Not on my full-range system.
High Current Amp/Pre-amp recommendation needed - Power for Infinity Kappa 9 pair
- Thread starter edisonbaggins
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Ok, latest discoveries:
Both of my intended amps, at this point, have unbalanced inputs.
My Emotiva UMC-200 preamp has Zone 2 and Zone 3 capabilities. These are unbalanced stereo outputs.
So, I'm on the hunt for a good, but affordable, active crossover that will sit well between them, right?
Given that I'll have a Crown D150A and an Adcom GFA 5300 to play with initially, which would you put on top and which on the bottom?
Both of my intended amps, at this point, have unbalanced inputs.
My Emotiva UMC-200 preamp has Zone 2 and Zone 3 capabilities. These are unbalanced stereo outputs.
So, I'm on the hunt for a good, but affordable, active crossover that will sit well between them, right?
Given that I'll have a Crown D150A and an Adcom GFA 5300 to play with initially, which would you put on top and which on the bottom?
What would an @edisonbaggins thread be without a good curveball, huh?
I'm hearing that success can be had powering kappa 9's with a low-watt (like 20w) push-pull tube (valve) amp. Without even bi-amping. Though some say you get better bass control by throwing a high-current SS on the bottom.
If it's true, that a push-pull can work well with the k9's, thoughts on a good, yet affordable model?
I'm hearing that success can be had powering kappa 9's with a low-watt (like 20w) push-pull tube (valve) amp. Without even bi-amping. Though some say you get better bass control by throwing a high-current SS on the bottom.
If it's true, that a push-pull can work well with the k9's, thoughts on a good, yet affordable model?
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I'm growing interested in a mini DSP 2x4 HD. It seems like it will do the job, but it might be too complex for me to figure out! I can do 2-way on up to 5-way active crossover. I guess the software can, but not sure how this would be achieved with only 4 outputs. Maybe you have to buy more units?
It's late. I'm confused.
Good question & I have what might be a semi-interesting answer. Officially my 555’s were later MK I but they had already made some improvements most recognizable was changing the bridge switch from cheapo slide type to a high quality toggle switch. So if anyone shops for a used 555 & sees a slide switch on the back panel, it is the oldest of the oldies.
After a few weeks of my Adcom/Infinity set up I felt I was ready to push the limits & see how much oomph & power & loudness this could deliver. I chose a demo CD popular in the early days of digital. I forget the name but the 1st track was the theme to Star Trek. It started out with a synth intro that was sort of a white noise low level and growly bass mixed in & over maybe a 10 sec spread it increased on an exponential scale until BOOM and immediately the Star Trek theme was launched.
I turned my pre-amp to 11 & let ‘er rip. All was good but kinda scary and as soon as it got to the sonic boom there was a slight pop & the front chs went dead. Power light still on. Dead. I checked the output fuses & they were ok. So I took it back into the store I purchased it at as they had quite a good service center & it was under warranty, haha despite how I tortured it.
In about a week, before they had a chance to get to it, Adcom had sent out a service bulletin. The important part read that “some newer designs of Infinity speakers have a very low impedance & may cause driver transistor failure.” The driver transistors handle final voltage amplification before driving the out put transistors that deliver the current needed to feed a speaker. In this case the output stage survived just fine but the demands on the drivers just sucked the life out of them & they smoked.
The service bulletin suggested a much more robust replacement for the drivers. And because this was in the age of good customer service it was suggested I bring my perfectly functioning rear ch amp in for the upgrade as well, all free of charge.
When the 555 MK II came out I inquired about trading up & get the new ones. Again from the guy at the most ethical stereo shop I’ve ever known his reply was “ no need . You’ve already got the MK II upgrade.”
So there ya go, short story long. Only problem I've ever had with these amps.
They are both so similar in power output (5300/80 WPC, D150A/75 WPC) that I see nothing decisive there. However the Crown does a very high damping factor, in excess of my Adcom 555, & has bi-polar outputs which makes for better current dumps than the 5300 MOSFET. I would suggest low pass the Crown & use the Adcom for the high end.
Still sounds terribly under powered even bi-amping but if that's your starting point then go for it.
One thing I'd suggest if you haven't already done it, is before you jump into filters & bi-amping, just hook the Crown up by itself as a test. Play some music at not too loud level & listen to the over all sound & ear to each speaker driver & make sure it's working, no buzzes or other strange stuff.
A friend of mine purchased some Infinity speaks of the RS line that had 2, 8" woofers, mid & tweeter. The seller said the woofers were professionally re-foamed & visually they looked very good. But when the owner re-installed the woofers, they were wired in series, and the connecting wire between wasn't hooked up right. The woofs were out of phase with each other & drove my friend nuts why he wasn't getting any bass. We took them out of the enclosure & I saw the problem right away. So check 1st before moving to the next level.
Was this someones post that was made on April 1st?
I guess it depends on what you call "success" running like this. I'm sure it would sound different than high power solid state but if it sounds better I wouldn't venture to say.
At least compared to low power solid state amps a tube amp has an output transformer & no matter what the speaker load the output tubes only sees the transformer primary load. So the output tubes would always be protected. The output transformer can only deliver so much no matter what the speaker impedance is calling for so in that respect tubes beat SS for ruggedness. For myself I would never spend & time much less $$ chasing this approach.
In addition to the suggestions Gene made I might second your motion to consider using DSP. For the low cost I'd even suggest considering a 4x8 unit:
https://www.parts-express.com/dayto...nal-processor-for-home-and-car-audio--230-500
The nifty thing about a product like this is you can so easily control filter crossover points, the slope, the over all level, and even click & reverse the polarity on high or low sections. One of the challenges doing this on a speaker like yours is the bass crosses over very low; on my Kappa 8 it's 80Hz. This is quite low but that means there's a whole lot of audio energy left over for the high pass section. Keep in mind that when they say a filter point is 80 Hz it is already -3dB so you wouldn't want to cause a dip by setting the line level filter at the same. My starting point might be low pass at 160Hz with no need for super sharp cut off maybe -6dB or 12dB per octave. On the high end you might want to set the high pass filter say 6oHz & use a very sharp cut off, say 24 dB per octave.
I have considered buying the Dayton DSP unit for my own purposes so I downloaded the app & put it on my PC. I immediately got frustrated ( I do this when I can't figure something out right away) but after about 10 mins it smoothed out. It didn't suit my usage for what I was looking for but really is a pretty cool amazingly flexible product. And you can get a phone app for it too!
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I forgot to mention the Dayton 408. Could very well be a good economical as well as FLEXIBLE starting point. I think ( have never seen one in person) Parts express likely to give refund if you are in time frame and unhappy with theproduct. It does most of the tricks a dsp is supposed to do. The super tweeter and tweeter can be driven by the same amp.
never ever use tubes. there is NO reason to ever use tubes anymore. Unless you LIKE the sound of harmonic distortion. And having to replace tubes every few (fill in the blank depending on how bad the design is). And space heaters in your amp space even in summer. (Note: I rejected some of the first transistor amps because they did not sound as good as my many dyna MkIIIs , Stereo 70s Mark IV Bs , MacIntosh tube amps (LOTS of them) until the mid seventies or so. I built many of the aforementioned dynas from kits and repaired many others. I have felt the bite of a 700 volt plate supply on my hand) My very first biamped system had a dyna stereo 70 driving the jbl horns. Because it sounded better full range than the solid state power amp(SAE mk something) that was driving the woofer. Them days are OVER. (yes everybody has an opinion and that is mine)
If your system is unbalanced and you get a balanced pro power amp usually there is an op amp stage that is the balanced line receiver and converts the signal to local unbalanced. You usually can easily bypass this stage and in the case of some pro amps they even may provide the exact procedure. It is easier to just find consumer grade unbalanced power amps. But crossover networks are easier and cheaper to find with balanced. (Hint Because PROS like to use them AND won't participate in absurd pricing.)
never ever use tubes. there is NO reason to ever use tubes anymore. Unless you LIKE the sound of harmonic distortion. And having to replace tubes every few (fill in the blank depending on how bad the design is). And space heaters in your amp space even in summer. (Note: I rejected some of the first transistor amps because they did not sound as good as my many dyna MkIIIs , Stereo 70s Mark IV Bs , MacIntosh tube amps (LOTS of them) until the mid seventies or so. I built many of the aforementioned dynas from kits and repaired many others. I have felt the bite of a 700 volt plate supply on my hand) My very first biamped system had a dyna stereo 70 driving the jbl horns. Because it sounded better full range than the solid state power amp(SAE mk something) that was driving the woofer. Them days are OVER. (yes everybody has an opinion and that is mine)
If your system is unbalanced and you get a balanced pro power amp usually there is an op amp stage that is the balanced line receiver and converts the signal to local unbalanced. You usually can easily bypass this stage and in the case of some pro amps they even may provide the exact procedure. It is easier to just find consumer grade unbalanced power amps. But crossover networks are easier and cheaper to find with balanced. (Hint Because PROS like to use them AND won't participate in absurd pricing.)
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I totally disagree with you about tubes, tubes always sound good (at worst) great at best. Tubes are much more reliable than people give them credit for. Normally after years of use valves start to become weak and need to be changed out but they don't seem to fail catastrophically the way solid state amps do. I wouldn't recommend them for a bass or sub base amp due to their lower damping factor however. Yes tubes generally produce a bit more harmonic distortion, but I think that there is more to their great sound than added harmonics, possibly less or lack of TIM (caused by use of excessive amounts of feedback). On the negative side tube amps can be very expensive, but if you build amps yourself they are quite economical. If you live in a hot climate the heat might be a problem, here in Canada we can use a little extra room heat most of the year. My tube amps are in the basement which is cool year round.
Having low impedance outputs means it can drive most inputs (so probably from a few 100-Ohms upwards, studio audio gear is often 600-Ohm) with no issue. I do wonder what they mean by 'High Voltage' though! As 0dB into 600-Ω is 1V, 0dBu into 600-Ω is 0.775V, so often studio levels are +4dBu so 1.228V. There is the possibility you could over drive the Power Amp input!
Ok. MK II it is! Follow up question is, how is the power consumption of your HC units? Do you have to be careful which outlet you use? What kind of surge protection do you use? Do you brown out your neighbors? Does your power bill skyrocket?
I might be closing a deal on a Jolida (wooden chassis, looks classy) JD-302B soon.
Any idea how the Dayton stacks up in quality against the mini DSP? And the mini DSP HD? What is the advantage of the DSP part?
The follow up question here is... how do you wire the kappa 9's to work with one amp? Do you wire to only one set of binding posts on the k9's? Or do you have to use some sort of y splitter, so you can wire to both sets of posts? Are those posts bridgable or jumperable? Sorry, this all might be in the manual. I figured you might know off the top of your head though.
Well, the advantage of the DSP part id it is Digital Signal Processing rather than analog. The Dayton 408, the MiniDSP & MiniDSP HD are more similar than not & both will do what you want. the Dayton & miniDSP work at 24/48 while the MiniDSP HD functions at 32/96, a considerable improvement.
The Dayton unit is ready to go out the box, just hook up to your PC & start setting it up. The MiniDSP's need to go online to get the plug ins you need. The MiniDSP's must be connected to a PC to make changes while the Dayton has an optional Bluetooth dongle that you can use with your phone, no wires, in the sweet spot a real benefit.
The user GUI's between the MiniDSP's & Dayton is significantly different, the former being more like a mix board which I prefer. The Dayton PC app can be DL'ed for free & you can play with that as if you had the real thing. The MiniDSP people don't do that.
So a it's a mixed bag. I think you can scratch off the MiniDSP & choose between the Dayton or MiniDSP HD. The latter will have thoreticaly best quality, the former will be more flexible & easier to use.
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Quite interesting thanks for the link. I'd have to hear it to believe it but the OP seems very passionate about it, no BS trolling. Buy your Jolida & let us know!
My speakers came with a pair of very nice fitting gold straps that connect the speaker posts. But otherwise to test with a single amp just hook the amp to the low connection & jumper low ground to high ground, low positive to high positive.
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I know my statement was provocative. We shall have to agree to disagree.
TIM hasn't been a problem since the 80s. (Matti Otala's seminal paper on the subject was published in about 1974 see reference #2 https://pdfs.semanticscholar.org/b3c0/a892a982ebde91f83f228905dac30186f827.pdf )
Feedback is a very good thing. Amplifiers are supposed to be a straight wire with gain. (They are not supposed to "have a sound" unless they are a guitar or other musical istrument amp.) I had lots of KT-88s fail catastrophically and it made a horrible noise in the speakers while lightning was happening inside the tube envelope. That was when I really decided to switch to transistor amps. It never blew anything but I think the reason was because I was quick to hit the power switches. ( was an extremely early adapter of power strips. SGL Waber 1968. ) Tubes also get gassy, and lose their vacuum. Hydrogen and Helium in the atmosphere easily diffuse through glass and make tubes gassy. I have heard of people "repumping" unobtainium vacuum tubes. But that leads to another problem. Who is it that is actually manufacturing vacuum tubes. They used to be an entire industry with huge numbers of excellent engineers working for RCA , GE, Westinghouse, Sylvania and many others here.
Also tube lines from companies like Phillips (Amperex) GE of England (Genalex Gold Lion probably the best KT 88s) Telefunken and others. These tube lines are all gone and so is some of the deep knowledge that was present in those plants. If tubes were better there would be scientific instruments manufactured that would use them. There are no such instruments. If you want a scientific instrument preamp with perfect waveform fidelity you don't even use discrete solid state components. Integrated circuits are used. The thing that got me off the dime to switch to transistors was multi amping and the fact that I could not get good KT 88 Matched Pairs to save my life. (For a pair of MC 75s in the very early seventies) There are people selling tubes now but they are going after audiophile money not scientific excellence.
I watched with concern and regret as American tube companies closed down. (At the time I still preferred 12AX7A powered preamps too. Where you gonna buy one of those today?). Tube rolling is not a new pass time I assure you. However like incandescent lighing tubes are a thing whose time has passed. I have thought that for decades and I think that it is time to take a public stand against companies who build overpriced tube amps to relieve uninformed audiophiles of their hard earned cash. If you want to build or restore a tube amp it is an extremely educational experience (don't get electrocuted and keep kids and pets away from tube amps). But you should not delude yourself into thinking it is going be "better" than a transistor amp. There is nothing in the output of an audio amp that can't be easily measured these days in spite of what some claim. Go over to Audio Science Review and see what Amir does to amps and other pieces of gear (lately including speakers.) Using scientific and objectively reproducible analysis.
TIM hasn't been a problem since the 80s. (Matti Otala's seminal paper on the subject was published in about 1974 see reference #2 https://pdfs.semanticscholar.org/b3c0/a892a982ebde91f83f228905dac30186f827.pdf )
Feedback is a very good thing. Amplifiers are supposed to be a straight wire with gain. (They are not supposed to "have a sound" unless they are a guitar or other musical istrument amp.) I had lots of KT-88s fail catastrophically and it made a horrible noise in the speakers while lightning was happening inside the tube envelope. That was when I really decided to switch to transistor amps. It never blew anything but I think the reason was because I was quick to hit the power switches. ( was an extremely early adapter of power strips. SGL Waber 1968. ) Tubes also get gassy, and lose their vacuum. Hydrogen and Helium in the atmosphere easily diffuse through glass and make tubes gassy. I have heard of people "repumping" unobtainium vacuum tubes. But that leads to another problem. Who is it that is actually manufacturing vacuum tubes. They used to be an entire industry with huge numbers of excellent engineers working for RCA , GE, Westinghouse, Sylvania and many others here.
Also tube lines from companies like Phillips (Amperex) GE of England (Genalex Gold Lion probably the best KT 88s) Telefunken and others. These tube lines are all gone and so is some of the deep knowledge that was present in those plants. If tubes were better there would be scientific instruments manufactured that would use them. There are no such instruments. If you want a scientific instrument preamp with perfect waveform fidelity you don't even use discrete solid state components. Integrated circuits are used. The thing that got me off the dime to switch to transistors was multi amping and the fact that I could not get good KT 88 Matched Pairs to save my life. (For a pair of MC 75s in the very early seventies) There are people selling tubes now but they are going after audiophile money not scientific excellence.
I watched with concern and regret as American tube companies closed down. (At the time I still preferred 12AX7A powered preamps too. Where you gonna buy one of those today?). Tube rolling is not a new pass time I assure you. However like incandescent lighing tubes are a thing whose time has passed. I have thought that for decades and I think that it is time to take a public stand against companies who build overpriced tube amps to relieve uninformed audiophiles of their hard earned cash. If you want to build or restore a tube amp it is an extremely educational experience (don't get electrocuted and keep kids and pets away from tube amps). But you should not delude yourself into thinking it is going be "better" than a transistor amp. There is nothing in the output of an audio amp that can't be easily measured these days in spite of what some claim. Go over to Audio Science Review and see what Amir does to amps and other pieces of gear (lately including speakers.) Using scientific and objectively reproducible analysis.
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