100W Ultimate Fidelity Amplifier

FX12 with DC offset pot.
 

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I think many sellers mistakenly specify polyester as MKP ("P" as plastic/poly).

Polyester/mylar (MKT/MKS/MKN) is the cheapest and most produced.

Polyprophylene (MKP) has lower dielectric constant and thus relatively bigger in size.

Just look at the size. If it is relatively small it cannot be MKP. Or you can even listen to it 😉. MKP is more frequency linear. In general this is good but depends on quality this can be fatiguing. MKT is not as linear and the sound is thin, strange or exaggerating certain frequency band (can be interpreted as transparent).

You are right 🙂
I thought about that after writing my message,
I already received MKT capacitors by ordering MKP capacitors 🙁
I agree on MKP capacitors, I love red WIMA capacitors on sound path
 
[QUOTE
Fake transistors usually work but specs are usually much worse than originals. But do not expect some huge improvement in sound with originals.

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Ivan that is true, but who can we find a serious source?- It is real difficult.

I love red WIMA capacitors on sound path
Hi camelator.
you have forget to tell that they needs many hours(~150) to burn in. After that you can
feel the real good sound.
Otherwise it can give some Frustration, by not minding that.
My Favorit actually Vishay 715P needs also this long time.

Today i have done a Order on kikipcb for FX-8 sonal/prasi gerber files Boards, but fault sourced.
Juan- vargas used kikipcb, i have seen on his clip, so i visit side and, to late, it cost more
than in seeedstudio.

Aaarrrggggg!

By now rereading and tip from XRK i also would build the FH9, but with 2SJ201/SK1530-
must i have any attention?- changing part values?

Regards Bangla.
 
Fake transistors usually work but specs are usually much worse than originals. But do not expect some huge improvement in sound with originals.

In the case of my "fake" SK1058/SJ162's they actually measured with lower distortion than the "real" ones. Maybe my real source was fake ($15/pair) and the fake one ($5/pair) was real?

China is the OEM for many many electronic parts. Most of the world's electronics, computers etc are made in China. I think it's a fallacy to assume that just because a part originates from China it is somehow inferior.

If someone has a transistor curve tracer I would be glad to send you my fakes (TO-92's and TO-126) to test.
 
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I never said that Chinese produced parts are bad. Also, you can not say if transistor is fake by comparing prices. It is perfectly possible that cheap parts were originals. I think that Renesas factory that currently produce SK1058/SJ162 is actually situated in China.
 
I think it's a fallacy to assume that just because a part originates from China it is somehow inferior.

It's not a fallacy at all.

It's even disappointing for me to find good quality products here. Products are manufactured in China for a reason. Sellers (and government officers) are only looking for profits. The market is not aware of the issues. First, if the product is cheap, the useful life may be short (or it can even endanger the circuit or engine as a whole), thus the cheap price is a fallacy. Second, if the product is branded, the price cannot be cheap (while the quality suffers).

This is true for many products (may not include medicine 😀), but even one will tell you the standard of the general manufacturing quality. Swimming goggles for example. If you're looking for very cheap goggles, fake Speedos are cheap and they last long, no problemo. If you are after higher quality, you may find disappointment as most big sellers carry only Speedo made in China. You need to find small entity who import from UK, US or Japan to find the real one (yes, they are very different).

With electronic parts, you need to have a lot of experience using the products to know the issue.