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Need Some NHT Crossover Assistance, Please
- Thread starter Dr. Morbius
- Start date
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
You have your speakers plugged into your fax machine? ...How does that sound?:scratch2:
Ink jet printers are the new tube amps. There is a pair of Belden 6100UE wires running into the next room where there's a receiver and computer.
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
:sigh: Yeah, I've been putting off finishing up a couple of DCM projects. I need to get on it.
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
Thanks. Yes I enlarged the holes in the PCB, but made them too big. That was the wrong thing to do. I need to get a few more drill bits to do it right.
Peel & Seal has an aluminum backing, but this version from Menard's has a white vinyl backing so it can go on the outside of gutters or siding. Other than that it's the same stuff.
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
Thanks. Yes, they sound great in that 10' x 11' room. :thmbsp:
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
I had an epiphany today while standing in line for hours at the BMV to get my tags and driver's license renewed. :scratch2:
It dawned on me that I have some extra 22 AWG silver plated copper wire with a Teflon jacket for a different project. Rather than use left over snippets from the capacitor leads, I could use some of this uberwire. :nerd: So after wasting most of an afternoon, I came home with tags and license in hand ready to give it a try.
After a dab of solder and some heat shrink to cover the unsightly solder blob and to help protect the exposed conductive leads to the caps, this is how they turned out. Yep, I think it's going to work. Whenever I find some extra motivation I'll begin recapping the 2nd NHT Super Two. I wish I'd thought of this earlier, although it's too late to go back and redo the other crossover.
It dawned on me that I have some extra 22 AWG silver plated copper wire with a Teflon jacket for a different project. Rather than use left over snippets from the capacitor leads, I could use some of this uberwire. :nerd: So after wasting most of an afternoon, I came home with tags and license in hand ready to give it a try.
After a dab of solder and some heat shrink to cover the unsightly solder blob and to help protect the exposed conductive leads to the caps, this is how they turned out. Yep, I think it's going to work. Whenever I find some extra motivation I'll begin recapping the 2nd NHT Super Two. I wish I'd thought of this earlier, although it's too late to go back and redo the other crossover.
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ThanatosOfOn
Klipsch Fanboy.
When I did the upgrade on my Super Zero's, I just got a small breadboard and made it the capacitor board, then jumped from that board to the xover board with some silver wire I had laying around. not near enough room on that board for the caps I used...wish I had taken pics...
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
Oh man, I could have used that suggestion. I was thinking about mounting the PCB to the inside of the cabinet, but fortunately these caps were small enough for everything to fit back the way it was.
ken kantor
Fowl Humor
I had an epiphany today while standing in line for hours at the BMV to get my tags and driver's license renewed. :scratch2:
It dawned on me that I have some extra 22 AWG silver plated copper wire with a Teflon jacket for a different project. Rather than use left over snippets from the capacitor leads, I could use some of this uberwire. :nerd: So after wasting most of an afternoon, I came home with tags and license in hand ready to give it a try.
After a dab of solder and some heat shrink to cover the unsightly solder blob and to help protect the exposed conductive leads to the caps, this is how they turned out. Yep, I think it's going to work. Whenever I find some extra motivation I'll begin recapping the 2nd NHT Super Two. I wish I'd thought of this earlier, although it's too late to go back and redo the other crossover.
Right on! AMS is one of our best dealers!
To continue the discussion from the other thread: no, I don't think you can improve the speakers by using different caps. A good designer optimizes the performance with the exact parts used. So, if you are hearing "more detail" or some such thing, you would hear the exact same thing by bumping up an equalizer band, or nudging a tone control, or lowering the tweeter series resistor. Nothing wrong with that, at all. But it isn't an "improvement" of the product, just a modification. If I wanted that response in the first place, I would have used a smaller tweeter resistor, so that the ESR+tweeter resistor total would have been lower and the speaker would have been brighter. All that the film caps are doing is lowering the ESR, thus accomplishing the same thing. Imagining that you are putting in "better" caps is simply altering the frequency response, period, end of story.
I know its a big fashion to "recap" these days, fed by obscenely greedy cap manufacturers, and by people wanting to fuss with their gear however they can. (Gear is not as easy to mess with as it was 30 years ago, and caps are one of the few ways left.) But frankly, any pro in the biz will tell you it is nonsense.
I've been designing speakers professionally for almost 40 years. Sorry, the Internets in general are not going to "improve" a product that took me 18 months non-stop to design, supported by driver and crossover vendors and a team of very talented engineers. If a film cap would have improved the performance of any speaker I made, I would have used it. As I sometimes did. If I didn't, there was a good reason.
I support it, since I support having fun with audio, but modkateering is silly, really.
-k
PS- the VERY FIRST electronics thing I ever did was replace a blown cap in the power supply of my '63 Bandmaster! Those caps are a completely different technology than the ones used in modern crossovers, and were also stressed 10,000 times more.
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
I've bought some gear through them and some Moagami cables so they send these catalogs all the time. They're great to solder on.
So instead of using the caps I used, I could have lowered the 3.3 ohm resistor that was in series with the tweeter to, say 3 ohms? And the 5.5 ohm resistor to 5ish ohms and it would yield the same results? OK, that makes sense. I need to read up more on ESR. All I know about ESR is that it's the bad/undesirable stuff in a capacitor.
Thanks for the feedback. I appreciate it very much. Modding is fun though. And I stay away from the real expensive/boutique caps and components.
Would you say that the caps of the mid-'80s are as robust as what you had available at NHT? The reason I ask is I have a mid-'80s Adcom GFA-555 amp and preamp I thought about having serviced. If the caps from that era are robust then there isn't any real need to have it serviced, is there?
Oh man! That's one of the ultimate "surf" amps on the planet. They're probably 1 notch below the Showman of that same era popularized by Dick Dale. I'd kill to have brownface Bandmaster with a big 15" JBL D130F in a closed back cab. They cost too much today though.
Thanks again for the 'splainin'. :thmbsp:
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ken kantor
Fowl Humor
I still have that Bandmaster, but it's cream with dual 12's. Exactly like the one on the Blind Faith album.... you know, cause I can play that well....
You are exactly correct about lowering the resistor. The only time you NEED to use films is when you want the series resistance to be as close to zero as possible, and so have no resistor to compensate them with.
Caps got good by the end of the 80's, so the Adcom is borderline. (Yes, there was an episode of defective caps more recently, but that was due to a process error caused by industrial espionage intrigue. http://en.wikipedia.org/wiki/Capacitor_plague)
The stress on caps in power supplies is totally different than the one's in crossovers. Chances are the Adcom is fine, but you never know about the power supply caps. Those are the ones I would replace out of caution. But, I haven't heard of any particular problems with them. I have several amps still in service from that era, and a couple of Dynacos I built in the 70's, none of which has ever had a cap failure. I don't think it is a particularly common problem in consumer amps. The high voltage caps in guitar amps of the 60's and 70's are a different story.
-k
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Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
I hear ya. If I ever get around to recording a CD I'm going to call it Ears Of Pain. :sigh:
I had a couple of Epox motherboards that suffered the plague. Every cap on both boards had leaked electrolyte sauce.
Thanks. I'll look into getting some replacements for the Adcom just to be on the safe side. There are 4 big 'uns in that amp.
I appreciate the time you've spent answering my questions. I know you have better things to do on a Saturday.
ken kantor
Fowl Humor
Nah, I'm the "All Audio, All The Time" channel. Answers, advice, opinions and arguments 24/7!
-k
Dr. Morbius
I.N.T.E.R.O.C.I.T.O.R.
It's great that you're willing to share what you know here. I think a lot of others appreciate it too. :thmbsp:
Just out of curiosity, what were your top 3 favorite NHT speakers from when you were at the helm? I'm guessing the 3.3s would be one of them?
chicks
Lunatic Member
qft
My Hafler DH110 failed due to caps, the mute would not release.
Also an Advent receiver, and a Nak cassette deck.
30 to 40 year old electros are certainly reaching end of life, especially if
you don't use the equipment for long periods of time.
I recapped the low voltage side on our central electrostatic air cleaner
when it stopped working. It will now probably work for another 30 years.
I do have better things to do so I'm not doing this for kicks - the gear was
non-functional.
High reliability industial equipment use solid tantalum caps rather than normal
electros. Not suggested for speakers by the way.
Also an Advent receiver, and a Nak cassette deck.
30 to 40 year old electros are certainly reaching end of life, especially if
you don't use the equipment for long periods of time.
I recapped the low voltage side on our central electrostatic air cleaner
when it stopped working. It will now probably work for another 30 years.
I do have better things to do so I'm not doing this for kicks - the gear was
non-functional.
High reliability industial equipment use solid tantalum caps rather than normal
electros. Not suggested for speakers by the way.
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cratz2
Addicted Member
It's great that you're willing to share what you know here. I think a lot of others appreciate it too. :thmbsp:
Just out of curiosity, what were your top 3 favorite NHT speakers from when you were at the helm? I'm guessing the 3.3s would be one of them?
I'd be very interested in hearing your answer as well.
I've said it before, but I ran a pair of 2.5is for about 10 years in a mixed music/HT setup and biamped them so I could easily nudge the bass up for HT or keep it at the proper level for music. I got them right after they came out and the dealer still had two pairs of 2.3s. I definitely think the 2.5i was a significant improvement over the 2.3 but were pretty solid as well.
I heard the 3.3s pretty extensively at Progressive Audio in Columbus, OH. Very impressive all around, but I loved how the bass didn't constantly draw attention to itself until needed, at which point it was very impressive, but still not distracting. I've heard a lot of great (and EXPENSIVE!) speakers before and since, but I think the 3.3s would be my reference if building a speaker that got well into the 20s.
I've heard Doc's Super Twos (pre-upgrade) enough to know that I like them very much and, while I appreciate the innovation and advantages of the angked baffle designs, I think the Super Twos might be my favorite NHT, aesthetically speaking.
The Super Ones were probably my most recommended speakers for a number of years, esp if I didn't think the person wanted to consider a sub and the Super Zeros (circa 1995-2000 version) never failed to impress with how, when combined with an SW2, absolutely destroyed the similarly-priced 'competition' from a well-known company.
I never heard the 2.9 as extensively as the 2.5 or 3.3, but there's little doubt I could live with them for a good long time.
Sorry to sound line a suck up fan boy, but from about 1995 on, I thought you struck about the ideal balance between sound quality, price and looks. There's no shortage of great speakers out there, but I was never crazy about the looks of Vandersteen, Alon, von Zchweikert etc which were among my other favorite sounding speakers we could have afforded.
OK... I'll shut up now.
ken kantor
Fowl Humor
It's great that you're willing to share what you know here. I think a lot of others appreciate it too. :thmbsp:
Just out of curiosity, what were your top 3 favorite NHT speakers from when you were at the helm? I'm guessing the 3.3s would be one of them?
It changes by the day. I like different products for different reasons, including reasons that would be obscure to anyone but me... association with life events, a technique proven, establishment of a category, certain details of performance, etc.
For today, I'll say: Model 1, SuperZero, 3.3.
Some days, it's: 1.3a, 2.5i, VT-2.
Some days it's: 1xu, VT-1, HDP-1.
A20, SW2/2p, does the AR 303 count?
-k
ken kantor
Fowl Humor
Yeah, I'd agree with you that 40 years is pushing it. (For almost any component.) And there are surely designs out there that do not use best practices and stress the caps. I've seen 16V 'lytics used on 15V rails. 10% high and you are over-voltaging the cap. But, you can't condemn all caps because there are some field failures. After all, for every internet failure report, there could well be 100,000 or 1M similar units functioning perfectly well. And, as you point out, crossovers are a unique application. In certain ways, xovers demand a great deal from a cap compared to other apps. In other ways, xovers are an easy gig.
-k