Mirko
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and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
That's correct. R50/R51 on cfa3productionss.pdf There is none but you can do it like I did and use relays to short/open the positions. -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
I built that one, Dukei is my handle on hf. 47uF cap is installed on the backside on the smd position. -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
Another CFA is alive and well. Sorted out the issue with the bias when using the SS/ZF switch by doing the following (board rev 1.2): - Remove the 4 ZF jumpers near the 600pF - Increase R44/R49 to 50K - Increase R50/R51 to 4.2K - Remove C9/C10 Set at 190mA, plays beautifly in both modes. A must-have as reference in the amp collection. Thanks to KG for developing this amazing circuit! -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
Thanks KG, will try it out. -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
Maybe my post was a little ambiguous. Right now have it at 200mA in ZF. I shut it down and "jump" the amp to SS. When I power it up I get something like ~300mA bias. My ultimate question is: should it act like this? Seems cumbersome adjusting bias up and down between the different modes. -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
Have the V1.2 boards so they should be good? -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
Running my CFA at 200mA bias in ZF mode, works perfectly but when I try to go over to SS mode it acts funny. Bias jumps up way high when only the SS jumpers are engaged, is this normal behaviour? Using the latest boards. -
and now for something completely different part 3
Mirko replied to kevin gilmore's topic in Do It Yourself
@RudeWolf Nice build! What transistors are using instead of that340? -
@jamesmking is the heater from pin 7 on el34 connected correctly on your schematic? Seems that it's connected to the junction of r28/29 on the original schematic?
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What do we think of SBCP56-16T1G and SBCP53-16T1G as replacement for pzta06/pzta56?
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SJ109 (and sk389) are extinct for ages...Your best shot is to find linear systems parts, lsj689. But it is pricey
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@spritzer Did you listen to it, how does it sound?
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now that is what I call a mini, well done JoaMat!
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how big are the size of the boards? Looks like there are some space that can be further shaved off...
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Hi guys, quick question; what´s the current draw of the VAS transistors on the dynahi? Measuring the R17-R20 resistors gives me 4,6V (15mA). Is this the correct value?