Cheap enough, Kapton is also used here in France by a famous speakers manufacturer.
25 feet 24 AWG Shielded Silver Teflon Wire Twisted Pair items in John's Silver Teflon Wire Shop store on eBay!
25 feet 24 AWG Shielded Silver Teflon Wire Twisted Pair items in John's Silver Teflon Wire Shop store on eBay!
suggestion
I use cables from Chord Company. Very good quality for the money, you can buy per meter from ebay.
I use cables from Chord Company. Very good quality for the money, you can buy per meter from ebay.
24 or 26 awg gauge wire is very thin for more than 1watt output. You should only use 18 awg or thicker.
Those wires seem to be pure silver, aren't they? I'm not sure a speaker cable should be pure silver, silver-plated copper at most.
So here's my situation - I've got a 2.1, bi-amped DIY system: 15" Dayton subwoofer, Bohlender Graebner NEO-3PDRW planar tweeters and Peerless 6.5" woofers.
I'll be building active crossovers, so I need 5 channels of amplification. I'm looking at a 4x100w sure board and then another 2x100w sure board.
Excuse me for not searching through hundreds of pages of threads, but I would like to know three things in brief:
1)I'd like to power these at 32v with a PSU that can deliver a full 600W. By my calculations, that's 18.75A. What's my most economical power supply option?
2)Is it possible to bridge together the two channels of the 2*100w board to power my 4ohm subwoofer?
3)Is there a page besides the wiki that summarizes modifications? I'm mostly looking to replace caps/inductors for the most accurate/extended treble response and to correct midrange.
Thanks in advance!
I'll be building active crossovers, so I need 5 channels of amplification. I'm looking at a 4x100w sure board and then another 2x100w sure board.
Excuse me for not searching through hundreds of pages of threads, but I would like to know three things in brief:
1)I'd like to power these at 32v with a PSU that can deliver a full 600W. By my calculations, that's 18.75A. What's my most economical power supply option?
2)Is it possible to bridge together the two channels of the 2*100w board to power my 4ohm subwoofer?
3)Is there a page besides the wiki that summarizes modifications? I'm mostly looking to replace caps/inductors for the most accurate/extended treble response and to correct midrange.
Thanks in advance!
1) Its better to use a separate psu for both channels. Use a third psu for the sub. It creates better stereo-separation. You might want to look at the T1 or T2 from hifimediy, they start of with a better sound quality and have less need for modifications. Also, you can use a T3 from hifimediy to power your sub: it has 300w of power@4ohm.
2) no, it is not. The channels are already bridged. This should be in the manual sure provides on their website too.
3) as I said above: start of with a better quality board: the sure boards are quite low-quality.
If you really want to make the best of the sure boards, here are some mods I did to mine:
- Replaced the buffer caps with panasonic FM caps, placed a few underneath the board close to the output chips.
- Replaced the input caps with westcaps, bypassed with some dayton polypro foil caps.
- Replaced the output coils with wurth xxl 4.7uH
- replaced the fan heatsink with a zalman northbridge cooler (fanless)
All together this did cost me more in parts than the premium you pay for better boards, and you always have the risk or ruining the boards while replacing stuff.
2) no, it is not. The channels are already bridged. This should be in the manual sure provides on their website too.
3) as I said above: start of with a better quality board: the sure boards are quite low-quality.
If you really want to make the best of the sure boards, here are some mods I did to mine:
- Replaced the buffer caps with panasonic FM caps, placed a few underneath the board close to the output chips.
- Replaced the input caps with westcaps, bypassed with some dayton polypro foil caps.
- Replaced the output coils with wurth xxl 4.7uH
- replaced the fan heatsink with a zalman northbridge cooler (fanless)
All together this did cost me more in parts than the premium you pay for better boards, and you always have the risk or ruining the boards while replacing stuff.
VU Meter
Nosian,
I'm not an expert with VU meters but looks like most of them for audio purposes work like:
"The rectifier is a type developed for performance under wide variations of frequency. Internal impedance of the insrument is 3900 Ohms. A 3600 Ohm external resistor is required to give total resistence of 7500 Ohms. Required voltage to drive meter to 0 VU is 1.228V RMS, which is +4dBm, referenced to 600 Ohm impedance"
I believe you can run the meter off an RCA line, however; I'm not sure how this will degrade the original audio signal. This might also be meter specific as I don't think there is a standard circuit for interface/driving the meter. If it was me I might tap off the audio signal with a decent op amp/RCA line driver circuit (power isolated from the audio power supply to be super safe) before going to the VU meter just to be safe.
Please upload a picture if you get these working!!!
Nosian,
I'm not an expert with VU meters but looks like most of them for audio purposes work like:
"The rectifier is a type developed for performance under wide variations of frequency. Internal impedance of the insrument is 3900 Ohms. A 3600 Ohm external resistor is required to give total resistence of 7500 Ohms. Required voltage to drive meter to 0 VU is 1.228V RMS, which is +4dBm, referenced to 600 Ohm impedance"
I believe you can run the meter off an RCA line, however; I'm not sure how this will degrade the original audio signal. This might also be meter specific as I don't think there is a standard circuit for interface/driving the meter. If it was me I might tap off the audio signal with a decent op amp/RCA line driver circuit (power isolated from the audio power supply to be super safe) before going to the VU meter just to be safe.
Please upload a picture if you get these working!!!
Nosian,
Some of the older amps I built used a diode bridge and a resistor to limit and a trimmer to adjust the meter swing and it came from the output jacks,It was a full wave bridge with the AC connected to the output speaker terminals you could do that much and read the dc and go from there.
Separate power supplies are the way to go, unless your going to use 600 watts you might not need that much,I use the meanwells with mine and it gets loud enough I am using the 4x100 and those run my 2 midrange and 2 hi end in a 6 way system.
Good luck!! You might find some amps that use those meters and look and see how they did it !
Some of the older amps I built used a diode bridge and a resistor to limit and a trimmer to adjust the meter swing and it came from the output jacks,It was a full wave bridge with the AC connected to the output speaker terminals you could do that much and read the dc and go from there.
Separate power supplies are the way to go, unless your going to use 600 watts you might not need that much,I use the meanwells with mine and it gets loud enough I am using the 4x100 and those run my 2 midrange and 2 hi end in a 6 way system.
Good luck!! You might find some amps that use those meters and look and see how they did it !
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I Installed the replacement board from Sure. It is ok now.
First impressions (un-modded). It cannot even bit the masses of bass & liquid highs of my modded Audiolab 8000p amplifiier paired with my modded Cayin hybrid 70's siemens match paired 6dj8 tubes/mosfet pre-amp.
Grainy highs, very good mids & lack of bass is my first imression. (burn in time 72 hours continuously).
I will wait for warranty to expire first & then modd the board but again it looks so sensitive that i will just keep it for kids party & don't bother with modifying it. Even the small moddified Lepai i recently finished sounds better , natural & worth every euro i paid for it + buying parts to make it better.
I ordered a new HifimeDIY T2 amp, which i think should have been my first choice from the beginning.
Anyway from my point of view, at a scale of 10 i give it 5. If i ever do the modds i might give it a higher rate. I wouldn't buy the same board again.
Vassilis
First impressions (un-modded). It cannot even bit the masses of bass & liquid highs of my modded Audiolab 8000p amplifiier paired with my modded Cayin hybrid 70's siemens match paired 6dj8 tubes/mosfet pre-amp.
Grainy highs, very good mids & lack of bass is my first imression. (burn in time 72 hours continuously).
I will wait for warranty to expire first & then modd the board but again it looks so sensitive that i will just keep it for kids party & don't bother with modifying it. Even the small moddified Lepai i recently finished sounds better , natural & worth every euro i paid for it + buying parts to make it better.
I ordered a new HifimeDIY T2 amp, which i think should have been my first choice from the beginning.
Anyway from my point of view, at a scale of 10 i give it 5. If i ever do the modds i might give it a higher rate. I wouldn't buy the same board again.
Vassilis
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