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Old 19th May 2010, 09:07 PM   #1461
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Quote:
Originally Posted by Salas View Post
It will still remain a bit unequal for voltages. He is referring to running currents. Since there are differences in Vgs between PMOS and NMOS batches, same Rset values don't produce same currents in both sides. Gfs will not significantly change if they are already roughly near for current though. Some report very near Rset Vdrop in builds some not. Random.
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.
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Old 19th May 2010, 11:12 PM   #1462
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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?
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Old 20th May 2010, 12:11 AM   #1463
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It is correct. Changing CCS to a different value shouldn't affect to output voltage. The CCS resistor only sets the current that will be constantly consumed by the shunt regulator.
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Old 23rd May 2010, 07:32 PM   #1464
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Default 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?
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Old 23rd May 2010, 07:47 PM   #1465
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I can't see any problem why you shouldn't use them. In this part of the circuit, there is only one way for the current, so I supposse that it doesn't matter to have a reverse diode placed all the time.

Regards
Regi
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Old 24th May 2010, 11:58 AM   #1466
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Default t-amp & dcb1

Just wondering if it's ok to borrow 9v~14v dc from the dcb1 to power a t-amp?

I'd like to but the two units into one case, and integrate them together.

Where might I be able to find the required dc voltage on the dcb1?
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Old 24th May 2010, 12:22 PM   #1467
Salas is online now Salas  Greece
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Using the HYPNOTIZE as a general shunt reg PCB
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Old 24th May 2010, 01:17 PM   #1468
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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?
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Old 24th May 2010, 04:20 PM   #1469
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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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File Type: jpg 23052010038(1) (Small).jpg (58.2 KB, 424 views)

Last edited by pengboon; 24th May 2010 at 04:22 PM.
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Old 24th May 2010, 05:22 PM   #1470
Salas is online now Salas  Greece
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I like that slim chassis. Is that chassis not ready made, but DIY from aluminum panels? Congratulations for the build, you can organize it later inside, most important is that you got the sound you liked. What is the rest of the system made of?
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