What do you guys think of a B22 as headphone duty and preamp duty? How do you think feel about a B22 as a preamp? Is it a bad idea?

If you want a headphone amp and preamp I'd build an M3, not a beta22. That's currently part of my plan.

Any reason why?

because the B22 isn't as well suited to being a preamp as the M3?

What he said. Unless you insist on discrete components or need the power of the beta the m3 is the better preamp from a #'s perspective. Look at amb's own measurements if you need more convincing.

Where are the measurements? I browsed both projects and the only measurements I found were in specifications, and I don't understand them.

The specs are where you'd want to look. The M3 consistently performs better in Noise, Dynamic Range, Harmonic Distortion, IMD and Crosstalk. Don't get me wrong, the Beta22 is an excellent performer and a fine preamp but it is both expensive and complicated to build and to me seems like a bit of a waste as a preamp. I mean do you really need a 15W/ch preamp? That doesn't sound like a preamp to me? Also, it's much simpler to implement a gain switch on the M3 which makes it more flexible in switching between preamp and headphone amp duty.

My current plan is to build a balanced, 4-channel M3. We'll see how far I get with that but right now it doesn't look like I'll get to start it before summer time.

The specs are where you'd want to look. The M3 consistently performs better in Noise, Dynamic Range, Harmonic Distortion, IMD and Crosstalk. Don't get me wrong, the Beta22 is an excellent performer and a fine preamp but it is both expensive and complicated to build and to me seems like a bit of a waste as a preamp. I mean do you really need a 15W/ch preamp? That doesn't sound like a preamp to me? Also, it's much simpler to implement a gain switch on the M3 which makes it more flexible in switching between preamp and headphone amp duty.

My current plan is to build a balanced, 4-channel M3. We'll see how far I get with that but right now it doesn't look like I'll get to start it before summer time.

Nate, the B22 is also overkill in terms of power for headphones,

the M3 would be more than enough for most headphones.

The M3, does indeed have better measurements than the B22, but then why do people consider the B22 a better amplifier (at least for headphones) than the M3?

I mean, don't the B22 design principles and advantages for headphone amplification apply to pre-amplification?

Not trying to be an ass, just didn't understand your POV.

I mean, don't the B22 design principles and advantages for headphone amplification apply to pre-amplification?

Not trying to be an ass, just didn't understand your POV.

Isn't the B22 really a small power amplifier? It stands to reason that it would have more noise, etc. than a small signal amplifier... which might not matter at all when driving a headphone load, but would make the B22 less optimal as a preamp.

But how much better is the M3 than a B22? Are the differences negligable? Are the differences in numbers just on paper that doesn't translate to real world application?

Nate, the B22 is also overkill in terms of power for headphones,

the M3 would be more than enough for most headphones.

The M3, does indeed have better measurements than the B22, but then why do people consider the B22 a better amplifier (at least for headphones) than the M3?

Generally speaking I'd say I've found the beta to be the better sounding headphone amp compared to the M

Isn't the B22 really a small power amplifier? It stands to reason that it would have more noise, etc. than a small signal amplifier... which might not matter at all when driving a headphone load, but would make the B22 less optimal as a preamp.

Oh no it isn't small in any way. This is an interesting thread, particularly MASanto' question.

If you can socket the parts that control gain, can't you put a switch there to toggle between a gain of lets say, 2 and 5 (I think 5 is the common number people use)?

I think you should get a Beta22 and trade it for my m^3

If you can socket the parts that control gain, can't you put a switch there to toggle between a gain of lets say, 2 and 5 (I think 5 is the common number people use)?

On the beta22 there are at least 6 parts (4 caps, two resistors) per channel that would need to be switched. If you want to figure out a way to do that efficiently in a 4-ch balanced amp go for it, I'm all set.

And I freely admit that there are other ways to provide a pseudo gain switch on the beta22 but that's only one of the things I listed that makes it a less than optimal preamp.

If you want a fully discrete design the next best choice is probably the dynalo.

Well, that utterly buggers my upgrade plan!

Well, that utterly buggers my upgrade plan!

Indeed!

IMHO, if you're looking for a preamp, starting from the list of available headphone amps and deciding which would make a good preamp is sorta putting the cart before the horse. Assuming you're looking for dual duty, I'd still start with a list of preamp designs.

In my case, I was looking for a preamp with gobs of voltage swing, and even in this case, the beta22 would be a poor choice. So, everything in this thread really depends on your specific application.

Not to muddy the waters, but here are some counterpoints...

Both M

What do you guys think would serve as the better pre/headphone amp combo?

B22 of Dynafet? =T

Outside Kevin I don't think anyone has heard a Dynafet so there's no answer to your question.

I figured there'd be some theoretical talk since you guys mentioned a M3 being begger based off measurements.

Not to muddy the waters, but here are some counterpoints...

Hi amb,

I want to thank you for that extremely useful and informative post. It clears up a lot of the Beta22 questions I had.

USG

Outside Kevin I don't think anyone has heard a Dynafet so there's no answer to your question.

Inside Kevin, it's too dark to read...HAH!

Come to think of it...several manufactures stretch their product line and maintain a dual purpose component by taking the statement headphone amp combining with preamp features.

But the magic and convenience, for me, blurs the line. Headphone amps are next to my favorite chair and pre-amps are on the other side of the room snuggled in a rack being the heart of a two channel speaker rig.

IMHO, if you're looking for a preamp, starting from the list of available headphone amps and deciding which would make a good preamp is sorta putting the cart before the horse. Assuming you're looking for dual duty, I'd still start with a list of preamp designs.

Please elaborate. I started a thread about this on HF, and the only definitive information that I got was that Tom Hankins thinks Singlepower makes the best preamp he's ever heard. I'm not sure exactly how much his amp cost (money, time, frustration), but that's another story.