Balanced Millet Hybrid

[USER NAME:]

With all the new Millet Hybrid PCB's floating around, has anybody considered a balanced version? Better yet, has anybody done this? I sure know that I've been thinking about it. Please let me know what you guys think.

 

[drewd]

There's no question that you can do it. In fact, please do! I'll bet that there are a lot of people who would be very interested in learning about how it sounds.

The only negative that I can think of is that you'd be effectively turning a SET (sort of) amp into a push-pull amp, but I'm not sure if that would be a terrible thing or not. It may be more of a religious battle than a practical one

-Drew

 

[USER NAME:]

I WILL DO IT!
It may take a week or more, but it will happen. The wheels are turning in my cranium. I just need to figure out which power supplies I'm going to use.

 

[n_maher]

If it were me I'd go for 2 TREADS for the power supply.

1. They're cheap.

2. They're adjustable so you can fine tune the voltage so both channels have exactly the same value.

3. I think amps that require two plugs are evil

My 0.02.

Nate

 

[rickcr42]

Quote:

The only negative that I can think of is that you'd be effectively turning a SET (sort of) amp into a push-pull amp, but I'm not sure if that would be a terrible thing or not. It may be more of a religious battle than a practical one

Not really.

Just add a phase splitter to the front end and take the headphone leads from the now "two" hots instead of hot and ground and the original.
This topology is called SEPP (single ended push pull) and you lose nothing to SE but do gain noise cancelling at the input.

 

[USER NAME:]

Quote:

Originally Posted by n_maher 3. I think amps that require two plugs are evil Nate

Agreed!

I think I'll try a variant of this Jan Meier supply that I worked up.

Quote:

Originally Posted by rickcr42 This topology is called SEPP (single ended push pull) and you lose nothing to SE but do gain noise cancelling at the input.

This is the goal, so let's see what happens.

 

[USER NAME:]

Rick,

Let me just toss this out there. Rather than a fully balanced version. Lets say somebody utilized three channels from two seperate boards and created sort of differential drive Millet style amplifier (a three channel amp) what would this be called? SED? Single Ended Differential? I'm just throwing some ideas out there. The possiblities never end.

 

[rickcr42]

In my opinion this would much things up by taking a simple topology and making it complex which usually means headaches.

since we are talking straight balanced output to the headphones while retaining the basic circuit even the power supply if beefy enough need not be changed but just used normally to drive two stereo amps instead of just the one.The question then becomes how to get the input of this stereo pair now used as a single balaned channel and there is where you have choices and can decide how far to go with this.

1-the expensive but best soltion would be to use an SE-To-Balanced lne transformer.These babies would set you back at least $50 per channel but offer the ability to use the input either full balanced or single ended while producing a "true" split +/- output to drive the single amp in a balanced mode.
You would want the 15K/15K jensen line transformer if utmost quality is of importor one of the Edcors for a low cost solution (around eight bucks or so).


2-one of the various TI/BB/ADI balanced audio line driver chips.A self contained monolithic solution costing way less than option #1

3-A discrete jfet differential amp.This could be as simple as two N-Channel JFETs (or one N-CH Dual) or as compicated as a full cascoded ccsed differential jfet amp.The borbely Audio xPress JFET articles can be a guide there (pdf download at borbely audio)

I like things simple unless there is a true gain to be had from comlicating things and would personally choose #1 option or #3 option for most such work but in this case I think the monolithic solution is not only fine but maybe the best solution all else considered.

Check the DRV134 chip sheet at TI and have fun,what this is all about right ?

 

[Jaypetermen]

Would the balanced Millet-Hybrid require a new PCB board design or is the idea to add/modify the new Millet -Hybrid boards for the resent group buy.

I would be interested in a balance Millet-Hybrid since I am currently planning on using an extra Millet-Hybrid board, for the resent group buy, as a pre-amp to a Tripath Amp1. This amp would primarily use for driving speakers.

I think that a true balanced Millet-Hybrid would be preferred for this application?

 

[n_maher]

Quote:

Originally Posted by Jaypetermen Would the balanced Millet-Hybrid require a new PCB board design or is the idea to add/modify the new Millet -Hybrid boards for the resent group buy.

A. Currently Head-Fi does not permit group buys.

B. I have no intention of further modifying the Millett design, as I've said in the past this one was done as a way to give back. My wallet won't let me give any more

.

C. You could build a true balanced amp with the use of two boards.

D. If you didn't get enough boards to do this through the GB there are "other sources" for the boards, I leave it to you to find them.

N

 

[Jaypetermen]

n_maher,

Sorry for the confusion. I already have a sufficient quanity of Millet-Hybrid boards and I thank you for that

.

Let me try to rephrase my quesiton. Is the intent to add on the "group buy" Millet-Hybrid board to make it balanced or make a completely new board?