Passive volume control options for the Behringer DCCX

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Hello,

I have been exporing options for a qualtiy passive volume control for the DCX and I thought i would get some ideas here- My setup is all +4dBu balanced XLR's so this complicates things a little-

There is the 6 gang DACT- I would need two pairs to be balanced so that is a good $1200 or so-

http://www.nutshellhifi.com/dact.html

Or the Blue Sky BMC controller-

http://www.abluesky.com/p_s_gb/p3s3.html

The SPL one

http://www.soundperformancelab.com/smc/smc_E.html

Or the Colman one-

http://www.mercenary.com/colaudsrsurs.html

There are also some outragously expensive units that are made for surround monitoring and feature decoders and stuff that would be totally useless in my application-

any ideas here would be great- I know that some people were dicussing/building a DIY one- wich is cool but unless it is somthing simple like the DACT setup it might be a bit out of my league. the bluesky BMC appeals to me because the litte knob is only a (wired) remote control- All the major electronics could use short cables and be hidden in the back somwhere (they are in a rackmount box). I also like the Idea of not having 10 or more cables on my desk (this is a studio). I guess I am just posting so that people can check out these options as much as being able to get some opinions from whoever- thanks again,

Ryan
 
Passive volume control options for the Behringer DCX

Thanks, Ryan, for the various VC sites. Have you seen www.decibelhifi.com.au ? They have two volume controls available--one is a simple RCA/RCA box with individual pots for $30 (I believe the same box that Steve Dodds uses between his DCX and amps for his Bob Dipoles) the other is a rack-mount unit with infrared remote capabilities and runs $260 to $450 or so kit/wired. Not sure if it's balanced or unbalanced, though--will need to take another look at their page.

I'm looking for a good 6-channel volume control to use between a DSP such as the DCX and the inputs of three amps for the dipoles I am building similar to Steve's setup mentioned above. I may try the $30 box first and see how it goes but those DACT precision pots sure look nice. If I am running a balanced output converted to unbalanced into the VC and unbalanced into the amps then wouldn't I need just one 6 gang DACT to do the job?

Jeff
 
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Yep, it's still in use with my DCX and working great. I've also built a prototype 8-channel control using the SSM2164 that works pretty well. Even cheaper and takes up quite a bit less real estate.

However, I've found that if someone has made up their mind that a passive attenuator is the best option there'll be no convincing them that VCA's, digital pots, etc are viable options.

Cheers,

Davey.
 
Cool,

I'm not necessicarily tied to passive vs VCA or anything else- I just don't want to get into a major electrical project as this is not my stong suit- As far as I can tell it seems like the bluesky BMC is probably VCA based- I know some people don't like VCA's and I imagine that the DACT setup might be a bit better but I think we are closing in on 98% of diminishing returns- The dact setup finished and looking nice would probably cost $1500 and I can't keep the cables that short from the volume control to the amp so the benifits of it could easily be lost- I am leaning toward the Blusky simply because it fits my system- the SPL or the Coleman both require a ton of cableing that would clutter up my desk- Plus the SPL has some routing options that could be a bit scary for this use- It seems as though the wrong button could end up sending the Bass channel to the tweeter channel- this would be bad- Anyway thanks for the input-

Ryan
 
I went for http://www.apoxcontrols.com/apox.htm using the 6 units of SHM (which I assisted somewhat in the layout of).

I think it is a very good option, but it is not free. For me, the SHM version was the way to go and it is slightly more expensive than the other boards (system is modular, there are multiple 3 relay switched volume controls).

Total cost is: USD 505 for the version I went for. Then there is the cabinet and power (note passive system so power is cheap). You get nice display, lots of features + full remote. This setup handles balanced as well as single ended and should scale to 8 "mono" channels.

I really like it!

Petter
 
Davey,

I looked at your volume control again and I must say that it is a very credible job. In fact, I expressed in the past some reservations in using the VCA’s for the Hi-end type of audio that we are all involved in, however, with introduction of a SSM2018 in E-grade the VCA deserves another look.

Tell me, do you have any more boards available for your project, as I would like to try it? In my case, I will need to build a 12-channel unit. Also how do you deal with the rather high output voltage from the DCX before your volume control? Although the data sheet for SSM2018T specifies the maximum input voltage at 22 dBu, still the THD suffers tremendously at those levels. I presume you attenuate the DCX output first, right? In any event, is there a way for me to purchase the boards? I’ll be also interested in getting the boards for SSM2164 if you have them.
 
6 channel post-DCX volume control

Vadim, I just ordered one of Dave Reite's VCA-type 6ch VCs from Paul Hilgeman to go between my DCX and three Nakamichi amps. Paul is offering to build or help build these VCs with fairly high quality parts for those who need such a device and he claims that they don't add any noticeable sonic signature (at least that his golden ears can detect)... Although they appear fairly simple to build my eyesight is not what it used to be so I've hired Paul to do all the construction. I expect to have it in my system sometime around late August and will post my first impressions here at that time also.

See his post elsewhere on the forum here if you or anyone else is interested. I believe the title is along the lines of "Anyone needing 6 channels of volume control?" and was posted about a week ago.

Jeff in Hawaii:cool:
 
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Jeff,

You won't be disappointed in the performance of this unit. The VCA's sound transparent to me also....but I don't have golden ears. :) Phil Bamberg at http://www.bamberglab.com also auditioned my prototype unit awhile back and reported excellent performance in conjunction with his DCX2496.

If there gets to be enough interest in the future it might be worth designing a pc board with some added features and improvements. This is low on my priority list currently, but possibly Paul or somebody else could tackle the job.

Cheers,

Davey.
 
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