Solid State or Tubes with your NX-series speakers?

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KTS

Re: Solid State or Tubes with your NX-series speakers?
« Reply #320 on: 23 Jul 2025, 12:13 am »
This is the Aleph Jzm it is the Zen Mod’s version available on the DIY audio website and uses 3.3uF cap in the c-1 position, I mention that because the original Aleph J used a 1uF cap and I am not sure which version you have and did not want to lead you astray. I built this one as a dual mono, it sounds more to my liking than anything I have had to this point.

Tyson

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #321 on: 23 Jul 2025, 05:59 am »
This is the Aleph Jzm it is the Zen Mod’s version available on the DIY audio website and uses 3.3uF cap in the c-1 position, I mention that because the original Aleph J used a 1uF cap and I am not sure which version you have and did not want to lead you astray. I built this one as a dual mono, it sounds more to my liking than anything I have had to this point.

Mine are all 1uf.  Which cap should I replace?  It looks from your picture that it's the one in the middle of the board?

KTS

Re: Solid State or Tubes with your NX-series speakers?
« Reply #322 on: 23 Jul 2025, 01:32 pm »
Mine are all 1uf.  Which cap should I replace?  It looks from your picture that it's the one in the middle of the board?

It should be C1, but I am not sure what iteration you have. It is best to find the schematic and use it to determine, however all the Aleph J’s I have built it has always been notated as C1 on the board and the schematic.

Tyson

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #323 on: 23 Jul 2025, 05:09 pm »
Perfect- thank you!

KTS

Re: Solid State or Tubes with your NX-series speakers?
« Reply #324 on: 24 Jul 2025, 12:07 am »






Not sure if you have the rectangle or square boards, but here is how I set mine up, be sure you cover your leads with heat shrink to prevent any unwanted contact if you run them behind the board to solder.

jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #325 on: 24 Jul 2025, 01:17 pm »
I can say my First Watt Aleph is a great match for the NX Oticas and the BA3 is great with the Line Forces. 

I’m actually excited for you to get those line arrays.

Me too, and Thank You for your advice!

jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #326 on: 24 Jul 2025, 01:24 pm »
jmimac351, thanks for the insight on the SIT-3 and SIT-5. It’s definitely a game of speaker matching with the First Watt amps. They are all unique, if you get it wrong it’s a bit disappointing, but get it right and it’s amazing. The ones that really are more universal to speakers are the F5/F5M, J2, and AlephJ. F5/F5M being the safest bet for most speakers considering power and neutrality. I will probably take a break from further Pass offerings for a while. I have an upcoming Wolverine amp project which should be interesting. It’s more of a high powered (200+watt)neutral amp with distortion numbers lower than even the lowest distortion production amps, but it’s going to be built with all the best parts. So we’ll see what comes out of it. Probably tackle that one in the fall.

Some may find this interesting and / or already be aware.  So, in a thread about First Watt F7, I found this, referencing "F5 stuff":




And then there was this:




And then there was this for "timing"... "Halloween" / "Christmas"...




But wait, there's more... then I found this, and spoke to a dealer who confirms new stuff coming.  It appears to fit... across the board price increase just hit.  So they got pricing out of the way and then will introduce a new series with "replacements" but "pricing stays the same". "New amps but we kept pricing the same!"

Maybe I just made all of this up...



« Last Edit: 24 Jul 2025, 08:32 pm by jmimac351 »

jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #327 on: 26 Jul 2025, 04:19 pm »
So, with the First Watt SIT-3 having 11.5dB input gain because of a gain stage(s) being eliminated, "drive it with a preamp", etc... it would help if the preamp would output higher gain.  In fact, I haven't actually heard the SIT-3 "at full power", and Danny's Dodd preamp didn't drive it to full output either.

Well, my KX-5 Twenty will output higher voltage, by swapping out 2 resistors - and I'm just now getting to it. 

I can add 6db of gain with a pair of resistors I got from Ayre a few years ago and never "needed", until now.  I can likely go much higher than 6db with another value (and am digging into that too, because why not?).   

Below is a picture of one of the boards inside the KX-5 Twenty.  Then you can see a closeup of the resistor that needs to be swapped.  The leads are pre-bent to help getting installed. 

Question... Am I looking at needing the smallest allen key on the planet to loosen a couple of allen screws down in there?  I have a hunch a few of you have dealt with connectors just like this.  I have not, and don't want to tear anything up. 

I have as small as 1.5mm allen key...whatever the smallest one is that I have, it's too big.  If someone happens to have experience with these little connectors, know size, etc. - I'm all ears. I can find out next week, but trying to play with it this weekend.

Thank you.













jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #329 on: 26 Jul 2025, 07:06 pm »
Thank you!  I have a small electronics kit that has one T-5, and that looks super small to me.  I had no idea some of the fasteners you all are playing with are that small!  It's hard to even tell if it's a torx bit, I guess so.  Can't hardly even see it... you just sort of have to smell it for "size".  :green:  I'm sure they never get lost rattling around inside an enclosure! 

I've got a kit coming tomorrow, then we'll give that little SIT-3 amp the spurs (maybe).  It seemed to do OK with the Duette, for the gain I could supply it.  I would like to hear it with the Encore... and then the "new Encore", which reminds me... Danny had some renderings I was going to see, and then a phone rang or something... 



jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #330 on: 27 Jul 2025, 10:54 pm »
I HAVE MORE GAIN! HAPPY!

Amazon brought one of these kits this morning with little bits with OD of a human hair.  Sheesh.

I see what's going on it there with that pickup point and got the resistor swapped out, which is supposed to provide another 6db of gain for the SIT-3 11.5dB input gain. 

Well, it sure sounds like it did, and that did the trick... I now have output gain from the KX-5 Twenty that I need for the SIT-3, but I am going to see how much more gain I can add - will reach out to Ayre.  Jake seemed indicate it could go higher.  Also, I am digging into whether there are some better quality of this type for the application, who knows.  I've reach out to Nick and HFC about what he thinks.  Apparently Audio Note has some good ones.  If there are other "known" good resistors for this application, let me know.  Perhaps what I have is fine.  Sounds good!

Here is the other thing... I've really learned more about what speakers the SIT-3 likes.  I put the Duette back in and it was Happy Happy Happy... it just did not like that Clearwave speaker.  And... that very like also means - X-LS Encore should be really, really good. 

Which is cool, because Danny has a new Encore coming out. 

I will still try the SIT-3 with the 20/21 Line Arrays, just because. 

Bottom line for me as it relates to SIT-3 (and probably SIT-5)... stick to 2-way speakers that are EASY to handle. 

Have 2-ways that don't have "issues" and are squared away on their own.  Do they "need" am amp to throw them around?  Not this amp. 

He's what has happened with the Duette... after Danny put his brain on the crossover, this SIT-3 amp is just letting that Scan-Speak 8" EAT.  The speaker has become fuller, but not "flabby".  I have lowered the volume on the sub, don't need as much low end.  The speaker is just able to breathe and do its thing, while being fed watts that sound like "Triode Tube Amp". 

Just because the First Watt description says "4-8ohms" - be careful.  The speaker has to be "buttoned up".

And... make sure your preamp has some horsepower on tap - if needed.

However, if you get it right... it is really, really good.  I wish I could hear the new Encore with this FW Sit-3 amp and preamp.  One day.

In the meantime, I will hookup the Studios and see how they play ball.  Could be that many of Danny's 2-ways would like the SIT-3, if your preamp has the gain to run it.








jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #331 on: 27 Jul 2025, 11:56 pm »
So, for those flying at 35,000 ft thinking about a First Watt SIT-3...

A 2-way speaker with this sort of impedance works great with it... if you have the preamp to drive it.

Wilson Audio Duette with GR-Research crossover.

I'll update others as I find they work... Encore next up.  Maybe this is useful to others, maybe not.  I'm connecting my own dots and sharing.


jmimac351

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Re: Solid State or Tubes with your NX-series speakers?
« Reply #332 on: 31 Jul 2025, 12:13 am »
The GR-Research X-LS Encore also is a great match with the First Watt SIT-3.  So, the Wilson Duette loves it and the Encore loves it.. both 2-ways that don't cause a lot of trouble, don't need a bunch of current to be happy. 

I suspect it will also be great with the NX-Bravo and various other 2-ways Danny has.  It's too bad - when Danny heard it it sounded broken with the NX-Treme... and Encores were sitting right there, as well as the new transmission line tower.  Ron would have loved it at his place.

As for the SIT-3 overall, since it's been hard for me to find definitive opinions about what to match it with, perhaps this is helpful.  Believe me when I tell you, I have asked different people "in the know" the same general questions different ways...they all dance around it.

You're going to have to find out for yourself, but these guardrails may help with some of the "First Watt Stuff".

As for the First Watt SIT-3:

  • Don't assume any "4 to 8ohm" speakers will work, just because it fits that spec and that is mentioned as one of the criteria... 16ohm speakers don't work either!
  • Don't assume an "easy 8ohm, 95dB speaker" will work, if it has more than 2 drivers in each enclosure... don't assume an "efficient 8ohm speaker will be a great match for the SIT-3."  The NX-Treme sure wasn't.  I thought it was going to be awesome, in fact, it was unlistenable.
  • Make sure you have a preamp that allows you to increase OUPTUT voltage / gain, not just the ability to adjust the INPUT sensitivity of the source to match it with sources of different output levels - you must be able to provide more output voltage to the amplifier. After swapping out the output gain resistors in my KX-5 Twenty, this amp is getting the juice it needed. That was with resistors to provide +6dB gain. The amp has 11.5dB gain. So +6db is right at the low end of what's needed, after listening.  I have the resistor specs needed to go to +9dB and +12dB.  I LOVE MY PREAMP!
  • The SIT-3 is "missing an input stage" on purpose, to make it "purer"... but your preamp has to pickup the slack to get the output from the SIT-3 you'd expect - figure on running your preamp WIDE OPEN THROTTLE if you cannot adjust its output gain. Even with that, you might get the SIT-3 to about 2/3 of its total output. (That was enough to give me a taste and I wanted MORE). The SIT-3 needs about 3.1V at the input (UNBALANCED) to reach full output.
  • If you have the preamp to run it, and match it with speakers like I've described, you may think it's the best amp you've ever heard, or not.
  • It is not heavy, at all, and is so nice to be able to move around.  It's like a little Magic Box.
  • The reason Nelson and anyone at Pass won't tell you how well it will work with "your" speakers is because, if they haven't heard the matchup... it is risky to recommend and they just don't know.  This is probably why KE at Pass elegantly ignored my inquiry about the SIT-5 and steered me toward the XA25... he was doing me a favor, he was watching out for me and I didn't realize it at the time - but now I have heard "Why".  Although... I am also certain the SIT-5 would be fairly incredible on the Duette, and the Duette could handle their power... but I was inquiring about an amp to pair with 41 driver Line Arrays.  I could have ended up with a very expensive disappointment!
  • Think "Proper tool for the job" when matching this amp up, ESPECIALLY for this amp.
  • I got great advice from Nelson and Kent at Pass... as frustrating that I could NOT have my cake and eat it too was... they looked out for "The Customer" - and Nelson has built a great company and surrounded himself with Good People.


If you are willing to deal with that, and can use simple 2-ways, you may love it - but expect a mix of speaker pairing disappointment and "Wow... I have never heard THAT before..."  Such is life.