Benesesso

Given the price of brass screws, I have little doubt that some beancounter tried his best to keep using steel screws. Fortunately some tech. or someone managed to convince/override him. OK, what happens to an AA if the only changes made are yanking the screw and adding the 1 uF bridge cap? I still have the zener diodes connected. Should I yank them too?

Wolfram, Make sure to send me an e-mail when you decide to move on to something else! I don't mind being one or two steps behind you. Your ex-Wright 2A3's are doing well. Dan

I *think* I've done all I can for all that music below 50 Hz.

If the tone arm doesn't swing side-to-side, see if it moves up and down because of a warped LP. I made some simple alum. clips to hold the high spots down to the platter to fix this. If your TT just has rumble, a low-cut filter will help-they used to call them "rumble filters".

I've got one of those old AR TTs. Paid $57 for it back around 1967. Still has the orig. belt! I threw the small "starter motor" belt/o-ring away long ago. I just start the platter spinning a little by hand. Rigged up my own anti-skating with a weight and a thread running over a small support. Put it close to the pivot to lessen friction effects. Look at the tone arm when you hear wow. If it's drifting back and forth, it's an off-center hole in the record.

Fortunately the house I'm living in (in Italy for ~3 more years) has concrete/tile walls! Before I bought my Khorns (1982), I had a pair of Altec VOTT (500 Hz). The bass-reflexes just didn't cut it, having been intended for the movies optical sound tracks, which didn't get that low. I had an active equalizer, but it just didn't make it until I got the 1st pair of Earthquakes from Universal Studios. That works pretty well, but I sold it all when I moved from PA to AZ, intending to buy the Khorns. I did, finding a very nice pair in unfinished birch for $925! Everything was fine until I played a CD of St. Saens "Organ" Sym No.3. Major distortion on the lows. Fortunately Universal still had about 8 Earthquakes plus 2 huge "1st design" Earthquakes which wouldn't fit into a house left in storage in Tucson, but I had to buy all or nothing. So I bought them all, including a couple of C-V A-2200 amps. Had to borrow a long trailer for my truck. I use one for each channel, and those organ notes are RELIGIOUS! I like the long sustained low bass, not the pulsing mid-bass of disco-can't stand it. One of these days I'll hook up my Wright SETs to them and see what happens. They're folded horns, and I think the efficiency is the same as a Khorn. Right now the Wrights power the Khorns above ~40-50 Hz, and my old Dynaco ST-150 (SS) handles the Earthquakes. It's a shame that so many people today weren't around for those Sensurround movies-they were simply incredible!

Al, Thanks for the reply. I guess this is a subject I'll never really understand. I had been thinking that the tweeter inductor was somehow making some kind of resonant circuit with some/all of the caps., but your answer takes care of THAT wrong thought. I think I see how the tweeter receives more HF energy via the bypass cap (lower resistance/impedance), but how it causes the big dip in energy at ~3200 Hz I just don't get. WHERE does this energy go? Not to ground, because the inductor remains the same. I'm just baffled.

Al, When I look at the schematic of the AA, the voltage to the tweeter first goes thru the 13 uF cap., and then thru two 2 uF caps. in series (with the inductor bleed-to-ground in between). So, two 2 uF caps. in series would be 1 uF. The BYPASS cap. is in parallel with the two 2 uF caps., making a total of 2 uF, minus the slight effect of the 13 uF, right? Maybe paralleling two caps. with one is called a delta, but if the numbers above aren't right, can you explain why? I'm really not into math.

Something doesn't make sense to me about this bypass cap. From what little I know, it appears to be adding 1.0 uFd in parallel. Paralleled caps. just add up in capacitance, which means lower Hz gets thru to the tweeter. This is obviously NOT what happens, so my question is WHY?

Thanks, Al. Found it. After rereading that thread, it appears I should put the 1.0 uFd's back in and go buy a decent graphic or parametric equalizer to reduce the loud high's on some CD's. Any thoughts on which kind to get? Benesesso

FWIW, I changed the value of my AA 1.0 uFd bypass caps. to 0.47. With the 1.0s some music (Elton John's) has a LOT of close-mic'd. cymbal brushes and it was just too strong-at least in my listening room which is on the "hard" side. I have been searching this forum for an hour trying to find Al K's. graph which shows freq. resp. vs bypass-cap. value. I had saved it on my HDD, but for some reason it won't display now.

Al, Break the news to me gently-should I get the expensive caps. for this or not? How goes your steep-slope Khorn Xover design?

$22!? Uh oh. I just used whatever caps. the store had in stock--I think they were ~90 cents ea. SO, does the "quality" of the caps. affect the sound for these bypasses?

I took a look at how good the fit was between the walls (smooth-finish concrete faced) and the Khorn. They seem to fit very well, with very little/no gap. Has anyone noticed "better sound" after weatherstrip sealing when they had a very close fit before? How much air leakage is OK?

But you can have both---!

Anyone else like "Washington Square" by the "Village Stompers"?

You're right! Can't believe I forgot the low end of "The King of Instruments"! BTW, I love the sound/feel of continuous low notes-the kind that fill the room. Reminds me of the church I attended in Newark, NJ when I was a kid. Had a real, pretty big pipe organ. Made that church rumble enough to put a little religion into me.

To add a bit of clarification, I do not run the Earthquakes from the 2A3's--which are about to be replaced with #45's and the correct resistors. I probably won't be able to hear any diff., but I thought I'd try the 45's even tho the power drops from 3.5 to 2 watts. For years I ran the subs with an orig. Cerwin-Vega A-2200 amp. They were all modified by C-V to deliver 400 watts RMS per channel at low freq., at "the expense of slightly higher distortion" as I was told. When I bought the Wright SETs I started using the Dynaco ST-150 for the subs--no diff. that I can hear. Since the subs are folded horns, I probably only put a few watts into them anyway.

First, the Khorns sound very good by themselves, esp. with the 1.0 uFd bypass cap. to extend the high end. Also, I am fully aware that there is little/no music other than synthetic below 41 Hz, which the Khorns are fully capable of reaching. But one day, when powered with my old Dynaco St-150 (75 w/ch) I played a CD of Saint-Saens Organ Symphony. I like really strong low end, and the Khorn woofers went into gross distortion (I don't think it was the amp.) The Earthquakes solved *that* in a hurry. Bi-amping wouldn't cut it for me. I am not a believer of "high fidelity" in the sense of simply recreating what someone (composer/conductor) supposedly intended. For example, I simply cannot listen to most recordings of Beethoven's 5th sym. other than Bernstein's recording with the NY Phil.-even in the old dreadful NY Phil. Hall-pre A Fisher, IIRC. Bernstein may have taken a lot of liberties with his conducting, but to me they sound GREAT! The purists probably shudder with it-I have no problem with that. I am also aware that most conductors will take all the bass they can get out of a hall and then some. I use a Dod "active" crossover (not too expensive) to cross to the Earthquakes around 50 Hz--steep slope. The Dod has separate vol. controls for high/low, and I find some CD's bass-heavy and others bass-light. By simply setting the Xover Hz at zero everything goes into the Khorns. Some CD's have so little bass it makes no diff.

20 watts? Bass takes power-how low and loud do you want to go?

One interesting thing to me about the Civil War was to dig a little into the life of JW Booth and learn a bit about why he shot Lincoln and how future life in the US would be as he saw it. TBrennan-Yes, it was mine until I sold it to a RR club near St. Louis about 8 years ago. I didn't build it-took a guy in Kansas 15 years to make, and he never ran it. Check out the Wasbash et. al. RR club on the net. The subs are genuine Universal Studios Earthquakes, made by CV. Folded horns like Khorns, but with a long-excursion 18" driver. Low-freq. cutoff is ~18 Hz. I roll them over to the Khorns ~50 Hz at 24 dB/octave.

This photo (sorry for the poor quality) shows how small a Klipschorn looks next to a pair of Earthquakes (stacked)with the huge "extendors". Now I just fire them into the rear corners w/o the extenders-keeps the wife happier.

The train was work-this was play. Or was it the other way around? I can't remember---.

Don't tell nobody, but I'm a engineer.

Mah favorite song is "Dixie"!