I will take some pics sometime this week as I'm getting ready for the Audio Show. I still need to attach the Naksa badge you sent me. (and I may do some more cable routing within the enclosure since I'm posting the pics in public now ) My previous speakers were the Zus, which were actually 101db, 16ohm - worked great with an OTL amp at the time. The new ones are my design, open baffle, with a 15" mid and dipole AMT-style tweeter, with 2 more 15" woofers per side. It was VERY dynamic with the Naksa 80. Great tone, and I'm sure things will improve as the amp breaks in.
Just back home from the show. I'll get some pictures posted by tomorrow night. The Naksa 80 did very well driving my OBs. It took about 20-25 position changes (speakers and couch) to get the speakers dialed in to the room. By noon or so on Saturday, things were sounding pretty balanced. The Naksa 80 is terrific on vocals and guitar. Hugh has worked some magic here, as several folks commented that the amp had good tube harmonics, with solid state drive and clarity.
Thanks Brad!
Wonderful, the NAKSA has had a showing in Texas - and after your careful setup, it revealed some magic!
Interesting that it had good tube harmonics, with SS drive and clarity - this was precisely what I was aiming for! Years ago this was done empirically, now I have a lot of help from LTSpice. That is very satisfying, Brad, and thank you very much for doing the work.
Cheers,
Hugh
Wonderful, the NAKSA has had a showing in Texas - and after your careful setup, it revealed some magic!
Interesting that it had good tube harmonics, with SS drive and clarity - this was precisely what I was aiming for! Years ago this was done empirically, now I have a lot of help from LTSpice. That is very satisfying, Brad, and thank you very much for doing the work.
Cheers,
Hugh
Yeah, I think Hugh's lost his way.
I mean ... everyone knows that the best amps have 0.00000000001% harmonic distortion (which tubes can never do) and now he's deliberately making his amps sound like a tube amp! Regards,
Andy
Hi Hugh,
Still in the UK (Bedford). I moved from outright writing into Tech PR about 3 years ago for a large computer vendor. Is going well but so busy that I don't have time to scratch my **** most of the time..hehe
Put me down for a Naksa125 fully built. I've always meant to get one of your amps and I think now is the time my friend
-Raja
These are open baffle.
The Naksa 80 is driving the top 2 drivers.
They are crossed passively at 12db/1900hz, and a fairly flat impedance.
Tweeter is 4 ohm, midwoofer is 8.
The 15" midwoofer rolls off naturally at ~45hz
The Crown XLS under the table in the photo is driving the 4 15" subs, low passed at 63hz.
The photo is from Lone Star Audio Fest, so I'll pass along my compliments to the Embassy Suites
MY room has a lot more clutter and is a bit bigger.
The Naksa 80 is driving the top 2 drivers.
They are crossed passively at 12db/1900hz, and a fairly flat impedance.
Tweeter is 4 ohm, midwoofer is 8.
The 15" midwoofer rolls off naturally at ~45hz
The Crown XLS under the table in the photo is driving the 4 15" subs, low passed at 63hz.
The photo is from Lone Star Audio Fest, so I'll pass along my compliments to the Embassy Suites
MY room has a lot more clutter and is a bit bigger.
Hi John,
Ah, good question!
I've been unwell and reduced energy at present but getting better.
I'm working hard to release a new, more powerful amp.
I'm not a good marketer, and since my stroke I find writing difficult.
However, I would urge anyone out there who is curious, or pleased, about their NAKSAs......
Ciao,
Hugh
Ah, good question!
I've been unwell and reduced energy at present but getting better.
I'm working hard to release a new, more powerful amp.
I'm not a good marketer, and since my stroke I find writing difficult.
However, I would urge anyone out there who is curious, or pleased, about their NAKSAs......
Ciao,
Hugh
Last edited:
I look forward to being able to hear my N80s (powering mids and ribbons in my 3-way active Maggies).
Unfortunately, I have encountered a problem with the new active XOs that I was planning to implement at the same time. So either:
* I will be able to solve this problem, or
* I will stick with my current active XOs and solve the new active XO problem, later.
Regards,
Andy
Hopefully nothing insurmountable, Hugh.
As I think I showed you, the new active XO uses buffers made with a complementary pair of 2SK246 and 2SJ103, having a pot between the 2 Sources to get zero DC offset.Out of 60 of each, I was able to get 14 complementary pairs having Idss matched to within 0.1ma - so I thought I was travelling well!
I made up one of your E-F PSes to give +/-25v and the first pair I tried worked well - a Source res of 24.8 ohms on the 2SK246 and 50.3 ohms on the 2SJ103 resulted a DC offset less than 0.1v. So I thought I was onto a good thing!
However, with the next pair of 2SK246 & 2SJ103 I tried, I couldn't get zero DC offset, no matter what the Source resistors were!
So I put it aside and got on with some other things and will go back to it in a week or two. I need to check that, by mistake, I didn't have the 2SJ103 'flipped' (in terms Source & Drain) and I'll try a 3rd pair of 2SK246 & 2SJ103, to see what I get from them.
Regards,
Andy
This is unfortunate. Producing a series of identical jfet designs is fraught with problems; the buggers have a huge tolerarance, and if you don't have lots of nfb, it's very difficult to predict the outcome like a bipolar circuit.
I admire your perseverance. You've done a lot of finicky building!
Hugh
I admire your perseverance. You've done a lot of finicky building!
Hugh
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.