Buckeye Amps: 2nd Generation Purifi EIGENTAKT 1ET9040BA Amplifier

[Analoglesspursuit]

I’ve been lurking here with much hope for these amplifiers, as I thought they might be the practical answer for speakers I’ve been longing for, but had previously disqualified due to their impractical amplification needs.
At first I was a bit disappointed that their 8 Ohm rating of 400 Watts didn’t double down to 1600 Watts into 2 Ohms. Now I’m further disappointed that the sensitivity doesn’t allow for the 2.1 / 4.2 Volt output from my DAC for full power output from the amplification to the speakers.
Oh, well. The amplifier search continues.

 

[Julf]

I’ve been lurking here with much hope for these amplifiers, as I thought they might be the practical answer for speakers I’ve been longing for, but had previously disqualified due to their impractical amplification needs.
At first I was a bit disappointed that their 8 Ohm rating of 400 Watts didn’t double down to 1600 Watts into 2 Ohms. Now I’m further disappointed that the sensitivity doesn’t allow for the 2.1 / 4.2 Volt output from my DAC for full power output from the amplification to the speakers.
Oh, well. The amplifier search continues.

Why would you need 1600 W? Using your amps for welding?

 

[Buckeye Amps]

I’ve been lurking here with much hope for these amplifiers, as I thought they might be the practical answer for speakers I’ve been longing for, but had previously disqualified due to their impractical amplification needs.
At first I was a bit disappointed that their 8 Ohm rating of 400 Watts didn’t double down to 1600 Watts into 2 Ohms. Now I’m further disappointed that the sensitivity doesn’t allow for the 2.1 / 4.2 Volt output from my DAC for full power output from the amplification to the speakers.
Oh, well. The amplifier search continues.

The 8ohm rating is 375w, which doubles into 750w into 4ohm, which nearly doubles into 1400w.
And using the High gain setting you can get full power output with a 4v source.

 

[Analoglesspursuit]

The 8ohm rating is 375w, which doubles into 750w into 4ohm, which nearly doubles into 1400w.
And using the High gain setting you can get full power output with a 4v source.

Why would you need 1600 W? Using your amps for welding?

 

[Analoglesspursuit]

At <2 Ohms it’s comparable to 400 Watts into 8 Ohms.

 

[Analoglesspursuit]

The 8ohm rating is 375w, which doubles into 750w into 4ohm, which nearly doubles into 1400w.
And using the High gain setting you can get full power output with a 4v source.

Ideally I’d like to have safe full range use of the volume control.

 

[Julf]

At <2 Ohms it’s comparable to 400 Watts into 8 Ohms.

If by "comparable" you mean "same amount of current", then perhaps, but why is that relevant? Power is what really counts.

 

[Julf]

Ideally I’d like to have safe full range use of the volume control.

Why? Does the last 1 or 2 dB really matter?

 

[Buckeye Amps]

I can understand wanting everything to be perfect. But the "issue" of someone feeding 4v to the amp and using High gain (which allows max power with just 2.9v) is really not the issue it may seem. You will reach full power output of the amplifier before you reach full voltage output of the source except maybe in the most niche of situations (and that maybe has quite a few variables to it as well).

 

[Analoglesspursuit]

I can understand wanting everything to be perfect. But the "issue" of someone feeding 4v to the amp and using High gain (which allows max power with just 2.9v) is really not the issue it may seem. You will reach full power output of the amplifier before you reach full voltage output of the source except maybe in the most niche of situations (and that maybe has quite a few variables to it as well).

With established standards such as 2 V for CD and 2.2 V for HDCD and the proliferation of DACs with 32 bit resolution and suitable volume controls suggest manufacturers make amps that make best use of those standards.
I appreciate what you’re doing and i do wish you the best of luck with your endeavors.

 

[Buckeye Amps]

With established standards such as 2 V for CD and 2.2 V for HDCD and the proliferation of DACs with 32 bit resolution and suitable volume controls suggest manufacturers make amps that make best use of those standards.
I appreciate what you’re doing and i do wish you the best of luck with your endeavors.

Understood but again it is a lot simpler than that.

 

[Analoglesspursuit]

The average listener uses less than 10W for normal playback levels, but many people think they absolutely need 400W even though they couldn't stand being in the room at less than half that SPL. It would be funny if modern amps had an LED on the front that displayed the amount of watts in use. People would start to realize how bizarre the request for 1200W is.

…And use exponentially more power during peaks. Low sensitivity speakers with other redeeming qualities in large rooms benefit from the extra power.

 

[Julf]

With established standards such as 2 V for CD and 2.2 V for HDCD and the proliferation of DACs with 32 bit resolution and suitable volume controls suggest manufacturers make amps that make best use of those standards.
I appreciate what you’re doing and i do wish you the best of luck with your endeavors.

There are no DACs with 32 bit resolution - not that it matters, I haven't come across many commercial recordings that would use even the full range of 16 bits.

 

[Sal1950]

Just something to thing about. Every very high power amp I've seen real world tested couldn't actually make spec due
to the power line voltage drooping under that current demand. At minimum, you better run a dedicated 20a line for that amp if you hope to see near the max power spec.

"The Dan D'Agostino M400 MxV is specified as offering maximum output powers of 400W into 8 ohms, 800W into 4 ohms, and 1600W into 2 ohms (all powers equivalent to 26dBW). With our definition of clipping, which is when the output's percentage of THD+noise reaches 1%, the M400 MxV clipped with a 1kHz signal at 442W into 8 ohms (26.45dBW, fig.4) and at 778W into 4 ohms (25.9dBW, fig.5). The AC wall voltage had dropped from 119.7V with the amplifier idling to 118.7V with the amplifier clipping into 4 ohms, which is why the M400 MxV didn't quite meet its specified power into this load. Similarly, although I measured a clipping power of 1050W into 2 ohms, the wall voltage had dropped to 116V at this power."

Dan D'Agostino Momentum M400 MxV monoblock power amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

 

[Julf]

…And use exponentially more power during peaks. Low sensitivity speakers with other redeeming qualities in large rooms benefit from the extra power.

At what frequency does your speaker hit 2 Ω?

 

[Analoglesspursuit]

There are no DACs with 32 bit resolution - not that it matters, I haven't come across many commercial recordings that would use even the full range of 16 bits.

The extra bits come in handy to deal with house keeping such as volume control.

 

[EdW]

With established standards such as 2 V for CD and 2.2 V for HDCD and the proliferation of DACs with 32 bit resolution and suitable volume controls suggest manufacturers make amps that make best use of those standards.
I appreciate what you’re doing and i do wish you the best of luck with your endeavors.

The fact that the high sensitivity option will overload when your DAC gets a fully modulated signal at 0db could also be seen as an advantage - set the volume in the DAC a dB or two below overload and you have additional protection against intersample overs in the DAC. Also the last dB or two of a DAC’s dynamic range doesn’t usually give a pro rata increase in SINAD - the characteristic flattens off.

Another thing - many live broadcasts are transmitted with recording levels many dBs down since the recording engineer has only one opportunity to get it right - so a bit of additional gain may be a good idea if you really want to damage your hearing!

I’m not familiar with many great loudspeakers with impedance minima around the bass/mid frequencies at or below 2 ohms and it is only at these frequencies that you are likely to encounter very high signal levels.

My own experience is that with a heavily modulated rock track at approx. 25W max power I get nearly 110dB SPL at 2.5m listening distance, 88dB speaker sensitivity. Obviously a bit of room gain there but plenty loud enough!

 

[Julf]

The extra bits come in handy to deal with house keeping such as volume control.

Extra bits come handy when doing digital processing, yes, which is why modern DACs do stuff like volume control using 32-bit precision - but that doesn't change the fact that the best DACs have an output resolution of 21-22 bits on a good day - but that gives 5-6 bits to "waste" before you start losing precision, so you don't need to worry about using every single dB of output range...

 

[Analoglesspursuit]

The point being that volume control on many contemporary DACs are more satisfactory than older low bit DACs, and can be more suitably matched with appropriate amplification.
Perhaps, we should return to the original subject at hand?

 

[goryu]

Curious as to the sinad of the amp at different gain levels. I recall several amps tested here in which the performance was shown to be best without any buffer, which actually degraded performance. What, if any, effect, does higher levels of gain from the buffer have on performance? While likely inaudible in any case, it would be nice to see some measurements.