 for around £199 on UK streets.

The view you take of the various compatibility problems I experienced or heard about during my tests will also vary. When writing reviews I always scan a variety of Internet forums to gauge expectations and opinions about particular products and I noticed that a number of existing Core 2 users also experienced problems during installation, as well as conflicts with other soundcards and with Athlon‑based PCs. However, some of these may now have been resolved by the latest driver updates, and Lexicon claim to be working hard to resolve outstanding compatibility problems with specific software such as Cakewalk Pro Audio 9. Nevertheless, based on these stories and my own experiences with the Gina card, it would seem that at the time of my review, the Core 2 is rather sensitive about working reliably alongside certain other soundcards — so using it as a stand‑alone card in an Intel‑based PC is probably your safest bet at the time of writing. This may suit you if you are in the market for your first soundcard, but if you already have others installed, you might have problems, and and ought to check compatibility with your dealer first or the UK distributor, Pure Distribution.

To sum up, I found that Lexicon's Core 2 offered excellent audio recording quality and some unique features for its price, but I did encounter a few irksome aspects to its operation during my time with it. However, these pros and cons may not affect your setup and the way you work, so consider carefully before you part with your cash.