Cable capacitance and resistence MAKE differences.
But I think that the cables start to make diference when they are long...
Of course, if your speaker cable @ 3mts have 1 Ohm or more, it will definitivelly change your bass quality and distort the signal. If resistors can be noisy, cables can be too.
And if you have a very long signal in cable on your lovely pré, that have capacitance, naturally you will loose highs like a LP xover, and also have a distorced signal.
Go and buy those hard wires used in buildings that interconnects your lamps at your house, something rated to 15A.... Conect your speakers with, and you will be suprised of how good this horrible thing will sound, just because there's no loss on the signal or capacitance along the cable.
Then buy an coax cable, like your cable TV cable, and conect it to your pre-amp, WOW! CHEAP and GREAT. Why ? No noise, no capacitance...
Things are LOGICAL...
If you use a capacitive cable, on your input, you'll loose definition and also distort your music signal.
If you use a too much resistive cable on your speakers, you'll loose bass attack (will sound fool) and will distort your signal obviously, affecting the highs.
Things are simple, I don't know why all this discussion, and how one person can spend lots of money in a famous cable.
Cheers !
But I think that the cables start to make diference when they are long...
Of course, if your speaker cable @ 3mts have 1 Ohm or more, it will definitivelly change your bass quality and distort the signal. If resistors can be noisy, cables can be too.
And if you have a very long signal in cable on your lovely pré, that have capacitance, naturally you will loose highs like a LP xover, and also have a distorced signal.
Go and buy those hard wires used in buildings that interconnects your lamps at your house, something rated to 15A.... Conect your speakers with, and you will be suprised of how good this horrible thing will sound, just because there's no loss on the signal or capacitance along the cable.
Then buy an coax cable, like your cable TV cable, and conect it to your pre-amp, WOW! CHEAP and GREAT. Why ? No noise, no capacitance...
Things are LOGICAL...
If you use a capacitive cable, on your input, you'll loose definition and also distort your music signal.
If you use a too much resistive cable on your speakers, you'll loose bass attack (will sound fool) and will distort your signal obviously, affecting the highs.
Things are simple, I don't know why all this discussion, and how one person can spend lots of money in a famous cable.
Cheers !
-_nando-_ said:Things are simple, I don't know why all this discussion, and how one person can spend lots of money in a famous cable.
Cheers !
You forgot a very important factor, inductance. Esepcially with longer cables a real problem. Also Skin effect (A side effect of inductance). Both effects are fighted with the special construction of the Kimber cable. That simple !
Mike
MikeB said:
Just a small correction so that there is no misunderstanding: skin effect is an electromagnetic effect and not related to the actual inductance of a cable. It is very much related to the construction, though. IT should also be mentioned that skin effect increaes the RESISTANCE of the cable, not the reactance. Very big difference, as reactance is non dissipative and produces phase shift, while resistance is the oposite.
PS OT: very common mistake with home made speaker cables is separating the two wires. They should be as close together as possible, to minimize effective loop area, as this minimizes inductance. This can be quite a problem with long cables and proximity to ferromagnetic materials, and other cables (especially power).
Couldn't you make one of these braided things yourself for cheaper? I think that it is quite a neat concept, but I think I could manage a lot better making my own and not having to pay so much (yes, I know how to braid... 🙄 ). I don't have anything against these guys, but didn't the guy who invented the 4PR stuff use ordinary materials in the first place?
Also, I would think that the inductance would filter out RF more than it filters details, if this were a static room. But in any case I would advise to just build your own to test and compare and see what's up for yourselves. I'm gonna braid myself some speaker wire, just to see if I can hear a difference. 😎
Hmmm... Which would be better - flat braid or round?
- keantoken
Also, I would think that the inductance would filter out RF more than it filters details, if this were a static room. But in any case I would advise to just build your own to test and compare and see what's up for yourselves. I'm gonna braid myself some speaker wire, just to see if I can hear a difference. 😎
Hmmm... Which would be better - flat braid or round?
- keantoken
Ilimzn, thanks for pointing that out, all i know about skin effect is that the current flowing induces a magnetic field, forcing the electrons to flow in the outer side of the cable, increasing resistance. Shouldn't this even increase resistance in relation to the current, creating 3rd harmonic distortion ?
Keantoken, yes you could braid your own cable. It would be helpful to use low dielectric insulation to reduce capacitance.
For the skin effect, Kimber has an additional braiding inside the cable, using different thickness for several wires inside the insulation.
As you have low impedances, already small inductances can cause considerable phasehift and attenuation of trebles.
Mike
Keantoken, yes you could braid your own cable. It would be helpful to use low dielectric insulation to reduce capacitance.
For the skin effect, Kimber has an additional braiding inside the cable, using different thickness for several wires inside the insulation.
As you have low impedances, already small inductances can cause considerable phasehift and attenuation of trebles.
Mike
Mike
My cables are EXACTLY done that way, the braids are twisted with
4 pairs. Curiously I've never heard of this 4TC (my fault) and I already
had my home made braids for 6 or seven years....Interesting!
My cables are EXACTLY done that way, the braids are twisted with
4 pairs. Curiously I've never heard of this 4TC (my fault) and I already
had my home made braids for 6 or seven years....Interesting!
Oh dear.
The crossconnected bi-wired RG214 was $20/stereo meter.
In about 6 months time that will have cost me $1 a year.
Next month you can see me on the telly, i'm the one they call Ebenezer.
The crossconnected bi-wired RG214 was $20/stereo meter.
In about 6 months time that will have cost me $1 a year.
Next month you can see me on the telly, i'm the one they call Ebenezer.
Although the symassym use some expensive critical capacitors (input and feedback, and also those 330 and 100pF), it's not expensive at all !
All transistors from farnell cost about 23USD. The caps and other things (except heatsink and supply) shouldn't be more than 10usd.
Total cost of the parts is about 35USD. 😎
I ordered parts for two amplifiers, it will take about 3 weeks to arrive. Then I'll have the pleasure to listen it in stereo configuration with Beyma Speakers, and I'll try it bridged too ! Bridged it should give about 180 ~ 200W RMS into 8 Ohms load, great ! 😀
Kind Regards,
Fernando
All transistors from farnell cost about 23USD. The caps and other things (except heatsink and supply) shouldn't be more than 10usd.
Total cost of the parts is about 35USD. 😎
I ordered parts for two amplifiers, it will take about 3 weeks to arrive. Then I'll have the pleasure to listen it in stereo configuration with Beyma Speakers, and I'll try it bridged too ! Bridged it should give about 180 ~ 200W RMS into 8 Ohms load, great ! 😀
Kind Regards,
Fernando
Fernando, keeping the amp reasonably cheap was one of the design goals, the original intention was for use as HT-amp, using multichannel.
My very first design goal was a 5 channel ClassA, but after collecting some experience, quickly rejected...
A few years ago...
Mike
My very first design goal was a 5 channel ClassA, but after collecting some experience, quickly rejected...
A few years ago...Mike
-_nando-_ said:
Whoa - did I miss something? Symasym wasn't designed to be bridged... You'd need several more output pairs to handle that power... Has anyone actually tried it in this config?
Cheers!
Hi Clem,
I'm not a fan of bridged amplifiers. The Symasym might be okay at 8 ohms minimum and 35 VDC. How does that sound Mike?
-Chris
I'm not a fan of bridged amplifiers. The Symasym might be okay at 8 ohms minimum and 35 VDC. How does that sound Mike?
-Chris
I don't see any problems in bridging symasym into 8ohm with max 36v supply. Of course i can't guarantee.
I am using my symasyms into 4ohm, no problem here.
The bridged configuration can only be used into 8 ohms min, any impedance below will be dangerous.
Clem_o, you don't need more outputdevices here, principally they are already "doubled up" through bridging, and supply voltages are not increased. It's just a 4ohm load for each amp.
Fernando, you will need an external signal invertor to one of the amps, best use an opamp in inverting configuration here.
Mike
I am using my symasyms into 4ohm, no problem here.
The bridged configuration can only be used into 8 ohms min, any impedance below will be dangerous.
Clem_o, you don't need more outputdevices here, principally they are already "doubled up" through bridging, and supply voltages are not increased. It's just a 4ohm load for each amp.
Fernando, you will need an external signal invertor to one of the amps, best use an opamp in inverting configuration here.
Mike
Symassym is a guarantee of satisfaction.
Nando will construct a very powerfull unit..... this is a portuguese short form of Fernando.
Those bridged amplifiers normally do not sound so good as separated units producing a stereo.
Every transistor stage, with gain one, will fit Nando's needs as inverter.... the transistor will feed one amplifier only, when the other will receive the source signal directly.
Modification not too much apreciated, as will reduce quality.
My subjective point of view Nando.....but may fit your need of power...so....go ahead!
No need of more parts..using 8 ohms speaker those amplifiers will hold the load.... supplies must be hudge.
regards,
Carlos
Nando will construct a very powerfull unit..... this is a portuguese short form of Fernando.
Those bridged amplifiers normally do not sound so good as separated units producing a stereo.
Every transistor stage, with gain one, will fit Nando's needs as inverter.... the transistor will feed one amplifier only, when the other will receive the source signal directly.
Modification not too much apreciated, as will reduce quality.
My subjective point of view Nando.....but may fit your need of power...so....go ahead!
No need of more parts..using 8 ohms speaker those amplifiers will hold the load.... supplies must be hudge.
regards,
Carlos
Hello,
This rainy day of november makes me things about power supply design : Is someone here used a regulator in is PSU design ?
After reading the datasheet of several voltage regs, I've seen they are able to provide 5 A ( LT 1084 ) or 7,5 A ( LT 1083 ) so they're good for us. But in my head, it stays one question without answers : with the Ohm law, we can consider for one channel the output current for a 4 R load is :
I = sqrt( P / R ) = sqrt( P ) / sqrt ( R ) = sqrt(100)/sqrt(4) = 10 / 2 = 5 A
By using a dual mono power supply, you could use a reg easily.
This rainy day of november makes me things about power supply design : Is someone here used a regulator in is PSU design ?
After reading the datasheet of several voltage regs, I've seen they are able to provide 5 A ( LT 1084 ) or 7,5 A ( LT 1083 ) so they're good for us. But in my head, it stays one question without answers : with the Ohm law, we can consider for one channel the output current for a 4 R load is :
I = sqrt( P / R ) = sqrt( P ) / sqrt ( R ) = sqrt(100)/sqrt(4) = 10 / 2 = 5 A
By using a dual mono power supply, you could use a reg easily.
Regulator may be interesting..using big electrolitics in its output.
Pouquoi n'a marche pas?...parce que est pluie?
Why not move....go ahead...because raining?
regards,
Carlos
Pouquoi n'a marche pas?...parce que est pluie?
Why not move....go ahead...because raining?
regards,
Carlos
Hi MaxS, i am not sure if regulators to the outputstage do make sense. About the currents, assuming a 30v peak into 4ohms, you get max current of 7.5A. Assuming an unclipped sine wave, you will get an average current of ~2.7A (because of half waves). Using large caps you can average out this current, but this will fail for low freqs.
It might be better to ensure that the regulator will be able to deliver 10A peak.
Mike
It might be better to ensure that the regulator will be able to deliver 10A peak.
Mike
Yes, ca marche pas 😀
In four hours, I've my electronics lessons, not before.
Outside, it is a thunder and rain, a good start for a sing but not for the rest.
Else, what do you think about regulator in power supply design ?
In four hours, I've my electronics lessons, not before.
Outside, it is a thunder and rain, a good start for a sing but not for the rest.
Else, what do you think about regulator in power supply design ?
Hi Chris & Mike,
Yeah, the "8 ohms" thing of nando didn't register in my brain - 'twas early in the morning for me... 🙂
Cheers!
Yeah, the "8 ohms" thing of nando didn't register in my brain - 'twas early in the morning for me... 🙂
Cheers!