uncle_leon said:
Wey Hey..
Report back on what you find obviously.
I dont think you will be disapointed.
JB
I also built a four-channel GC for bi-amping (passively) and the improvement over using the two channel GC was significant! 
That, or take it a step further and build yourself an active crossover.
Benefits over passive biamp are:
more effective power, though tweets don't take much power, so this is mainly a benefit in 3 way, or fullrange+sub type setups (low xo freqs)
Better damping, which makes more or less difference depending how well behaved your speakers are.
More crossover options/tweakability. Cheap small components due to the high impedances. If you decide that you don't really like the way it sounds, you replace a $0.30 part to change it, not a $30 one.
Seemed pretty irresistible to me. I built a 3 channel amp, and am doing all of my crossover and volume control digitally before it leaves the computer.
So far I have only run the subs on their own channels, and the main (woof/tweet) on another pair, since I wanted to be sure the amp is good and stable before hooking it to a tweeter protected only by a large film cap. Seems good, so I'll be switching it over shortly.
I'm betting I can come up with a crossover setup far beyond what I could ever afford to tweak to through passive parts. No added expense except for time.
-Nick
Benefits over passive biamp are:
more effective power, though tweets don't take much power, so this is mainly a benefit in 3 way, or fullrange+sub type setups (low xo freqs)
Better damping, which makes more or less difference depending how well behaved your speakers are.
More crossover options/tweakability. Cheap small components due to the high impedances. If you decide that you don't really like the way it sounds, you replace a $0.30 part to change it, not a $30 one.
Seemed pretty irresistible to me. I built a 3 channel amp, and am doing all of my crossover and volume control digitally before it leaves the computer.
So far I have only run the subs on their own channels, and the main (woof/tweet) on another pair, since I wanted to be sure the amp is good and stable before hooking it to a tweeter protected only by a large film cap. Seems good, so I'll be switching it over shortly.
I'm betting I can come up with a crossover setup far beyond what I could ever afford to tweak to through passive parts. No added expense except for time.
-Nick
I've just realised that I'm going to need a second pair of speaker wires, and by the way came up with an idea many of you will probably find laughable (if not outright stupid): I thought that since I'm not going to drive high currents to the tweeter anyway, I can use thinner wire... but of better quality. In other words, I'm considering use of a 0.50mm (24awg) teflon jacketed '4N silver' wire. I can buy it at reasonable price of £3.5/m (which would be some 2.15$/ft). I'm sure it will make a good interconnect and hook-up wire, but is it sensible to use it for speakers?
Edit: I've just found some old, cheap speaker wire (about 1mm conductor diameter), so I might as well try it for tests, instead of knocking myself out on silver in advance 😛
Edit: I've just found some old, cheap speaker wire (about 1mm conductor diameter), so I might as well try it for tests, instead of knocking myself out on silver in advance 😛
I think that should be fine for a tweeter. Thin wires usually have lower inductance, which is good. you're trading off inductance against dc resistance with wire guage. For a tweeter the inductance may be significant.
I wouldn't bother with the silver wire either. The only thing it will help is dc resistance. There's a ton of thin copper wire in the voice coil. another 10 feet isn't goint to change much.
-Nick
I wouldn't bother with the silver wire either. The only thing it will help is dc resistance. There's a ton of thin copper wire in the voice coil. another 10 feet isn't goint to change much.
-Nick
Effective upgrades
You appear to know what you are doing with relation to superior parts and I believe this is what can make a good amplifier great. It also sets it aside from the ‘also-rans” of the world. I also believe that every little upgrade to better components does collectively make a difference. So I am not going to even mention other components.
What I would like to talk about is resonances. The guy that design and built the first Giancard, Junji, spoke of resonance in an interview (which I can’t relocate). He is not talking about vibration which is different but also important. If you have ever felt a hose which is running hard you have experienced the effects of resonance. Now down to a smaller level think of an electron moving through a wire. Not very exciting but very excitable. The electron, which only moves at a centimetre a second is bashing into millions of other moving electrons. So there is a resonance in the wire itself. Also as light diffracts as it passes through different materials of varying diffractive index, as the electron goes from a wire, through solder and to a copper pad (and so on) so to the resonance at these points builds and changes. Enough of the theory, how to control it.
As Junji said you can never get rid of it. You can minimise resonance and control it. Smaller component count and less differing materials help immensely. So the Caincard was born – small component count, solid construction and the shortest signal path possible. Also a heavy case well bolted together. Light aluminium cases are for biscuits. So if you want your amp to deliver the emotional content of a biscuit-use a light aluminium can! Glue speaker plastic/ rubber dampening material on all cool surfaces. Glue a huge piece on the bottom of the amp. Heavy isolation feet bolted to the base plate of your amp and sitting onto ½” marble or ½” glass isolation plates (300mm X 400mm). The marble or glass plates must have thick silicon feet to further isolate them.
Try mass-loading the amp with pointed isolation feet direct on to 2” think wooden chopping board (300mm X 400mm) itself sitting on multiple silicon feet. A block of fine grain wood on top of the case with the lid lined with dampening material. If you are using cct. brds, rubber grommet (sandwich) mount them. Your friends will think you are mad until they hear the difference. Also use a MEI power filter at the amp mains, gold plated RCAs and solid silver hook-up wire for the audio path. I have found this works well.
You appear to know what you are doing with relation to superior parts and I believe this is what can make a good amplifier great. It also sets it aside from the ‘also-rans” of the world. I also believe that every little upgrade to better components does collectively make a difference. So I am not going to even mention other components.
What I would like to talk about is resonances. The guy that design and built the first Giancard, Junji, spoke of resonance in an interview (which I can’t relocate). He is not talking about vibration which is different but also important. If you have ever felt a hose which is running hard you have experienced the effects of resonance. Now down to a smaller level think of an electron moving through a wire. Not very exciting but very excitable. The electron, which only moves at a centimetre a second is bashing into millions of other moving electrons. So there is a resonance in the wire itself. Also as light diffracts as it passes through different materials of varying diffractive index, as the electron goes from a wire, through solder and to a copper pad (and so on) so to the resonance at these points builds and changes. Enough of the theory, how to control it.
As Junji said you can never get rid of it. You can minimise resonance and control it. Smaller component count and less differing materials help immensely. So the Caincard was born – small component count, solid construction and the shortest signal path possible. Also a heavy case well bolted together. Light aluminium cases are for biscuits. So if you want your amp to deliver the emotional content of a biscuit-use a light aluminium can! Glue speaker plastic/ rubber dampening material on all cool surfaces. Glue a huge piece on the bottom of the amp. Heavy isolation feet bolted to the base plate of your amp and sitting onto ½” marble or ½” glass isolation plates (300mm X 400mm). The marble or glass plates must have thick silicon feet to further isolate them.
Try mass-loading the amp with pointed isolation feet direct on to 2” think wooden chopping board (300mm X 400mm) itself sitting on multiple silicon feet. A block of fine grain wood on top of the case with the lid lined with dampening material. If you are using cct. brds, rubber grommet (sandwich) mount them. Your friends will think you are mad until they hear the difference. Also use a MEI power filter at the amp mains, gold plated RCAs and solid silver hook-up wire for the audio path. I have found this works well.
Mhouston, don't take it as an offence, but even for open-minded person as myself, some things you said sounded like utter nonsense. Damping materials in amplifier case? "Marble or glass further insulated with silicon feet"? This simply can't have any influence on your amp, unless you happen to live near some stable time-space singularity altering dielectric properties of matter.
I can believe that one esoteric cable sounds better than other, because, basically, there IS some actual difference in resistances/capacitances/inductances they present in audio path - however small and neglegible. I can even find some remote sense in reports of different sound from amp after changing its heatsink (it may have been shielding off some interferrences and different materials have different damping factors).
But placing the amplifier on glass has nothing to do with audio path whatsoever. If there is a difference, it will be purely psychological or aesthetical. Try doing some double blind tests, you'll see for yourself.
PS. Air has dielectric strength of three milion Volts/m, and I find it to be quite sufficient insulation for my amp.
I can believe that one esoteric cable sounds better than other, because, basically, there IS some actual difference in resistances/capacitances/inductances they present in audio path - however small and neglegible. I can even find some remote sense in reports of different sound from amp after changing its heatsink (it may have been shielding off some interferrences and different materials have different damping factors).
But placing the amplifier on glass has nothing to do with audio path whatsoever. If there is a difference, it will be purely psychological or aesthetical. Try doing some double blind tests, you'll see for yourself.
PS. Air has dielectric strength of three milion Volts/m, and I find it to be quite sufficient insulation for my amp.
Actually, the part you are quoting is quite correct from the physics point of view. There are such resonances, and they are one of the reasons responsible for the famous 'skin effect' (which is a good 'esoteric' topic in its own right). But the question is: should we bother about them at all?
Well, It'll keep it from rattling off the shelf when you turn it up too loud. 😉
Sounds like voodoo to me. As long as your case doesn't rattle or electrically affect the circuit it's fine IMHO. I guess if your parts are microphonic it might matter, but the only part I can imagine would be the caps, and they're not in the signal path, so you should be in the clear even if you do manage to find some that amazingly bad.
Regarding "resonance", I think you're using the wrong term. There is some reflection whenever the signal passes an abrupt change in impedance. given insufficient (electical) damping you can get standing waves, phase shift, etc. If you're building your amp for a microwave transmitter it might even matter. 😉
Solid silver isn't necessary. If you have a nice layout, there shouldn't be much wire anyways, and most of what is there is connected to resistors anyways (lol). Minimizing your resistance on the way to a resistor seems silly to me, how about you?
At the impedances involved with input wiring there's very nearly zero current. I just used some 30ga silver plated copper wire with kynar insulation. 24 ga copper with teflon insulation for the signal grounds. (Aka "Wire Wrap" wire and plenum rated solid Cat 5) My choice of wires was based on what happened to be sitting on my desk at the time. Red kynar for signal, green teflon for ground.
If you want to have the minimum influence on the sound, you'll concentrate on minimizing capacitance. Don't twist your signal wires together. In fact, you'll get the lowest capacitance just running them loose, not particularily close to each other.
for output wiring, I think you would have to do something really stupid to have any effect considering the short length of wire involved.
Don't waste your money on the audiofool bits until you've taken care of the stuff that matters.
1. Build an amp that meets your needs.
2. Use good (not necessarily expensive) connectors so you don't have to replace them in a year when they get sloppy/scratchy.
3. Use good (not necessarily expensive) controls so you don't have to replace them in a year when they get sloppy/scratchy.
4. a) Build a really nice chassis if you want it to look pretty on the shelf.
b) Find a relatively solid biscuit tin if you just want it to sound good.
5. Quit messing with it. Go get some music and listen for a while. If you still want to make it sound better, look somewhere else... Maybe speakers/crossover. There's lots more room for improvement there than in your amplifier.
-Nick
Sounds like voodoo to me. As long as your case doesn't rattle or electrically affect the circuit it's fine IMHO. I guess if your parts are microphonic it might matter, but the only part I can imagine would be the caps, and they're not in the signal path, so you should be in the clear even if you do manage to find some that amazingly bad.
Regarding "resonance", I think you're using the wrong term. There is some reflection whenever the signal passes an abrupt change in impedance. given insufficient (electical) damping you can get standing waves, phase shift, etc. If you're building your amp for a microwave transmitter it might even matter. 😉
Solid silver isn't necessary. If you have a nice layout, there shouldn't be much wire anyways, and most of what is there is connected to resistors anyways (lol). Minimizing your resistance on the way to a resistor seems silly to me, how about you?
At the impedances involved with input wiring there's very nearly zero current. I just used some 30ga silver plated copper wire with kynar insulation. 24 ga copper with teflon insulation for the signal grounds. (Aka "Wire Wrap" wire and plenum rated solid Cat 5) My choice of wires was based on what happened to be sitting on my desk at the time. Red kynar for signal, green teflon for ground.
If you want to have the minimum influence on the sound, you'll concentrate on minimizing capacitance. Don't twist your signal wires together. In fact, you'll get the lowest capacitance just running them loose, not particularily close to each other.
for output wiring, I think you would have to do something really stupid to have any effect considering the short length of wire involved.
Don't waste your money on the audiofool bits until you've taken care of the stuff that matters.
1. Build an amp that meets your needs.
2. Use good (not necessarily expensive) connectors so you don't have to replace them in a year when they get sloppy/scratchy.
3. Use good (not necessarily expensive) controls so you don't have to replace them in a year when they get sloppy/scratchy.
4. a) Build a really nice chassis if you want it to look pretty on the shelf.
b) Find a relatively solid biscuit tin if you just want it to sound good.
5. Quit messing with it. Go get some music and listen for a while. If you still want to make it sound better, look somewhere else... Maybe speakers/crossover. There's lots more room for improvement there than in your amplifier.
-Nick
Snake Oil and case dampening
Evidently MJL21193 has never held a hose. And speaking of snake oil. The isolation feet I use have brass pucks or pads that they sits in. These have small dimples to seat the pointed heavy brass feet from the amp or preamp. One or two drops of snake, silicon or cooking oil in these dimples helps dampen resonances between the feet and the pucks themselves. Do you ever wonder why Simaudio Moon Rock MONO amps weigh 220lb. Not because they can’t find good biscuit tins. Because they know what internal resonance does to quality audio. Well that and good power conditioning.
http://www.stereophile.com/solidpoweramps/905sim/index.html
Uncle_leon I am happy to talk of skin effect or even space-time continuums. At least you had a good listen. Try what I have suggested in total. If you cannot tell the difference I will shout you a beer. Just be at my local and it’s my shout. The things I have spoken about do work and I have tested them.
Arx It sounds like you’re not convinced either way. Remember it is internally generated resonance not vibration. Don’t get me started on vibration.
Evidently MJL21193 has never held a hose. And speaking of snake oil. The isolation feet I use have brass pucks or pads that they sits in. These have small dimples to seat the pointed heavy brass feet from the amp or preamp. One or two drops of snake, silicon or cooking oil in these dimples helps dampen resonances between the feet and the pucks themselves. Do you ever wonder why Simaudio Moon Rock MONO amps weigh 220lb. Not because they can’t find good biscuit tins. Because they know what internal resonance does to quality audio. Well that and good power conditioning.
http://www.stereophile.com/solidpoweramps/905sim/index.html
Uncle_leon I am happy to talk of skin effect or even space-time continuums. At least you had a good listen. Try what I have suggested in total. If you cannot tell the difference I will shout you a beer. Just be at my local and it’s my shout. The things I have spoken about do work and I have tested them.
Arx It sounds like you’re not convinced either way. Remember it is internally generated resonance not vibration. Don’t get me started on vibration.
I am not going to say that Mhouston is wrong, I have not myself noticed any difference when playing about with internal wires etc. I did get an improvement replacing speaker cable. I changed to runs of heavy guage magnet wire which beat the pants off of any of the mid priced speaker cables I had in my parts bin.
However Arx makes a very valid comment. Replacing other parts elsewhere in your audio chain will make more of a difference than fancy dampening or hookup wires. I replaced my Cambridge Audio DAC 1 with a usb dddac and was blown away.
1 thing amp wise that did make a difference for me. When I switched over to a kookaburra preamp, I was initially unsure about the new sound. I took out the input caps to the gainclone and measured the DC. It was actually less without them than with! The sound improvement was noticable.
However Arx makes a very valid comment. Replacing other parts elsewhere in your audio chain will make more of a difference than fancy dampening or hookup wires. I replaced my Cambridge Audio DAC 1 with a usb dddac and was blown away.
1 thing amp wise that did make a difference for me. When I switched over to a kookaburra preamp, I was initially unsure about the new sound. I took out the input caps to the gainclone and measured the DC. It was actually less without them than with! The sound improvement was noticable.
I'm from the school that believes the best upgrade for a GC is a better source/buffer or preamp.... those have made the most improvement in my system based on My_ref C. Also there was a slight improvement going from thin lamp cord to a 4mm wire... for the speakers.... some other minor things that incremented the sound quality were low ESR caps (the ones close to the chips), and quality input caps made by Ampohm in the UK.
...but as much as they did, it never lost the chipamp flavour, which is why I am retireing my chipamp now for solidstate.
...but as much as they did, it never lost the chipamp flavour, which is why I am retireing my chipamp now for solidstate.
If you guys want to write off what mhouston is telling you then you are ignoring a very good 'signpost' to better sound!
I've read thousands of posts on this subject and all they show is that very few people acutally understand the subject, or know what is going on.
Ask yourself - do you understand the difference between coupling, de-coupling and damping?
BTW teflon/PTFE is not a good insulator as it has a 'memory effect'. Good old cheap copper wire (solid core) works fine IF you know how to use it properly! 😉
actually calling a chip amp, op amp is small component count is a misnomer.........look inside the chip
Hi Nuuk,
I'm not trying to start a debate on audibility of cable or anything here, but we better keep it simple and focus on more important issues.
"BTW teflon/PTFE is not a good insulator as it has a 'memory effect'."
maybe we better not make uncle_Leon confused, your website says different :
"Materials such as PTFE are considered better than the usual PVC types (although they are usually only found on silver-plated conductors)."
http://myweb.tiscali.co.uk/nuukspot/decdun/cabling.html#mainscables
It would be better if you can tell uncle_Leon to use which type of cable and where to place in the circuit, and what differences in sonic if a specific cable is used there.
regards,
Hartono
I'm not trying to start a debate on audibility of cable or anything here, but we better keep it simple and focus on more important issues.
"BTW teflon/PTFE is not a good insulator as it has a 'memory effect'."
maybe we better not make uncle_Leon confused, your website says different :
"Materials such as PTFE are considered better than the usual PVC types (although they are usually only found on silver-plated conductors)."
http://myweb.tiscali.co.uk/nuukspot/decdun/cabling.html#mainscables
It would be better if you can tell uncle_Leon to use which type of cable and where to place in the circuit, and what differences in sonic if a specific cable is used there.
regards,
Hartono
Yes, I did say "considered", and wrote that before I was told about the 'memory effect' issue. Due to time constraints, and writing for TNT, it is difificult for me to update such a large web site! But good to see that you are paying attention! 😀
I would advise a beginner to use 0.6mm equipment wire (solid core) for internal wiring! Use it everywhere, except may be for the speaker terminal connections where I use a 1mm diameter wire taken out of a mains cable.
I'm afraid I can't go into detail about how I actually use it as that is somebody else's 'secret', used in a commercial product, and I am sworn not to reveal the details.
What I can say is that you should think of vibration in much the same way that you think of electricity. The clue being that (most of) the electricty flows through the part of the circuit with least resistance. In the same way you can 'take' vibration where you want it! 😉
I would advise a beginner to use 0.6mm equipment wire (solid core) for internal wiring! Use it everywhere, except may be for the speaker terminal connections where I use a 1mm diameter wire taken out of a mains cable.
I'm afraid I can't go into detail about how I actually use it as that is somebody else's 'secret', used in a commercial product, and I am sworn not to reveal the details.
What I can say is that you should think of vibration in much the same way that you think of electricity. The clue being that (most of) the electricty flows through the part of the circuit with least resistance. In the same way you can 'take' vibration where you want it! 😉
Hi,uncle_leon said:
I haven't read the recent replies yet, so this may be double posting.
If you parallel connect a pair of amplifiers (for passive bi-amping or any other duty), then at least one of the amplifier inputs MUST have a DC block in series with the input.
If both (or all) the amps are DC connected at the input and then paralleled, the input offset currents will interact and the output DC (offset voltage) from each amp could be anywhere. DC block one or both amplifier inputs to prevent this interaction.
Do you have a stereo (two channel) amp?
Then feed the same signal to each input using a Y RCA connector. The outputs from the two channels then feed your two drivers with VERY SHORT cables, since you WILL be placing the two channel amplifier right next to the speaker terminals.
Grounding the unused inputs is a good idea with respect to the output sound. Just check that each source is not damaged by grounding it's output signal.
You may need a two channel switch for each of the inputs to achieve this. This would require a 12position switch to be set up as a 4 pole 3way switch allowing three stereo sources to be switched. One of the sources could be a dummy zero ohm input load for testing/first start-up of the day.
justblair said:
I would recommend passive biamping. If you condsider the relatively low cost of adding two more gainclone stages to your existing supply, IMHO the benefits are very much cost effective.
I did exactly this in my current setup, My Mission 753's sounded quite a bit better. The bass was more solid, more controlled and the highs became more fluid and musical. The character of the sound changed substantially for the better.
Of course it was not "twice as good", but I would step outside for a fight with you if you took the extra two stages back off me!
Next stage is to build a further two and convert my 753's to triamps. Then the bass assist will have its own gainclone stages. I'm not sure wether the load might be too much for my smps array, if not I will build a second and run each channel off of four skynets each.
That is not to say that adding a filter(crossover) prior to the amps would not be the best solution, however I dont think I am ready for that project just yet
- I don't understand baffle steps, phase difference etc enough to know how it would effect my sound
- The missions are 2 way with bass assist (possibly) I haven't seen a filter project that gives this
- Active filters tend to use op amps, I dont want to spend time finding the optimum one just yet
- I just spent a few quid replacing the crossover componenets in my missions, I want to get some pleasure from the enhanced sound
- I have just built a 12 chip dddac, its so awsome, I will upgrade to 24 or 36 first
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Though Mission 753's with 10 gainclones and an active filter might just be amazing
Hi Just,
your sound benefits are very similar to what I found when I went to passive bi-amping.
I think the major benefit with bi-amping (or tri-) is the raising of impedance seen by each amplifier that feeds just it's respective half (or a third) of the passive crossover. This reduces the loading seen by the amplifier and allows it to amplify more accurately. This effect is more significant if the amplifier is at or near it's inherent limits when trying to send peak signals to the speaker. Or even worse if the amp were to exceed it's limits when sending peak signals.
Could you explain this further please? I don't think I know what you exatlctly mean.
As to DC blocking - it means simply putting a capacitor somewhere on the input signal wire, right? But what value should I choose?
I understand that this capacitor should best be placed in tweeter amp's input, because degradation of low frequency would then not matter?
I also have another question about speaker cabling. I used that cheap wire to bi-wire the speaker, and I must say, there is an improvement already (mainly at high volume levels). But the question is: should I best tie the cables together, or better leave them dangling separately? Or it doesn't really matter?
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