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-   -   Is the F4 the most-suitable FW amp for me? (http://www.diyaudio.com/forums/pass-labs/183241-f4-most-suitable-fw-amp-me.html)

jeffreybehr 15th February 2011 10:21 PM

Is the F4 the most-suitable FW amp for me?
 
But first--
1. I LOVE large-scale Classical and film music, and I hear a lot of real music. The real stuff I hear is NEVER edgy even if it's too bright--as in the trumpets are playing too loudly--and it never sounds thin unless the composer orchestrates it that way.
2. I love my reproduced music a bit warm in the bottom-4 octaves and a bit dark in the top 3. 'Warm' doesn't mean thick or syrupy, it means rich and real sounding. 'A bit dark' doesn't mean 'dull' to me, it means the trumpets don't hurt my ears.
3. Last summer I bought a pair of Audio Physic Avanti III speakers and have been improving them ever since. They have new cable to the drivers, the MR/treble x-over is outboarded, all the caps and resistors feeding the MR and treble drivers have been eliminated* or replaced, I've added a diffractionbegone.com pad around the tweeter, I've tossed the woofer x-over and actively filter and amp the bass, etc. While doing this, I've upgraded other aspects of my system--parts in the c-j MET1 preamp, new main IC (Audiquest silver-conductor Niagrara) to the poweramps, better discplayer (an Oppo '83SE), etc.
4. For months I drove the top-8 octaves of the 4-Ohm, 89dB-sensitive Avantis with Music Reference EM7-12 SET ('Tiny Twelve') poweramps. These are rated at only 12 Watts but sounded excellent except for some hardness at high (for me) levels, due, I believe, to amp clipping.

Well, the upgrade bug** has bitten hard after I (perhaps stupidly) sold the EM7-12s. I've listened to Monarchy Audio SM70 Pros and bought and improved a pair of Marantz M-22s, the latter 75-into-4, class-A-biased members of the Music Link series of c. 1990. Both these amps sound/sounded quite good***--quick, clean, tonally neutral, etc., but both lack the magic that the Tiny Twelves had. I'm now looking at Pass amps; I quickly decided that I don't want to spend the money for Pass Labs amps, so I've been investigating the First Watt stuff, and the F4 is highly fascinating--and affordable.

My system has plenty of frontend gain. The c-j preamp operates at 38 - 40 dB of attenuation at fairly loud acoustic levels, and an average position of 30dB down is WAY too loud. The Tiny Twelves had maybe 10dB less gain so the preamp operated at average levels of about 70 (= 30dB below full output).

If the Tiny Twelves' 10 - 12 Watts into 3 Ohms drove the Avantis to quite-satisfying levels 99% of the time, a pair of F4s' about-10dB more power (paralleled) should produce satisfying high levels without clipping and bring to my system the sense of ease that enough of the right kind of power brings. Also highly appealing is the 'open architecture' of the amps, as I'm an incorrigible tweak.

I've read 6 Moons' review and a pair of them sounds like the right thing for me.

What do you think? What have I left out of my analysis?


* I use a smaller coupling cap in the poweramps for the MR hi-pass filter, and removing the bank of cheap plasic-film caps from the crossovers increased the clarity AND smoothness of the MR dramatically.
** I do indeed suffer from audiofoolia nervosa.
*** I may be a hi-end audiofool, but I'm not much of a golden-eared audiofile, so I don't hear all sorts of differences in amps, especially short-term.

6L6 16th February 2011 04:54 AM

I am not seeing any gaps in your analysis...

Go '4' it! :D


(Sorry for the bad pun...)

ra7 16th February 2011 05:08 AM

Yup, looks like the F4 will be good. Why do you need a pair though?

Melon Head 16th February 2011 06:09 AM

I tend to agree also

jeffreybehr 16th February 2011 07:55 AM

Quote:

Originally Posted by ra7 (Post 2470553)
Yup, looks like the F4 will be good. Why do you need a pair though?

A pair with channels paralleled will push up to about 100 Watts into each speaker, whereas one stereo amp will push a max of about 'only' 50 Watts into each speaker. Also, my custom-wound speakercable is very short and setup for monoamps. I managed to run the 4 Common conductors of the new speakercable unbroken from the Furutech OCC-copper spadelugs all the way to the driver terminals, and I'd rather not add to it.
http://i89.photobucket.com/albums/k2...rear_1280w.jpg

weskoki 16th February 2011 08:51 AM

F
 
I had the Monarchy pro 70 it's great amp,detailed,dynamic,good soundstage but compared to push pull tube amp it still sounded very much like SS.
My only experience is with the F5.Best strenght?Amazing power of analilis. Large scale music is like under the microscope.Now don't expect to sound like tubes in the midrange.I don't find it rich or warm but that's my experience.

Melon Head 16th February 2011 09:18 AM

I thought we were talking about the F4 driven by a valve amp which is totally different to the F5.

weskoki 16th February 2011 11:23 AM

F4
 
Totally different jes,but sound wise similar.
Unless you don't believe Papa's words.
"The F4 is the closest relative. They both have a clean extended bottom and I consider them almost equivalent, with neither having a distinct advantage. The F4 is a little bit warmer in the mid and might be preferred on simple material at modest volume levels, that is to say a solo vocal or instrument or maybe a string quartet. You could say it's a little more tubey. ;)

jeffreybehr 16th February 2011 05:25 PM

"...a little bit warmer in the mid and might be preferred on simple material at modest volume levels, that is to say a solo vocal or instrument or maybe a string quartet. You could say it's a little more tubey" is just what I'm looking for.

What I got from the system with the Tiny Twelves was occasional evenings of goose-bumps listening, moments when the music would distract me from whatever was distracting me from the music. I'd turn off all the lites, stare at the center of that dark screen...
http://i89.photobucket.com/albums/k2...pano_1280w.jpg
...and thank God for this wonderful music pouring from this fabulous-sounding system. Haven't had one of those since the Tiny Twelves left.

A pair of Monarchy Audio SE160s--hybrid with a 12AT7 gain stage, MOSFET outputs biased Class-A to c. 50 Watts, NO negative FB--should arrive this week. I have 30 days to fall in love with them or return them. They're certainly not as easy to tweak as the F4s would be--Mr. Poon doesn't issue schematics, and it looks as if it's difficult to get the board out of the amp--and being an incorrigible tweek, that will bother me. Nelson's FW stuff is so open I'm amazed.

I guess I'll control my infatuation with the F4 and give the SE160s a fair listen.

Thx, all, for your thoughts. I'll write again.

Melon Head 16th February 2011 05:41 PM

Quote:

Originally Posted by weskoki (Post 2470800)
Totally different jes,but sound wise similar.
Unless you don't believe Papa's words.
"The F4 is the closest relative. They both have a clean extended bottom and I consider them almost equivalent, with neither having a distinct advantage. The F4 is a little bit warmer in the mid and might be preferred on simple material at modest volume levels, that is to say a solo vocal or instrument or maybe a string quartet. You could say it's a little more tubey. ;)

I could be wrong here but I don't agree with that. I think you are taking Nelsons words out of context.
If you drive the F4 direct from a cd player then I agree that the sound will be similar to the F5, however if you drive it with a valve preamp or valve power amp then I don't agree it will sound similar to the F5.

The F4 will sound different depending on what it is driven by, and since a cd player does not have enough voltage to drive the F4 to decent power levels most people will be a putting some sought of high gain preamp or power amp in front of it which will heavily influence the sound coming out of the speakers.


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