DIYtube ST-70 driver Resistor Substitution question

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DIYtube ST-70 driver Resistor Substitution question

Postby Aljaheejus » Tue Feb 07, 2012 11:14 pm

Can I substitute the following in my DIYtube ST-70 driver build?

470K PRP brand 1/4W for R3, R4 in lieu of specified 475K 1/4W?
47K TKD brand 2W 1% metal film for R19, R20, R21, R22 in lieu of specified 43K value

Also, is there any downside to using 1/4W resistors where 1/8W are called for?

Thanks in advance
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Postby EWBrown » Wed Feb 08, 2012 11:18 am

Can I substitute the following in my DIYtube ST-70 driver build?

470K PRP brand 1/4W for R3, R4 in lieu of specified 475K 1/4W?
47K TKD brand 2W 1% metal film for R19, R20, R21, R22 in lieu of specified 43K value

Also, is there any downside to using 1/4W resistors where 1/8W are called for?




You can use the alternate resistors and values you have listed, they will work perfectly well in the ST70 circuit. Using 47 K in place of 43K will have little effect, in the performance of the LTPI stage.

1/4 watt resistors can be used to substitute for the 1/8 watt resistors, no problems.
HTH

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Postby Aljaheejus » Wed Feb 08, 2012 11:57 am

Thanks for the help!

I just found out that partsconnexion only has three (3) of the 47K TKD brand 2W 1% metal film for R19, R20, R21, R22

So, I have some direction now to find either the original mouser part or another in the 43 - 47K vicinity.

I really appreciate the assistance, David
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Postby Scott Novak » Mon Apr 09, 2012 5:33 am

Keep in mind that different brands of the same type of resistor can sound noticeably different. The brand of resistor may be more important that the variance from the design value in some cases.

I also like to match the corresponding right and left channel resistors as the imaging is usually a little better. It's not necessarily a huge difference, but every little improvement helps and the improvements are cumulative.

It is usually advantageous to use larger wattage resistors in place of smaller wattage resistors. A larger resistor won't get as hot and as such it's resistance won't change as much.

Also, there may be slightly reduced noise levels with larger resistors.

Also, last but not least, larger wattage resistors are usually rated for higher voltage. Many people forget to check the voltage rating of resistors. I have over voltaged resistors before and it is not good thing.

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