First Watt F5 vs Aleph 5

[Rony1]

Hi,

For those who had the privilege to listen to both amps please explain the differences. I am wondering what is the difference in the sound between the 2 amps.

How are the detail in the mids and highs compare?

What is the difference in the Bass sound?

I am currently using an F5 and was thinking about replacing with the Aleph 5 (for more power) and wondering what to expect. I listen to classical music and sometimes like to listen loud, the F5 is amazing but it will start to distort at high volume.

Thank you in advance.

 

[Bill Fuss]

Try it, you'll like it.

 

[Nelson Bass]

I listen to classical music and sometimes like to listen loud, the F5 is amazing but it will start to distort at high volume.

Thank you in advance.

IME more power lead to more unnatural sound due to paralleled devices.

I suggest you look in the direction for more efficient speakers that also will provide you with better dynamics and more open sound.
Look into something above 94 dB/1W and you'll be a happy camper.

 

[Rony1]

All my speakers are DIY and sensitivity varies between 86 to 89 dB, this is what I have to live with. I love the sound of those tang bands , this is why I am thinking of a higher power amp.

IME more power lead to more unnatural sound due to paralleled devices.

I suggest you look in the direction for more efficient speakers that also will provide you with better dynamics and more open sound.
Look into something above 94 dB/1W and you'll be a happy camper.

 

[uvellani]

vs Aleph 3

I don't know about the Aleph 5, but I built the Aleph3 as well as the F5. The aleph3 is much better in the mids and highs (like a good tube SET) and despite the fact that they have the same rating also seems to play louder into the same speakers (89db 4 ohms). The F5 is fuller in the lower end and probably goes deeper too. I would think that the sound of the Aleph3 would compare to the Aleph5 which looks like a more powerful version of it.

I use the A3 generally for small ensemble music, acoustic and vocals etc. and the F5 generally for larger scale music that needs to play loud. I have them both in the same enclosure using the same PS and heatsinks and switchable via several toggles for power and inputs and outputs etc.

 

[dyrevennen]

I am glad you ask this question, because I am about to start my first DIY amplifier project in about 20 years. And I have a hard time choosing which design to go for.
I built a JLH 10 W class A amplifier long time ago and I am really happy with it. However, I am currently borrowing a Pass A40 (built by a friend of mine) and it is great, and far superior to the JLH.

Thus I am inspired to build my own Pass Amplifier. I am not in need of huge power, and my candidates are either the F5 or the Aleph J. The F5 seems attractive due to no need for matching output devices, but I am slightly concerned about oscillations if I am unlucky/sloppy with the PCB design.

Any feedback on the differences between the two are most welcome, both from a sound perspective and a DIY perspective. I listen mostly to classical and jazz and will use a conventional boxed loudspeaker.

I would like to thank all you guys for contributing to this forum, by the way. I have been reading a lot here lately and I am very impressed and thankful for you willingness to share your experience! This is particularly true for Mr. Pass himself, of course. It is very inspiring!

 

[Nelson Pass]

Build any of them, and there's a good chance you'll come
back later and build one of the others.

 

[vitalstates]

Build any of them, and there's a good chance you'll come
back later and build one of the others.

Papa, its possible to read that the wrong way.........

snigger

 

[vdi_nenna]

I have heard both of them in one day. Both DIY projects.
The A5 is sweeter and has a more rounded sound. The F5 is more defined.
Both are very good, but at a minimum, they are different in sound character.

It's going to come down to what you like best with your associated equipment. Can't lose.

Edit:
Also, I didn't hear that the bass was less powerful with the F5 because of less power.
I feel it is tighter. I listened on 89 db sens. speakers that stayed around 8 ohms.
Are your speakers easy to drive?

 

[VladimirK]

I have heard both of them in one day. Both DIY projects.
The A5 is sweeter and has a more rounded sound. The F5 is more defined.
Both are very good, but at a minimum, they are different in sound character.

It's going to come down to what you like best with your associated equipment. Can't lose.

In Aleph topologies, "rounded sound" could result from a single electrolytic, standing at important point of schematics. Using BG or Elna Cerafines could make Aleph sound as detailed as F5, but with a bit tuby character. But, at the end, it comes much more expensive than F5. So, Aleph requires more audiophile-nature efforts.

 

[vdi_nenna]

In Aleph topologies, "rounded sound" could result from a single electrolytic, standing at important point of schematics. Using BG or Elna Cerafines could make Aleph sound as detailed as F5, but with a bit tuby character.

The A5 caps are by-passed, and "very expensive at $80 each" caps were used in the power supply. The A5 also used ultra-fast rectifiers and a bunch other nice tweeks. A5 still has that smooth tube sound w/ weight. Says a lot about the topologies involved: SE vs P-P.

In my opinion, maybe if it were an A5J, it could grab more detail, like the F5.
The F5 is just a fast amp.

 

[joho]

Damping factor

Edit:
Also, I didn't hear that the bass was less powerful with the F5 because of less power.
I feel it is tighter. I listened on 89 db sens. speakers that stayed around 8 ohms.
[/QUOTE]

A few weeks ago I measured the damping factor of different Pass designs.
The test frequency and load was 50hz/6 ohm. Results:

Aleph5 around 25
AX (4 fets 30Watt each) around 20
F5 around 40
BA2 (6 fets a channel 20 watt each)around 40

So it's logical the F5 is tighter at the low end than the A5.
But less powerfull? I.M.H.O no.

At the moment I'm comparing a AX with the F5.

Gr.
Johan

 

[vdi_nenna]

So it's logical the F5 is tighter at the low end than the A5.
But less powerfull? I.M.H.O no.

Gr.
Johan

Yes, more control is another way to put it.

 

[alazira]

The Alerions bass response seems to prefer amplifier output impedances in the region of about 1 ohm or so, for a damping factor of about 8. Less than this, and the bottom end gets a little bloated, more than this, and it starts to lose some life.

Hi Nelson,

Would it be fair to say that each driver has a damping factor "sweet spot" for bass response?

 

[Zen Mod]

Hi Nelson,

Would it be fair to say that each driver has a damping factor "sweet spot" for bass response?

take that as driver/enclosure combo ;

matter of construction approach - with some you count on DF/series resistance influence on overall Q factor , with some you dismiss that influence

 

[Rony1]

I have heard both of them in one day. Both DIY projects.
The A5 is sweeter and has a more rounded sound. The F5 is more defined.
Both are very good, but at a minimum, they are different in sound character.

It's going to come down to what you like best with your associated equipment. Can't lose.

Edit:
Also, I didn't hear that the bass was less powerful with the F5 because of less power.
I feel it is tighter. I listened on 89 db sens. speakers that stayed around 8 ohms.
Are your speakers easy to drive?

My current speakers have sensitivity of ~86 dB ~4 Ohms. Interesting what you say about the bass, I found out that many things could influence bass tightness, for example,

My modified Shanling CD-T80 had "more" bass with original Op-Amps, with the new ones the bass seemed to be a little lower, but in actuality it was tighter.

Same thing when I added a new preamp, more bass but not as tight.

Thanks for the information guys.

 

[galop]

I make both F5 and A5. F5 is wery pleasant for ears ,fast and deep bass,very open sound,
A5 is more smooth,very detailed and has more dinamic and power than F5.Both good amplifiers.I have one problem with A5 with crc PSU.when i turn it on i have big thump on loudspeakers,about 6 v DC.what do you suggest?

this is aleph 5 ,but is not finished yet.

 

[VladimirK]

I would propose, when one compare or characterize different amps, to add some info about their practical use. Just for instance, like " I prefer A5 for jazz, but F5 for rock" etc. If possible, of course. I am sure this would help to better understand different sound characters.

 

[bobodioulasso]

Galop,
i would not fit the bridges on the main heatsinks, which vill run them uselessly warm. The bottom plate is a better place, imo.

 

[galop]

Thank you,i will put bridges on bottom plate when will replace PSU resistors with coils,because bottom plate is even hotter.Hm i think the aleph 5 is better ,after listening about 5 hours of jazz and acoustic music on A5 i plug back F5 and sound become less detailed and open,more flat,maybe because of my loudspeakers.Dont understand me wrong,F5 still sound superb, but A5 is sounds better on my speakers.