ART Cleanbox mod thread

**ccdoggy** · **06-27-07, 06:12 PM**

I am always interested in moding devices to improve their performance. and with the release of the info that the Cleanbox is really killing the low end I think that we all need to pool our knowledge to mod them to improve where it is lacking.

I personally have no real technical knowledge of how this stuff even works, but I can give you high quality pics and any detailed info you want about it in the effort to improve. I am forced into using it, or something more expensive.

http://www.ccdoggy.net/Art/labled%20copy.jpg
http://www.ccdoggy.net/Art/IMG_1147.jpg
http://www.ccdoggy.net/Art/IMG_1148.jpg

I will be getting more pics later once my room mate comes home to tell me how to use his camera.

I just thought this needed a new thread as the other one is just bringing the news to light.

if you need any info at all just ask, i still have it all torn apart.

**ccdoggy** · **06-28-07, 01:37 AM**

The green caps say 473J 100uf

I have added allot of pics, www.ccdoggy.net/Art/ anything else just ask.

**ccdoggy** · **06-28-07, 12:32 PM**

what would be the difference going with a 1uF compared to a .47uF?

thinkin i might try and get a few caps today and see what happens.

**ccdoggy** · **06-28-07, 01:18 PM**

so it would be fine if i wired them in parallel for testing to show the difference right as it would be a minor increase with the .047 in there.

Also polarity wise does it matter or which prong on the green is positive?

**ccdoggy** · **06-28-07, 02:13 PM**

I picked up some Metalized-Film caps 1.0 uF, 250WVDC max. thats all they had for 1.0uF at radio shack.

I dont have any way of measuring a difference using REW as the ART converts to XLR and i cant plug that into my computer.

I could loop it through itself but that would be maybe doubling the problem? worth a shot i guess just to see before trying to mod it.

and that is true about source equipment, but i think i got that covered. My reciever is a Arcam AVR-300 with a Denon 2800 dvd player and a computer connected.

**ccdoggy** · **06-28-07, 02:41 PM**

I tried to loop it back on itself and measure but it came out really flat the first time, and almost as flat the second time. so what ill do is to use my SPL meter and a tone generator to take some measurements by hand and that should show some difference.

**ccdoggy** · **06-28-07, 05:12 PM**

So i attached the 1uf cap to both green caps and took measurments before and after. looks like i do get a bit better response out of the lower end and it is definetly flatter when taking measurments.

although my testing method has many holes, Using a RS spl meter, using a digital connection to reciever that would take a good amount of effort to calibrate, room not so great its a small box of a room, and construction goin on accross the street noisy.

but i think it does show some improvment. alas i cannot test as others have on its exact response as it converts to XLR and i have no way of connecting an XLR cable to my computer to measure.

just listened to some blueman group and the bass drums do seem a bit punchier and allot more noticeable.

Now that we know it works (nothing on fire) is there anyone out there that could do the mod and post some graphs on how it improved?

here is what i came up with,

Hz Before After mod
10 74.5 85
15 78.3 85.2
20 88.5 104.3
25 101.7 108.1
30 96.7 101.3
35 85 90.2
40 94.8 97.6
45 96.6 97.3
50 94.2 94.6

**Ilkka** · **06-28-07, 05:25 PM**

Quote:

ccdoggy wrote:

Now that we know it works (nothing on fire) is there anyone out there that could do the mod and post some graphs on how it improved?

I can do the mod and measure it, but not until after a few weeks.

**ccdoggy** · **06-28-07, 10:29 PM**

i can get a pic up maybe tomorrow or so. Its kinda sorta half assed on there right now, but will do a better job once it is confirmed and no more mods needed or what not.

I must say that the response is all around better, but still lackin a tad in the low end, but i think thats an issue with my computer's digital output and not with the Art. then again i cant really tell as i cant really measure it very well. But it is better and thats what counts.

**brucek** · **06-28-07, 10:58 PM**

Quote:

i cant really tell as i cant really measure it very well.

Why not? Doesn't your soundcard have an analog line-out and analog line-out for use with REW?

brucek

**ccdoggy** · **06-29-07, 12:55 PM**

yea im using my DVD player also for source material.

going to try my favorite bass hungry movies soon.

**brucek** · **06-29-07, 01:27 PM**

Quote:

yea im using my DVD player also for source material.

Why are you not testing the results with REW?

brucek

**Efalegalo** · **06-29-07, 03:57 PM**

Wanted to find out if anyone here had the chance to do a proper mod and could potentially post pictures.

I know nothing about electical engineering but can solder. If anyone of you would be so kind to take a couple before and after pictures - it would be much appreciated.
Thanks

**brucek** · **06-29-07, 04:11 PM**

Quote:

If anyone of you would be so kind to take a couple before and after pictures - it would be much appreciated.

I would think it important to test the mod with REW first?

brucek

**soho54** · **06-30-07, 02:59 PM**

By "green caps" I am assuming you mean at c7 & c8, correct?

**Wayne A. Pflughaupt** · **06-30-07, 04:32 PM**

Not sure I get the reasoning for this exercise. Why not just get one of these mini-mixers? Overall, it should do a lot better job at getting a hotter signal from a line-level input than the ART.

Frequency response: 10Hz – 150 ±1 dB
S/N ratio: ~100 dB C-weighted
Max. output level: +22 dBu unbalanced
List price: $55.00

Regards,
Wayne

**soho54** · **06-30-07, 04:35 PM**

I have been playing with this today. Sorry, but my laptop is dead. No REW.

First I added a jumper for no HP. This did not work with my setup. It stayed on for about 5 seconds. Moving on...

Next, I added two .22uF PolyFilm Caps each to c7 & c8. It should be at ~.47uF per now.
Before _____After
40Hz=80dB__80dB
35Hz=77dB__79dB
30Hz=75dB__77dB
25Hz=75dB__79dB
20Hz=76dB__81dB (Large room node at 22Hz)
15Hz=73dB__80dB
13Hz=68dB__76dB
10Hz=60dB__71dB

This is in-room, with a digital RS Meter (no corrections.). Two large Sono's tuned to ~13.5Hz. ( I can't remember the exact tuning, and my build thread is gone now for some reason.

) All EQ was removed for this test. I started at 80Hz, but it was exactly the same from 40Hz on.

With the two .22uF caps, I have the option of clipping one off each position to raise the HP some if I feel the need later.

**ccdoggy** · **06-30-07, 04:59 PM**

Yes, C7 and C8.

why do this? because i am a poor college student and dont want to spend more money on my addiction at this time. this is a cheap quick "fix" thats not hard to do for those of us that already have the clean box.

**bobgpsr** · **06-30-07, 05:25 PM**

Quote:

Wayne A. Pflughaupt wrote:

Not sure I get the reasoning for this exercise. Why not just get one of these mini-mixers? Overall, it should do a lot better job at getting a hotter signal from a line-level input than the ART.

Looking at the schematic for that mini-mixer it does not do the basic single ended commerical level to balanced pro level conversion. It should have gain - but getting a nice balanced drive output near the source lets you have a long XLR balanced cable run to the pro amp (and not get any hum pickup). Too bad we have to modify the ART Cleanbox to level out the 30 Hz to 10 Hz bottom end freq response.

**Efalegalo** · **07-01-07, 06:02 PM**

Quote:

soho54 wrote:

I have been playing with this today. Sorry, but my laptop is dead. No REW.

First I added a jumper for no HP. This did not work with my setup. It stayed on for about 5 seconds. Moving on...

Next, I added two .22uF PolyFilm Caps each to c7 & c8. It should be at ~.47uF per now.
Before _____After
40Hz=80dB__80dB
35Hz=77dB__79dB
30Hz=75dB__77dB
25Hz=75dB__79dB
20Hz=76dB__81dB (Large room node at 22Hz)
15Hz=73dB__80dB
13Hz=68dB__76dB
10Hz=60dB__71dB

This is in-room, with a digital RS Meter (no corrections.). Two large Sono's tuned to ~13.5Hz. ( I can't remember the exact tuning, and my build thread is gone now for some reason.

) All EQ was removed for this test. I started at 80Hz, but it was exactly the same from 40Hz on.

With the two .22uF caps, I have the option of clipping one off each position to raise the HP some if I feel the need later.

Soho,
I know nothing about schematics and etc. - hence I was hoping you could detail your mod for me if you don't mind. More than anything, if you could tell me where/what parts were used and a few pictures - that would be awesome. I too (unfortunately) am using an ArtCleanbox. Thanks a million for sharing.

**soho54** · **07-02-07, 09:50 AM**

Efalegalo, it is a pretty standard component swap. There are only two parts to change. The two green Poly/Film Caps at c7 & c8. If you look at the OP's pics, it is the two green caps directly behind the trim/volume pots.

If you have never done anything like this find something broken, remove all the parts and put them back in. You should get the hang of it pretty quickly.

Now just go to RS, and ask for two .47uF Poly/Film Caps, or if they are out four .22uF Poly/Film Caps.

De-solder the old caps out, and slap the new ones in. Clip the leads down to size and you are done.

A pic would only show you two slightly larger green caps in the old ones places.

If you have never done anything like this before, I can't see an electronics shop charging you more than $10 for labor, or so. I's only a 5min job. Good luck.

**Efalegalo** · **07-02-07, 10:09 AM**

Quote:

soho54 wrote:

Efalegalo, it is a pretty standard component swap. There are only two parts to change. The two green Poly/Film Caps at c7 & c8. If you look at the OP's pics, it is the two green caps directly behind the trim/volume pots.

If you have never done anything like this find something broken, remove all the parts and put them back in. You should get the hang of it pretty quickly.

Now just go to RS, and ask for two .47uF Poly/Film Caps, or if they are out four .22uF Poly/Film Caps.

De-solder the old caps out, and slap the new ones in. Clip the leads down to size and you are done.

A pic would only show you two slightly larger green caps in the old ones places.

If you have never done anything like this before, I can't see an electronics shop charging you more than $10 for labor, or so. I's only a 5min job. Good luck.

You guys are the best! - I will do this today and let you know how it worked out. Thanks once again.

**brucek** · **07-02-07, 11:38 AM**

Quote:

I will do this today and let you know how it worked out

Maybe you can be the first one to actually test this modification with REW to prove its effectiveness, and post the REW graph of before and after........ no one else seems willing....

brucek

**Efalegalo** · **07-02-07, 11:52 AM**

Sure, I will gladly put up the mesurements I take. However, i must ad that I am very new to all this and the only measurements I know how to take is manually with the Radio Shack SPL meter and Soho's audio calibration test dvd.

I took measurements. I will also take measurements after the mod. I wanted to know if you guys can tell me which of the following would be the best for the modification:

Two of these:

http://www.radioshack.com/product/in...entPage=search

Two of these:

http://www.radioshack.com/product/in...entPage=search

Or four of these:

http://www.radioshack.com/product/in...entPage=search

My question is what differece is the following going to have:
- 250VDC or 50VDC
-which one would be best "PC Mount" - "Metal-Film" - or "Axial-Lead Non-Polarized"

Thanks once again.

**JimPeitersen** · **07-02-07, 12:03 PM**

Wayne,
That seems like a good idea, but how do we know that the freq. response of those cheap mixers is even close to the specs? I think that everyone believed that the Cleanbox would have a fairly wide response and not cut-off the low frequencies.

JP

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