26 February 2013

Building a high gain amplifier part 1.5: The preamp continued.

I didn't get much time to take photos during this part as I was rushing somewhat as I had other things on later in the evening.

In this post you will see the board populated with the coupling & bypass caps. Some people will swear by one brand and type of cap whilst others will say that it doesn't make a blind bit of difference. In my experience it does but not as much as some would have you believe.

I have chosen Sprague 716p Orange Drops for the majority of the preamp because they have a certain hifi vibe to them that I like and seem well balanced tonally. For the 1uf bypass caps I have gone for Vishay MKT's, these are polyester caps and have more of a gritty feel to them. Another reason that I chose these for these positions is purely based on the physical size as a 225p orange drop is a really tight squeeze and  I like thing to look nice and clean in my builds so these are not an option.

Below is a quick comparison shot of the 225p and the MKT as you can see the 225p is gigantic!

In this next shot you can see the preamp fully populated with 716ps and the MKTs

And here is the lone Mallory 150 2.2nf cap as I forgot to order the 716p in this value. Luckily I had this kicking about.

And finally we have a bunch of leg cut offs from the caps. I'm going to save a couple of these as they will come in handy for the next post

In a few days I should have part 2 of this log up which is the power amp.

Thanks for reading
TK