# Integral preamp parts question



## dlazzarini (Jul 11, 2019)

Hey guys. I’m in the process of part shopping for the integral preamp. Having trouble locating the transistors. Tayda has BC548. There’s no “C” at the like there is on the parts list. Will this transistor work? Also if you could suggest a 4.7uF box cap that would fit in C4. It looks like a tight fit. Any advice would be greatly appreciated. Thank you


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## Robert (Jul 11, 2019)

I used BC54*9*C in mine.   Want me to send you one along with the PCB?


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## Robert (Jul 11, 2019)

BTW C4 is 4n7 (that's 4.7nF), not 4.7uF.









						4.7nF 0.0047uF 100V 5% JFJ Polyester Film Box Type Capacitor
					

JB Capacitors - Get It Fast - Same Day Shipping




					www.taydaelectronics.com


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## dlazzarini (Jul 11, 2019)

Robert said:


> I used BC54*9*C in mine.   Want me to send you one along with the PCB?


It calls for 2 of them. Sure if you have them tack em on to my order. That would be great.


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## dlazzarini (Jul 11, 2019)

Robert said:


> BTW C4 is 4n7 (that's 4.7nF), not 4.7uF.
> 
> 
> 
> ...


Thanks for correcting me. My mind gets blurry after looking for all this stuff


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## Robert (Jul 11, 2019)

They'll be shipping out tomorrow morning.


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## dlazzarini (Jul 11, 2019)

Robert said:


> They'll be shipping out tomorrow morning.


Thank you. You’ve been extremely helpful


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## dlazzarini (Jul 12, 2019)

Robert said:


> They'll be shipping out tomorrow morning.


One more quick question about the omittited capacitor. Just leave it empty or do I need to place a jumper there.


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## Robert (Jul 12, 2019)

Just leave it out.


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## dlazzarini (Jul 12, 2019)

Robert said:


> Just leave it out.


? thanks


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## Chuck D. Bones (Jul 13, 2019)

Just FYI, _any _low-noise, high gain transistor will work fine in this circuit.  The transistor is run in a linear region and does not contribute anything to the sound.  If you look at the original Integrated Preamp schematic, the opamp was a 741.  Those little buggers are noisy and no doubt TC Electronics put the transistor there to boost the signal going into the opamp to lower the noise floor.  There are much better opamps available now and the transistor is pretty much superfluous.  But it wouldn't be an *Integrated Preamp* without it.


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## dlazzarini (Jul 13, 2019)

Chuck D. Bones said:


> Just FYI, _any _low-noise, high gain transistor will work fine in this circuit.  The transistor is run in a linear region and does not contribute anything to the sound.  If you look at the original Integrated Preamp schematic, the opamp was a 741.  Those little buggers are noisy and no doubt TC Electronics put the transistor there to boost the signal going into the opamp to lower the noise floor.  There are much better opamps available now and the transistor is pretty much superfluous.  But it wouldn't be an *Integrated Preamp* without it.


Thanks for the input. I’m slowly learning


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