Fostex F120A

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chrisby

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Fostex F120A
« on: 9 Jul 2008, 09:59 pm »
OK, Jim - to start things off,  this is more or less a duplicate of a post earlier today at DIYAudio:

Had an interesting short session last night with a variety of amps (3 tubed & 1 special DIY SS ), along a pair of FE127EN Fonkens, and the first test of Fonkensteens with "Purvinized" F120As.

System; Jolida CD player, Bottlehead ForeplayII (EI 12BH7), budget interconnects and DIY single strand CAT5 speaker wire, O-Netics "Ground Pools"

Power amps: Vaughn Audio Carina, Bottlehead ParamourII (stock transformers), Wright Audio Mono7 300B, Jolida 302B (modded – triode / no feedback), DIY Project SS amp (with a new wrinkle?)


There were 4 sets of ears present, and while we could all use different degree of terse or verbose prose to describe our subjective impressions, I think I can speak for the consensus:

Vaughn Audio Carina - can be dialed from deliciously smooth (triode/ "Tone" B setting), to "in your face" UL/"Tone" A - but in even the latter case may not have enough ultimate torque for all situations, most particularly low sensitivity speaker systems - whether single or multi driver.

I've had occasion to hear this amp in a much larger venue than my own, on a succession of Fostex SD based systems:
1) Hornshoppe Horn, stock & fully treated FE126E;
2) C&C Abby with FF165K-EN;
3) FE206ESR in the big-ar$e recommended BLH.

The last item on the list is a magic but not flawless combination with the Carina, and the speakers certainly a bit unwieldy. Funny how it works that the extra 4dB of nominal sensitivity and gargantuan box could make that big a difference?

Back to last evenings event:

At moderate to "louder" levels ( I guess that's entirely subjective - in over 3 hours, we never surpassed 90dB on the Radio Shack digital meter at Fast C weighted setting), the Carina was more than a little stressed an congested on the triode/B setting, and at the other extreme (UL/A), a bit too aggressive with both the FE127 and F120A. Below this confusion threshold, an absolutely delicious and musical unit.

Bottlehead Paramour 2A3 (new stock EH Gold Grid / vintage Mullard 12AT7) . While the nominal power is approx only .5 watt higher than the Carina in UL mode, and with all due respect to talented and experienced amplifier designers, this is a perfect example that for any number of real world reasons, not all watts sound the same. It’s about synergy.
Still not quite enough to avoid compression and confusion on the upper midrange on the F120A above about 85dB SPL. These drivers are not as euphonically forgiving as the FE127E

Wright Sound Mono7 (300B / 6SN7 stock tubes and O’Netics OPT) – much more like it: this ain’t your grampa’s technocoloured, syrupy 300B. Think “2A3 with (just enough) balls”. Now we’re attaining SPL’s to the point that the little room is the major limiting factor.

While I’ll admit an abiding affection for the FE127EN/Fonken, this is were the F120A’s definitely start to distinguish themselves. It’s quite a cunning stunt indeed to extract this much dynamic snap, and low end authority / articulation from such a small driver / enclosure, without resorting to horn loading or EQ tricks. The only real premium that of sensitivity (well, that an the initial sticker shock of landed cost for fully EnABLed pair)

Modded Jolida 302 (EL34 P/P triode / no feedback) – Well, this was my first tube amp (almost 10yrs now), and at about 25 watts in modded form, this is the most powerful amp in the house. Unfortunately, it’s also the least refined. (yet – it’s been at least 3 years since the bottom was off for any serious tweakage )

Here’s a surprise – there’s still musical life left in the old (analog) SS device designbook. Sometimes it’s a matter of stripping down to the barest bones of simplicity (a la gainclones, etc.), and sometimes it’s a matter of thorough and very precise engineering, even if outside of the normal box, or taken to certain extremes (a la Nelson Pass First Watt family or Gary Pimm’s stunning SS Tabor to name just a couple). No doubt numerous other examples abound in both the commercial marketplace for those of us with bottomless pocketbooks, or the truly adventurous DIYers.

Which brings us to those out of left-field projects that have you scratching your head when you look at the parts count/quality or breadboarded circuit. An example of the latter most is an interesting design (by DUO of the DIYAudio forums) of a variable transconductance amp with real-time user adjustable output impedance. Even a quickly hobbled together prototype with “non-audiophile approved” parts is quite an interesting revelation, most particularly when you can dial an adjustment to the pace of that dance that occurs in the matrix that is the room/loudspeaker/amplifier damping factor/source material interface.

For a value of surplus parts less than the cost my last pair of EH 2A3 Gold Grids, (i.e. less than $80), and a few hours labor, this cute little beige box is not easily embarrassed in the company of the big boys.


the floor is yours, gentlemen.... :thumb:

jrebman

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Re: Fostex F120
« Reply #1 on: 9 Jul 2008, 10:16 pm »
Chris,

Thanks so much (again) for the very detailed account of the first Fonkensteen listening test!  Sounds like something that I'm going to be very happy with -- dynamic snap and bottom end authority -- I like that :D.

I finally did find info on the Mono 7s and they even look affordable!  Bet those in combination with one of his preamps would make a nice front end.

Just got off the phone with Eddie -- looks like Carina will be here next week, and although the speakers she'll be driving are set, I will at least want to try them on Fonkensteen.

Thanks again,

Jim

jrebman

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Re: Fostex F120A
« Reply #2 on: 10 Jul 2008, 06:01 pm »
Chris,

Couple more questions:

Amplifier raw power aside, was there any particularly noteworthy tonal synergy with any of the amps -- specifically did the EL84, EL34, 300B or 2A3 stand out in terms of overall presentation and/or synergy with the F120A?

Can you also say a bit more about the sonics of the speaker in terms of resolution, tonal balance, bottom and top extension, etc.?

And last but not least, how big was the room you were listening in?

Thanks,

Jim

chrisby

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Re: Fostex F120A
« Reply #3 on: 11 Jul 2008, 06:48 pm »
Chris,

Couple more questions:

Amplifier raw power aside, was there any particularly noteworthy tonal synergy with any of the amps -- specifically did the EL84, EL34, 300B or 2A3 stand out in terms of overall presentation and/or synergy with the F120A?

Can you also say a bit more about the sonics of the speaker in terms of resolution, tonal balance, bottom and top extension, etc.?

And last but not least, how big was the room you were listening in?

Thanks,

Jim


Aye, that's certainly a factor - my little room is so small ......

(OK, chris, how small is it?)


.... you need to step outside to change your mind


Actually, it's a converted bedroom, approx 220sq ft - of which 20% is an alcove at one end were the equipment stands and spare speakers are located (at last count 5 pairs in the room)

The next session this weekend will be in a much larger space at Dave's - for both some measurements, and more critical test of listening. I think few of us possess "perfect" listening rooms, but this space tends to get in the way far less than any other we have readily available.  Approximately 400sq ft, open plan - it's the lofted ceiling from 74" to over 16ft that makes for a calculated 350cubic meters of air  - that's approx 7.5 times the volume of my room.     

Regarding the amps , to make it short, the Mono7's were by a clear margin the most synergetic match of this group.  The session also reaffirmed my personal predilection for moderate powered DHT's, although now doubt higher powered SETs (transmitter tubes, etc)  could likely also float my boat. On the few occasions that I've heard such big-bore single-strokers (i.e. at VSAC shows) , it's always been to demonstrate just how effing loud the system can play. My hearing is already severely damaged / deteriorated - I don't need to further the degradation.

So, in other words, as much as I loved the sound of the Carina, and other low powered EL84 SE amps I've heard from the Decware Zen to the Glow, I suspect that the F120A & FX120 will need more torque than that to get the job done in anything but a small space and at modest SPL's,  but as always, YMMV.

   
how's that for equivocation? 

TerryO

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Re: Fostex F120A
« Reply #4 on: 11 Jul 2008, 07:20 pm »
Chris,

Was your modded Scott amp among the cited amps? I know that I thought they were very good the last time I heard them up on "The Mountain." I have no doubt that the Mono 7's also sounded good. The Wright Sound products have always been highly regarded for sound AND value, although they don't get as much press as they deserve.

Will we be hearing this combo in August?

Best Regards,
TerryO

jrebman

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Re: Fostex F120A
« Reply #5 on: 11 Jul 2008, 07:36 pm »

Aye, that's certainly a factor - my little room is so small ......

(OK, chris, how small is it?)


.... you need to step outside to change your mind

Ba-da-bump


Actually, it's a converted bedroom, approx 220sq ft - of which 20% is an alcove at one end were the equipment stands and spare speakers are located (at last count 5 pairs in the room)

Sounds like my officeexcept it's only 140 SF and has two pairs of speakers (unless you want to include the Heresys that are in their boxes and waiting for me to make up my mind what to do with them.

The next session this weekend will be in a much larger space at Dave's - for both some measurements, and more critical test of listening. I think few of us possess "perfect" listening rooms, but this space tends to get in the way far less than any other we have readily available.  Approximately 400sq ft, open plan - it's the lofted ceiling from 74" to over 16ft that makes for a calculated 350cubic meters of air  - that's approx 7.5 times the volume of my room.     

That's very close to what I have except with a constant 9' ceiling and two large stairwell openings.  That sounds like it will much more closely approximate my space.

Regarding the amps , to make it short, the Mono7's were by a clear margin the most synergetic match of this group.  The session also reaffirmed my personal predilection for moderate powered DHT's, although now doubt higher powered SETs (transmitter tubes, etc)  could likely also float my boat. On the few occasions that I've heard such big-bore single-strokers (i.e. at VSAC shows) , it's always been to demonstrate just how effing loud the system can play. My hearing is already severely damaged / deteriorated - I don't need to further the degradation.

Well actually, top candidate right now is 6c33c based (not Lamm ML 2.1s though :-).)

So, in other words, as much as I loved the sound of the Carina, and other low powered EL84 SE amps I've heard from the Decware Zen to the Glow, I suspect that the F120A & FX120 will need more torque than that to get the job done in anything but a small space and at modest SPL's,  but as always, YMMV.

   
how's that for equivocation? 

Actually, great info -- thanks for taking the time to explain.

-- Jim

chrisby

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Re: Fostex F120A
« Reply #6 on: 12 Jul 2008, 02:49 am »
Chris,

Was your modded Scott amp among the cited amps? I know that I thought they were very good the last time I heard them up on "The Mountain." I have no doubt that the Mono 7's also sounded good. The Wright Sound products have always been highly regarded for sound AND value, although they don't get as much press as they deserve.

Will we be hearing this combo in August?

Best Regards,
TerryO


Terry:
Actually, no - after some recent tinkering, the EL84P/P it developed a bit of a hum that I haven't had the time to chase down yet.  With 3 other tube amps in the room and several more at the mountain, there's not been any particular urgency to resolve.  The Vaughn Audio Carina was the EL84 amp at this particular party.

The Mono7's will likely be attending in August, hopefully with an FX120 version, (Fonkexsteen?), and one or two new FE series boxes, but by that time the F120As should be well ensconced in their new home.

 
Jim:

Your main listening space sounds very interesting indeed - as does the 6C33 amp  - will that be sportin an Arkansaw  drawl?

cheers, y'all

jrebman

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Re: Fostex F120A
« Reply #7 on: 12 Jul 2008, 10:36 am »
Chris,

No, no Arkansas drawl this time, but my favorite sushi chef should be able to read the manual for me :D.

Hope to hear what you folks all thought of these in Dave's larger room.  All very encouraging so far.

-- Jim

JLM

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Re: Fostex F120A
« Reply #8 on: 14 Jul 2008, 06:01 pm »
I've been satisfied with my F200A with Channel Island Audio chip based 40 watt VMB-1 monoblocks (no longer in production  :( ), so I can understand the enjoyment you found in the F120A/SS pairing.  I've also tried a couple of different tube amps with the F200As and found them lacking horsepower or control of deep bass.

Is the F120A still available?

opnly bafld

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Re: Fostex F120A
« Reply #9 on: 14 Jul 2008, 06:17 pm »

Is the F120A still available?

Madisound still has both the F200 and F120 on their website.

JLM

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Re: Fostex F120A
« Reply #10 on: 14 Jul 2008, 08:19 pm »
Three or four years back Fostex had stopped importing the F120A to the U.S. and were considering the same for the F200A.

chrisby

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Re: Fostex F120A
« Reply #11 on: 14 Jul 2008, 08:50 pm »
Three or four years back Fostex had stopped importing the F120A to the U.S. and were considering the same for the F200A.

That'd be a shame - I had a chance to hear a fully "Purvinized" pair of F200A in the master's own lab a few weeks back. No cabinet or baffle of any kind, just perched on top of a pair of stands, as is Bud's preferred method for chasing out "nasties" (it's also no doubt an appeasement to the Sue factor)  :shh:     

chrisby

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Re: Fostex F120A
« Reply #12 on: 14 Jul 2008, 08:57 pm »

Is the F120A still available?

Madisound still has both the F200 and F120 on their website.


At $388 & $227, plus the shipping costs on approx 10lbs and 5lbs each,  it'd be no surprise if stock didn't rotate as quickly as say the FE126 or FE127.  Madisound could well be sitting on inventory of these and other higher priced models more than a year old.

floobydust

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Re: Fostex F120A
« Reply #13 on: 15 Jul 2008, 05:10 am »
 When I bought the (first) pair of F120A from Madisound in early 2007, I was pretty impressed... after talking to Adam (at Madisound) he informed me that Fostex would only be accepting custom build orders until the remaining stock of parts were used up (quantity unknown). He ordered another batch and I grabbed another 4 pieces. Not sure how many he ordered but apparently he still has some left. Needless to say they are considerably more expensive than the common FE/FF series that most DIYers are familiar with, but they are certainly a large step up. When you factor in the cost versus performance, I still think they are a good deal, a very good deal.

 Regards, KM

JLM

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Re: Fostex F120A
« Reply #14 on: 15 Jul 2008, 11:43 am »
chrisby,

Could you please link/define "Purvinized"?

I investigated flea amps for a couple of years, but got fustrated by the lack of affordable, uncolored speakers that could provide a "full range" sound (sufficient deep bass for music) and still be efficient enough to mate with a couple of watts.  And I'm a "speaker guy" so eventually went back to building a system around speaker ideals.  The ability of the F200A to reach deep and have such rich tone for still a half-way reasonable price is what lead me to them. 


chrisby

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Re: Fostex F120A
« Reply #15 on: 15 Jul 2008, 06:09 pm »
chrisby,

Could you please link/define "Purvinized"?


Treated / tweaked / enhanced by Bud Purvine, personally, rather than by proxy. 

In addition to the EnABL, Bud has a couple of other tricks up his sleeve - most notably that I've heard are his wonderful SE O/P transformers, and those silly little magnet wire pigtails (Electron Ground Pools)

Bless his soul, these things work, but sometimes his descriptions of "how/why" are a bit hard to follow.  :scratch:


Quote

I investigated flea amps for a couple of years, but got fustrated by the lack of affordable, uncolored speakers that could provide a "full range" sound (sufficient deep bass for music) and still be efficient enough to mate with a couple of watts. 

 

ah, yup - that's certainly a tall order. Providing your listening levels and space aren't huge, there are many candidates for the sensitivity and bass extension - but retaining dynamics and presence without coloration or constipation shortens the list considerably, and if domestic acceptance is a factor - you're pretty much toast.  "sure the living-room has the best sound honey, but not those in here, you don't"  :nono:
"oh, BTW dear, did I tell you my sister will be staying with us for a couple of weeks, so your meetings will need to be rescheduled?"  :o

this is a great hobby for bachelors!

Quote

And I'm a "speaker guy" so eventually went back to building a system around speaker ideals.  The ability of the F200A to reach deep and have such rich tone for still a half-way reasonable price is what lead me to them. 



If you want a really enthusiastic impression of the F200A, talk to the aforementioned Purvinator.

Sorry, I can't help myself,  maybe it's time to revisit my medication.


chrisby

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Re: Fostex F120A
« Reply #16 on: 19 Aug 2008, 06:58 am »
For anyone interested, and not following the thread at DIYAudio - I've been enjoying the heck out listening to these chameleons over the past few days - whether it's a matter of the legendary Fostex break-in, or just some very synergistic combinations, but  I'm really getting used to these things

 "Jim, can I write you a check?"  (just kidding )

Although at first the purchase price gave me pause, particularly after a couple of years with FE127'sin various enclosures, this recent weekend could best be described as an epiphany - too bad if this driver disappears from the catalog.

Jim - I hope you enjoy them as much as I have the past few days

cheers,

chris

jrebman

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Re: Fostex F120A
« Reply #17 on: 19 Aug 2008, 11:06 am »
Chris,

Thanks, and I'll be looking forward to trying them here with the RWA 30.2.  I'll also be looking forward to any reports coming from the speakerfest this coming weekend.  Bud will be taking them to his place for putting some polka dots on the boxes, and then next stop should be right here, where I'm thinking they'll be no more than 20 minutes from delivery to playing music :D.  I'm hopeful that everything is going to be very sweet and synergistic, then a bunch of changes to the rest of the system will come into play -- all aimed at simplification while taking everything up a few notches.

Glad you've been enjoying them, and as master builder you always have visitation rights.

Take care,

Jim

jrebman

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Re: Fostex F120A
« Reply #18 on: 2 Sep 2008, 08:49 pm »
Just a little update for those who might be following this thread.  The F120A Fonkens - a.k.a. the Fonkensteens - got a lot of very positive comments from the folks at the Vancouver DIY fest and now Bud P. has them in his possession in Washington state, has listened to them and is so far very impressed, but has a few things he's going to do to further improve them.  Then they will be on their way here, and a follow-up report will be coming sometime after that.

-- Jim


floobydust

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Re: Fostex F120A
« Reply #19 on: 4 Sep 2008, 06:54 pm »
 Hi Jim,

 Yes, be quite interested to hear your review on these... I emailed Dave and got the prelim plans... big box! Makes the driver look tiny, but it's the results that count.

 I still want to try an old-fashioned TL for a pair of these.. wish I had more free time.

 Regards, KM