[Bluetick]

I want the most neutral sounding, best performing stepped attenuator I can find. I have narrowed it down to either a DACT CT2 or the GoldPoint MINI-V (and perhaps even the nicer TDK's).

Any opinions or preferences?

Are there any other candidates you feel should be considered?

Thanks for you help- all of it welcomed.

Mike.

 

[linuxworks]

relay based instead of turn-the-crank based?

same kind of atten quality but you can remote control it.

 

[m1abrams]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif relay based instead of turn-the-crank based? same kind of atten quality but you can remote control it.

Curious as to whether you hear a chatter of relays clicking when you adjust the volume? Or are the small latching relays pretty silent?

I personally am not a fan of the click of relays but can tolerate for items that only switch once and awhile, not sure I would like that noise everytime I adjust the volume.

Note I do like the idea of the relay based atten. But think the relay chatter might be a bit much.

 

[linuxworks]

agreed that its not silent. depends on how you mount, how you acoustically isolate the relay 'banger board' and so on. also depends HIGHLY on which relays you use and also how you sequence them. I'm actually working on code now to sequence them and try to keep them semi quiet.

on a solid state vol control (like the PGA) I like to have slow ramp up/down fades. but on relays you cannot do that! so you have to give up the ramping and just go 'immediately' to the vol level.

one thing that can help is to have user memories so that you can go to a few set levels and 'zoom' to them without having to 'walk' up or down by steps to get there; another software thing that could help.

I'm also toying with the idea of doing something hybrid with relays and maybe something solid state for 'tweaks'. just a thought, nothing firm at this point

I would never go with a 'turn the knob' thing anymore. they're not remote-able and they are HELLA expensive for what they really are. no reason why a switch with R's should cost a kings ransom

I've seen people put metal rods in their gear to 'reach' pots or attens to try to shorten the wire distance. I have to admit to laughing hard at such things; but if you really need to achieve 'short wire distances' you can move your relay bank to the back of the chassis, if that makes you feel better

then put the GUI part up front where it just does not matter, in a sound POV.

heck, for purists you can even have the relay box be JUST a box by itself. have it be a 'snake box' with all the wires going into and out of it, including the remote control pair that varies the volume over the digital command channel (i2c often). that way you can make the atten its own separate 'process' and insert it inline anywhere.

 

[pabbi1]

Luvdunhill has a REALLY nice solution - not sure if he is ready for disclosure or not. I heard it at the Dallas meet, and it really is the way forward.

I currently have DACT, GoldPoint, TKD, and Acoustic Dimensions attenuators, and all have their tradeoffs, so, there is no one good answer in mechanical attenuators, and all come at a cost.

 

[Steve Eddy]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif I would never go with a 'turn the knob' thing anymore. they're not remote-able and they are HELLA expensive for what they really are.

They are indeed remotable.

John Chapman at Bent Audio has developed remote control for switched attenuators using a stepper motor.

se

 

[Steve Eddy]

Quote:

Originally Posted by Bluetick /img/forum/go_quote.gif I want the most neutral sounding, best performing stepped attenuator I can find. I have narrowed it down to either a DACT CT2 or the GoldPoint MINI-V (and perhaps even the nicer TDK's).

I have a four deck DACT here for a build I'm doing for someone and I don't like the feel of it at all. It's sort of gritty and the steps are rather indistinct. The Goldpoint I have is much better in that regard with nice tactile clicks from step to step, though admittedly the Goldpoint is a two deck so I don't know if the Goldpoint four deck would feel the same as the DACT four deck.

If you decide to go with the TKD's, get them from Michael Percy. He's still selling some he has left from before TKD's big price increase some years back. $260 for stereo units, $175 for mono units.

se

 

[linuxworks]

how does that motor or stepper know, exactly, how to stop? does it always hit the center 'detent' ok? any drift over time? how does one calibrate or fix it?

seems like an ok solution if you INSIST on having a motor turn a crank. not sure I agree its a good use of money (can't be cheap, that hook-up!)

 

[cobaltmute]

PGA + Arduino + Rotary encoder. At least that is my goal that I'm working on right now.

 

[Steve Eddy]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif how does that motor or stepper know, exactly, how to stop? does it always hit the center 'detent' ok? any drift over time? how does one calibrate or fix it?

Knowing how to stop is a matter of programming. Knowing what the indexing angle is on the rotary switch, you can program to have the stepper step however many steps it takes for a given amount of rotation.

As for your other questions, I can't really give any definitive answers seeing as I haven't installed and used the unit yet. However I can say that there is an intermediate coupler that fits to the motor's shaft with set screws. You loosen the set screws, turn the attenuator's switch to the first position, and then tighten down the set screws. That's your calibration.

Quote:

seems like an ok solution if you INSIST on having a motor turn a crank. not sure I agree its a good use of money (can't be cheap, that hook-up!)

Personally I prefer to use my hand to turn a crank. Remotes are for lazy people, and are a waste of a perfectly good opposable thumb.

se

 

[Bluetick]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif I have a four deck DACT here for a build I'm doing for someone and I don't like the feel of it at all. It's sort of gritty and the steps are rather indistinct. The Goldpoint I have is much better in that regard with nice tactile clicks from step to step, though admittedly the Goldpoint is a two deck so I don't know if the Goldpoint four deck would feel the same as the DACT four deck. If you decide to go with the TKD's, get them from Michael Percy. He's still selling some he has left from before TKD's big price increase some years back. $260 for stereo units, $175 for mono units. se

Thank you!

I think you are experiencing the special indexing GoldPoint is famous for which is sort of a ball-in-socket (for lack of the vernacular) type of stop. You are not the first person to say they have a 'nice tactile click'.
Nor are you the first to say the DACT feels flimsy and cheap by comparison. You have helped me make my decision....and as a bonus the GoldPoint is roughly $50 cheaper.

 

[Bluetick]

Quote:

Originally Posted by cobaltmute /img/forum/go_quote.gif PGA + Arduino + Rotary encoder. At least that is my goal that I'm working on right now.

I stumbled on to that in my quest...I think I need to do more research...perhaps for my next project.

Thanks!

 

[Bluetick]

Thanks, LinuxWorks!

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif on a solid state vol control (like the PGA) I like to have slow ramp up/down fades. but on relays you cannot do that! so you have to give up the ramping and just go 'immediately' to the vol level.

I'm the kinda guy who will set the volume at a certain sweet spot and leave it there for days...Heck- maybe I just need a grayhill selector and three resistors.

Quote:

I would never go with a 'turn the knob' thing anymore. they're not remote-able and they are HELLA expensive for what they really are. no reason why a switch with R's should cost a kings ransom

They can be motorized. ALPS has been doing that for at least 15 years now. I have an old AMC pre (made in 1992) with a factory motorized ALPS pot. The motor is powered by a seperate 12V supply, and the remote volume works like a charm. However, this pot is NOT a stepped atenuator. To motorize a stepped attenuator the motor operates in "pulses" so as to power it perfectly between clicks. It is not anything more complicated or unserviceable than the solution you suggest- works quite well, actually.....I just don't need a remote.

Quote:

I've seen people put metal rods in their gear to 'reach' pots or attens to try to shorten the wire distance. I have to admit to laughing hard at such things; but if you really need to achieve 'short wire distances'.....

I can understand why you would laugh, but there is merit to doing such things- especially when you are trying to use a passive atten as a "preamp". Every little bit of wire saved helps maintain the gain coming from the source. It also decreases the potential EMI and/or RFI on the signal chain. A 10" extension rod costs about $3, but some good signal wire can cost more for the same length.


Quote:

heck, for purists you can even have the relay box be JUST a box by itself. have it be a 'snake box' with all the wires going into and out of it, including the remote control pair that varies the volume over the digital command channel (i2c often). that way you can make the atten its own separate 'process' and insert it inline anywhere.

The crank-the-knob- guys have been doing this for a long time:

I disagree with most of what you said but I certainly do appreciate you taking the time to offer your opinion. Thank you!!!

cheers.

 

[Steve Eddy]

Quote:

Originally Posted by Bluetick /img/forum/go_quote.gif I think you are experiencing the special indexing GoldPoint is famous for which is sort of a ball-in-socket (for lack of the vernacular) type of stop. You are not the first person to say they have a 'nice tactile click'. Nor are you the first to say the DACT feels flimsy and cheap by comparison.

Both DACT and Goldpoint use the same Elma switch which uses a pair of spring loaded ball bearings that ride on teeth inside the body of the switch. The springs in the stock switches are rather stiff and give an industrial clunk-clunk-clunk-clunk feel. Elma can supply what they call a light detent spring which isn't nearly as stiff and gives a very nice tactile feel and I'm pretty sure they're the same springs that Goldpoint uses as they feel the same.

I'm thinking that DACT is using an even lighter spring than this and/or a heavier spring in the wiper mechanism which would cause greater pressure and could also account for the gritty feel of the switch.

Anyway, all I know is that I didn't like the feel of the DACT at all compared to the Goldpoint.

Quote:

You have helped me make my decision....and as a bonus the GoldPoint is roughly $50 cheaper.

Glad I could help.

se

 

[Steve Eddy]

Now, if you really want to go crazy, load one of these beauties up with your favorite resistors.

se