[RAZRr1275]

What do you guys think about a Concero or Bushmaster MKII dac for the HE-6 to go with my Bantam Gold as an upgrade for the ODAC?

 

[potterma]

I certainly understand your confusion. Answers are all over the road, and not having any experience with the HE-6s, I'm afraid I can't offer you anything more definitive.

Suffice to say that if you want 10 watts into 60 ohms, you need an amp that will push about 75 watts into 8 ohms. On the other hand, if the F5 will drive the HE-6 to sufficient levels, then all that's really needed is a few watts into 60 ohms in which case you're talking about an amp that'll do about 25 watts into 8 ohms.

And of course a given person's estimation of what's needed can depend a lot on what kind of music they listen to. If they're listening to music that's had a lot of compression applied during recording leaving little in terms of dynamic range, they would likely tend to be ok with less power. But those who listen to music with fairly high dynamic range, they may call for more power.

se

@Steve Eddy
 
Yes, but one thing you don't realize, Steve, is that the F5 will push 8 Watts into 50 ohms.   So will the F1/FlJ.   First Watt amps are not rated the same way "common" amps are rated.  The ratiometric approach is not correct.  The F5 and F1 (and a few of the other First Watt amps) will put out 20 V peak ( >14 Vrms).  They don't have the current capacity to do that into 8 ohms, but into higher impedance, like the HE-6, they will deliver.

 

[potterma]

I listened to the f3 and j2. And they are not suitable for the he6. And we heard them both clip. And the presentation to me was bright and base light. Craig should chime in on this too. He ended up taking my krell home again to listen to it .

Al

Did I not tell you, Al?  The F3 will only do +/- 13 V peak.  You want to target +/-20 Volts, at least.  Give an F5 or an F1 a run....
 
@cradon   As I said above, the F3 will only do +/- 13 V peak.  F5 and F1/F1J will do +/-20 V peak.

 

[ohhgourami]

Sounds like my decision is made. As for the plugging the HE6's to the amp, would I have to use the HE-adapter or is it safe to directly hook it up? I've read about people plugging theirs into 300+wpc amps without much trouble but I just want to make sure.

Also, from what I understand, I would need xlr to banana plugs to use with the wire that comes with the HE6's to hook up to speaker connectors. Any pointers on what cables are nice? I'm told that BTG audio stuff is nice along with them being able to replace the poorly designed connectors on the headphones with some better ones.
Thanks!

As long as you watch the volume knob you should be fine, but your Krell might have some hiss like mine so I recommend getting some resistors to attenuate that. Because my amp has a lot of gain, I have a lot of attenuation using 100ohm and 3ohm resistors (-32dB). If you buy wirewound, you will not get coloration or reduction in SQ unlike the HE-adapter.
 
BTG does indeed make some nice stuff. The queue might be a bit long these days. If you have absolutely no need for the TRS adapter that Hifiman provides, you good cut that up to use an adapter for the time being.

 

[potterma]

  Yeah no issues here either, and the F5 is more than 2x the output of the F1J too. That makes you, potterma, dubstep girl, me and some others I can't think of that are satisfied. Something is fishy. Oh well, atleast you guys found something you are happy with.

@brunk  and others who care:  the difference is the amp.  F2, F3 and some others do not have the voltage output swing that the F5 and the F1/F1J do.  Simple math, really.  Its a lower voltage limit on some of the First Watt amps.  They've the current ability, but not the voltage swing...  With the First Watt amps, its about voltage swing, not rated power into 8 ohms!!!

 

[devlinchang]

Alright, I'll keep that in mind. Thanks for the help.

 

[StryGR]

I said it on a previous post. Having capability to handle 25 V rms peaks, Hifimans need an amplifier with a voltage swing that exceeds this value. Take a 100 W @ 8 ohm as the reference, ideal power rating for the amp.
I would hunt for the best such amp to mate with my Hifimans.
Irrelevant: yesterday, I unpacked my HD-650s and (tried to) have a listen. Senns felt on my head like a feather! And all their good assets ended there. And they were packed back to their box...  

 

[NZtechfreak]

Oh, found the model name for that Luxman I was listening to: L-507U

 

[StryGR]

Very nice vintage amp! Now what do you listen to?

 

[NZtechfreak]

Very nice vintage amp! Now what do you listen to?

Bit of everything, metal and rock the main priorities.

 

[preproman]

  @Steve Eddy
 
Yes, but one thing you don't realize, Steve, is that the F5 will push 8 Watts into 50 ohms.   So will the F1/FlJ.   First Watt amps are not rated the same way "common" amps are rated.  The ratiometric approach is not correct.  The F5 and F1 (and a few of the other First Watt amps) will put out 20 V peak ( >14 Vrms).  They don't have the current capacity to do that into 8 ohms, but into higher impedance, like the HE-6, they will deliver.

 
What's the math on on both a single F4 (SE) and dual F4s in balanced mode?

 

[ALRAINBOW]

Wow dual bal cool .... I do not know what the krell output is.in volts but it drives them very well. I owe oh a an appology. I have said in the past I could not hear a difference from my woo to the krell. Well there is. , the woo has detail then the krell. It's not much though and it required me to play several songs a few times each while going back and forth between them both on at the same time. A
Though it is there . It is very smal and for me not worth spending almost 6 k compared to the krell at 1800. Now the aragon to the krell , there is nothing that either me or craig cpuld tell . I am sorry Bout my reamrks about the F3. It really is a remarkable amp with the hd800. And I intend to have brunk build mea a F5. I will PM him later today .

Al

 

[preproman]

Not from me but from Nelson:

F4 Power Buffer

Like everything else from First Watt the F4 is a unique amplifier. It has no feedback and no voltage gain, only current gain. This design is sometimes called an “impedance converting amplifier”, but more commonly referred to as a buffer – in this case, a power buffer.

The F4 is Class A impedance converting amplifier, having no voltage gain or feedback. Its input impedance is 47,000 ohms, and its output impedance is about 0.2 ohms. It is suitable for driving a high sensitivity loudspeaker with the output voltage of a preamp or other line-level audio source. It is also useful with a less sensitive loudspeaker in a bi-amped configuration where it takes input from the output of a conventional amplifier.

As a stereo amplifier with single-ended inputs and outputs, it will deliver up to 25 watts into 8 ohms with a damping factor of 40. It will do 50 watts into 4 ohms, and as a mono-block amplifier with parallel inputs and outputs, it will do about 100 watts into 2 ohms. As a mono-block amplifier with balanced inputs and outputs the power output rating is 100 watts into 8 ohms at 1%.

The amplifier operates Class A to 25 watts (50 peak), and the distortion is 2^nd and 3^rd harmonic in character, rising or declining in proportion to the output power. The amplifier has a direct coupled input and output, with a -0.5 dB rolloff around .1 Hz and 200 KHz. It does a clean square wave at 100 Khz.

The simplified circuit of the F4:

The combination of a simple Class A circuit operated without feedback and the good objective performance gives us a superb sounding amplifier. The low distortion, bandwidth extension, and high damping results in midrange clarity, treble detail, and control on the bottom end. While these are available from most good solid state amplifiers, the F4 also brings depth, imaging, midrange warmth and top-end sweetness.

Overall, it is one of the best sounding amplifiers, and if you can live with unity voltage gain in your amplifier, it is possibly your best choice.

 

[ALRAINBOW]

I can vouch for the denon AVR3805. I have that very good amp. And I have the denon 5805 CI as well and very good as well.

Al

 

[gjc11028]

@brunk
  and others who care:  the difference is the amp.  F2, F3 and some others do not have the voltage output swing that the F5 and the F1/F1J do.  Simple math, really.  Its a lower voltage limit on some of the First Watt amps.  They've the current ability, but not the voltage swing...  With the First Watt amps, its about voltage swing, not rated power into 8 ohms!!!

Thanks. This is really helpful and addresses some of the confusion that I had. Can I ask about the j2? The manual does not have the maximum output voltage in the way that it is listed for the. F amps. Thanks