NKOTB - TTVJ/Millett 307A Headphone Amp

[recstar24]

Not sure what the current Balancing Act sounds like, but the TTVJ/Millett 307A blows away the earlier versions I have heard. I haven't had a chance to look at the impressions from that meet but I expect it was good times.

Damn, not what I wanted to hear, as the BA is somewhat "reasonable" and within grasp, that Millet is near unobtanium.

I am actually looking for a balanced preamp. I've got this truly balanced dual differential source in the meridian 508.24 with its pretty balanced outs, might as well put it to good use. Specifically, balanced in, then balanced out to the moth which is single ended. The moth is integrated, with a passive volume control, but I could use a bit more gain to really rock the room. The volume pot when maxxed is basically invisible to the signal. I am thinking the older pass aleph preamp possibly.

[luvdunhill]

Damn, not what I wanted to hear, as the BA is somewhat "reasonable" and within grasp, that Millet is near unobtanium.

I am actually looking for a balanced preamp. I've got this truly balanced dual differential source in the meridian 508.24 with its pretty balanced outs, might as well put it to good use. Specifically, balanced in, then balanced out to the moth which is single ended. The moth is integrated, with a passive volume control, but I could use a bit more gain to really rock the room. The volume pot when maxxed is basically invisible to the signal. I am thinking the older pass aleph preamp possibly.

Are you not worried about balanced to single-ended conversion issues, such as phase problems?

[grawk]

My understanding is both the BA and the TTVJ 307a aren't differential amps, they just use transformers at input and output. So you won't necessarily see the benefits you're looking for from either of them.

[Dreadhead]

Sounding good and actually taking full advantage of the balanced input are separate things.

[Torpedo]

it's my understanding that trafo coupled amps like that can be as good as "true" balanced amps because they avoid inevitable matching issues.

Kind of agree. It's all up to the trannies quality, which in most cases aren't good enough.

[grawk]

I'm not saying it's not as good, I'm saying he might lose the voltage swing increase he's looking for.

The TTVJ 307/a and the balanced output amp craig brought to canjam (not sure which it was) were both spectacular amps.

[n_maher]

I've been toying with the idea of putting an input trafo on the Menace for exactly the reason Jacob bring up, also they help eliminate the potential for ground loops from your source.

And Ryan, I don't see how using one half the balanced output of the Meridian is a bad thing. Sure, it'd be great to have a balalnced amp too but holy hell they get expensive for the good stuff don't they?

[909]

Here's an excerpt from an email a knowledgeable friend sent me a while back...

"In the balanced line world one of the biggest issues is ground loops between equipment. Electronically balanced equipment like X are two identical amplifiers running opposite polarity. They are true balanced amplifiers with all the benefits of common mode reduction but they share the same ground so there is no benefit breaking ground over a single ended, or unbalanced piece of equipment. All the Pro audio gear from the Beatles early recordings and until solid-state were transformer balanced. The best Pro audio gear today is still transformer balanced even though the amplifier may be solid-state."

[Voltron]

I'm not saying it's not as good, I'm saying he might lose the voltage swing increase he's looking for.

The TTVJ 307/a and the balanced output amp craig brought to canjam (not sure which it was) were both spectacular amps.

Craig literally shit-canned the Balancing Act he brought to CanJam, seemingly because the TTVJ 307A knocked the snot out of it. Craig took his amp over to Todd's room early Sunday, and he was crestfallen by the comparison. I think he told Todd as much. The fact that Craig then decided to design a 307A version of his amp kinda confirms it.

[Dreadhead]

sure, but if you have the first, what does the second particularly matter?

I would have to say no. The only reason I use my system fully balanced is for the headroom insurance it provides. To be honest with the SA5000s I think they sound the same SE as long as the amp has enough juice.

[recstar24]

Are you not worried about balanced to single-ended conversion issues, such as phase problems?

As far as I know, the properly designed stuff like the pass preamps would not have such phase issues, or that they would be of such insignificance to not be heard.

Another easier/cheaper solution would be to just use balanced to single ended xlr-rca adaptors. I do not want to muddy this thread, so if anyone has any comments regarding this, please post in the thread I will start in the appropriate section.

EDIT: http://www.head-case.org/forums/audio-accessories/4835-xlr-rca-balanced-single-ended-adaptors-help-needed.html#post174827

I'm with David on the transformer input and output for balanced as well. Seems the transformer at least for the balanced input is a better idea for balanced as it isolates the ground. Jacob, you make a great point as well, using a transformer to balance the input is much easier and probably gives a similar level of performance if not better than trying to electrically balance and match both sections.

[recstar24]

I've been toying with the idea of putting an input trafo on the Menace for exactly the reason Jacob bring up, also they help eliminate the potential for ground loops from your source.

And Ryan, I don't see how using one half the balanced output of the Meridian is a bad thing. Sure, it'd be great to have a balalnced amp too but holy hell they get expensive for the good stuff don't they?

Nate,

http://www.head-case.org/forums/audio-accessories/4835-xlr-rca-balanced-single-ended-adaptors-help-needed.html#post174827

Is this what you are referring to? Feel free to chime in and others as well, appreciate it.

[grawk]

I picked up a few THAT 1200 ICs that are good for summing balanced signals to single ended. I didn't end up doing what I'd planned with them, but I'd be glad to send them along if you can find someone to build the appropriate box for you

[recstar24]

I picked up a few THAT 1200 ICs that are good for summing balanced signals to single ended. I didn't end up doing what I'd planned with them, but I'd be glad to send them along if you can find someone to build the appropriate box for you

Just checked them - sounds like a great idea. Unfortunately, I have no idea who could build the box for me:palm: It sounds easy enough, it's just an IC that takes in the balanced input and sums it to single ended output, I mean that is what opamps are supposed to do. All it would need is the feedback resistor and a DC source to make it work, with the necessary xlr input and rca output. If you have any more details I am missing, feel free to shoot them over. If anyone wants to take pity on my, and build me a simple opamp, resistor, and DC source in a small hammond box with an xlr input and rca output, I sure would appreciate it:)

[Dreadhead]

In general you will not want to take the XLR outputs and sum them for the RCA unless you attenuate the signal as well since the balanced output on most gear is operating at more than 2x the voltage of the single ended stuff.

I have never heard the argument that trafo coupled should be better than properly designed balanced gear and I'd need a lot more convincing.

Edit:

Wikipedia to the rescue:

[ame=http://en.wikipedia.org/wiki/Balanced_audio]Balanced audio - Wikipedia, the free encyclopedia[/ame]

"Fully balanced internal circuitry has been promoted as yielding 3dB better dynamic range."

From that it appears that fully balanced amps do not need transformer coupling on the inputs to avoid ground loop issues.

[recstar24]

http://www.thatcorp.com/datashts/1200data.pdf

page 8 - pretty simple enough. bypass caps for the + and - power supply rails. a cap between Cm in to Cm out, pin 5 to 8. Who wants to be a pal:)?

[recstar24]

In general you will not want to take the XLR outputs and sum them for the RCA unless you attenuate the signal as well since the balanced output on most gear is operating at more than 2x the voltage of the single ended stuff.

That is the point - I need the extra voltage. That should be plenty for my integrated and my listening needs.

[grawk]

I don't have many details at all, but your description matches my understanding. input 12v dc, +, -, and output a summed signal.

[n_maher]

If anyone wants to take pity on my, and build me a simple opamp, resistor, and DC source in a small hammond box with an xlr input and rca output, I sure would appreciate it:)

See your other thread, I don't think you want to go introducing another stage to the output of you source.

[n_maher]

I happened to look at Todd's site this morning (which is new?!?) and the 307A is no longer listed.

[Dreadhead]

Well that's a loss

[grawk]

An opening in the market for nugget audio

[n_maher]

I don't expect it's a permanent hole in Todd's lineup but I don't have any idea what (if any) replacement would look like.

And nothing Nugget Audio would or could ever produce would replace the TTVJ 307A.

[morphsci]

^^^ I think you will want to come to CanJam, hehehe

[aardvark baguette]

I think it was 4n6 that mentioned on HF that there was something new coming, but I dont know if he meant specifically from TTVJ or not.