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First Watt ~ ALEPH J -vs- F3 ~


Born2RockU
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                                                                     Who here has one ?

  

(http://www.firstwatt.com/alephj.html) Aleph J -vs- F3 (http://www.firstwatt.com/f3.html) ? 

                                           What the pro's and cons of these two amps ?

 

                            I would be demoing them on my K-402 Horn's on my Jubilees !

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I believe @richieb has an F3. Jubes too.

 

I have a J2. Except for a couple of specs JFET vs MOSFET the J2 and Alpha J look similar on paper.

 

I really like my J2. Sold my VRDs and Wright 2A3 mono blocks. To me the First Watt is more like the 2A3, than VRDs in a good way. Dead quiet, huge sound stage, crisp and clear. I never thought I'd see a day with no tube amps....Never say never

 

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55 minutes ago, Schu said:

sit-1 or sit-3... that's where you want to be.

https://www.stereophile.com/content/first-watt-sit-3-power-amplifier 

The Sit-3 seems to be the 'moutnain top' of First Watts.  Anyone have one here ? Or, have demo'd one before?

I would consider a SIT-3 if I can get some friends comments of a Sit-3 on Jubilee K-402 Horns...

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I think that the application (on K-402s driving the 2" compression drivers) says a little more consideration is needed than a single recommendation of "buy this", unfortunately.  Here is the current First Watt amplifier comparison chart that tells you a little more:

 

2053607048_2020FirstWattamplifiercomparisonchart.thumb.JPG.7e150181a6c9feb611f1d94665be6f22.JPG

 

The amplifier that I use is the F3.  I was looking for an F5 at that time (2011--nine years ago), but the F5 had been discontinued by that time after selling 100 units.  The F3 stayed much longer in Mr. Pass's inventory and apparently sold many more units (reportedly until the sales started to decline and the FETs stopped being available from the manufacturer--SemiSouth). 

 

As you can see above, the F3 has the lowest distortion and one of the lowest noise levels of all the First Watt designs to this day.  For a comparison, the SIT-3 has 20x the harmonic distortion as the F3--something that I'd pay a little attention to in the probably more audible application driving the Jubilee compression driver.  The noise level (50 microvolts) is also one of the lowest that Mr. Pass specified--something that I also find to be quite critical.  My F3 is actually a little noisier than I'd like it to be--but this is mostly due to the connections (unbalanced RCA connectors) even using hybrid XLR-RCA cables with shielding running the length of the cable to cut down on the common mode noise to the degree possible. These are important factors for the application, I've found, and are much different than using a First Watt amplifier to mono-amp a three-way La Scala or Khorn, etc.

 

If you can find a used F3, that would be be my first recommendation, since there are so many more of these that were sold.  However, the F1J or F2J are transconductance amplifiers (i.e., extremely high output impedance--greater than 15 ohms) and are even cleaner in terms of their output using compression drivers since the transconductance nature of their operation means that they totally ignore the back-EMF from the driver.  They wouldn't work in a mono-amping application trying to drive loudspeakers using passive crossovers.

 

Note that the smallest FETs on the F3 tend to de-solder themselves over time because of the higher temperatures that are seen at their soldering lugs.  That's the small devices at the bottom underside left and right Allen-head screws fastening the little PC boards to the heat sink in the picture below.  It only takes me 5 minutes to disassemble the bottom panel of the unit and put a soldering iron on the terminals to reflow the solder again --and I'm good for another 3-4 years before it has to be done again:

 

2_hero_open.jpg

 

Chris

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53 minutes ago, Schu said:

sit-1 or sit-3... that's where you want to be.


And you say this after hearing some or all others listed?  I can’t make that same statement  with only hearing/owing the F3 and ACA amps. Did own the Pass XA25 - it’s gone, still have the F3. From Pass himself the F3 was the finest sounding single stage solid state amp available.Granted this was before the SIT series but still speaks volumes. Oh, and did own VRD, three times I believe - still have the F3. Every FW has some degree of a family sound, small differences in power and design but from all reports sound extremely good. The JFET amps are reputed to be the most single ended tube like sound.
 

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One thing to watch when buying second hand--overseas amplifiers usually have 240V (incoming AC power voltage) transformers--while those in the North America use 120V.  This is an issue if you're thinking about buying an amp from across the pond.

 

Chris

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26 minutes ago, richieb said:

The JFET amps are reputed to be the most single ended tube like sound

 

32 minutes ago, Chris A said:

My F3 is actually a little noisier than I'd like it to be--but this is mostly due to the connections (unbalanced RCA connectors)

 

I specifically wanted the J2 for the balanced connections. The F1J has balanced connections and JFET but is not available new. Just another data point.

 

FWIW, I've never heard another First Watt and I bought the J2 on reputation alone. Happy I did. Seems to be enough good feedback out there that there would be little risk in buying used, trying in your system and selling if you did not like it. Your room, your equipment is about the only way to really know.

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There is much info over at DIYAUDIO on these amplifiers.

 

These are both designs that use JFETS. If you build it yourself (which I encourage), you may have to work hard to obtain some of the parts. If you buy factory versions (new or used), you may also need to do a bit of searching, since they both had limited production runs. If you buy a used DIY one, it is a bit of a crap-shoot regarding quality (one hint - be very wary of any that were built by Tim Rawson)

 

Good luck,

-Tom

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The J2 series are much easier to find than F3, that being they are still in limited production. At some point First Watt production was shifted to Pass Labs and family relatives to Pass were overlooking that production. The early F series were all made by Pass himself as a “kitchen table” project. Pass bought all the JFET inventory of the now defunct SemiSouth hence production of the J2 continues. The F3 was pre SemiSouth and used JFET from Lovoltech with production at around 100 amps + - . 
As much as I enjoy the F3 I may well try and J2 but with only 10 additional watts and reports of very much the same presentation I may save my shekels. One thing to keep in mind at least with the J and F3 is they run fairly hot while consuming 200 watts at the wall. Class A doncha’ know —

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I'm sitting here listening to WWOZ jazz festival in place with Klipsch Horns, one from the late fifties and the other from the early sixties, the original '90's Aleph 1, and a Supratek pre amp. This system has been gold to me for the lat ten years. I do wonder what a few more than these 30 watts might do for me from time to time (like right now)?

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Rich, He was asking about the Aleph-J not the J2. My understanding is that the Aleph-J is no longer in production. 

 

If the OP is interested in factory versions (new or used), there is a vendor in Reno that carries them. I believe he also has a liberal return policy if things don't work out. 

 

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23 hours ago, Born2RockU said:

              .

                                                                     Who here has one ?

  

(http://www.firstwatt.com/alephj.html) Aleph J -vs- F3 (http://www.firstwatt.com/f3.html) ? 

                                           What the pro's and cons of these two amps ?

 

                            I would be demoing them on my K-402 Horn's on my Jubilees !


I have done vertical bi-amping of my Jubs with a pair of F3 amps and have found them to be excellent sounding and they have been extremely quite on the K402 where I would have to put my ear right at the mouth of the K402 to detect any hiss.

 

There is also another feature of the F3 design that has a benefit when driving expensive drivers like my TAD 4002 and that is due to it’s design using capacitors coupling to the loudspeaker which offers DC Voltage protection for the loudspeaker should it have a failure.  The Aleph J (like many amplifiers) has no such protection and under certain failure conditions could send DC Voltage to the loudspeaker driver leading to its destruction so if you choose it you might want to consider a safety capacitor for the HF driver at least.

 

miketn

 

 

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9 hours ago, Chris A said:

My F3 is actually a little noisier than I'd like it to be--but this is mostly due to the connections (unbalanced RCA connectors) even using hybrid XLR-RCA cables with shielding running the length of the cable to cut down on the common mode noise to the degree possible.


Chris while I haven’t had any significant issues mixing balanced and unbalanced equipment in my system but I have spent a significant amount of time looking into the issues while helping some others who have suffered with noise issues.

 

I have installed high quality Jensen Isolation Transformers at the input of all my amplifiers because in the real world issues of connecting our equipment into a system it offers the best solution IMHO from a noise and signal preservation perspective and allows the equivalent combinations to perform at their best and while not inexpensive it is worth the investment for me.

 

miketn

 

My Jensen ISO MAXX Collection 👍🙂

 

These are Mono and  2 Channel versions with 1:1 ratio transformers and the input/output connections can be configured with XLR or RCA if desired. 
 

I prefer the XLR in/out and if needed I use a short balanced to unbalanced cable for the amplifiers requiring a single ended RCA unbalanced connection.

 

I also recommend these 1:1 ratio versions for the F3 due to it benefiting from a higher drive level on its input.

 

097DC6CD-4902-49DA-8282-C32702970DF5.thumb.jpeg.0790fbfe9e63b2507da8be2f2d5c097b.jpeg

 

CA4ED7FE-C572-46E7-A583-5E9AC5C95065.thumb.jpeg.80b5927e0f58aaab76a36b16a12a3a97.jpeg

 

 

The PC-2XR below is designed for pro level to consumer level equipment matching offering about -13db voltage reduction due to a 4:1 ratio transformer which can offer real benefits when a system has to much gain especially when matched with high efficiency loudspeakers.

I use these with my Cary 2A3 amplifiers.

 

AFFF8F31-F79C-497F-957D-BAD78988D6D9.thumb.jpeg.865f20c40788a0f0d96c9ce6bb4c93f4.jpeg

 

 

 

 

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On 4/24/2020 at 8:28 PM, Born2RockU said:

              .

                                                                     Who here has one ?

  

(http://www.firstwatt.com/alephj.html) Aleph J -vs- F3 (http://www.firstwatt.com/f3.html) ? 

                                           What the pro's and cons of these two amps ?

 

                            I would be demoing them on my K-402 Horn's on my Jubilees !

I've had both on my jubes. Still have the F3.

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10 hours ago, Born2RockU said:

https://www.stereophile.com/content/first-watt-sit-3-power-amplifier 

The Sit-3 seems to be the 'moutnain top' of First Watts.  Anyone have one here ? Or, have demo'd one before?

I would consider a SIT-3 if I can get some friends comments of a Sit-3 on Jubilee K-402 Horns...

Ivanhoe bought my jubes. He has all the SIT amps, including the SIT-3 on the jubes.

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