Project Polaris

When you have relocated C11 to the bottom of the PCB (parallel to C12) the high BW setting will have a roll-off point of 350kHz (-3dB)
The mid/low BW setting will have a roll-off point of around 25kHz (-3dB) but already starts sloping downwards from about 10kHz.
This is audible and about similar to 'my' low setting and Jeremy's 'mid' setting.

When you find the mid/low setting too rolled off already you can try using only C12 (so C11 not in parallel) or soldering a 47pF cap in parallel to C12 (so not using C11)
This way the roll-off is at 35kHz (-3dB) and very mild at 20kHz (as in my 'mid' setting)
You do not have to remove C12 as C11 and C12 have the same value (220pF)

The Beyer Dt770 and DT990 both make a mouth watering match with the Polaris. They both have a 'u' shape curve so the Polaris really takes off with them both. What a great combo to have - a matching closed and semi-open headphone that really light up on this amp.

Why not Ember? I think the main reason is because of the amounts of bass perceived. The Polaris definitely seems cleaner sounding than the Ember and just not as 'valve' like probably because it's relatively more even handed. These two headphones make the Polaris really spark to life. So far, I've been using the K612 with 702 pads. That combo is in itself very smooth and bassy, but the brightness of the Beyers opens the window.

The thinking behind these amps really addresses something that I've always found to be a problem. The idea that an amp is reviewed without any consideration as to what headphone they are going to drive. I have never found one amp good for all headphones and yet, we see them reviewed with no regard for what they are actually driving. Get the synergy right and even a mundane headphone can sound quite nice. Well, these two Beyers sound more like what my work headphones sound like when they've been eq'd by tech guys. The bass hits hard and disappears. The raised treble of them both is no longer a problem so you're left with a headphone that has big speaker impact. I took the amp in to compare with some masters running through. It's really close to my eq'd DT150.

On the Ember, I found both very hefty in the bass so I used the k612 more than anything in order to lessen it. The tubes I was using were 'eb's' which stand for extra bass. So the Ember gives one massive load of clout down below in the bass regions. Transferring the K612 to the Polaris reveals the clean sounding clarity of the Polaris. The sound is less tube like than the Ember which is probably why I noticed straight away that the biggest difference for me was there in the bass. The Polaris has less of the tube harmonics going on so it is heard as slightly lighter. The DT990 and 770 put the clout back down in the bass and suddenly, the Polaris takes on a very Ember like quality again. They sound like floor standing speakers.

Having said that, the Polaris also has so many configuration options, that you can tweak away until you get the sound that you basically want.

For me though, they Beyers have announced 'lift off' big time.

Big, lush fruity sound with more presence than the K612. I've always been a bit suspect of the pad mod on the AKG but it works with the Ember. Not as good with the Polaris. It might be better with the stock pads actually.

Beyer brings the music alive and not only that, but you get this 'tube' type sound with the reliability of solid state. It's a really great match. It really sounds 'speaker like' and full bodied. I can't live with headphones that screech and squawk like so many seem to love. For me, even if it's not accurate, I much prefer a speaker type sound with (God forbid) a slightly raised bass and no treble screech. That way, you can listen low down in volume but also turn up to get a rich,detailed warm and live sounding playback that for me is much more like what I hear live.

So many headphones make music sound hemmed in to me with no real presence and no body of sound. They play cymbal and fizz away beautifully, but cymbals really don't sound like that. You hear a body of sound under the fizz that many headphones just don't play. In live music, bass hits and moves your chest. Headphones just don't do that so the slightly raised level kind of helps. I wonder what the ideal headphone curve really is? Have we really got it right yet? I'm not convinced but engineers seem to find a balance of sound that is very close to what the ears hear and don't worry about how 'flat' the headphone is. They just eq for a live sound that encourages musicians to play their best into the body of sound that they hear in the headphone. Well, if you played Into a screechy headphone, you'd break the keyboard trying to get some form of presence in the playback. The quality of sound that you hear in a headphone really affects how you play in studios.

DT990 and 770 with Polaris is a gorgeoeus full bodied sound that makes you keep turning up because it's so lovely sounding.

Imo, we need to seriously look at what an ideal curve is for a headphone in particular. It may not be the most revealing sound (like speakers aren't always that revealing) but headphone lovers tend to focus on that very detail which makes it not sound like music to me. Yes, it's clear and extended, but it's not really quite right. So is the ideal curve for a headphone one that is less revealing of absolute detail in order to make it sound musical rather than analytical?

The Polaris makes real music with this combo and is worth trying for sure.

Settings - wide bandwidth, low output impedance. Sounds really excellent.

Hi Musicman. Yes, I agree about what you're describing in the bass on the Ember. It has a fruity quality and a big 'fun' sound that when you put it up with the Polaris, shows the Polaris as perhaps better behaved and more polite with a 'hint' of Ember there.

Frans original design used another chip to make the Polaris produce similar levels of tube distortions as the Ember, but the chip is no longer easily available, so the Polaris, I think produces less. In fact, I can instantly hear less in the form of a more polite bass.

My dilemma is that I like the fruity behaviour of the Ember and I like the cleanness of the Polaris. The Polaris and the Beyers puts a bit of fruit back though. So I think it's a case of matching the headphones to each.

I do have a Senn hd650 but mine has Chinese pads that don't sound the same as the Senn ones. I think I get less bass on them and a really strong mid. That's why I avoided using them and writing about it publicly, since with Senn pads, everything might be different. They cost too much imo and I'm trying not to support them with their previous pads.

I really like the Polaris a lot and now it's flying. I'd say that the Ember is real musical fun; especially with the fantastic tube rolling and the Polaris gives you a hint of that fun with real clarity and clout!!

The Polaris has got me using the Beyers again today though big time.

My biggest problem is that I like all of the Garage amps. I loved the sound of the Horizon and the Sunrise and there is a kind of 'house' sound that goes through them all with regards to frequency response and that lovely smooth treble. I guess I should have all four!!!! Then grow another three heads?

Mine are 250 Ohm Dicky. So they have less bass. I like them a lot although they can veer on a bit strident up top. However, that works in their favour on the Polaris. You get a flavour of the 80 ohm bass but not as fat. I think they are a bit underestimated because of the 80 ohm bass version.

Both the Beyers sound super from the Polaris. I'm liking the Polaris more and more with its balance and cleanness. I still also like very much the big hearted Ember though as well!! The Ember is a real treat with a big fun sound and the Polaris is kind of between the Ember and an SS sound I guess. It's not as clinical as many SS amps which is what I like with these two headphones.

Btw, I'll get your new board off to you tomorrow.

With the new board, you'll get a full bandwidth setting. It'll brighten up a fraction from what you currently have. I like it a lot that way though.

I don't think there'd be any point, Simon. The Polaris is very loud as it is and has adjustable input so it doesn't need to be any louder on that side. At the moment, I don't know what to do with the Ember. I really like that one for its entertainment and really 'musical' sound. The Polaris has very similar characteristics but a different kind of bass. That's the only way I can describe its differences really. You notice that the bass is no longer a tube type bass. It's similar, but not the same. Some may prefer a tube sound and others not. I must admit, the choice is difficult for people wanting to buy one or the other.

It's mainly a question of whether you like a valve type bass or not. I know some don't, but the Polaris has really etched the differences between SS and valve bass on me the instant I heard the Polaris.

It slightly reminds me (in sound) of the Panda S2 but not as sharp in the treble.

I guess the Ember will do bedroom duty for now.

Mind you, the Ember is a really good controller into my active speakers. (Therefore being used as a preamp before a preamp!!) doing so with the Polaris would raise the gain too much and would introduce more noise, although it would sound more like a tube bass!!