Behringer/Klark Teknik 3rd Dimension BBD-320

[thetwlo]

so, the new clone of the Dimension D claims to to exact.So what BBD chips are they using?
The 3207 clones are for pedal voltages, limited headroom.
OR, do they have mn3007 clones as used in the Roland, with the correct headroom for the Dim D?

[p_shoulder]

I imagine that they will use the Coolaudio V3207, a chip that is functionally equivalent to the MN3207 (which I believe is similar to the MN3007 that is used in the Dimension D, but is run at lower voltage).

It's been reported that the new Boss CE-2W pedal uses this chip.
More relevantly, the same has been reported for the Boss DC-2W pedal which contains both a Dimension C mode and a Dimension D mode.

[Diabolik!]

is this the same chorus thats in the RS-09?

[Dave Kendall]

For those who may not yet have seen them, Xvive make a newly manufactured MN3007.
New Xvive BBD ICs
Though it's a bit alarming to see both the MN3007 and 3009 captioned in their respective photos as "TWO-PHASE CLOCK GENERATOR FOR BBDs"

Let's hope the engineering staff are more diligent than the proof readers . . .

[coolshirtdotjpg]

If this is a real clone and not something awful like the June 60, I'm pretty interested. I always wanted a dimension D, it seems weird that there aren't any cheap clones of it.

[thetwlo]

hopefully it's close and not 3207 based.
why is it 2u? I assume it has no large xformers in it. Make it half of 1u or 1u, but 2u?
What's with the giant enclosure? From a company that won't make full sized moog module clones,
This is weird.

[StillNotWorking]

It's been reported that the new Boss CE-2W pedal uses this chip.
More relevantly, the same has been reported for the Boss DC-2W pedal which contains both a Dimension C mode and a Dimension D mode.

Open up the TC branded but dumbed down version of the DC-2 I guess one will find out. Belive they call it 3D or something. Their old CC300 had stereo out at least.

hopefully it's close and not 3207 based.
why is it 2u? I assume it has no large xformers in it. Make it half of 1u or 1u, but 2u?
What's with the giant enclosure? From a company that won't make full sized moog module clones,
This is weird.

Once a highly respected company the KT brand are now used to sell familiar face plates never historically associated with the brand.

Edit: removed video as it will provoke some. But with regards to the form factor here is the blurb on KT page

Rugged 2U rackmount chassis for durability in portable applications

2U cabinet are by their standard portable? I will compared it to a truly rugged Boss DC-2W (Wasa Craft) pedal with stereo in/out different itself only by lacking the ballanced in/out, meter and true bypass. It also has longer warranty, 5 year meaning manufacture believe it truly is rugget.

[Synthbuilder]

Mine just arrived from Thomann.

I've already taken it apart and had a bit of a look inside.

The BBDs are V3207 running from 8V. From a quick inspection the circuit topology looks like the original, but I need to dig deeper before I can say for sure. There's way too much exposed mains voltage around though, so I need to work out some additional insulation before I really start to poke about in there.

I'm not quite sure about the balanced outputs though. The hot seems to be 'hotter' than the cold - they should be the same size just inverted. Again, I need to have a longer play with it to work out what's going on there.

The basic sound seems right and it has true relay switched bypass which is nice.

There's two trimmers per side, one for BBD output balance, the other for BBD input bias.

There's a ton of room in there under the main board behind the panel for some modifications. I'm hoping to add an LFO speed, depth and stereo wide controls. There's four PCBs inside, one little one with the nasty mains voltage and power switch, one holds the switch bank, one is the main audio board, and the fourth is the IO and power supply. Board interconnnects that carry audio and switching seem to be ordinary 2.54mm headers which can easily pulled apart. The high voltage ones are bigger and glued into place.

They could have easily fitted this into 1U but that extra height will come in handy for mods.

Tony

[Synthbuilder]

A video - not mine - that shows quite nicely the basic sound:

[anselmi]

A video - not mine - that shows quite nicely the basic sound:

I´m in headphones and the stereo is wide and clean whitout being too obvious, but the differences between presets are more subtle than I expected.

The preset system is a classic and It´s good to have them here, but I think that more control (modulation rate and depth) would be much better


I hope they release a clone of the SVC-350 vocoder

[Synthbuilder]

Warning: Total nerdy post.

So I have had a bit of time to look into the circuitry of the BBD-320. Of course, being surface mount I've not been able to trace out the whole schematic but I've looked at some of what I think are the important bits.

The circuit as expected is very similar to the Roland. The key difference being that the Roland used MN3007 BBDs running from 0V and -14V while the KT uses the V3207 running from +8V and 0V. This doesn't really have a massive impact on the sound of the unit on its own but the swap from a negative supply to a positive one does have an important effect on the high frequency VCO circuits that directly control the delay time of the BBDs. The reason being is that the LFO, the slow modulation oscillator, outputs a signal that goes from around +3V to -3V. This is piped through a resistor (or two) to the VCOs which control the delay time. Thus the Roland's BBD circuitry always sees an LFO signal above its own operating voltage. While the KT sees the LFO signal below its operating voltage.

For Modes 2, 3 and 4, this change in BBD supply voltage should not affect operation too much if the correct resistor vales are used in the KT's VCO circuits. However, Mode 1 uses a simple FET transistor and resistor to change the depth of the LFO modulation. When engaged in Mode 1 this crude circuit not only lowers the modulation depth but also runs the VCOs at a much lower frequency. Thus in the original unit the delay in Mode 1 is significantly longer than in Modes 2, 3, and 4. Whether this was a deliberate design decision who can say.

Mode 1: The Roland SDD-320 produces a delay time that varies from 8ms to 12ms. In the KT BBD-320, it varies from 3.8ms to 7.1ms. The modulation depth is thus 4ms in the Roland and 3.3ms in the KT. However, the key difference is those absolute delay figures which are almost half that of the Roland.

Mode 2: The Roland is 5ms to 10ms. The KT is 3.7ms to 8.5ms. Again the modulation depth is similar but the delay time overall is less.

Modes 3 and 4: The Roland is 6ms to 9ms. The KT is 4.7ms to 7.6ms. Again the modulation depth is similar but the delay time overall is less.

The upshot of all of this is that Modes 2, 3 and 4 probably don't sound that much different to the original Roland, at least a with a simple synth sound which is what I was testing it with. But there is a difference, both measurable and audible.

Mode 1, however, sounds a lot different. The Roland's longer delay times sound better to my ears.

On my unit changing R87 and R128 from 5K1 to 5K6 helped bring modes 2, 3 and 4 in line with the original. These resistors I think are 0603 size so it is possible to hand solder them in. So I would recommend doing this. However, although it improves things for mode 1 too, it doesn't fix it completely. And, because of the change from a negative to positive power supply to the BBDs, clock drivers and VCOs, getting Mode 1 on the KT to match the original is not trivial.

I have some success with using the output of the Mode 1 switch which is a +15V/-15V control signal that turns on the FET attenuators that control the LFO depth. Take a 1N4148 and a 30K resistor in series from the wiper of the mode 1 switch (it's the middle pin of the connector that goes to the switch board) to the lower pad of R87, and then do the same for R128. The diodes are aligned so that the cathodes face the connector. This will engage a small negative current into the VCO control inputs and lower the clock to give you bigger delay times. I am now getting a delay between 7.6ms and 10.4ms. Not quite the 8ms and 12ms but close enough I think. It certainly sounds better.

[Synthbuilder]

I've done some more work on my BBD-320 to make it behave like a real SDD-320.

Here is the LFO (left hand side based around the TL074) and the two high frequency VCOs each based around a 4069UBE. This is after I have replaced the four resistors.



I replaced R87 and R128 with 5K6 0602 1% thick film resistors. This drops the average delay time to be more like the original SDD-320 in Modes 2, 3 and 4.

I replaced R100 and R109 with 2K7 0402 1% thick film resistors. This increased modulation depth in Mode 1.

I then added two series combinations, each of one 30K 1% metal film resistor and one 1N4148 diode. These are each connected to the lower pads of R87 and R128 respectively. The diodes are connected together to pin 6 of the interconnect that goes to the switch PCB. Pin 6 is the middle pin of the interconnect. This lowers the delay time in Mode 1 to match that of the original.



It's a bit of a cludge but it seems to be secure enough. Note that soldering the 0602 resistors and in particular the 0402 resistors is a challenge for those with just an ordinary soldering iron.

It's also worth noting that your unit may need different values to achieve the same delay times as the SDD-320. But the values I have used would certainly be a good starting point.

[Hermetech Mastering]

Let us know what you think of this vs. the DC-2W please Synthbuilder, if you have one to compare. I've owned the original SDD-320, original DC-2 and DC-3, and currently have the Fromel Seraph Deluxe and the DC-2W.

The Fromel sounds a bit warmer and has different modes (a deeper "vibrato" mode), manual control of Speed and Depth (as well as the presets), and an attenuated CV input for delay time, BUT I am actually preferring the sound and ease of use of the DC-2W overall, since I bought it a few weeks ago. I shall probably be selling the Fromel soon.

If this KT wasn't made by Behringer and was 1u, I'd definitely pick one up just to hear it.

[bwhittington]

I've done some more work on my BBD-320 to make it behave like a real SDD-320.

Really great posts. Thanks for sharing your efforts.

[Synthbuilder]

Let us know what you think of this vs. the DC-2W please Synthbuilder, if you have one to compare.

Sadly, I've not got a DC-2W to compare it to. I'd certainly love to try one though.

The DC-2W does the modulation and switch control with a microcontroller. No real chance of modifying that one easily.

[Synthbuilder]

Really great posts. Thanks for sharing your efforts.

Thank you.

More to come I think. I'm still not completely satisfied with the small difference in modulation depths in my reworking of the BBD-320 and the original SDD-320. I'm going to have another bash this weekend to get it right. I just don't like working with these tiny 0402 resistors though.

[thetwlo]

thanks Tony!!!

[thetwlo]

If this KT wasn't made by Behringer and was 1u, I'd definitely pick one up just to hear it.

WHY IS IT 2u? Fuck Uli, but if it was 1u, that's hard to not take a chance on.

it's bizarre, as they have many 2u effects that could be 1u(or STEREO) allowing consumers to buy more--in less space!
really odd.

[Hermetech Mastering]

Thanks Tony, not looking to mod the DC-2W as think it's pretty much perfect as is, but wondering about the sonic differences. I like the idea that all the control side is digital, it just sounds great.

Yeah, Scott Stites did a lovely build based on the DC-2, with loads of controls brought out to the front panel, in 1u. I think his redesign is what the Fromel Seraph Deluxe PCB/circuits are based on:

http://www.birthofasynth.com/Scott_Stit ... _main.html

http://www.birthofasynth.com/Scott_Stit ... build.html

http://www.birthofasynth.com/Scott_Stit ... ished.html

[Synthbuilder]

I had another go at trying to perfect the behaviour of the BBD-320 with regards to making it exactly match the delay times of the SDD-320. The following components have been changed in the KT unit:

C70, C95 150pF 2% C0G 0603
R86, R121 12K 1% 0402
R87, R128 12K 1% 0603
R88, R122 3K3 1% 0402
R89, R123 330K 1% 0402
R100, R109 2K7 1% 0402

Also the diode-resistor in series as described previously also has to be fitted (to enable the Mode 1 delay to be significantly increased over Modes 2, 3 and 4). The diodes are 1N4148 and the resistors are now 56K 1% metal film 1/4W and fitted as shown in the picture:



Note this is the original picture showing 30K resistors but the placement is the same.

I am very satisfied with the results of the modification. Given that these changes produce near identical results in both the VCO circuits inside my BBD-320, I think they should work well in other units as well.

[coolshirtdotjpg]

Under 200 with balanced I/O? Seems like a winner.

[flashheart]

If this KT wasn't made by Behringer and was 1u, I'd definitely pick one up just to hear it.

WHY IS IT 2u? Fuck Uli, but if it was 1u, that's hard to not take a chance on.

it's bizarre, as they have many 2u effects that could be 1u(or STEREO) allowing consumers to buy more--in less space!
really odd.

Why? Simple because it's meant to remind you of the original, down to choice of fonts and colour scheme.

[thetwlo]

Why? Simple because it's meant to remind you of the original, down to choice of fonts and colour scheme.
[/quote]

Yeah, I know, I just can't justify the space for something like that, as I'm not sure how much I would end up using it.
It just seems most buyers are going to run of space before $ to buy more at these prices.

[Hermetech Mastering]

If this KT wasn't made by Behringer and was 1u, I'd definitely pick one up just to hear it.

WHY IS IT 2u? Fuck Uli, but if it was 1u, that's hard to not take a chance on.

it's bizarre, as they have many 2u effects that could be 1u(or STEREO) allowing consumers to buy more--in less space!
really odd.

Why? Simple because it's meant to remind you of the original, down to choice of fonts and colour scheme.

But why copy how it looks, and then totally fail on how it sounds (see all of Synthbuilder's posts)?

A 1u unit that actually sounded like the original, I might be tempted to break my lifelong B boycott, but nah, I'll be sticking with my DC-2W and Fromel Seraph Deluxe.

[Synthbuilder]

Under 200 with balanced I/O? Seems like a winner.

It's definitely worth a punt. It sounds good enough straight out of the box.

The balanced input is pretty crude though. Don't expect a huge CMRR. It's a single op-amp (one half of a 4580) with four resistors. Better than an unbalanced input though.

The output is Klark Teknik's standard EBOS (electronically balanced output stage) circuit. Two op-amps with a relatively complex set of feedback loops to make it still work when you use an unbalanced lead into the TRS socket. Why they can't just use a single op-amp and impedance balance the output I don't know.