Headphone amp for the DL 1608

[WK154]

Great find  Have you tried it yet with the DL aux's? Any noise?
Found Hosa GPM179 similar part.

[Jerrylee]

There is no noise. That's the part I have been using for years. I had it long before the dl1608. It does work like a charm to use the aux outs and headphones.

I originally bought it to combine a music players signal to a mono source. A setup I had only had one in. Since then I have used it for many different things.

[Harpman]

As JL said, no noise at all. Working on setting up a limiter preset to use 10:1, fast attack, etc. Bill, you put some recommendations on a thread somewhere on what you would use.

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[Harpman]

Hosa GPM 179 are much cheaper.

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[WK154]

As JL said, no noise at all. Working on setting up a limiter preset to use 10:1, fast attack, etc. Bill, you put some recommendations on a thread somewhere on what you would use.

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Since the whole purpose of the limiter is protection for your ears a sharp knee fastest attack time and highest ratio is my choice and you don't want it dropping out so the longest decay time you can get. This all is removed when the signal drops below the threshold anyway. The important setting in this of course is the threshold and that would depend on your aux output levels and your ear-buds or headphones and your ear. I have a Pink Stick signal generator that runs off phantom power and has a pulse setting. This is what I would use and set the channel for clipping. This would be the typical situation to protect against. Set the limiter (aux output compressor) for what you want to tolerate in your ear. Remember that it should only be activated for protection and will be out of the way for normal use.
For the use of the aux outs to headphones you will no doubt need an extension cable. A normal stereo 3.5mm will eventually pick up noise and is also quite fragile. Here would be my choice for that extension cable. A TS connector at the DL aux with mic cable. The shield and the signal return connected to the shield. At the other end the shield unconnected the return to the shield of the 3.5mm female connector and the signal to the tip and ring (dual mono) of the 3.5mm connector. I would also attach a ferrite for RF protection near the 3,5mm connector. No adapter required since the cable as described would perform that conversion. The explanation for this is in Bill Whitlock's 2005 paper on Noise etc in audio section 3.6. As far as I know you can't buy this cable so warm up that soldering iron or let someone else do it for you. Belden #8760 is a excellent choice for a low impedance shield cable for most audio cabling.
Part # correction

[Harpman]

As JL said, no noise at all. Working on setting up a limiter preset to use 10:1, fast attack, etc. Bill, you put some recommendations on a thread somewhere on what you would use.

Sent from my SM-N900V using Tapatalk

Since the whole purpose of the limiter is protection for your ears a sharp knee fastest attack time and highest ratio is my choice and you don't want it dropping out so the longest decay time you can get. This all is removed when the signal drops below the threshold anyway. The important setting in this of course is the threshold and that would depend on your aux output levels and your ear-buds or headphones and your ear. I have a Pink Stick signal generator that runs off phantom power and has a pulse setting. This is what I would use and set the channel for clipping. This would be the typical situation to protect against. Set the limiter (aux output compressor) for what you want to tolerate in your ear. Remember that it should only be activated for protection and will be out of the way for normal use.

For the use of the aux outs to headphones you will no doubt need an extension cable. A normal stereo 3.5mm will eventually pick up noise and is also quite fragile. Here would be my choice for that extension cable. A TS connector at the DL aux with mic cable. The shield and the signal return connected to the shield. At the other end the shield unconnected the return to the shield of the 3.5mm female connector and the signal to the tip and ring (dual mono) of the 3.5mm connector. I would also attach a ferrite for RF protection near the 3,5mm connector. No adapter required since the cable as described would perform that conversion. The explanation for this is in Bill Whitlock's 2005 paper on Noise etc in audio section 3.6. As far as I know you can't buy this cable so warm up that soldering iron or let someone else do it for you. Belden #8241F is a excellent choice for a low impedance shield cable for most audio cabling.

I plan on putting the adapter at the musician end with a Female-to-Female 1/4" adapter and running 1/4" cable to the AUX.

[WK154]

I plan on putting the adapter at the musician end with a Female-to-Female 1/4" adapter and running 1/4" cable to the AUX.
It will make a difference whether you use a TRS or a TS 1/4" cable. TRS would merely extend the DL's aux output and would be my choice. TS would be an unbalanced cable extension just more rugged than the 3.5mm cable. More susceptible to noise. I like to keep the number of connections to a minimum. Bad habit from my IT days. 

[Harpman]

Going to use a TRS. Wanted to out the adapter at the musicians end in the event they want to disconnect at break. What would be ideal would be a 1/4" male to 1/4" female TRS cable the the adapter would plug into on the female end.

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[WK154]

Going to use a TRS. Wanted to out the adapter at the musicians end in the event they want to disconnect at break. What would be ideal would be a 1/4" male to 1/4" female TRS cable the the adapter would plug into on the female end.

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You mean like this:
http://www.cablewholesale.com/products/audio-video-products/audio-video-cables/product-10a1-62225.php
 
The after Christmas sale I was talking about. 

[Harpman]

That would be it

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[WK154]

Gio: Aux out's definitely cheap but after digging deeper may not be so good.  Turns out that the output impedance of the DL is way up there at 250/120 ohms and hooking 50-75ohm cans or worst 16 ohm or less for some in-ears into aux's may be a bad idea. Yes you'll get sound but distortion may kill it. Definitely don't adjust any eq's etc. using them. Singers may eq themselves into bad sound definitely not good. Here is an article that explains why.

http://nwavguy.blogspot.com/2011/02/headphone-amp-impedance.html
And this for earphones
http://nwavguy.blogspot.com/2011/02/headphone-impedance-explained.html

The Behringer P1 is specked at 10 ohms not so great but way better than aux's. I need to find one. Will check my 4700 and the Mackie headphone out for impedance values.

[Harpman]

I'll check it out. First IT day back and slammed

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[WK154]

Some test results from my headphone quest. Using the aux's with just the 25 ft. cable and the Rippoff Shacks adapter (none of the Best Buy carried stock apparently their hosing Hosa) GC was no better. There is a low but maybe tolerable hum with reasonable settings (Not maxed) and this is using the Mackie supply. I used a Apex HP90 50 ohm set of cans. The audio sounded subdued compared to my monitor Beritone CA50 at similar levels. Possibly from low level hum and possibly other reasons. I also set up my HA4700 and connected aux to HA main in (balanced). The sound was clearly improved much crisper about like the monitor. Next will be the better power supply to see if it matters. PS the adapter cause intermittent disconnects so much for RS junk. More to come including the impedance measurement on DL phone plug.

[Sting]

Some test results from my headphone quest. Using the aux's with just the 25 ft. cable and the Rippoff Shacks adapter (none of the Best Buy carried stock apparently their hosing Hosa) GC was no better. There is a low but maybe tolerable hum with reasonable settings (Not maxed) and this is using the Mackie supply. I used a Aphex HP90 50 ohm set of cans. The audio sounded subdued compared to my monitor Beritone CA50 at similar levels. Possibly from low level hum and possibly other reasons. I also set up my HA4700 and connected aux to HA main in (balanced). The sound was clearly improved much crisper about like the monitor. Next will be the better power supply to see if it matters. PS the adapter cause intermittent disconnects so much for RS junk. More to come including the impedance measurement on DL phone plug.

I had trouble with 2 Rat Shack adapters...sound coming from one side only.   We used the Hosa plugs at practice,worked fine.  We ran silent with guitars using just preamps and e drums and headphones direct from aux sends.  Noise was very minimal although I was mixing from the main headphone jack but no one complained.   Made my first recordings with the DL1608 and excellent quality.  One guy commented that it sounds better than the studio stuff we've done.  I don't know about that but very nice!

[Jerrylee]

Which radio shack adapters are you referring too? If you are not using the mono to L/R adapter then you will only get sound from one side. That's why you need the correct adapter. Me thinks you didn't have it.