[andy2667]

I am going to buy a pair of ASL wave AV-8 to drive my pair of newly purchased Diatone P610 MB full range speaker. I intend to use my MG-head as a preamp so that I can transform my headphone system to a headphone/stereo speaker system. I intend to use the small headphone jack as the pre-amp out. Here are my questions:

1. The headphone jack has three terminals while a line out stereo system requires 4 terminals. Is one of the headphone jack terminals a common groung for both the left channel & right channel?

2. Starting from the tip of the head phone plug, which one is the left channel - hot connection, which one is the right channel hot connection & which one is the common ground for both left & right channels? I need to identify them for making a headphoe jack/line out transformation interconnect.

3. I have seen some where in this forum saying that the MG-head volume control will form hair trigger effedt when used as a preamp. Can I improve this by addition of a resister to the line level interconnect?

4. I may try Mr Lau's Mod on trasforming the MG-head to an OTL amp after expirary of my MG-head warranty in December. Can I still use the transformed OTL MG-Head as a pre-amp?

Thank you for your advise

 

[rickcr42]

Quote:

1. The headphone jack has three terminals while a line out stereo system requires 4 terminals. Is one of the headphone jack terminals a common groung for both the left channel & right channel

Yes,you will need to whip up some interconnects.Two ways to do this
1) stereo microphone cable with 1/4 inch phone plugs at each end and then a 1/4 inch phone to dual RCA adapter,or
2) DIY cable.An easy one would be to use either 20 guage magnet wire and twist two pairs together or the same but with cat 5.At one end attach the phone plug and tie the grounds together,at the other end the two RCA jacks

TIP=L
RING=R
BARREL=ground

The hair trigger issue may be resolved by possibly checking here
http://www.users.qwest.net/~pspwr/12...ure_Shunt.html a little product specific but gobs of good info,you should be abl to apply it to your situation

good luck

 

[Videoshielded]

I have the same equipment around the house and, at times, use the MG Head as the preamp for the AV-8's.

I'd suggest going to Rat Shack or similar store and getting an adapter. They have a sterei mini plug on one end and a pair of RCA females on the other. So, you can plug your existing RCA cables into the adaper, and then just plug that into the output jack of the MG Head.

This arrangement doubtlessly leaves a little fidelity on the table, but (unless your AV-8's are modified), this is good enough for your system. If you manage to solder a pair of decent-quality insulated, shielded cables onto a mini-plug yourself, call Markertek -- they need you to work for them as a pro cable assembler for big $$$$.

The volume is a little hair-trigger, but I seriously doubt you'll have any problems with it. I'd say give it a try before you decide to pad with a resistor.

Typically, padding preamp output robs the sound of dynamics, so I'd pad the input from the CD player instead. The resistor just goes in series with the center conductor of each RCA cable. The proper resistor size will be trial and error. You might try starting with a dual-gang log pot (like the $3 100K dual audio taper Rat Shack sells in its stores) to get it right, then measure the resistance at the desired setting, and buy high-quaility bulk foils or Rikken Ohm resistors of that size for permanent installation.

I don't know how a converted MG HEAD/OTL will sound as a preamp, but it will at least work as a preamp. My dedicated preamp is an OTL circuit.

 

[andy2667]

Hi rickcr42,Videoshielded,

Thank you for your respond. I am preparing my diatone cabinet & will proceed the MG-Head/AV 8 scheme.

Videoshielded, are your AV8 sound good compared with other inexpensive decant tube amp?

 

[Videoshielded]

Andy, sorry to be a slow response.

So far, the AV-8's haven't changed my life instantly, like my first pair of Senns or my first pair of Magnepans.

But, let me finish my new speakers, and modify the amps. Then, we'll see what we've got.