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Old 23rd February 2013, 07:32 PM   #2741
stajo is offline stajo  Sweden
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Quote:
Originally Posted by mantha3 View Post

If you happen to know what resistor got ya down to the 3VDC let me know.
It is not the voltage you take down, you limit the current to the diodes spec

Best regards
Staffan
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Old 23rd February 2013, 08:36 PM   #2742
Renron is offline Renron  United States
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Stajo,
Correct! Absolutely right. it's the mA and forward voltage that counts! I used 3V as a reference to about what the forward voltage should be after the R. I would start off with 10mA and determine the brightness you desire. Better safe than sorry.
Ron
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Old 23rd February 2013, 08:43 PM   #2743
mantha3 is offline mantha3  United States
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That makes sense now... learning as I go. Thanks for dropping some knowledge my way all.
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Old 24th February 2013, 12:00 AM   #2744
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Further to my trials with Russian caps...

I have just replaced the kit Wimas with 0.2uF FT3 teflon ones...

The results are .... are.... a....

OH MY GOD.... Seriously, if you are considering upgrades, this one is a major one... The change was similar to that of hotrodding towards the upper limit. Instruments are now much more focused and the stage depth is better defined. I also noticed some improvement in bass and highs but I cannot verify that for sure since it s late here so I can t listen to proper gut kicking volumes.

Kinda makes you wonder how better they can get after they properly break in...

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Last edited by dimkasta; 24th February 2013 at 12:10 AM.
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Old 25th February 2013, 01:01 PM   #2745
mantha3 is offline mantha3  United States
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What is the Glue/expoxy used to connect the heat sinks to the Matched quad 2SK170?
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Old 25th February 2013, 01:29 PM   #2746
Dimitris
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The jfets do not need heatsinking

The mosfets are usually screwed on the heatsink and we put thermal paste to help the heat transfer
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Old 25th February 2013, 06:51 PM   #2747
Dimitris
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With the 0,47uF coupling cap I used no referencing resistor and had no problems.

But after I have changed them with 2.2uF, I ve been having some bigish DC thumps when switching the amp off.
What I was wondering is if there is any rule on the value of the referencing resistor and how this could effect the sound.
At the moment the biggest value I have is 100k, but in some instances I have seen from 2k to 10k, while earlier in this thread Nikos talked about an 1M one.
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Old 25th February 2013, 07:00 PM   #2748
Salas is offline Salas  Greece
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Its down to specific cap leakage and value also. Don't use less than double your amp's input resistor in general.
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Old 25th February 2013, 07:19 PM   #2749
Dimitris
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Quote:
Originally Posted by Salas View Post
Don't use less than double your amp's input resistor in general.
Ah cr@p....
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Old 25th February 2013, 07:31 PM   #2750
Dimitris
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Quote:
Originally Posted by Salas View Post
Its down to specific cap leakage and value also. Don't use less than double your amp's input resistor in general.
I have no nice quality resistor at over 500K so I won t solder anything to the terminals yet.
However, my source selector is a make before break switch with a middle position were both inputs are connected.
Would it be ok if I soldered some cheap 1M resistors to some spare RCA plugs and plug these to the second source in.
I would listen music without these in the circuit, and right before I switched off the amp I would switch it to the middle position to put the resistor in parallel with the amp.
Do you see any problem with this as a temporary measure?
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