Hi,
My current reference amp, a JE Labs SRPP 45 SET, had a problem and so I borrowed an F3 clone. And was promptly reminded how much I love that amp. I've previously owned an F3 clone and a Pass F3. I am now considering buying either a Pass F3 or J2.
My speakers are now a Fostex BLH and will be (shortly) Tonian Labs Classic 12s using the 12" PHY driver. I listen at moderate volumes and have found the 45 enough power for speakers in the 95 dB/W range that are an easy load in my large room so power is not really an issue.
I like the SET sound but realize the FWs are not quite SETs (just different, and better in many ways). But I what I value more than anything else are body, timbre, and smoothness! I cannot handle an amp that sounds not quite fleshed out or lacking proper timbre. I found that the F3 absolutely did NOT have problems of this sort. In fact I only went back to SET due to boredom, the occasionally need to hear that "magic big vocalist" thing, and an apparent unconscious fetish for tubes.
I guess what I'm getting around to is this: could someone compare the F3 to the J2 for me in the criteria I outlined above? Are the mids and highs very similar? Anything else I should know about?
Since the designs are so similar I would expect a lot of similarity. The J2 seems to have newer/"better" parts which maybe does something. The F3 I believe is one gain stage which to me is an advantage as I don't need the extra gain or power.
The techie nerd in me is wondering about the differences in NFB as well.
My current reference amp, a JE Labs SRPP 45 SET, had a problem and so I borrowed an F3 clone. And was promptly reminded how much I love that amp. I've previously owned an F3 clone and a Pass F3. I am now considering buying either a Pass F3 or J2.
My speakers are now a Fostex BLH and will be (shortly) Tonian Labs Classic 12s using the 12" PHY driver. I listen at moderate volumes and have found the 45 enough power for speakers in the 95 dB/W range that are an easy load in my large room so power is not really an issue.
I like the SET sound but realize the FWs are not quite SETs (just different, and better in many ways). But I what I value more than anything else are body, timbre, and smoothness! I cannot handle an amp that sounds not quite fleshed out or lacking proper timbre. I found that the F3 absolutely did NOT have problems of this sort. In fact I only went back to SET due to boredom, the occasionally need to hear that "magic big vocalist" thing, and an apparent unconscious fetish for tubes.
I guess what I'm getting around to is this: could someone compare the F3 to the J2 for me in the criteria I outlined above? Are the mids and highs very similar? Anything else I should know about?
Since the designs are so similar I would expect a lot of similarity. The J2 seems to have newer/"better" parts which maybe does something. The F3 I believe is one gain stage which to me is an advantage as I don't need the extra gain or power.
The techie nerd in me is wondering about the differences in NFB as well.
J2 v F3
Man, if you like an SET, and enjoy the F3, you will love the J2. It sounds much closer to an SET than the F3, with that "sweet" sound that SET's have. But it comes with the extended bandwidth and top to bottom coherence of SS. Neat trick.
So good even my teenage son is coming home and listening to music after school. Never had that happen before.
Man, if you like an SET, and enjoy the F3, you will love the J2. It sounds much closer to an SET than the F3, with that "sweet" sound that SET's have. But it comes with the extended bandwidth and top to bottom coherence of SS. Neat trick.
So good even my teenage son is coming home and listening to music after school. Never had that happen before.
Thanks for the feedback, John!
I assume you are running Lowthers?
What linestage? I am thinking the F3 might be better with higher-gain linestages given its low gain. With such a linestage its single gain stage could be an advantage. OTOH the J2 might sound better with passive or low-gain line stages?
I assume you are running Lowthers?
What linestage? I am thinking the F3 might be better with higher-gain linestages given its low gain. With such a linestage its single gain stage could be an advantage. OTOH the J2 might sound better with passive or low-gain line stages?
According to FW site it's .4 ohms (J2) vs 1 ohm - a pretty trivial difference into almost any load, I think. But maybe not.
I have often found no real diff in DF once it gets above 3-4. Of course that is very speaker-dependent.
For the most part I think most widebanders sound as good or better with low DF. So I think that is a + for the F3 if anything.
F3 vs. J2
Personally, I'd give the nod to the J2 particularly for how it handles the treble. But as you suspect, it's a close call. I'd not think you'd give up anything in the midrange. I just had the J2 on my Rethm Saadhanas (Lowther DX-55 modified) and liked it better than my Yamamoto 300B. Sacrilege and holy cows gone to hell but there it is
Personally, I'd give the nod to the J2 particularly for how it handles the treble. But as you suspect, it's a close call. I'd not think you'd give up anything in the midrange. I just had the J2 on my Rethm Saadhanas (Lowther DX-55 modified) and liked it better than my Yamamoto 300B. Sacrilege and holy cows gone to hell but there it is
Yes. My comment was based on the wrong assumption that like the F2 the J2 output impedance was 15 ohms... looks like the F2J (thats the one i want, alas i'll have to live with the F2 until the output devices become more reaonably prices or i become richer)
dave
J2 is quite different from the F2. There are a few people who
have played with the F2J (I know, this is getting confusing)
and it is a strong improvement over the F2 because the
distortion is much lower. It still has a 16 ohm output
impedance, and for that reason, a lot of people will prefer the
F3. With some of the exceptionally detailed FR drivers, I
think the F3 sits in the top rank.
Obviously i'm in the set of the confused
I went looking at the J part of the F2J but set it aside when i saw the ~$50 part cost (am i confused there too?). Once F2 is actually built it will be time to examinf cash-flow again.
dave
You should try even skinner. Solid & 24g from a length of Cat 5 is a cheap experiment.
dave
Holy cow, indeed, Srajan! Looks like Nelson finally gotcha! And my guess is that as silicon carbide JFET technology evolves things will get even better sounding and better thermionically.Personally, I'd give the nod to the J2 particularly for how it handles the treble. But as you suspect, it's a close call. I'd not think you'd give up anything in the midrange. I just had the J2 on my Rethm Saadhanas (Lowther DX-55 modified) and liked it better than my Yamamoto 300B. Sacrilege and holy cows gone to hell but there it is
Lately I have been using Clear Day which is a very thin (22g?) single-core silver. Quite good stuff for cheap.
J2 is quite different from the F2. There are a few people who
have played with the F2J (I know, this is getting confusing)
and it is a strong improvement over the F2 because the
distortion is much lower. It still has a 16 ohm output
impedance, and for that reason, a lot of people will prefer the
F3. With some of the exceptionally detailed FR drivers, I
think the F3 sits in the top rank.
Thank you for chiming in, sir. (Thank you also Srajan.) I am not sure if the F2(J) would work with my Tonian speakers or not - there is an xover as it has a ribbon tweeter and I don't think it's just a single-cap affair. Tony's xovers are top-secret stuff (and amazing like the rest of his speakers).
I see Reno has a demo F3 now which I am very very tempted to snag. I'm sure the power is plenty. The 10K Zin might concern me but for whatever reason the F3 seems to work just fine with tube pres with relatively high Zout. I could detect no signs of impedance mismatch at all last time I had one.
Then again it seems the J2 is probably even better.
Allen is your friend ?
Yes. I was his Mac tech support person for quite a while (by email, phone & post). He came and stayed with us when he visited the last real VSAC.
dave
Thanks for the feedback, John!
I assume you are running Lowthers?
What linestage? I am thinking the F3 might be better with higher-gain linestages given its low gain. With such a linestage its single gain stage could be an advantage. OTOH the J2 might sound better with passive or low-gain line stages?
Hi Paul:
Yes. DX4's right now as I am tuning up a customers system.
Using the Pass Labs X1 line stage, so I have plenty of drive. Not sure how a passive pre would affect the sound with these, I just have not tried it.
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