My Rset Vdrop is higher in the rail that produces a higher voltage, so CCS is higher. My measurements I assumed that this has something linear involved. What I didn't knew is that people are having randomly unexpected results in this area of a similar design.
William, do that change as the only one change, so you can compare if you perceive any subjective difference by balancing that.
It could be awhile. I plan on making some bigger (taller) "wings" for these fets. So as to be able to run it long hours, in a warmer room (summer's coming), without worrying about possible overheated fets. Will need to do another parts order anyhow for the resistors, and might pull the trigger on rest of parts for a J2 style amp (have small signal jfets already, Semisouth's here soon). Still letting these Elna's settle in, and just getting used to / enjoying what I have right now. Still need to compare the red and the pinks (PRP,Takman) to see If I can tell a difference. All in time.
I was under the impression I could balance the currents, but still have the voltage offset as intended. Is this incorrect?
I was under the impression I could balance the currents, but still have the voltage offset as intended. Is this incorrect?
bi-color leds for ccs string???
hello,
i ran across 50 of these baby's.....
Mouser P/N - 607-4301F1/5
biased one way they glow green, reversed biased they glow red......
on my test jig with 9volts and 1k ohm red = 1.725vdc green = 1.995vdc
see attached datasheet...
can i use these in the circuit?
hello,
i ran across 50 of these baby's.....
Mouser P/N - 607-4301F1/5
biased one way they glow green, reversed biased they glow red......
on my test jig with 9volts and 1k ohm red = 1.725vdc green = 1.995vdc
see attached datasheet...
can i use these in the circuit?
But what you want to do is sharing both preamp and poweramp from the same DCB1. And nothing less that powering a poweramp from it!
Giving a CCS raised DCB1 to 250mA and an output voltage of +/-10v, If my calcs are correct will give you a max power of 5W.
And appart from that, you will be sharing the same PSU, so the high current fluctuations from the poweramp will greatly affect the preamp performance. The preamp section is only 2 transistors, so PSRR is very low.
Have I understood well what you are trying to achieve?
Giving a CCS raised DCB1 to 250mA and an output voltage of +/-10v, If my calcs are correct will give you a max power of 5W.
And appart from that, you will be sharing the same PSU, so the high current fluctuations from the poweramp will greatly affect the preamp performance. The preamp section is only 2 transistors, so PSRR is very low.
Have I understood well what you are trying to achieve?
My DCB1. pls pardon the untidy wiring, am trying out the LDR vol control, with Uriah's control boards. Was also experimenting with the LEDs, so just soldered to the leads. But once I got it to work and played music, just left it as it is! Using WIMA MPK10 0.68uf and CCS has been hot-rodded so chassis does get a bit warm! 
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Thanks to Salas for the tremendous help rendered during the build!!
Got it from a local store, think they CNC-ed a a few sets for hobbyists. But yeah I guess it's DIY from some aluminium panels.
The DCB1 is currently driving a Rythmik sub and a TDA2020 amp powering Coral Beta 8s. IMHO, sound is superb to me, even the wife says so!
The trafo is an upside down toroid ment for pcb´s..
I am going tu use the B1 between my CS4398 DAC with trafo output and the F5,and the volume control is done digital in my digital mixer.Since there was some strange problem with heat rise in F5 if I connect the DAC directly to it,I will try with the B1 inbetween.
I am going tu use the B1 between my CS4398 DAC with trafo output and the F5,and the volume control is done digital in my digital mixer.Since there was some strange problem with heat rise in F5 if I connect the DAC directly to it,I will try with the B1 inbetween.
regiregi22, Thanks for the confirmation.
Since Memorial day weekend gives me some time to try the DCB1 with Lightspeed control I thought I would ask how some of you might be doing this. I have done some thread searches but have not found any answers yet. Ya, I know, I probably didn't use the right search terms. Anyway, it appears that the input impedance for the circuit should be a little less than 220k ohms. I have read that the Lightspeed control works best with impedances greater than 50k ohms so I do not think there is going to be a problem. I have gutted a CD player case and am ready to start putting this together.
Am I seeing the circuit correctly? I am assuming the gate impedance of the JFET's is far higher than the 220k resistor across the input. Or would it be better to use an adjustable input for balance or trimming purposes? I will be using a CD player as a source.
I'm not an expert but I do use the Lightspeed in my DCB1. The circuit is designed for a pot in the 15k - 25k range. Your LS will be a bit less than this which is fine. The idea is to maintain a 1:10 ratio, i.e. 22k pot:220k resistor on gate, but I don't think this is critical, just a guideline. In fact, I do something a bit different than most, and drive two DCB1's with the LS, works fine. CD player into the LS should be OK, output impedance on those typically quite low.
What happens is we want to have good extension much beyond audio so the impedance that drives the high gate capacitance of the 2SK170 does not slow down square wave performance. Up to 20-22K pot I found it subjectively not much detectable and it was high enough not to challenge most of the sources I could think of as well. If sources are very low impedance with good drive, then 10K pots or less are even ''faster'' driving the gates.