My Altec system Tweaking Including DCX, DEQ and Other Stuff.

[mah]

History:

http://www.hostboard.com/forums/f700...cold-feet.html

http://www.hostboard.com/forums/f700...-assembly.html

http://www.hostboard.com/forums/f700...deadening.html

http://www.hostboard.com/forums/f700...b-damping.html

http://www.hostboard.com/forums/f700...fastening.html

Present: http://www.hostboard.com/forums/f700...altecs-go.html




New stuff:

Simple PC signal generator and level meter Test Generator

Dry joint(s) in pre-main amp(CDs) causing erratic operation. I will substitute a little NAD amp, putting the DEQ and DCX in the tape-loop.

DEQ info. Note the article is written for radio guys but there is some good general info there. NU9N - Behringer DEQ-2496 Initial Setup for SSB eSSB Hi-fi Audio

[cradeldorf]

So...is it getting better? are you closer to that perfect sound?

[mah]

Cradeldorf, the perfect sound is the Holy Grail of others. Just plain Damn Excellent will suffice. Currently being obstructed by old SS amp ailments. Fixable but takes time. However I can 'taste' the potential but will let it all happen as it happens. I am happy to have got this far. Stay tuned.

[Panomaniac]

You can do a hell of a lot with the DCX and DEQ inline. I dropped the DCX for a passive crossover that I designed, but I could not have found the way without the DCX.
Still use the DEQ to do somw room and box correction. It works great. So great, in fact, that it's my DAC. I've modified it for to a transformer output stage.

[mah]

I had a lack of bass. I made some l-pads to attenuate the CDs and re-adjusted the Lo/Hi levels and the bass magically appeared. WOW!

Next job is to eliminate hum and buzz - most likely caused by balanced-unbalanced interconnect grounding. Less likely by house wiring.

[mah]

Hum and buzz is eliminated.

After making interconnects, as shown in various Rane, Jensen and Sony publications, with no success I found this wonderful document: Grounding and Shielding Audio Devices. MAGIC.

Step 1. Read Note 151(link) thoroughly and read again.

Check each piece of equipment to see if it is Mains Grounded or Signal Grounded.

If the power cord doesn't have an Earth Pin it will be Signal Grounded.

If the power cord HAS an Earth Pin it could be either Mains Grounded or Signal Grounded.

- Connect an Ohmmeter to the power cord Earth pin and to an RCA socket shield/XLR pin 3 on the Unbalanced/Balanced terminal of interest.
- A short-circuit indicates Earth Grounding
- An open-circuit indicates Signal Grounding

The appropriate interconnect wiring configuration can then be selected from Figure 5 in Rane Note 151.

I hope this method can save others from the problems that I encountered along the way.

Cheers, Marshall.

[Alien_Shore]

I almost heard the gnashing of teeth from here...

[cradeldorf]

Glad to hear you conquered the problem buddy. : )

[mah]

Yeah, the teeth got a good workout - a very frustrating part of the project. I still think the simpler arrangement of a single amp with passive crossover has a lot going for it.