Silent Fly

[quote name='AndyTravis' post='811989' date='Apr 19 2010, 09:11 PM']Drum Machine £225 all in?

Bump[/quote]


[b]Free bump[/b] for the BOSS DR-880 - great drum machine at a fantastic price.

[quote name='the someone' post='809734' date='Apr 17 2010, 06:07 PM'](...)
BOSS EN-2 ENHANCER its mint £38
(...)[/quote]

Are you sure it's not E[u]H[/u]-2 ?




(free bump)

[quote name='Mr. Foxen' post='804272' date='Apr 12 2010, 09:09 PM'](...) What other options?[/quote]
[url="http://www.sfxsound.co.uk/mainpage.asp?page=splitmix"]Micro mixer[/url]

This is torture...

Great price, fantastic product.

(Have a free bump)

[quote name='cheddatom' post='789271' date='Mar 29 2010, 10:47 AM'](...)
RE a crossover - I tried this before, using my peavey combo for clean bass, and my pedals and guitar combo for effects. It sounds awful compared to running both amps from the effects (with the low tuned out fo the guitar combo).(...)[/quote]
Splitting the frequencies can create problems. If the two components are sent to separate amplifiers, it is possible (very likely actually) that the different frequencies response of the amps combined with the effect of the crossover creates gaps or worse, overlaps in the overall frequency response.

This is essentially why I said "[i]The two components are processed separately [b]and then recombined[/b][/i]". If the two processed sides are recombined and sent to the same amp, the effect of different frequency responses are not present and the sound should be much more solid.

Alternatively, the two amps can be exactly the same but they need to properly positioned.

[quote name='cheddatom' post='789271' date='Mar 29 2010, 10:47 AM'](...) Maybe I just like it when the low frequencies are distorted.[/quote]
With some effects I like low frequency distorted as well

* [i]Only buy FX that really don't negatively affect tone?[/i]
It is a way to go but sometimes there are effects we like that do effect the tone.

* [i]Use a blender/line-switcher/looper?[/i]
A looper (aka external true-bypass switch) does not address the problem. It simply removes the pedal from the signal path.

Blenders are a very effective and popular solutions to address this. The only drawback is that unprocessed sound is added to the sound.

If you are interested, I am designing a blender that should be ready in a few weeks.

* [i]Use two separate amps (one clean & one effected)?[/i]
Not exactly the simplest solution but it would work. In practice you can get very similar results with a blender.

* [i]Send two separate clean & effected signals to the PA?[/i]
It is like using a blender with the difference that the two components (clean and processed) are mixed in the mixer instead of being mixed by you in the blender.

* [i]Something else?[/i]
In my opinion the best solution is a crossover. The signal is split in low and high frequencies. The two components are processed separately and then recombined. In this way it is possible leave the low frequencies untouched and process only the treble (or vice versa)

...strangely enough I am designing a crossover in pedal format with integrated mixer. It is a relatively complex design that requires some custom components I have ordered that should be ready in around 4 weeks.

[quote name='Jean-Luc Pickguard' post='788115' date='Mar 27 2010, 07:20 PM']I soak my cables in vinegar[/quote]

[quote name='Mr. Foxen' post='788277' date='Mar 27 2010, 11:41 PM']I'd like to see a side by side with the standard BDDI.
(...)[/quote]

It would be a very interesting test.

If two volunteers are ready to send me their pedals for the test, I'll be happy to do it.

[quote name='dood' post='787965' date='Mar 27 2010, 04:16 PM']Hey Max! Great review! - I have to admit, being a geek, this is the kind of review I really like to read. Not surprisingly, I make sure I have the latest issue of Bass Gear Magazine as soon as it comes out!

I've recently purchased a Para driver - which is excellent! - I've also found many of the other Sansamp products schematics on the net - not difficult to locate, so your review makes a lot of sense; I feel that most of the Sansamp range share a lot in common, design wise.[/quote]

Thanks for your kind words Dood.

I used to have a ParaDriver. Nice pedal but I never managed to make it sound totaly clean and linear.

[quote name='Grand Wazoo' post='787968' date='Mar 27 2010, 04:18 PM'](...)Anyway... have you by any chance reviewed any of the Mark Bass effects yet? I have the Compressore and I really rate it. But I am also interested in their Distorsore and I was wondering how it compared with the Sans Amp VT you've just reviewed.(...)[/quote]

I write reviews very rarely. Usually I do it when there is some technical or functional aspect that I find innovative.

Having said that, if anybody has a pedal and would like to me to send it to me to try and write a review, I'll be happy to do it.

I am sorry but I never tried any of the pedals you mentioned.

Recently, a friend lent me a Tech21 SansAmp VT Bass to try. The net is full of user reviews on the VT but I though it was a good opportunity to write a review focussed on the technical aspects and the construction.

I hope you will find it interesting.

[b]/// Construction[/b] 3/5
The VT is built in a nice and solid aluminium box. It is the same box used by a lot of other pedals and the size is the same of other Tech21 pedals like the SansAmp Classic or the Bass DI.

The circuit board is completely SMD with part of the circuit inside a resin blob. I guess the resin part is to protect the design from reverse engineering attempts. An effort that in the vast majority of cases is totally pointless.

The consequence is that if the pedal stops working you are pretty much on your own. On the positive side, the pedal is cheaper to produce and it costs less.

The potentiometers appear to be of good quality. The battery door looks a little bit delicate but in these days not too many people use batteries anyway.

[b]/// Bypass[/b] 5/5
The pedal is not true-bypass but the bypass works very well. The frequency response is flat with the pedal in bypass.

[b]/// Connections[/b] 5/5
Input. I didn’t measure it but it should be 1 M ohm. The same input impedance of almost al Boss pedals and other brand’s pedals.

Output. Accordingly to the manual, it can drive low impedance devices like mixers. In other words [i]you do not need a DI to connect the VT to a mixer[/i]. If you need to connect the VT to an XLR input, [i]a jack to XLR cable is more than adequate[/i].

In my opinion this is a good choice. In a recording environment, cables are usually short and XLR connections are not essential. Moreover, the lack of XLR-balanced connector helps keep the costs down making the pedal more affordable.

[b]/// Cabinet simulation[/b] 3/5
It is essentially a steep low pass filter set to cut everything above roughly 4.5 kHz.

It also cuts around -3dB at 30Hz. If you play 5/6 string and you have a cabinet that can go that low, you may hear a little bit less presence on the low-B but it shouldn’t be that strong. Unfortunately, it can’t be compensated by turning up the low knob. The low control combined to the low cut produces more or less a mid control tuned on 90Hz.

There is also a slight emphasis (+2dB) around 3kHz.

Unfortunately, because it cuts everything above 4.5kHz the zing that a lot of slap players like is totally removed. I would have like a switch to remove the cab simulation. It would have made the pedal more flexible. (Tech21 added a button to remove the cab simulation from the processing in a new series of Character pedals).

[b]/// Controls[/b] 4/5
I analysed the frequency response of the pedal and I discovered I few interesting facts.

The high control is a boost only control (the manual says that the controls are +/- 12dB). For a flat position I had to turn the high knob all the way down. The mid controls is not at 500Hz (as indicated in the manual) but around 865Hz

I usually don’t like boost-only high but I must admit that with the VT it works well. Because the cab simulation, the pedal is a relatively "dark" sounding and the boost-only makes the control effective and musical.

The low knob works also well. It doesn’t sound boomy or too aggressive. It makes the sound fatter without changing the tone of the bass too much.

[b]/// Mid and Character[/b] 4/5
Believe it or not, Mid and Character are almost the same control. Frequency wise there are some differences: Mid boost is set to 865Hz, Character boost is 1462Hz but Character and Mid cut overlap perfectly: 880Hz.

If you are not convinced try the following:
- Drive =0
- Volume = same volume bypass/active
- High = 0
- Low = 12:00
- Character = 12:00

Turn down mid to 0 and play something. Turn up the mid to 12:00 and set Character to 0. The sound should be the same.

So why do they operate differently? The reason is the position in the circuit. Character is [i]before[/i] distortion, the low/mid/high controls are [i]after[/i] distortion.

It is a simple but very effective solution probably inherited directly from the SansAmp Classic. In practical terms the Character knob pushes the saturation forward (or backward) on the midrange. Because the mid control is tuned in the same area, the tone effects of the Character control can be compensated post-distortion if the mids are too strong.

The drawback is that the Character control can generate a lot of noise if turned up above a certain level.

[b]/// Sound[/b] 5/5
I am not heavy user of saturation/distortion/fuzz but the VT was a pleasant surprise. Not unexpectedly, it excels in reproducing amp-like saturation but even used without saturation it is a good sounding pedal.

I recommend it if you are looking for a pedal that can give you a fat/saturated sound. If you are looking for a way to EQ your tone I think there are better solutions.

It might be one of transistors that doesn't work as it should or a capacitor that is at the end of its lifetime.

I'll be happy to have a look for you if you want. Please feel free to send me an email (the address is in my signature).

I don't think there is a fixed rule.

I like EQ pre compressor but post distortion/overdrive/fuzz. The other way around would sound different but it would work equally well.

This is how I see it.

A DI should not add anything to the sound. In other words, it should not “have a sound”. If it does, it becomes a signal processor with XLR output. When the DI contribution to the signal is distortion is obviously a bad thing.

Apart from the usual characteristics that apply to every product (e.g. cost/performance, customer service, reliability…) the most important thing about a DI is its transparency. How this is achieved is not that important. There are excellent DIs that are transformer based, other that are equally good that are transformerless.

There are several web sites that explain the pros and cons of active and passive DIs but all of them agree on one thing – the choice of active/passive should be based on the application and requirements.

So… does the strength of the signal matter? Does it enter in the “application and requirement” equation? It does but indirectly.

DIs perform two separate functions: convert the impedance and convert the connection from unbalanced to balanced.

/// impedance conversion
Converting the impedance is the most important function of a DI. Guitar and basses are designed to be connected to high impedance devices. If they need to be connected to a recording desk with low impedance input, they need an interface.

If another device (e.g. a pedal) is placed between instrument and recording interface, the impedance conversion may not be necessary because [i]the majority of pedals convert the impedance[/i]. The instrument sees the high impedance of the pedal, the pedal see the low impedance of the recording interface.

/// unbalanced to balanced conversion
The vast majority of the recording interfaces and mixers have XLR-balanced input. Because DIs main purpose is to be connected to mixers it makes sense to have a XLR-balanced output.

Balanced connections are designed to minimize electromagnet noise but in a studio environment where electromagnetic fields are minimal this is rarely an issue. Moreover, cables are usually short this also reduces the likelihood of picking up electromagnetic noise.


If the signal strength becomes an issue, because for instance some device clips, it is very unlikely that the signal is coming from a guitar or a bass. Almost certainly the signal comes from an active device. Active devices can be connected directly to a mixer or recording interface without a DI.

[i]If a DI clips with a guitar or bass, it means only one thing: the DI cannot perform its basic function. [/i]

/// DI clipping: active vs passive
Active DI clip for one reason: the peak of the signal amplitude is too close to the [i]internal[/i] power supply level. To increase the headroom, the DI needs a higher voltage power supply. (Just to be clear it doesn’t mean that you can take a DI design to operate a 9V and connected it to an 18V power supply to increase the headroom – the DI needs to be designed to operate at higher voltage).

Passive DIs don’t have power supply so in theory cannot clip …and they don’t. In practice something more complex happens.

Passive DIs are based on transformers. A coil converts the input signal in a magnetic field. The magnetic field, through a metallic core, is send to another coil. This second coil converts back the magnetic field in an electrical signal.

Everything works nicely (more about it later) if the signal is below a certain level. Above a threshold, the magnetic core looses its linearity and start distorting the sound. The deviation from linearity takes place gradually and for weak signals the distortion is more a colouration but if the signal is too strong the colouration becomes audible.

With an active DI, to remove the clipping is necessary increase the power supply. For a passive DI the non-linearity can only be removed using special (and often expensive) materials that have limited non-linearity.

/// Why I prefer active DIs
I have nothing against passive DIs. They work nicely and they have the great advantage of operating without power supply.

When I described the way the transformer inside the passive DIs works I assumed an almost theoretical environment. Apart from the non linearity of the transformer coil, there is also to consider the fact that transformer coils interact with the pickups creating a filter that inevitably change the frequency response (non necessarily in a bad way).

If properly designed and built, active DIs can address all the issues of passive DIs with the advantage of being more compact, easier to repair and more suitable for tweaking if required.

/// Sansamp VT Bass and DIs (active or passive?)
Providing a DI is necessary, this is a case where [i]a good quality[/i] passive DIs can perform as well as an active DIs.

The reason is not the fact that passive DIs do not clip. The main reason is that the impedance conversion has already being performed by the pedal. The DI input is connected to an active device and the only thing it does is convert the unbalanced line to balanced.

[quote name='escholl' post='782582' date='Mar 22 2010, 05:15 PM'](...)
It sounds to me like a lot of people (no offense intended guys) who just haven't set their gain stages correctly, and thus are overloading the input. Or are just using cheap actives. Or both.(...)[/quote]
This was my first reaction as well. I may be missing something though.

[quote name='escholl' post='782582' date='Mar 22 2010, 05:15 PM'](...)More than that -- running a passive bass direct into a transformer will present it with a load that has resistance, capacitance, and inductance. Also known as a filter. And not just for highs, depending on how it reacts with the inductance, capacitance, and resistance of the bass pickups and cable, it will reshape the frequency response all over.[/quote]
I agree.

Having said that, the [i]frequency response reshape[/i] may be pleasant to hear.

Thanks Mark for the mini-review.

Do you know how the [i]polytune[/i] tracks with a 5/6 string?

Max

[quote name='JackLondon' post='780785' date='Mar 20 2010, 02:06 PM']I think that if you want to maintain that VT tone you'll be better with having a passive DI(...)[/quote]
[quote name='BigRedX' post='780795' date='Mar 20 2010, 02:19 PM']IMO If you don't want to change the sound just capture it you can't beat a good passive transformer based DI box.(...)[/quote]
[quote name='BassBod' post='780806' date='Mar 20 2010, 02:30 PM']A good passive DI will do the trick and retain your sound..(...)[/quote]
[quote name='BigRedX' post='780864' date='Mar 20 2010, 03:41 PM']A good passive DI has as few components as possible between to inputs and outputs and high quality transformers to ensure that the DI output is as uncoloured as possible.(...)[/quote]

I disagree but I may be totally wrong of course.

Can someone of you guys tell me the reasons behind what you say? (Technical reasons, experience, A/B blind tests...)

[quote name='BassBod' post='780823' date='Mar 20 2010, 02:55 PM'](...)
I forgot to say...the VT has a really high output (if you crank it) so I wouldn't use an active DI.(...)[/quote]

Again, I think the opposite is true but I may be wrong. Could you explain why an active DI wouldn’t be suitable for strong signals?

spaz91,

Could you check your PM inbox?

Thanks

I cannot comment on the sound quality because I never tried it extensively but I repaired two of them (Mod Factor and Time Factor) and the quality of the construction is excellent. One of the best I have seen.

You can add more than 1 pedal...

[url="http://www.sfxsound.co.uk/mainpage.asp?page=micro_eq"]Micro-EQ[/url]
[url="http://www.sfxsound.co.uk/mainpage.asp?page=micro_fuzz"]Micro-Fuzz[/url]
...

Not exacly half rack but you may like something like [url="http://basschat.co.uk/index.php?showtopic=71973&view=findpost&p=758247"]this[/url].

[quote name='Kirky' post='753253' date='Feb 21 2010, 09:05 PM'](...)
However I still don't understand why you, for example, make some of your pedals (Thumpinator, Ultratone etc) with a centre positive connector whilst others (H1, D1) are centre negative.

Doesn't that just make the provision of a power supply more difficult if you happen to have both sorts on your pedal board?[/quote]
You are absolutely right.

There is a very simple explanation: I made a terrible mistake in writing the website.

All [sfx] products are powered 9V, centre negative, 2.1mm connector.

[i](I just corrected the web site it should be ok now)[/i]

[url="http://basschat.co.uk/index.php?showtopic=71973&view=findpost&p=752607"]Here[/url] Kirky asked a question that I think other people can find interesting.


[quote name='Kirky' post='752607' date='Feb 21 2010, 10:52 AM'](...)
Probably a dumb question, but is there any particular reason why some effect pedals adopt a negative centre and others a positive?

Martin[/quote]

It is an excellent question. IMO, there are two school of thought.

Centre positive has the advantage that the external part of the connector is negative so it can electrically touch the enclosure. This allows the usage of non-isolated connectors for the power supply.

Centre negative has another, more complex advantage. If more pedals are in series, they share the same ground. This is because the patch cables that connect them connect the enclosures together. Please note that patch cables use shielded cables that have the outside connected to ground.

If it is all powered by batteries (one for each pedal) there is only one ground connection that propagates nicely from the amp, to the last pedal, to the first pedal to the bass/guitar.

If the pedals are daisy chained with a single power supply, things get more complicated: inevitably there is a second chain of ground connections that propagates through the power supply chain.

This creates a problem: the enclosure + patch cable + power supply create a loop. One loop for every pedal.

This type of loop is called ground loop and it is bad news because it is more or less like an aerial that picks up electromagnetic noise.

The situation would improve if we shielded the power supply cable. Unfortunately, we can’t shield the power supply with ground - we would end up doing exactly what we want to avoid. However... if we shield the power supply with the positive and we run the negative inside the shielded cable, the ground loop is mitigated.

Building a shielded cables with the centre negative but with the connector centre positive is a mechanical nightmare so we have cables and power supply connectors with centre negative.

[quote name='M4L666' post='745618' date='Feb 15 2010, 10:29 AM']Couldn't an EQ pedal with true bypass do the same job?[/quote]

I am not sure if your are asking me or nugget

Yes - This is what I would use.

Something like [url="http://www.sfxsound.co.uk/mainpage.asp?page=micro_eq"]this[/url] for example.

[quote name='The Burpster' post='745230' date='Feb 14 2010, 08:20 PM']My reply was aimed at, and meant for Shep.[/quote]

Please accept my apologies. I hope I didn’t offend you :blush:

I though I asked questions that other people could find interesting. I obviously misinterpreted your post. I didn't see it was a sort of public PM strictly addressed to Shep.

As Global Moderator please feel free to delete my questions if you feel they might be inappropriate.