rongon

The problem is that if you have two output devices going into one input, the two output devices can interact with each other in undesirable ways. Even if one is powered off, it's output circuits might look like a partial short circuit to the input of the succeeding stage, and the other output device that's connected to the first output device by the Y-cable. This would be especially bad if the output impedances of the two output devices were very different. The one with the lower output impedance would play much louder than the one with the higher output impedance. The one with the lower impedance could also load down the one with the higher impedance. That could cause frequency response problems, higher distortion, etc. You want a good switch in this situation.

I finally hooked up the KG 4.5's to my system and got a listen. As is usual with speakers, it's going to take some time to get used to their "personality," but I hear a lot of potential. What I hear that I like: The dynamics are EXCITING. These speakers are INTENSE. Rhythmic drive is GREAT. These speakers love to "breathe" with the drummer. Not sleepy in the slightest. Percussion is really good. Quick transients like rimshots sound almost like the real thing, just scaled down. The bass is nice and full, goes down low enough for me. The high-highs are very good, for my taste. Bells, harps, vibraphone, chimes, high notes on piano all sound percussive - "fast," like they should. "Clear as a bell." I like that a lot. Orchestral strings are bright, but very clear. When a soloist is spotlit, you hear it. They seem to change a lot with each different recording (within limits), which is a good sign (if each recording sounds different, the speakers should sound different playing them). Harsh sounding or distorted recordings sound harsh and/or distorted. These speakers do not smooth over rough edges. Depth and imaging (where a performer appears to be located in the mix, and the sound of the acoustic space in which the recording was made) seems to be good. Good enough for me. Not as good as my friend's EJ Jordan line array (4 small full range drivers per side with subwoofers added), but this pair of speakers is a heckuva lot cheaper and much more efficient. What I hear that I don't like: When I first auditioned them, driven by a mid-1970s Marantz receiver, I noticed a sort of sizzle or "hash" riding on top of the highs, especially cymbals (most noticeable on jazz ride cymbal). I still hear it, and it sounds pretty much the same through the tube amp as it did through the Marantz. I wonder if this could be the sound of the polymer tweeter diaphragm? Perhaps an upgrade to the titanium diaphragm would help that? Maybe the capacitors used in the crossover aren't the greatest? (Anybody know whether they are film or NP electrolytic?) I could change them to something better, maybe Axon polypropylene and foil (from Zalytron outside of NYC). Maybe the tweeter needs to be padded down just a hair. Maybe -1.5dB or -2dB. Everything seems just a bit too bright, just a little. The KG 4.5's are slightly more efficient than my Tannoy T185's. After adjusting for level, the T185's sound more polite in comparison, and not as bright. They sound "richer" and smoother, but not as exciting. It's like the old "West Coast" sound (JBL, Altec, etc.) versus the "British" sound (KEF, B&W). Tannoy is definitely British (Scottish, to be exact). The Klipsch "house sound" may be more brash. I remember that from the Heresy's I heard. I think this is a taste thing. Considering I spent $175 in 1984 dollars on a pair of B&W DM100's, and my Tannoy's would cost well over $500 to replace (if I could find another pair), and that I just spent $250 in 2011 dollars on these KG 4.5's, I'd have to say that these are a very good deal. They're fun and exciting to listen to, and easy for my weenie tube amp to drive. The only problem is that they can be a little harsh in the upper ranges. All in all, I'd say this is a success. I'll live with them for a little while and then swap in the RF-3's (which were a lot less money). That should be interesting... -=|=-

All are good answers, if yer askin' me. Best option would be to DIY, but only if you're comfortable with that. A good quality two-deck, five position switch can be had for pretty cheap. You could put the switch in one of those old network switchboxes (nice heavy stainless steel cases, but kinda ugly), or choose the instrument case of your choice (e.g. Hammond Mfg). Five pairs of RCA jacks for inputs, one pair of RCA jacks for outputs, and you've got an input switcher. On the other hand, you might do the time vs. money equation and come out on the side of spending a little more money for instant gratification. In that case, the Niles AXP-1 is pretty good. I needed something like that in a hurry, to audition a new attenuator (volume control) that wouldn't fit into my current line amp. The AXP-1 cost me about $90 and seems to work just fine. http://www.google.com/webhp?hl=en#sclient=psy&hl=en&site=webhp&source=hp&q=niles%20axp-1&aq=0&aqi=&aql=&oq=&pbx=1&bav=on.2,or.r_gc.r_pw.&fp=8a58e93555963d21&biw=1272&bih=862&pf=p&pdl=500 . It's an all passive, five stereo input to one stereo output switchbox in a reasonably good looking, decent quality steel enclosure. Small and simple. Made in China, though. That Esoteric Sound Super Connector would be the end-all right there. That's $299 list, so is a big step up. Sure does look nice, though. -=|=-

NOSValves doth speak the truth! But I wanted to add my slightly different opinion on this, on the chance that it might help you. Since your source will be a computer, it's likely that you don't even need a line level preamplifier (the preamp section in an integrated amp or receiver, or a separate preamp like the Dynaco PAS). Most power amps can be driven to full power with less than 1V RMS of signal from the source (that's equivalent to 1.414V peak). The standard maximum (0dBFS) output level from a CD player is 2V RMS (2.83V peak), so most any CD player can drive most any power amp to well beyond full power. Also, since you'll be using a computer as your sound source, it's likely that you will already have a volume control in its audio player software. Since you already have a digital volume control, why add a potentiometer (variable resistor) or stepped attenuator volume control? You actually don't need it. In audio, less is just about always more. Less passive hooey in the signal path will mean cleaner sound -- but possibly less convenience. So here's an idea for you -- Use your computer as the control center for your sound, including its volume control. Make sure you equip your computer with a really good sound card that puts out at least 2V RMS at 0dBFS (full scale, or the loudest level it can play). Then get a good quality, vintage stereo tube power amp, such as the Dynaco Stereo 70 ("ST70"), or the Dynaco ST35 (the little brick-shaped one with the 6BQ5 or EL84 output tubes). The ST35 is a really nice little amp, puts out an advertised 17.5 watts per channel. It might only be 15 watts per side in real life, but that's enough for most small apartments playing at moderate levels into efficient loudspeakers. I personally prefer the sound of a stock ST35 to a stock ST70. Other vintage power amps worth buying are from Fisher, McIntosh, Marantz, Eico, Heathkit, harman-kardon, Quad, Luxman, and so on. Dynaco will most likely be the easiest to find in good condition for reasonable cost. If you must have a volume control, selector switch and tone controls on the amp, and you are looking to spend about $300 to $600, you could do a lot worse than an H.H. Scott 233 or 299 model integrated amplifier. These have a 'romantic' sound to them, mostly because of their old school circuitry (including tone controls). There are others from Fisher, Eico, Heathkit, etc. But the Scott amps are the most common. The Dynaco SCA-35 is basically an ST35 power amp with a built in PAS preamp, in one box. The preamp circuit doesn't sound all that great (in my opinion), so I'd still recommend the ST-35 power amp over that... or a Scott or Fisher. Anyhow... I'm sure somebody will disagree with that approach, but I thought I'd lay it out there for you. Whatever you decide, I'm sure you'll enjoy it. --

Just a quick update -- I found a pair of RF-3 speakers for way cheap, so I picked them up too. Now I have two pair of Klipsch floorstanders I haven't listened to yet (KG4.5 and RF-3). I got to hear them both before buying them, and I have to say that they sounded completely different from each other. I don't know if this was because of the receivers driving them or if I was hearing something in the speakers themselves. They both sounded very good, with a lot of potential. I heard the the RF-3's driven by a Rotel integrated amp. I only heard some singer-songwriter music, with a bit of drums and percussion along with guitars and female vocals. The RF-3's sound very clear and fast, but more zingy than the mellower-sounding KG4.5's. Unfortunately, I have to clear a lot of stuff out of my place before I can start playing with floorstanding speakers. I'm making some headway this week... It should be very interesting to compare the two Klipsch models to each other and to my Tannoy T185's (10" concentric, black bextrene cones and butyl surrounds). -=|=-

There's always the possibility that a previous owner modified the amp to use 7199 instead of 6U8/6GH8A. Does your tube tester have the 7199 info on its reel?

+1 I'd like to know if there are impedance curves available for a number of current and recent Klipsch speakers. Why? Because Klipsch speakers are efficient and that means they should work well with low power tube amps. But low power tube amps have high output resistance, which means they can change their frequency response and transient character when presented with a load whose impedance varies a lot with frequency. That's not so bad in the bass (people who love little triode amps don't love them for their whompin' bass), but can be lethal in the crossover region(s). So if a crossover at 1000 Hz forms a wicked impedance peak, the tube amp might make that into an underdamped response peak near the crossover region, which can sound downright painful. So impedance curves for each speaker model would be a great help for the weenie tube amp fan. Thanks.

Oops, you beat me to it. Congratulations on the amp rebuild. It looks very nice! Incidentally, it's not hard to change the circuit so that you can use the much easier to find 6U8 or 6GH8A tubes instead of the now rare and expensive 7199. It should take moving a few wires on the 9-pin socket. So if you ever find yourself without 7199 tubes, don't panic. There are better options.

Hi there, I hope I can be of some help. That howl you heard when you powered up the amp was probably reversed polarity to the output transformer ("OPT") primary (blue and brown leads). You want *negative* feedback going from the OPT secondary (16 ohm tap) to the input of the amp. Negative feedback ("NFB") will lower the gain of the amp, because it's derived from the output fed back in opposite phase to the input. If you switch polarity, you have positive phase signal injected into the input, adding the output signal to the input and increasing the gain of the amp. This will result in oscillation ("howl") as the output is fed to the input and the output feeds the input some more, and the output feeds the input some more... So yes, try swapping the blue and brown leads between the two output tube anodes (pin 3 on the 6V6's). The color coding on the old OPT's might not correspond to the same polarity as the color coding on your new Hammonds. We want to get a negative polarity version of the output going to the point where it's injected into the input. Negative signal will detract from the gain at the input, but decreases distortion and frequency response at the output, which is usually considered a good thing. I think you're almost there. I'm dyin' to hear what you think when you wire your amp up in triode. But I agree that can wait. Careful with those big power supply capacitors! They pack a wallop. (Please don't ask me how I know...) Ron G

I heard the KG4.5's last night. Unfortunately, the source system was the (analog) line out from a Mac computer running iTunes, into a very pretty mid-1970s Marantz receiver. I played CDs, not AAC or MP3 files. The good part was that the speakers are in really good condition. Only little cosmetic blemishes, a couple of small white paint spots, probably from moving them. No dented corners, pushed in dust covers, etc. How did I like them? I liked them. The good points are the wide dynamic range and sense of "they are here in the room." I played a small vocal group CD (Cassandra Wilson "Blue Moon Daughter") and I felt like I was in a small club, seated at a table, listening to the band. Cassandra's voice was floating there in between the speakers, spookily real sounding. I listened to Bill Evans "Waltz for Debby" (1962 recording) and the piano was clear and bell-like, very pure sounding. The bass was tight and quick, none of the bloat I hear from my Tannoys. Wes Montgomery "Full House" (another live 1962 recording) was positively jumpin', with Johnny Griffin's tenor sax especially well reproduced. Jimmy Cobb's unique ride cymbal beat jumped right out of the speakers, like he was actually playing. Very nice. On the RCA Living Stereo CD of "Das Lied von der Erde," the orchestral chimes were as good as real, and the voices were scaled down nicely to something like the size you would hear from a mid-orchestra seat (on the floor of the hall), with the much larger orchestra all around the singers. Very realistic sizing of the audible "images." Those were the good points. The not-so-good points? Orchestral bowed strings had an unnatural "bite" with a metallic edge. Best described as an electronic "sizzle" riding over the top. That might have been the Mac computer sound. I played a fairly nice recording of Bach Violin Concertos, which sounded very engaging and fun, but not as "sweet" in the strings as real life. But that may have been the recording. However, the robust, smooth string tone on the RCA Living Stereo CD still came across with an electronic sheen, "harder" sounding than in real life. I hope that was the sound of the Mac computer and Marantz receiver, but I don't know... I could easily hear the flatness and sizzly top end of AAC files played from iTunes compared to the sound from CD. (How can people happily listen to MP3'? I'm afraid I can't do it and enjoy myself.) So yes, the KG4.5's are revealing of the source material -- which is an excellent sign! Maybe the KG4.5's will sound better driven from my tube stuff. I also heard a bit of discontinuity between the horn and the 10" woofer. It sounds like you are listening to the horn for most of the spectrum (which is probably a good thing), but the lower mids seem to be coming from a slightly different place on the baffle. I was in a small room, so it might be that you need 4 feet or so distance from the speakers for them to sound more like a single "point source." Incidentally, that's one of the strengths of the Tannoy coincident drivers. You can be right in front of them and the highs, mids and lows will always sound like they're coming from a single spot. They're great as nearfield monitors, which is how many recording engineers use them. I really don't know if my tube amp setup will tame the sizzle/edge I heard. I suspect the upgrade to titanium diaphragms would improve that. But I'd need to add another $50 to the price for that mod. Which brings me to a new, and possibly cheaper, development... I found a pair of RF-3 for sale, for quite a bit less money. They're another 3dB more efficient, which would be useful, and they have the titanium diaphragm tweeters and copper-colored woofers (two 8-inchers!). So, please excuse me for drifting, but... Any thoughts on RF-3 vs. KG4.5? In their stock config (no upgrades), which would have a smoother, more violin-friendly top end? Do you think the RF-3's titanium diaphragms would make a huge difference there? Thanks again everybody

Thanks Bruce. That does sound like what I heard. Very brash mids. Does the Heresy have user-accessible level controls for mids and highs? Or were you talking about crossover mods? I see your system profile includes a 2A3 amp and that you used to use an ST70. I know how that goes... Ron

I missed this post somehow. I think my impression of the Heresy was colored by the system it was in. J&R might have a pair of Heresy on display. You're convincing me that I should give them a second chance. Forte might be just the ticket, as I don't need rattle-the-walls bass. I just need some bass (-3dB down at 45 or 50 Hz would be nice). Hmmm... K-horns and La Scalas. I did like the K-horns I heard, and I've heard many good things about La Scala from weenie-tube amp users. I believe there is a consensus. Now all I need is the money! Thanks for your replies, they've helped me a lot. --

Thanks ironsave. The owner is asking $250 for the pair. He says they're in excellent condition. I'm not so much interested in knocking things off shelves as I am in giving my low-power tube amps a really easy load to drive. The triode tube amps are far more detailed and revealing than other amps I've had (Van Alstine-modified Dynaco Stereo 70, Hafler TA-1100, Scott 299). The pentode (Dyna, Scott) amps sound dark and wooly in comparison, the solid state amp sounds crispy and harsh by comparison. So for clarity, you'd choose Heresy or Forte, but for most bass whoomph for the money, you'd choose a KG floorstander? I guess I'll have to give a pair of Forte a serious listen. I was trying to recall what my friend's setup was like with the Heresy's, and I think it was a CD player straight into a stereo volume control ("passive preamp") into a single-ended triode-wired EL34 amp. It might be that the amp couldn't deal with the Heresy's impedance spike(s) around the crossover frequencies, and so blared in the mids. The other speakers he was using were a pair of Boston Acoustics bookshelf models, which are not in the same league. He might have been better off with a less demanding speaker with those amps. That was a long time ago, and I wish I knew then what I know now. (That's something I find myself saying a lot these days...) At any rate, I'm bringing some CDs with me to audition the KG4.5's tonight. Maybe they'll float my boat, maybe not. I'll let y'all know. -- PS -- I see the RB-61 is 95dB/1w/1m efficient, and goes down to 44Hz (-3dB). That's pretty impressive for less than $500 new. Can anyone give me their impressions on how RB-61 II sound compared to Forte or KG series?

Thanks fini. I live in NYC; will be moving up the river in a couple of months. Wuzzzer, that's what I expected after hearing from others about the Klipsch "house sound." Rock fans usually love Klipsch speakers because they make amplified music sound like you're there at the concert. It's the acoustic music people who tell me that they find them to be too aggressive. Then again, those same people -- who usually prefer B&W, Snell or Spendor -- also don't like the 1980s vintage Tannoy sound, which I happen to like. Hence my questions...

Oops, I meant RB-51 or RB-61.

Wow, that's a lot of answers! Thanks everybody. OK, where to start... First, I was using Chrome, which is based on similar stuff as Safari, so that answers the line breaks question. I'm using Internet Destroyer for this post. While I do listen to blues music once in awhile, I'm really more of an acoustic jazz and classical music person. I mostly listen to stuff like Miles Davis, Bill Evans, Sonny Rollins, Ornette Coleman, Bach, Mahler and Bartok. I'll listen to some B.B. King, T-Bone Walker or Muddy Waters every once in a while. Very rarely I'll put on some James Brown or Mahalia Jackson, or get nostalgic with some Weather Report or ******* Brew. I listen to a fair amount of LPs. I prefer SACD to CD, but I do have a lot of CDs. I listen to a local college FM station too (WKCR, Columbia University's station -- they have some great jazz, Indian and Western classical music on there). My SACD player is a Pioneer PD-D6-J. For CDs I use a Sony SCD-CE595 changer driving a Behringer SRC-2496, used as an upsampler/DAC (it's just OK). The tuner is a mid-1960s Lafayette LT-78 I picked out of the trash(!) and refurbished a bit (replaced leaky capacitors). Revealing speakers are fine by me! If the KG4.5 is very revealing, then I hope it'll reveal that I've carefully put together a little system that I think does justice to the source material. Technics SL1200MK2 with Denon DL110, all-tube phono preamp with triode-wired E810F and 5687 tubes, a simple little line amp with a 6N30P tube run at a hefty 20mA per side and an Intact Audio inductive attenuator (volume control), into my long-tailed pair 6N6P DC-coupled to push-pull 2A3 amp with Tango output transformers. BTW, it's not a single-ended triode (SET) amp, it's push-pull. Push-pull results in a lower output impedance and higher damping factor, so I find is better at driving most real-world loudspeakers than a comparable SET amp. My PP 2A3 amp pushes the Tannoy speakers pretty well, even though the speakers' rated efficiency is only 91dB/1W/1m. I get good bass from them, if a bit loose. The T185 model I have is known for that, as it has a passive radiator. I've found that low-power triode amps work best with speakers that have a fairly flat impedance curve, or at least one without any huge peaks and troughs. It's not a matter of efficiency by itself. Some fairly efficient speakers are a bear to drive, with wide variations in impedance at different frequencies. That can cause a weenie tube amp a lot of trouble. There are also some inefficient closed-box speakers that I've found work well with weenie tube amps, such as the Snell Type J (they sound good but don't go very loud). I'm sure I would love a pair of La Scala. But this year I'll need a new car, and I'll be moving soon. If I find that I love the Klipsch sound, then maybe that'll be something to save up for. Or maybe the Forte, if it sounds "warmer" than the Heresy. In the lower reaches of the Klipsch lines, I've noticed that the KSF 10 and KSF 20 models are well-regarded. They're also more efficient than the KG models. Does that mean they're more aggressive sounding too? Are KSF models closer in sound to the Heritage line than KG? What would you say are the most "relaxed" or "refined" sounding of the Klipsch models? What about the current models? Are they more "polite" sounding than the older models? I could go over to J&R and ask them to play something for me. I've just never had good luck auditioning speakers in showrooms. They always sound very different with tube amps and in my little home. thebes mentioned the KG bookshelf speakers as being easier to drive than the KG floorstanders. Maybe that puts the RF-51 and RF-61 into play? Do you think those would work with a PP 2A3 amp in a small room, listened to at close range, "near field monitor" style? At any rate, I'll be hearing the KG4.5's tomorrow evening. I'll let you know how it turns out. --

I don't know why my posts don't show line breaks. Kind of a drag that the words are all strung together... --------------- --------------- Hi Wuzzzer, thanks for your reply. ---------------- Are you more of a rock and pop fan, or more to the acoustic music (classical and jazz) side of things? I find that people's taste in music has a lot to do with what kind of sound reproduction they favor. For instance, a live concert of a string quartet does not involve any microphones or amplification, while a rock band will have lots of mics and amplification involved. Classical music fans usually like more "polite" sounding speakers than rock fans. Not always, but usually. That's why I ask... ----------

Hi there Klipsch fans! I've been searching the 'net for advice on larger, more efficient speakers, which of course led me here. I see there are a lot of people who dearly love their Klipsch speakers. I wonder if I would too? -------- I should mention that I am on a very low budget. That's probably why my searching has led to the KG series. I checked around and found a pair of used KG4.5 for sale near me. It's a bit of a hassle to get to them, and I won't get to hear them in my system before I buy. So I thought I'd ask for some advice first... -------- First some background. I have a little (homebrew) 6 watt-per-channel, push-pull 2A3 amp. It currently drives a pair of early 1980s Tannoy T185 Dorset. I like this combo a lot, but the woofer voice coils are beginning to rub, and there are no re-cone kits available for those drivers. It's inevitable that I will have to replace them, and Tannoy speakers ain't what they used to be... But I understand that the Tannoy sound is thought to be more "polite" than the Klipsch family sound. True? -------- I don't listen to contemporary pop music at all. I mostly like classic 1950s, '60s acoustic jazz (Blue Note, Prestige, etc.), a few contemporary jazz artists (Danilo Perez, Keith Jarrett, Kurt Rosenwinkel...), Late Romantic and Early Modern classical music, Beethoven string quartets, Bach, and some '50s and '60s blues recordings. ---------- I did have the good fortune to hear a pair of Klipshorn, back about twenty years ago. They were being driven by a big 1970s Japanese receiver. I expected them to sound like PA speakers, but no, they were *exceptional*. Better than Altec A7 VOT's, as subjectively clean and detailed as B&W 801, but oh my what dynamics! K-horns are among the best speakers I have ever heard. ---------- A few years later, a friend of mine got a pair of Heresy (I don't know which series, but this was about 1995 or so). He was driving them with small, single-ended triode amps, and I was expecting to really like the combination. But I was very disappointed. The Heresy confirmed my worst fears about horn speakers. They sounded great on old blues and rock music, like you were in the club -- but they sounded harsh and squawky playing a Beethoven string quartet, and not much better on orchestral recordings. They didn't seem to be at all similar to the K-horns. I was bummed, and scratched the less-expensive Klipsch speakers off my list. ------- I have read lots of raves about the La Scala. But I don't have the budget for those. I've read that the more contemporary Klipsch designs are "more refined," which I hope means better damped and so sound better playing classical music. Maybe they're more what I want than the Heresy... --------- I'll only be able to hear the KG4.5' speakers driven by a fairly standard receiver, which I don't expect to be much like my 2A3 amp. -------- Do you think there's a chance I'll like the KG4.5 driven by a 2A3 amp? Or is the KG4.5 a brash "rock n roll" speaker, more like the Heresy than a 1980s Tannoy? ------- Thanks for any advice you can send my way, and sorry for the long first post. --