Wednesday, February 17, 2010
Tiptop Audio Z8000 Review
by Steven Hayes
Tiptop Audio's Z8000 is a CV sequencer/programmer module. It differs from most analog sequencers in that provides ten individual sequencer tracks, eight of which are 4-step, and two that are 16-step. Programming the sequencer tracks is done via a 4x4 matrix of potentiometres, each with an associated LED.
The clever thing about the Z8000 is that the sequencers share the CV values specified by the pot matrix. More specifically, four of the 4-step sequencers produce CV sequences specified by columns of pots, the other four 4-step sequencers determine their CV values from rows of pots. The two 16-step sequencers take their programmed values from left-to-right, top-to-bottom order, and top-to-bottom, left-to-right order, respectively. A natural consequence of the programming pot sharing is that moving a single pot may affect the programming of up to ten sequencers.
Each sequence can respond to a individual clock, direction and reset inputs. Additionally, the clock inputs on the 4-step sequencers are "normalized" by row and column. For example, if you plug a clock source into the top-most row of the 4-step sequencers, the other three 4-step sequencers below it will also receive the same clock - sneaky! Ditto for the column sequences.
The build quality of the Z8000 is up there with the best. Two PCB's sandwiched in plane with the front panel means shallow chassis are fine with this module. I've been running the module on ±15V rails without issue.
The front panel design (28HP) is clearly set out. Although it is quite a dense layout, getting access to the sixteen programming pots isn't too awkward, even when there is a plug in every jack. The sixteen LED's associated with each programming pot are tri-colour, the intent being to give you some idea of which sequence is doing what according to LED colour.
Ins & Outs:
Each of the ten sequencers have separate clock, direction and reset input jacks. Naturally there are ten CV output jacks. Note that the Z8000 does not provide any kind of gate output.
By itself, the Z8000 can do very little. It requires an external clock source for starters. A clock divider would be very handy. Maybe a quantizer too...
If you want to accurately program notes on the CV outputs, I'd recommend using a manually gated source (instead of a clock) so you can step through each segement of a sequence at leisure, fine-tuning the CV outputs as you go. The CV output range is 10V peak, so accurately tuning each CV amount requires a very light touch on the pots.
Of course, it's far more fun to just plug a few clock sources into the Z8000, modulate a few things with the CV outputs and explore what results from mindless knob-tweaking. Having no plan means having no expectation, which invariably will lead to a wonderful surprise ;)
The Z8000 sequencer/programmer is fine addition to any Eurorack Modular. It is well focused on sequencing CV's, and provides simple mechanisims that can lead to the creation of complex grooves and modulations without much effort. If you are after a note-based sequencer, then there are better options out there, but if you are after a sequencer where modularity is paramount, then the Z8000 comes highly recommended.
Friday, February 12, 2010
Stackables (Banana patch cords for euro format!)
By Steven Hayes
Along with my Z-DSP came 20 of the Tiptop Stackable patch leads. That is, the plugs on these leads allow you to stack plugs together, much like banana plugs do. The quality of the cables feels excellent, the plugs provide good grip, and stacking one on top of the other gives a reassuring click and feels solid. The cable itself is fairly stiff, so it wants to keep itself away from the front panel - a good thing.
Oddly enough, my biggest concern about using Stackables has to do with the quality of the jacks on the module you're plugging in to. For example, the Bubblesound uLFO has very nice quality jacks, and I wouldn't think twice about using three Stackables high with it's jacks - the connection feels so solid. At the other end of the spectrum, the Elby kits use cheaper jacks that feel relativily loose when you plug into them. Stacking three or four high into these jacks may lead to excessive force on the jacks internal connectors, bending them to a degree where they may need to be replaced. Simple answer is to continue stacking from the other end of one of the cables, that is why there are 2 stacking points per each cable. No need for mults (:
SynthwerksFollowing on from our previous touch controller post. We now have the Synthwerks MG-1 and FSR-4.
The MG-1 is a manual gate SPDT arcade style pushbutton (fast action - built like a tank) that has one jack normalized to the +12v bus and switches it between the two other jacks (Up and Down). The switch is mechanical so is bi-directional. Any positive voltages present will light the LEDs when present. It is an 8HP module.
The FSR-4 has four separate circuits that produce a scalable CV out that changes depending on the pressure applied to the sensor pads at the bottom of the module (scalable from a very light touch to lean on it hard). The pads respond to pressure of any kind. The pressure CV is also read by a Gate output section and the gate goes high when the Pressure level crosses the front panel Threshold adjustment level. It is a 16HP module.
Thursday, February 11, 2010
Tiptop Audio Z-DSP Review: Part I
by Steven Hayes
The Z-DSP is 28HP wide, with a sandwich of PCB's stacked in plane with the front panel, so it's not very deep in the chassis. It looks fantastic. The display is bright and clear. The knobs are the same as what Elby ships (not yellow thank god). The knob spacing is about as tight as I'd like, but the knobs don't have any jacks above them, so nothing gets too obscured by your lovely spagetti.The jacks feel solid and tight as one plugs and unplugs. The build quality is better than average (average = Plan B headphone amp I once inspected).
The DSP software cards are actually PCBs with two SMDs covered in "stuff". The socket for the cards holds tightly, so you shouldn't expect anything to drop out mid-performance. It wouldn't matter - you can remove a card while the current program continues to run. Not sure it was such a good idea to colour the cards black though…
I've got the Z-DSP running on ±15V rails with no issues (I did check with Gur first ;) .
Ins & Outs:
The Z-DSP has two audio inputs (you can select between guitar and "synth" level inputs via jumpers), four outputs (two for feedback), plus the ability to insert other modules into the feedback chain via two extra inputs.
The Z-DSP has three CV inputs that are assigned to the current software program, as well as dedicated CV control for left and right channel feeback amounts. There's also CV control on wet/dry mix, program selection, program direction. Last, but not least, is the clock input, so you can control the speed that the program executes at.
I only been using the Z-DSP for a few hours, and have been concentrating on the "Dragonfly Delay". I am already amazed at some of the sounds and complex drones I've been able to get out of it with the CV control of feedback and DSP assigned controls.
It's pretty easy to let the sound run away when modulating the feedback via CV, which will result in clipping and a red LED doing a dance. Oddly enough, I actually like the way Z-DSP's clipping sounds…
There are two facets of the Z-DSP that I'm particularly enjoying at the moment:
1. CV control of feedback. This is so much fun! It is so easy to discover rythmic patterns by modulating the feedback to a delay program via CV, for example.
2. External clock input. It's impossible to describe the plethora of sounds that can be created when you plug a VCO into the Z-DSP's clock input, grab the VCO's tune knob and slowly sweep it. One second you're hearing raw FM, the next a massive bass note, the next is a high pitched squeal, and lots of amazing artifacts in between. It's completely unpredicatable in a wonderful way. The Z-DSP will function with a low frequecy input to the clock, but the lower the frequency the riskier things become, and it may crash. Having said that, I understand that there is a clock multiplier in the clock input circuit. Right this second I'm sending a 22Hz signal to the Z-DSP's clock input - and it hasn't crashed - and it's making an interesting sound - cool.
I've finally been able to unplug the "Dragonfly Delay" card and put the
"Bat Filter" through it's paces. 8 different filter programs are available, and they're not simple filters. Often there are two (even three) filters implemented in a program, some organised in series, others in parallel. Many of the filters are 8-pole too.
The filters sound pretty good, but I can tell they are DSP-based. There's a hardness, or at higher frequencies, a glassiness to the sound, that says "digital" to me. I'm not complaining however - I've got plenty of warm analog filters. The Z-DSP is all about flexibility after all, and that's definitely what we've got here.
Like the "Dragonfly Delay", the "Bat Filter" really got interesting for
me when I started messing with the feedback facilities of the Z-DSP. For example, take a CV from a sequencer and feed it to both a VCO and the "feedback" parameter in one of the Z-DSP's filter programs. Feed the VCO into the inputs of the Z-DSP too. The resulting distortion can sound really musical and really add character to the sound if you don't over do it. I like it!
I'm really impressed by the Z-DSP. It's a great concept, very well implemented. While it is easy to "get lost" with the Z-DSP, espcially when your CV usage is excessive, I've found that it can be incredibily musical when you don't ask it to do too much at once. I'm particularly fond of the "Dragonfly Delay" - It's just nuts! (in the best possible way)