[JoshK]

Hello Dr. Lloyd,

I noticed that there hasn't been much activity in here yet.  I suppose not many people are aware of your products yet, but then again there hasn't been a whole lot of activity in any of the manufacturers forums lately.

I had a few questions.  First, could you explain a little about headphone amps.  Maybe you don't want to give us all your secrets which is understandable but what would it take let's say to add a headphone output to the Line 2m?  Basically, I see you have an Ear+ product, which also seems to be a line preamp as well, and I am just trying to get a handle on what the headphone amp needs specifically except the obvious female headphone plug.  

Second, I am wondering for those who have ordered the Line 2m's prior to the newer version that comes with dual outputs, what it would take to add another set of RCA outs to our products?   Can the ALPs volume control be ordered for our Line 2m also?  And what would be the cost for the ALPs?  

I am not afraid of getting out my iron and getting my hands dirty, just wanted to know if these "upgrades" were supported.

TIA,
Josh

[Dr. Lloyd]

Good idea Josh. I have written up a description of my approach to designing the Ear+. It is a bit technical but should make sense to most of the group. You can view the pdf file in the usual way.

Design of the Ear+ Headphone Amplifier

Lloyd

[Dr. Lloyd]

The main changes to the MAD products for 2003 are the inclusion of parallel outputs on the Line 2m and Ultra 4m preamps, and the option of Alps volume controls on the Line 2m. Ultra 4m, Ear+, and Octal 6. The Alps pots are $35 extra at time of ordering. If you want to upgrade, you can obtain an Alps 100K Blue Velvet pots from Angela Instruments and save on shipping instead of buying from me. I am exploring an Asian source of these pots so may be able to offer them at lower cost in the future. The Blue Velvet controls should fit perfectly in place of the standard Alpha units and are wired the same.

Adding a parallel set of outputs to the Ear+ is easy. Just mount two RCA jacks above or below the current line outputs and wire in parallel. With the m series componenets, the jacks are all isolated from the chassis to aviod ground loops so adding additional jacks is not an easy retrofit. Of course, for the expert DIYs, it can certainly be done. You could even purchase a pair of jacks with built-in isolation washers.

Lloyd