More newbe construction questions

[ccereda]

Hi to everybody:

I still need some help here my questions:

A) I broke a resistor: R52 8.2K. I imagine it is not a problem if I replace it with anotherone of the same value (5% tolerance)taken out from another board I have hanging around.

B) Resistors R43 and R44 in the instructions is said to be 39 K but there is no resistor of 39 K in the kit. on the other hand you send a bag with two resistors of 47 K (replacement of 2 resistors in bag 5 of 47 by mistake) that are left unused, should I understand that this two resistors go in position R43 and R44? If not it is ok if I just buy them or look in my spare card if there are any?

C) I got two replacement input caps of Amp 6 intended to imporve my SI Tamp (already done the changes recommended by Michel Mardis, changed the inductors with toroidals and this cap with another one stolen from the hanging around board even if not low ESR) and a new potentometer.
The fact is that I mounted the cap the other way round and the amplifier does not work anymore, did I fried it? any idea, there is still hope?
(my basic electronics book says caps have no polarity, after reading the Amp 5 instructions: bull****).

Thank you everybody

Cosimo

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[thomaseliot]

Hi

A) Replace with 1% tolerance thin film 0,5mm

B) R43 and R44 are for setting input gain (Rfeedback), together with R32, R51 (Rin). If you want input gain = 1, for general use, then R43 R44 would be 22K (input gain = Rfdbk/Rin = 22K/22K = 1). In the kit you'll find a couple of 22K resistors for R43 R44. The 39K is a value for higher gain not included any more.

C) Only electrolytic caps have a polarity. If you mounted an electrolytic cap reversed, maybe it is damaged (only the cap, I hope).

[ccereda]

Molte grazie, Ottime e precise risposte

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