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Old 11th May 2012, 09:56 PM   #3891
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oh sorry. there's a part where he compares sonics of bunch of bjts and 639 is one of them.

edit: i just found out that my speaker ports were blocked off for the better part of the listening session all day... how embarassing (long story why i plugged them up)

Last edited by PreSapian; 11th May 2012 at 10:19 PM.
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Old 11th May 2012, 10:19 PM   #3892
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Quote:
Originally Posted by PreSapian View Post
oh sorry. there's a part where he compares sonics of bunch of bjts and 639 is one of them.
Thanks

But it don't rates badly the BC639...

And you must take in account that each manifacturer has its distinct sound signature, the best sounding are OnSemi and NXP, fuller and more balanced than Fairchild, ST are way worse.

And finally his findings are about using those transistors as buffers, not exactly the same application...
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Old 15th May 2012, 09:47 AM   #3893
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A pic of the first MyRef_X2 aka Evo2 prototype, almost fully populated (just missing the LM318/LF01 and a few passives) - the large metallic cylindrical component at front right is a 1uF Russian K71-5 Polystyrene. The rest of the stuff is more or less the Rev C BoM, with some uprated/larger-valued components and minor compensation changes. Just one monoblock so far - I hope to complete it as well as another identical monoblock for power-up by the weekend.
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Old 15th May 2012, 10:37 AM   #3894
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Looking wonderful ! Let's see how it sound ...
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Old 15th May 2012, 10:43 AM   #3895
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A pic of the first MyRef_X2 aka Evo2 prototype
...
I hope to complete it as well as another identical monoblock for power-up by the weekend.
Well done

We'll wait for your comments.

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Originally Posted by linuxguru View Post
the large metallic cylindrical component at front right is a 1uF Russian K71-5 Polystyrene.
Those caps are very good ones, I tried the axial version with great results.
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Old 18th May 2012, 05:53 AM   #3896
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could you tell me which pin that gets bypassed by c7 has the lower impedance? ill be connecting vcap cutf to that location and it talks about outer/inner foil here V-Cap Audio Capacitor Installation Notes

i must say, the caps are rather extreme but i'm still in the firm belief that c7 adfects the sound as much as c13.
and longer lead length or not, i have found full sized axial caps to sound uncomparably better than thruhole caps for this location
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Old 18th May 2012, 07:42 AM   #3897
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Originally Posted by PreSapian View Post
could you tell me which pin that gets bypassed by c7 has the lower impedance? ill be connecting vcap
C7 is a +12V to -12V rail-to-rail bypass for the LM318. It bypasses Pin 7 (+Vcc) to pin 4 (-Vcc). If you mean impedance to ground, it's hard to say which has the lower impedance, but in any event it's shunted by the dynamic impedance of the zener, which is in the tens of ohms, and much lower than the dynamic impedance to ground looking into any power pin of the LM318.

I'd advise against using any long-lead axial at that location. Any film/foil type with short leads does fine there - either FKP2, FKS2, FKC2, KC1850, KP1834/35 or similar.

For the LF01, choices are a bit restricted because of the 2.5mm lead pitch, but most of the above can be squeezed in by bending the leads inwards.
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Old 18th May 2012, 08:27 AM   #3898
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Quote:
Originally Posted by PreSapian View Post
could you tell me which pin that gets bypassed by c7 has the lower impedance? ill be connecting vcap cutf to that location and it talks about outer/inner foil here V-Cap Audio Capacitor Installation Notes
Connect the outer foil to V-

Quote:
Originally Posted by PreSapian View Post
I must say, the caps are rather extreme but i'm still in the firm belief that c7 adfects the sound as much as c13.
and longer lead length or not, i have found full sized axial caps to sound uncomparably better than thruhole caps for this location
As I've told several times, while you're right about C7 importance and impact on sound, you can't ignore the cap primary goal: DECOUPLING

So:

Quote:
Originally Posted by linuxguru View Post
I'd advise against using any long-lead axial at that location. Any film/foil type with short leads does fine there - either FKP2, FKS2, FKC2, KC1850, KP1834/35 or similar.
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Old 18th May 2012, 12:06 PM   #3899
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bypass is different from decoupling.

The two terms are not interchangeable.
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Old 18th May 2012, 12:30 PM   #3900
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bypass is different from decoupling.

The two terms are not interchangeable.
Hi Andrew,

I've thought that they were interchangeable but after a brief google search I understand that this is not so but the difference is not completely clear to me.

Can you define the exact difference,please?

Thanks in advance
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