JBryan

Jay, I will assume you are asking about rectifiers in regard to your Korneff amp (cool amp BTW, its one of the few amps that I wish I had held onto). Given its low gain, I would suggest trying a Sylvania 5U4G as its a bit smoother-edged than other US brands. I had an early version of Jeff's 45SE amp with the silver hammertone chassis and red bell covers but I don't remember which rectifier it used. I did quite a bit of tube rolling in it and found that the 6SN7's had the most impact on the sound but I didn't find much difference by changing the rectifier. I know he offered several rectifier choices over the years and with slight modifications, you can try a myriad of tubes - 5AR4/GZ-34, 83 mercury vapor, 5R4, etc. If I still had the amp and a bit of inspiration, I would give the GZ-34 a try.

The 5U4 has got to be the most popular rectifier tube out there. They are used in many audio and guitar amps and best of all, they are readily available and quite inexpensive. RCA, Sylvania, National Union, Raytheon, GE, KenRad - everybody made them by the boatload and to me, there's little discernible difference sound-wise between them. I guess my preference would be for the older 5U4G ST-type tubes from RCA and Sylvania. Of the common rectifiers, I prefer the 5AR4 for its slow-start capabilities (it ramps up the juice from the PS over a few seconds as opposed to instantaneously with tubes like the 5U4), then the 5R4. If you ever want to try out a few 5U4's, head to the next hamfest in your area where you'll find most US brands for @$5-10 each NOS or about $1 used (at least, that's the going rate 'round here). Have fun.

I find that once an active crossover with steep slopes and delay correction is employed to replace the stock crossovers, the need for tubes virtually disappears. YMMV. Just my $0.02. Chris Well, I've never tried SS amps on my top end but any amp will sound its best when coupled to a speaker system that is properly set up and aligned though I wouldn't imagine that it could go so far as to mask the very distinctive sound characteristics of differing topologies. In my experience, a good speaker system, properly set up accentuates the differences in amps and other gear.

I've never heard a SS amp on horns that I enjoyed as much as tubes - at least on the top end. I would use a Korneff 45 SET or Sun Audio 2A3 SET on the K-77, a Korneff EL84 SE or Brenneman Cavalier (EL34 SE) on the K-55. The bass bin needs some power but isn't too fussy about the amp as long as its fast and quiet. I prefer the speed and efficiency of digital amps. You can put a 150-200 watt Gainclone or Hypex monoblock in each cabinet and leave them on 24/7 since they use about the same electricity at idle as a small flashlight bulb. Or just find a nice SS amp from the likes of McIntosh, Conrad-Johnson, Krell and Audio Research...plenty to chose from. You'll probably need a digital xover to align the drivers, if not a Marchand XM-9 is quiet, fairly inexpensive and has a nice damping feature to adjust the response at each crossover point. There are far more amps at more reasonable prices out there but I've had experience with all this gear and that's what I'd try first. Have fun

I sorta went through the same thing a few years back when I was trying to replace the Khorn bass bin with something smaller. Over 12-15 months, I tried a few drivers in DR cabs (Fostex, BD-15, JBL among others) but in the end, preferred the way the horn integrated with my system and room. Using the same amps and cut-off point (160Hz), the DR's sounded good but they didn't go as low, have as much impact and weren't as tight and clean-sounding as the horns. To me, the higher efficiency, lower distortion, better transients and a bigger sound were a fair trade-off for the larger footprint but I can understand why others would prefer a different approach. After all, PWK wouldn't have gone to all that trouble designing his bass bin and Klipsch wouldn't have continued building it for the last 60+ years if the same results could be achieved by slapping a 15" driver on a 8 cu.ft. box....at least that's what I keep telling myself.

Thanks guys. There wasn't anything out of the ordinary that day. I just pulled the switch to listen to the radio - the same as I had done practically every day for the last 10 years and the 5AR4 suddenly filled with a blue/red/purple flash. I'll pop the hood and take a look but I guess its time for a restoration. Any suggestions for modifications - which caps sound best and should I make the switch from 7189's to EL-84's? What other mods have folks implemented to make the 222c sing? Thanks again!

Well, after 50 years of unrequited service, my Scott 222c (w/original tubes) finally complained. I switched on the power only to see a light show in the 5AR4 rectifier tube. I immediately shut the amp down and tested the tube....its dead. Has anyone else experienced this demise in a rectifier tube? I've never had one go out on me but I always figured it would just not fire up one day - no light show. I also figured that the other tubes would have faded away long before the rectifier - it gives me pause. While I didn't smell any smoke or notice anything else unusual, is there something I should check before installing another 5AR4 and firing the amp up or am I being overly cautious. Would this be a good time to check/adjust the bias? If so, any tips? Thanks in advance for your help. -Bryan

I read through the post w/o any trouble - Welcome to the Forum E-Springs and congrats on your Khorns. The need for a remote is a bit of a hurdle otherwise I'd suggest a restored integrated like Scott, Fisher or even Sherwood (the S5000 is a nice piece and a real bargain). These would be a good start at discovering what tubes can do and for many, they offer the best sound/price ratio out there. MAC gear sounds fine but tends to be overpriced compared to similar-sounding gear but you can usually get your $ back when you sell. My favorite MAC amps are the MC-30's and 225s - in that order and both will cost at least 2x more than comparable gear. In my book, a tubed preamp is more benefit to a system than a tube amp and there are plenty of decent vintage pres but alas, no remote. The Conrad Johnson PV-5 comes to mind - it sounds good, has a nice MM phono section and sells for @$500. If you're starting from scratch and want to incorporate streaming music from your computer, I would suggest looking into the new line of preamp/DACs from Sutherland, Eastern Electric, Wyred4Sound, etc. as they are catch all ('cept you'll need a phono stage) solutions for hi-Rez and streaming and most offer tube stages or buffers. I don't know enough about them to make a recommendation but don't be in a hurry as gear pops up all the time for dealing with this newer technology - 24/192 is the norm now but that will change in a month or so. Have fun

Snake oil or not, you'll never get a unbiased answer BUT if you're asking... you might be willing to try the DIY route. The Ward's Yardmaster cords are CHEAP - especially when they're on sale at Walmart and they are well regarded in several audio forums. Read the review from 6moons.com... http://www.6moons.com/audioreviews/whitelightning/moonshine.html Speaker cables can be made easily if you just want bare leads and you're in luck - the cords are sold in 40' lengths. Have fun

Actually, I just remembered that the Baldwin amp is still on loan and was hooked up to a pair of Urei 813c's. It sounded sweet on the tweeter horn but didn't have enough power to drive the woofers well. Wouldn't you know it - I finally have a use for the amp and its not available...jeez louise!

If you're asking me... I have yet to hook either amp to my speakers but I've loaned both out and heard them in friends' systems. One friend tried them with Cornwalls and I do remember that both of us preferred the Baldwin amp but thought the ST-70 had a little more 'kick' in the bottom end. The only other horn-type speaker I've heard the Baldwin on is the Cain & Cain Abby and it was completely quiet. The ST-70 has a little noise and mechanical hum but then, the dust on it is over 40 years old, the tubes are original and its never been opened so I'm sure that has something to do with it.

I have Mr. Vincent's rebuilt Baldwin. I actually just picked up a pair of Tannoy Windsors with 15" Gold concentric drivers and am going to try a few amps - one being Vincent's Baldwin as well as a Scott 222c and a pair of McIntosh MC-30's as those are the most powerful tube amps I have access to at the moment. I wasn't considering the ST-70 but this thread may inspire me to dust it off and give it a whirl.

All Khorns are from the 'Heritage' series, as are Cornwalls, Belles, Heresies, etc. You can look up the entire series on this site. In the mid 80's, Klipschorns used the AK-2 xover that allowed for bi-wiring. Klipsch divided the xover and put the bass section in the bass bin - thus the 2 sets of terminals. If you're not going to use bi-wires, then you'll need the straps between the terminals (top to bottom). If you don't have the straps, you can either simply run wire or I'm sure the folks at Klipsch would be happy to sell you a set. Have fun

My ST-70 is stock and probably could use newer caps and such while the Baldwin amp has obviously been recently rebuilt and modded so...grain of salt and such but I found the Baldwin offers a quieter and smoother presentation while the ST-70 is a bit veiled in the highs, a tad harsh in the upper mids but has more bottom end extension by comparison. Have fun

If you're talking vintage, looking back is easy... for example, most 60's era Klipsch speakers have doubled or tripled in value while JBL's and Altecs have tripled or quadrupled on average, mostly because they were pretty expensive to begin with at the time. But for the best return for a brand name may go to the classic Tannoys. I was just looking it up and a pair of Windsor cabinets with the 'Gold' 15" concentric drivers - originally $800/pr. now sell in the neighborhood of $3K-7K, depending on condition. Most folks just sell the drivers and xovers and toss or burn the cabinets..yikes! I you're considering buying new and want to forecast into the future, its not so easy because any current model/brand will depreciate immediately and may or may not gather a following down the road. If you're just looking at Khorns, recent limited runs like the 60th anniversary edition may not bring much more of a premium over the standard model now but because of its low production numbers, may become quite the collectible down the road. Over the long run, the stock market has always beaten the collectibles market but with audio, at least you can enjoy your investment while you wait for a return. Have fun.

Pauln said: "I have found that I need to buy about a dozen of these phono EQ stage tubes each year or so (but they are very inexpensive and easy to find). Out of 12, about half will be very nice and quiet. Of those, after a few months in service one may become noisy and need replacing from the "quiet stock" I keep on hand. It's the only way - buy, test listen, identify, and store for when needed." That's going through tubes pretty quickly. Unless you leave your phono pre on 24/7, that's too much wear and tear from the circuit or the tubes may not be the best match for it. I've had a dozen phono pres or stages and the only one that caused noisy tubes after a few months was an Audible Illusions Mod3A. It went through quite a few nice 6DJ8 variants (6922, ECC088, 7308, etc.) until I inserted Tungsram ECC88's. They were quiet and have stayed that way for over 6 years now (the AIMod3A ended up with my brother-in-law and he hasn't had to change the tubes yet). To Coytee's problem, you've already determined that you have a bad tube, by all means buy a selection of good ones and see which works and sounds best. I'm not familiar with the Peach but unless the circuit is particularly hard on tubes, you should expect preamp tubes to last at least 5 years with most lasting well beyond that. Have fun

I bought my first ZS over 35 years ago (really?!) and used it per the instructions with every record for the next 20+ years. It performed well - its abilities were especially noticeable on dry winter days. Of course, back then it only cost $20 and it was still working when I replaced it a few years back when I saw one on sale for $45. The price has jumped significantly since then but given its useful lifespan, I would consider it a good value. Pros - it works! Cons - After 10-12 years, the case began to come apart but a little electrical tape fixed it. Also, after tens (hundreds?) of thousands of squeezes, the trigger mechanism wears down and the gun loses its effectiveness. They used to include a little bulb to practice with and test the gun but I imagine most folks lost the bulb long before it was needed. I also remember reading a warning somewhere that the ZS can kill a cat which I would consider a CON but others may think otherwise.

Welcome to the forum....As mentioned, the stock Khorns will better the Apogees in the bottom end - faster, deeper bass while the Apogees will have cleaner, more detailed mids and highs and they image better (unless the room is sized especially for Khorns). Its obvious to me that you'll have to keep both of them...[] or modify the Khorns - false corners, xovers and/or a new top end for starters. First, measure the room as Khorns need a minimum area of 15' x 20' (or thereabouts) to work properly. Also consider that Apogees aren't too concerned about the amplification as long as there is lots of current and watts to handle the impedance swings while the Khorns don't require much power but are quite finicky about the upstream electronics. Most gear will sound noisy and lifeless but if well matched, the sound will be glorious. Quite the dilemma you got there, have fun with it!

Thanks again for all your replies. I'm not concerned about time alignment but when I was putting the speakers together, I used the measurement as a reference point and unfortunately, marked the stands' position with drafting tape which has since moved. I have no doubt that keeping the coils on the same line has little to do with any alignment concerns but coincidentally, the measurements I took located the Oris horn at that spot. I could just as easily make another reference point but I took a lot of measurements based on that original mark and would like to re-create it so I can reset the Oris horn without starting all over. Thanks again for the help but really, with all the builders and Khornophiles 'round here, I assumed some one would know the actual distance between the woofer and front of the Khorn.

'Most musical' is relevant only to the listener and not a comparable term in my opinion but Mark sparked a thought with his "Turn it DOWN!" comment. I've sat in front of many systems over the years and on several occasions, I've asked the fella demonstrating his system if he could turn it down a bit. Sometimes its because its just TOO LOUD as I have to yell my request but sometimes I only have to raise my voice a little to communicate. Some folks feel 'the louder, the better' and I can appreciate that but in some systems, a less than adequate setup or piece of gear will emphasize distortions or increase stridency which irritates me at higher volumes. With better sounding systems, I have experienced just the opposite where I'm very comfortable with the SPLs and its only when I turn to my friend to comment that I realize how loud the music actually is. I start to say something like "...sounds good!" and only then realize that he can't hear a word I'm saying. I've experienced this phenomenon with forward-sounding and laid back systems, horns and otherwise but it seems that those systems (usually built around efficient speakers) with good soundstage and imaging and lower or more pleasant distortion can be turned up quite a bit without any discomfort. It may be that I've become conditioned as a result of listening to low-wattage systems so long but this phenomenon seems to coincide with the better setups I've heard.

Thanks guys. I do understand the basic physics of acoustic alignment and time alignment is provided through my xover. That said, I played around with the top horn mount several years back and found (quite by accident) that I got good measurements and the best imaging with the drivers lined up. I had taped the position of the horn mount but the tape has since peeled away - D@#n drafting tape! Other projects took over and the system sat idle for a long while but I am now back into the game and of course, I felt compelled to start adjusting this and that and before I realized my folly, the horns had been repositioned. I just want to remark the original position so I have something to gauge my progress and can reset the horns if I need to.

Thanks Speakerfritz. What 'm looking for is the straight line distance from the front of the K33 magnet to the face of the Khorn. I measured this when I installed the woofers a while back and I should've written it down somewhere or made a mark but I didn't think that far ahead. I've been moving the top horn around a bit and want to keep the coil in the same line as the woofer. I found some plans on the net but they don't specify the distance nor the scale but I may pull out a scale and figure it out - roughly, in centimeters.

I'm trying to reset my horns and can't remember what the distance is from the K33 magnet to the face of the cabinet. Does anyone have that information or can you direct me to a blowup of a loaded Khorn with that measurement? I did a cursory search but couldn't find anything. Thanks!

I understand your dilemma. JBL Everests are very nice speakers but like all speaks, they have drawbacks. I'm not a fan of the tweeter and the L300 actually needs more power/current than most SET amps can offer comfortably. I'd suggest that you try a bit more power on the JBLs before you do anything drastic and given the age, replacing the caps in the crossovers and maybe even the wires should improve the sound. That said, you can easily sell the L300's and get a nice pair of used 'Scalas with $ left over to modify them. There are plenty of threads discussing ways to get the most from LS - do a search and get ideas. Personally, I liked the L300 but preferred the L200 in my setup. Though I did notice a bit of roll off on the top of the StudioMasters, I liked the imaging a little more. I haven't spent much time in front a LS's but I think you'll give up a little bit on the top and bottom compared to the L300 but the LS offers better transients, less distortion and more speed as well, you can easily drive them with a 300b amp up to 90dB depending on your room size. Have fun

Comparing speakers with similar designs is fairly straight-forward but different designs can be difficult as each comes with its own benefits and compromises. Maggies fill the room with authoritative, detailed sound and they can disappear in a well setup system. Planar speakers, and most electrostatics offer a similar sound but they also tend to congest and distort at high volumes and the bottom-end is less visceral than other designs. That doesn't make them a bad speaker and to some folks, the benefits far out weight the compromises. Horns are known for low distortion and super-fast transients but are very room and system dependent, require a lot of space to set up, come with a large footprint to achieve the lower octaves and lack depth in their soundstage. To my ears, horns offer one of the best values in sound reproduction and I can accept their short-comings but there is a larger group of audio enthusiasts that won't. After listening to horn set ups for years, I was somehow intrigued by the glowing reviews regarding the Zu Definition and when the opportunity arouse, I picked up a pair with their 2 full-range drivers, 4 rear-firing woofers and a single horn tweeter per cabinet. The positives were their small footprint, capabilities to be dialed in to almost any space, ability to seamlessly pump out sub-20Hz bass as well as over 30kHz highs in a design that emphasizes the imaging and depth that a full-range driver can provide. When I finally put together a system around them, set the parameters to factory spec for the Definitions and switched on the power, my first reaction was disappointment. After all the hype and my own expectations, the sound was no where near what I was hoping for. I didn't perceive as much detail and the image was more laid back compared to my modded Khorn system and the bass... simply overwhelming! I thought I'd made a big mistake..HUGE mistake but after a few hours of listening, my horn bias subsided and I began to understand the speakers' capabilities. I realized my failure was in trying to make them sound like horn speakers and once I was able to reset my listening criteria (not an easy task after listening to an all-horn system for +15 years), dialing them in became much easier and the sound has become exceptional and very satisfying. I'm still 'working' the set up and the sound is still getting better but I am already delighted with the outcome - the Definitions are indeed special in my book. My point is that with both systems optimized, if I were to compare them side-by-side, I'm not sure which I would prefer. The Zu's really shine at what they do well as do the Khorns and both offer a very distinct, yet very satisfying sound. There are so many choices in audio and for good reason - everyone's taste and preferences are evolving at a different pace and in different directions and there seems to be more diversity now than ever. The possibility of someone putting together the same system as someone else is miniscule so comparisons - even with similar speaker designs is difficult. As an aside, 'Hi-end' is a relative term and falls into the category of "someone's trash is someone else's treasure". Have fun