To DIY, or OEM PASS?

[AudioSan]

well. say the F5 CAN push 100W (it is very possible)
i cant see any difference from pushing the aleph4 in the same room with the same speakers. exept that the F5 will deliver more power on lowZ's.
so the F5 will do it better

[KatieandDad]

If you say so. I sold my F5 on E-Bay.

[Nelson Pass]

Originally Posted by KatieandDad

If Nelson himself had produced the Nirvana of amps he wouldn't keep on trying to improve on his designs !!!!

Each design is Nirvana to somebody.

[Uunderhill]

Originally Posted by KatieandDad

At the time of my F5 I has some B&W 683's the F5 couldn't cope with them.

I've just won a pair of YELLOW (that's another story) B&W 802D's, the F5 certainly wouldn't like them.

The Aleph 4 copes well with both the 683s and the 802D's

K & D,

Thanks for this info - its very useful.

The 683's drop down to Z = |3.0| - I don't think an F5 is designed for this.

My preference with B&W's is tubes in the preamp and MOSFET's in the power amp.
- and solid core copper speaker cables.
- something to look into is solid core OCC copper with teflon insulation.
there are only 3 companies licensed to make OCC copper wire and its sold under quite a few brand names.

With my N804's - I'm thinking of bi amping with a small class A MOSFET amp going to the mid/tweeter
and a Bi polar push - pull amp going to the bass.

B&W has really improved the crossovers with their Diamond series.

In my 603 s2's and N804's they used Bennic resistors and MKP caps.
What were they thinking ?
I rebuilt the tweeter crossover section in my 603's and it was a huge improvement.

I suspect an Aleph 4 can drive the 802D's because of a very low Zout
and they can deliver lots of current.
.
.

[buzzforb]

Originally Posted by Uunderhill

K & D,

Thanks for this info - its very useful.

The 683's drop down to Z = |3.0| - I don't think an F5 is designed for this.

My preference with B&W's is tubes in the preamp and MOSFET's in the power amp.
- and solid core copper speaker cables.
- something to look into is solid core OCC copper with teflon insulation.
there are only 3 companies licensed to make OCC copper wire and its sold under quite a few brand names.

With my N804's - I'm thinking of bi amping with a small class A MOSFET amp going to the mid/tweeter
and a Bi polar push - pull amp going to the bass.

B&W has really improved the crossovers with their Diamond series.

In my 603 s2's and N804's they used Bennic resistors and MKP caps.
What were they thinking ?
I rebuilt the tweeter crossover section in my 603's and it was a huge improvement.
.

Uunderhill,
Have you read the F5 article? HAve you read the F5T article? K&D may not like the f5, but he is simply wrong about its abilities. If the standard F5 is not suited for your speakers, the F5T V2 or V3 will EASILY drive your speakers. You may not like it, but it isnt because it is having trouble doing the job. Be careful that you check what others say. BTW, he is comparing a 25W F5 to a 100W A4.

[sakellogg]

Originally Posted by KatieandDad

If Nelson himself had produced the Nirvana of amps he wouldn't keep on trying to improve on his .

im going to have to dissagree. i may be overstepping my bounds by speaking for him but.....he has just as much fun diy as we do.
just like us, its fun to him. it just so happens hes one of the lucky ones who can pay the bills off his fun.

[Uunderhill]

Originally Posted by AudioSan

i have 3-way scan-speak (88db 6ohm) wich is much harder load. and my F5 drive them very well

AudioSam,

I think what makes a speaker an easy load is the magnitude of the impedance curve and its phase angles.

Speakers with mostly a real impedance where Z >= |4 | ohms are a reasonable load to drive.

Speakers that have large phase angles - where there is a large rate of change in the phase angle
combined with a low Z magnitude - can be hell for an amp.

IMO an amp with a very low Zout - combined with a huge power supply - is needed for speakers like these.

I don't know which 3 way Scan Speak speakers you have,
but from what I've seen from Seas and Scan Speak designs,
the real and imaginary components of the impedance, provide a reasonable load.
Have is Troels Gravesen's builds of Scan Speak's - bless this person.
ScanSpeak Projects
.
.
.

[AudioSan]

Unnderhill. my scan-speaks are my own design. based on the good old classic series.
2x8" bottom, 7"mid and 9500 tweeter.
the 8" drivers are custom 12ohm. not 8ohm as standar.

[Uunderhill]

Originally Posted by buzzforb

Uunderhill,
Have you read the F5 article? HAve you read the F5T article? K&D may not like the f5, but he is simply wrong about its abilities. If the standard F5 is not suited for your speakers, the F5T V2 or V3 will EASILY drive your speakers. You may not like it, but it isnt because it is having trouble doing the job. Be careful that you check what others say. BTW, he is comparing a 25W F5 to a 100W A4.

I've tinkered modding the F5 for a few weeks now.

Mr. Pass, Juma and Zen Mod have been very kind to help me with the mods.

The F5 has some great advantages
- its dead quiet
- there is no thump with switch on and off
- Beethoven piano Trios and Mozart piano concerti sound great with it.
- sonically I really like this amp

From a Zout point of view, the F5 has a parallel common source output stage.
So I think its really intended for speakers that are reasonable load.
It drives my 10" 2528 DC Tannoys beautifully.


K&D has B&W's where the Z =< |3.0| , with difficult phase angles - these speakers put huge demands on an amp.

The aleph 4 has a follower output - so I suspect its Zout is very low.
Plus the power supply could run a fork lift.
.

[buzzforb]

If you compared an F5T rated at 100W like the F5T v3, you would find the differences, other than sound, to be minimal. The two amps, equally rated in power, will aoun different due to topology, not the ability to drive the speakers effectively.