Deleted
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Post by Deleted on Apr 19, 2012 1:31:08 GMT
Hi Javier There have already been more than 600 JLH PCBs sold worldwide in a couple of Group Buys, and Greg is already well advanced with the latest version of his PCBs, due to the continuing demand for these very useful PCBs. Regards Alex.
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jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
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Post by jonclancy on Apr 19, 2012 8:18:59 GMT
It should be ideal for use with DACs etc. at +5V and +3.3V if a 1.4mA CRD such as the J506 is used to replace the 10K resistor . Sounds good!! Seems to me that there is a compromise required in the specs. Single vs Dual board, single vs double sided, solder mask colour etc. I can see a consensus developing, though. Hurry up, Greg!!! OT: 've been a bit tied up recently, so haven't been on too much (sorry), but here's some of my (poor) excuse - the ES11: www.pinkfishmedia.net/forum/showthread.php?t=118151Work still proceeds on the HA, and I have a bag of 50 white* LEDs in the post to me as we speak. Cheers Jon * White is the new Blue. You read it here first.
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Post by johngalt47 on May 14, 2012 17:51:48 GMT
Where in the US can I buy the Suntan caps? The places I usually order from don't carry them. BTW, I resumed working on the original batch of boards I bought from Jon during the group buy at diyaudio.
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Deleted
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Post by Deleted on May 14, 2012 22:04:18 GMT
Where in the US can I buy the Suntan caps? The places I usually order from don't carry them. BTW, I resumed working on the original batch of boards I bought from Jon during the group buy at diyaudio. I would suggest that you use a respected brand name 10 Volt low ESR type if possible (higher ripple ratings than 6.3V types, which could be used) and a normal type electrolytic of the same value in parallel. i.e. a low ESR + a normal type, instead of 2 low ESR types in parallel. You will most likely need to use 16Volt rated types for the normal electros due to availability. Regards Alex
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Post by johngalt47 on May 15, 2012 11:42:35 GMT
Please educate me....why not two low esr caps in parallel?
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Post by Deleted on May 15, 2012 12:20:17 GMT
Please educate me....why not two low esr caps in parallel? I have found that when using 2 x low ESR caps in parallel, due to their very low Z at 100kHZ, that they can tend to make upper treble sound a little too etched, and ultimately fatigueing. Best tonal balance with many different types of equipment, whether DACs, preamps, or even for the front end of Class A amplifiers, and with external +5V Linear PSUs for USB memory sticks, is when using a low ESR type in parallel with a normal type electro.IF your gear is slightly lacking at HF, use of 2 parallel low ESR types may help to compensate a little though.Also, if you are using the JLH at +5V or +3.3V , a further improvement at these low voltages will be obtained by replacing the 10K resistor with a Current Regulating Diode of around 1.5mA. A J506 is suitable.Alternatively a selected FET such as the 2N5484 with Gate and Source tied may be used. At voltages higher than 20V without the Current Limiter in use, a small heatsink should be fitted to the 2SC5171/2SA1930 with the 33 ohm emitter resistor. The JLH with the CL section bypassed, and supplied by a 3A voltage regulator such as the MC78T05 or MC78T12 will work at up to 2Amps, but input and output leads should preferably be 10A rated to reduce voltage drops. If several mV drop across the Earth and Supply rail tracks is a problem, then they can be supplemented with tinned copper wire under the PCB. Regards Alex
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