Hi
The Silicon Chip K5600 6 channel remote volume control
is still on special at Altronics with a rack
mount case. Specs look fairly good. I bought
one and will update the TL072s when I get round
to assembling it. Have not got the cash for the
DCX yet but will have to attenuate the DCX outputs
which I hope will not be an issue.
Regards
AnthonyPT
http://www.altronics.com.au/index.asp?area=item&id=K5600
The Silicon Chip K5600 6 channel remote volume control
is still on special at Altronics with a rack
mount case. Specs look fairly good. I bought
one and will update the TL072s when I get round
to assembling it. Have not got the cash for the
DCX yet but will have to attenuate the DCX outputs
which I hope will not be an issue.
Regards
AnthonyPT
http://www.altronics.com.au/index.asp?area=item&id=K5600
Hi
It uses a pic controller and LM1973s plus
Tl072 buffers. PDFs of the boards are available besides the kits
Also the Pic code is available.
That price is AUD$150 for the whole kit at present.
Regards
AnthonyPT
http://www.siliconchip.com.au/cms/A_30604/printArticle.html
It uses a pic controller and LM1973s plus
Tl072 buffers. PDFs of the boards are available besides the kits
Also the Pic code is available.
That price is AUD$150 for the whole kit at present.
Regards
AnthonyPT
http://www.siliconchip.com.au/cms/A_30604/printArticle.html
Attachments
janneman said:
Jan,
All the info/schematics are available on the DCX forum. Look at the top of the files section. It's been there for awhile.
http://groups.yahoo.com/group/DCX2496/
Davey.
I'm sure your tired of it...but..
Greetings,
I think I've been thru most of the info here and on the Yahoo grps page. I'm still in a quandray. I'm looking at the DCX2496 or the 3400(?) 3 way analog. Due to how my system will be laid out I MUST use the analog in and control volume BEFORE the X-over.
My pre will be a Bosoz (I think I can get some good levels out) and the 2 hi-pass amps will be aleph. My situation is that I need some solid opinions (surprise). Do you guys think that the front-end level issue can be overcome to equal the quality I will get with the analog unit, condidering the flexibility of the DCX. I am willing to do some careful level matching..In other words, 'Is it really THAT bad or is post attenuation just a bit better'? I know how tough a question this is. I am willing to do some mods to the DCX. The time alignment will be very useful to me and my setup, but not if it 'really' sounds like DOG. The WAF makes it tough to make purchasing mistakes and I want to be as sure as I can be before plunking the cash down.
Sorry to be a pain in the a~~!
Marc
Greetings,
I think I've been thru most of the info here and on the Yahoo grps page. I'm still in a quandray. I'm looking at the DCX2496 or the 3400(?) 3 way analog. Due to how my system will be laid out I MUST use the analog in and control volume BEFORE the X-over.
My pre will be a Bosoz (I think I can get some good levels out) and the 2 hi-pass amps will be aleph. My situation is that I need some solid opinions (surprise). Do you guys think that the front-end level issue can be overcome to equal the quality I will get with the analog unit, condidering the flexibility of the DCX. I am willing to do some careful level matching..In other words, 'Is it really THAT bad or is post attenuation just a bit better'? I know how tough a question this is. I am willing to do some mods to the DCX. The time alignment will be very useful to me and my setup, but not if it 'really' sounds like DOG. The WAF makes it tough to make purchasing mistakes and I want to be as sure as I can be before plunking the cash down.
Sorry to be a pain in the a~~!
Marc
Marc,
It's not a pain-in-the-..........it's actually the basic question that most users have with the DCX...for home use.
You could add fixed attenuators to the six outputs of the DCX and it will work fine for your configuration. Many DIY-audiophiles (myself included) tend to get a little obsessed with wringing the last bit of "performance" out of a piece of gear, but in the case of the DCX it's really not necessary....it's pretty darn good stock (used correctly.) You really don't need to mod it.
If you're using XLR/RCA adaptors on the outputs break the internal pin 1-3 connection on those. That will shift the internal levels of the DCX higher by 6db. If you want to take it farther you can add some external fixed-resistor attenuators to reduce the level a bit more....maybe 6db. That's an additional 12db voltage gain your preamp would have to provide, and that's assuming that you don't have lowish gain power amps and lowish efficiency speakers that would have already forced the internal levels too high.
Cheers,
Davey.
It's not a pain-in-the-..........it's actually the basic question that most users have with the DCX...for home use.
You could add fixed attenuators to the six outputs of the DCX and it will work fine for your configuration. Many DIY-audiophiles (myself included) tend to get a little obsessed with wringing the last bit of "performance" out of a piece of gear, but in the case of the DCX it's really not necessary....it's pretty darn good stock (used correctly.) You really don't need to mod it.
If you're using XLR/RCA adaptors on the outputs break the internal pin 1-3 connection on those. That will shift the internal levels of the DCX higher by 6db. If you want to take it farther you can add some external fixed-resistor attenuators to reduce the level a bit more....maybe 6db. That's an additional 12db voltage gain your preamp would have to provide, and that's assuming that you don't have lowish gain power amps and lowish efficiency speakers that would have already forced the internal levels too high.
Cheers,
Davey.
Thanks Davey,
As further info:
My amps are low power, lowish gain. My amps and pre are are all balanced. I will have ~12w to a 105dB compression driver, ~25w to a 96dB midbass, and sub us undecided...probably something 'horn-ish'. Reason for my Need to have level adj. prior to the Xover:
This setup will also serve double duty as the front stage of a home theater setup. The two front outputs from my sony es proc. will be fed into the preamp in a custom fixed level input(in the preamp) and home theater volume will be handled by the sony processor. Because of the consideration of the additional 3 HT channels (which will come directly from the proc and to dedicated amp channels)..I must adjust volume prior to the DCX.
Thanks a lot..
As further info:
My amps are low power, lowish gain. My amps and pre are are all balanced. I will have ~12w to a 105dB compression driver, ~25w to a 96dB midbass, and sub us undecided...probably something 'horn-ish'. Reason for my Need to have level adj. prior to the Xover:
This setup will also serve double duty as the front stage of a home theater setup. The two front outputs from my sony es proc. will be fed into the preamp in a custom fixed level input(in the preamp) and home theater volume will be handled by the sony processor. Because of the consideration of the additional 3 HT channels (which will come directly from the proc and to dedicated amp channels)..I must adjust volume prior to the DCX.
Thanks a lot..
" My amps are low power, lowish gain. My amps and pre are are all balanced. I will have ~12w to a 105dB compression driver, ~25w to a 96dB midbass, and sub us undecided...probably something 'horn-ish'. Reason for my Need to have level adj. prior to the Xover: "
You can do it, you just need to set levels in/out optimally. I'm doing it that way and it is fine.
With the high efficiency drivers you will need a lot of attenuation on your amps. Probably 20dB or more and it will take some time to get it set for each driver.
I'm running horns too (LaScala Bass bins, Altec 288/805B, JBL 2404H) and with the proper attenuation on the amps the Behringer is dead quiet. I had more of a problem just with the hiss in the amps themselves. The levels are setup such that the loudest I listen to (THX Ref level) playing 0dBFS pink noise is within a couple of dB of clipping the input and outputs of the Behringer.
Good luck,
Shawn
You can do it, you just need to set levels in/out optimally. I'm doing it that way and it is fine.
With the high efficiency drivers you will need a lot of attenuation on your amps. Probably 20dB or more and it will take some time to get it set for each driver.
I'm running horns too (LaScala Bass bins, Altec 288/805B, JBL 2404H) and with the proper attenuation on the amps the Behringer is dead quiet. I had more of a problem just with the hiss in the amps themselves. The levels are setup such that the loudest I listen to (THX Ref level) playing 0dBFS pink noise is within a couple of dB of clipping the input and outputs of the Behringer.
Good luck,
Shawn
Hi Akunec,
do not worry about needing high attenuation after DCX for a following high gain amp.
A low attenuation level requires a series resistor only slightly higher than the ground resistor. This leads to a high output resistance (impedance).
A high attenuation gives a low output resistance due to the NEED for a low value ground resistor.
This falls exactly into what YOU need - high attenuation AND low output resistance. No problems.
do not worry about needing high attenuation after DCX for a following high gain amp.
A low attenuation level requires a series resistor only slightly higher than the ground resistor. This leads to a high output resistance (impedance).
A high attenuation gives a low output resistance due to the NEED for a low value ground resistor.
This falls exactly into what YOU need - high attenuation AND low output resistance. No problems.
I have read the "Ramblings" http://mysite.verizon.net/vze4c5pt/id11.html about SRC,I have a Roland M-1000 digital mixer http://www.rolandus.com/products/details.asp?CatID=12&SubCatID=49&ProdID=M-1000
and it also does SRC,I have it before the DCX2496 (soon a DEQ2496 inbetween) it sounds fine on 44,1Khz and 48Khz but when I set it on 96Khz I get pop´s with 2 seconds inbetween,is it because DCX2496 is on 88.2 or what,my cd/DVD Pioneer DV668.('
')
and it also does SRC,I have it before the DCX2496 (soon a DEQ2496 inbetween) it sounds fine on 44,1Khz and 48Khz but when I set it on 96Khz I get pop´s with 2 seconds inbetween,is it because DCX2496 is on 88.2 or what,my cd/DVD Pioneer DV668.('
')
Konnichiwa,
+22dbu = 9.76V
You need to do two things. You need to change the input to balanced and you need to lower gain to what is needed (I'd say 10db), BUT the LM38XX series needs at least a gain of 10 (20db). The way around this is a suitable value resistor between positive and negative input to ensure the (noise) gain referred to the positive input remains greater or equal to 10.
For a balaned Input you take a pair of 330K Resistors, one as feedback resistor, the other from the positive input to ground. You then use a pair of 100K resistor to the respective inputs (+ to pin 2 and - to pin3, pin 1 of XLR grounded). To make sure the noise gain is high enough, con nect a 33k Resistor directly across the + & - input pin on the LM38XX Chip.
Like the attached (not tested but should work fine...).
Sayonara
akunec said:
+22dbu = 9.76V
akunec said:
You need to do two things. You need to change the input to balanced and you need to lower gain to what is needed (I'd say 10db), BUT the LM38XX series needs at least a gain of 10 (20db). The way around this is a suitable value resistor between positive and negative input to ensure the (noise) gain referred to the positive input remains greater or equal to 10.
For a balaned Input you take a pair of 330K Resistors, one as feedback resistor, the other from the positive input to ground. You then use a pair of 100K resistor to the respective inputs (+ to pin 2 and - to pin3, pin 1 of XLR grounded). To make sure the noise gain is high enough, con nect a 33k Resistor directly across the + & - input pin on the LM38XX Chip.
Like the attached (not tested but should work fine...).
Sayonara
Attachments
gain trial and error
Beyond matching the gain to clip at the same time you want to maximize digital resolution and signal /noise by having the total gain such that the outputs of the DCX are nearly maxed when you have the max listening level that you want. Hopefully this will be well below clipping the amp. You can reduce the gain of the amp but keep in mind most power amps become unstable below a certain gain. The LM3886 is supposed to be ok down to a gain of 10 which is pretty low though and should get you close to where you want to be. Most other power amp circuits I've seen have minimum gains in the 20's. The most flexible way is to use an adjustable L pad on the input of the amp as in the circuit that is recommended on the National Semi Data sheet for your amp.
This allows you to keep the output turned up on the DCX for the best sound and still get any listening level that you want.
Beyond matching the gain to clip at the same time you want to maximize digital resolution and signal /noise by having the total gain such that the outputs of the DCX are nearly maxed when you have the max listening level that you want. Hopefully this will be well below clipping the amp. You can reduce the gain of the amp but keep in mind most power amps become unstable below a certain gain. The LM3886 is supposed to be ok down to a gain of 10 which is pretty low though and should get you close to where you want to be. Most other power amp circuits I've seen have minimum gains in the 20's. The most flexible way is to use an adjustable L pad on the input of the amp as in the circuit that is recommended on the National Semi Data sheet for your amp.
This allows you to keep the output turned up on the DCX for the best sound and still get any listening level that you want.