so, I just scooped up a sytek . . .

[joelpatterson]

You're asking because he would know better than if you tried it yourself. I feel the same way!

[JeffStrong]

When DIYing a passive attenuator what is the relationship between dB drop and resistance load? Is there some sort of equation that I can plug a resistance value into to determine dB attenuation?

[stemwinder]

Hi,

I have this problem as well. On another board someone pointed me to the following instructions and schematics for DIY attenuators: http://www.uneeda-audio.com/pads/. Haven't tried them yet.

It includes a table on db drop vs. resistance.

Cheers, Darren

[Rigsby]

If you do get an attenuator, this is a good one.

http://www.adesignsaudio.com/atty.htm

I use it with my Sytek and RNP (and as a daw volume knob).

That is exactly what i need myself, thanks, is it really 'no-noise'?

[jrsgodfrey]

Rigsby,

The ATTY seems functionally transparent to me.

They're about $100 direct from A-designs.

Cheers,

Jay

[Rigsby]

Rigsby,

The ATTY seems functionally transparent to me.

They're about $100 direct from A-designs.

Cheers,

Jay

Nice one Jay, that's fantastic.

[Punkity]

I know people have different ways of solving audio problems, but I cannot understand why in the world someone would pay $100 for something that could be DIY-ed by someone who has zero practical experience with electronics and costs around $10 with a case and everything. In fact, I'm going to bet that the ATTY is exactly what I suggested above in a nice looking case. If you want to have even more control, and spend about a buck more, you could take my design and add a log-taper potentiometer. Here is another crappy schematic for ya':



For JeffStrong: I think, but am doubing, that the forumula that gives you the dB attenuation is ten times the log of the resistance of the added resistor divided by that impedance of the next peice of gear in line plus the resistance of the added resistor . OK, here is an example. If the next piece of gear in line has an impedance of 10k ohms and you add a 10k Ohm resistor, the signal is attenuated by 3dB [10xlog(10,000/(10,000+10,000))=-3]. If you want to attenuate the signal by 6db, you would have to have a resistor that is 1/3 the value of the impedance of the next piece in line [10xlog(3,333/(10,000+3,333))=-6]. A 9dB drop would require a resistor one-seventh the value of the impedance of the next piece of gear in line.

If someone could chime up regarding this formula, please do.

[jrsgodfrey]

Yeah, I'm sure the ATTY has few parts and is simple in design -- for good reason. As far as DIY goes, I cannot build a square box or get the knots out of my 5-year old's shoes. Ikea build-by-numbers is about my speed.

So $100 is a good deal for me for something that works in a lot of different ways.

Call me lazy.

[Punkity]

You lazy.

[jrsgodfrey]

Guilty.

[bad_dude_69]

votemiles - i like your avatar, john fahey is the best.

[E-cue]

If you do get an attenuator, this is a good one.

http://www.adesignsaudio.com/atty.htm

I use it with my Sytek and RNP (and as a daw volume knob).

That is exactly what i need myself, thanks, is it really 'no-noise'?

Yes. No noise and passive. I'm using the '5.1' rackmount version with my Sytek and Neotek Mic Max. First time I used them together, its was one of those "Hey, you got your chocolate in my peanut butter" experiences. Shure also makes some handy pads (3 levels of attenuation) , but the atty is more variable and has a mute.

They are also great with fixed gain pre's, such as some of the Telefunkens.