ART Cleanbox mod thread

**Canadian_Dude** · **07-11-08, 07:24 PM**

So what the input impedence for this?

**bobgpsr** · **07-24-08, 09:32 AM**

Quote:

Canadian_Dude wrote:

So what the input impedence for this?

Hmmm, not sure exactly at this moment -- not at the Cleanbox's location. IIRC it is a 0.047 uf cap going into a 100K (?) pot feeding a very high impedance op amp. So use 100000 ohms (the pot's resistance) for the R in the previous equation.

Better yet measure the pot's resistance value with a multimeter. It could be 10K. Or did one of the early posts mention the input pot's resistance?

Edit: Checked back with Ilkka's measured results . So 0.047uf and 100K ohms gives 34 Hz for the -3 dB point which approx matches Ilkka's test results.

**Canadian_Dude** · **07-24-08, 06:59 PM**

Thanks for the info but I already went ahead and used a 1uF cap. Here is before and after:
http://www.hometheatershack.com/foru...tml#post107393

**ringbearer3791** · **07-29-08, 09:19 AM**

I have a quick question regarding use of and need for the cleanbox. I just recently completed my subwoofer build and am powering with an ep2500. It is currently connected directly from my receiver to the amp with a rca/xlr cable. The receiver is a denon 4306 which states it has a subwoofer preout sensitivity of 1.2V and the 2500 lists its input sensitivity as 1.23V. I currently have the subwoofer gain on the receiver turns all the way up and signal is definitely getting to the sub but I was wondering if the cleanbox is necessary/will improve amp output. Thanks.

Josh

**Mike Cason** · **07-29-08, 11:02 AM**

I have an Arts box and even modified it like some of the members did with the new 1 uf caps, but I didn't like it after 2 minutes and took it out and shelfed it. (RECENCTLY SOLD TO A MEMBER WHO READ THIS POST)

I ordered a Reckhorn B-1 from CSS for about $85 bucks shipped. (from Washington state).

You can cut off all of your protection limiter switches on your amp and take full advantage of the power of the Europower. The limiters restrict some of the bass output. The Reckhorn is an easy install and uses rca cables instead of the more expensive XLR type.

It provides subsonic frequency protection, bass boost from 20 hz and up, and has a high pass filter.

This one of the best pieces of equipment I have in my HT equipment rack. It has a finely machined case and the controls feel very high quality. It is built in Germany with their superb engineering.

I had our Houston Soundsplinter DIY group meeting here Sunday and everyone was impressed with it's performance.

Click on the CSS link on my dealers page of my website to order it.

Have fun,
Mike

**TheGovernment** · **09-28-08, 07:49 PM**

where would I go to get the caps needed for the cleanbox mod in canada? we don't have RS anymore

**Canadian_Dude** · **09-28-08, 10:05 PM**

There are many small electronic repair stores around. Check your phonebook. The Source doesn't sell them for sure, I checked. Ask if they sell 1 micro farad metal polyester caps. 63V is plenty and they will fit easily.

**TheGovernment** · **09-28-08, 10:31 PM**

ok thanks, I'll give a look see.

**JCD** · **09-30-08, 12:25 AM**

You could always go here...

JCD

**TheGovernment** · **09-30-08, 12:32 AM**

which ones on that site would I be looking for? I've called the few that were in the phone book and they didn't have what I needed.

**Canadian_Dude** · **09-30-08, 11:55 PM**

Those aren't what people here are using. They may work but I wouldn't use those. They are better for crossovers and those ones are expensive. What part of Canada are you in?

**TheGovernment** · **10-01-08, 12:31 AM**

winnipeg, I've stopped in at a few repair shops but not many seem to carry what I need.

**Canadian_Dude** · **10-01-08, 07:08 PM**

You seem to have an active electronics in Winnipeg and that is where I got mine here in Edmonton. The part number you are after is MPY63V105-J5B. It is a 63v 1 uF Metal Polyester Capacitor. The store is here: http://maps.google.ca/maps?f=q&hl=en...OjyajHDw&cd=11

**TheGovernment** · **10-01-08, 08:16 PM**

woo cool thanks!! I'm only bout 15 minutes from there. I'm gonna head down there on the weekend.

**tcarcio** · **10-06-08, 11:31 AM**

Does anyone here use the Rolls mb15 instead of the Art. I talked to an engineer named Alex at Rolls and he assured me that the mb15 does not effect the low end at all. If this is so then why are people modding the Art instead of just useing the Rolls?

**bobgpsr** · **10-06-08, 01:19 PM**

Quote:

tcarcio wrote:

Does anyone here use the Rolls mb15 instead of the Art. I talked to an engineer named Alex at Rolls and he assured me that the mb15 does not effect the low end at all. If this is so then why are people modding the Art instead of just useing the Rolls?

Looking at the Rolls MB15b schematic I see a polarized 1uf capacitor into a 4700 ohm resistor that sets the input impedance. That gives the same 33.8 Hz -3dB down frequency response as the ART Cleanbox using the formula f = 1 / (2*pi*R*C).

**tcarcio** · **10-06-08, 04:08 PM**

Quote:

bobgpsr wrote:

Looking at the Rolls MB15b schematic I see a polarized 1uf capacitor into a 4700 ohm resistor that sets the input impedance. That gives the same 33.8 Hz -3dB down frequency response as the ART Cleanbox using the formula f = 1 / (2*pi*R*C).

Well then maybe these company's don't feel like that is a problem that would make a difference. Anyway couldn't you just use the Reckon or sms1 to boost that freq?

**Canadian_Dude** · **10-06-08, 07:22 PM**

These boxes are made so that the pro audio guys can use cd players and such with their amps and dsp's. In the pro world the cost of having sound below 30Hz is too much for them to bother with.

**tcarcio** · **10-06-08, 09:11 PM**

Makes sense, I am sure they are more interested in the 40 to 60hz range for the low end in music.

**TheGovernment** · **01-11-09, 04:23 PM**

I finally got around to modding my cleanbox yesterday and my subs have much more "umph" @ 20hz and below as it did before. Very easy to do and worth the $3 in parts and the 20 minutes to do it!!

Thanks to the makers of this thread.

**digital desire** · **02-05-09, 10:07 PM**

Well, after playing with Art for some time, I have come to the conclusion it's not for me. I need it to make a long balanced cable run as my EP now is another room for its noisy fan.
I installed mine in the bassis eq for a one box solution. I am now going to scratch together a different solution from THAT: http://www.thatcorp.com/datashts/1600data.pdf which hopefully will be noise free.

If you look at the art, they put electrolytic caps in the signal chain also. While I'm not a geek about my sound, I do think the cleanbox is not the best solution. I grounded everything in a star type ground and still can not make it perfectly quiet.

Here is the cleanbox living inside the bassis.

I think maybe part of the problem is that does not use a bi polar power supply like the bassis, it only uses the top half of the bassis supply. This may shift the ground potential a bit? Dunno. The THAT chip is your typical bipolar op amp deal.

**digital desire** · **02-08-09, 08:48 PM**

OK, just replaced that cleanbox with this:

I like much better.
http://www.thatcorp.com/datashts/1600data.pdf

**collo** · **04-06-09, 06:49 PM**

I've also done this mod. My writeup includes these views, which I've not seen published before...

Track side of circuit board

Ghosted onto component side

XLR side of box

Underside of box

**dynamowhum** · **04-28-09, 10:22 PM**

I ordered the parts today looking forward to doing this mod. The photos from the beginning are gone could someone please update them

**dynamowhum** · **05-05-09, 12:57 PM**

Finally got some time off so I can do the mod. Just took apart the case and removed the board. Man this thing is put together to take abuse in the pro world alright. Now to fire up the old iron.

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