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Direct injection is certainly one of the ways to achieve Hi-Fi and it can produce exceptional results. Although I've noticed some major differences between "outboard audio" and changing the audio caps in the AF stages. Having run the outboard modulating equipment in several setups before, I have to ask have you not noticed extra attention was required to keep RFI feedback out of the external mic pre-amps? That can be a particularly stubborn problem with AM.

The mic amp stages in CB radios almost always use discrete transistors that have their individual base to emitter junction RF bypassed with a ceramic cap. Most modern studio pre-amps and "export" radios use an IC chip as the pre-amp which presents a situation were you cannot bypass the many internal transistors used in high gain stages. You also have to be very careful about not creating any ground loops and providing the correct gain distribution between stages otherwise you get hum and inside noise.

You will need an external compressor / limiter in order to keep the peaks from flat topping or reaching RF cutoff. Modifying the internal audio circuits allows you to repurpose the original AMC circuit in the CB. While we often notice aggressive compression even when the stock circuit has its potentiometer wide open, it's very easy to increase the point at which compression begins. That will make the AMC circuit a bit more desirable to leave intact.

Perhaps the biggest difference is the fact that once you modify the internal AF stages you actually get to hear the improvement in your receiver where direct injection only allows you to transmit in Hi-Fi. For those who question others who have an interest in Hi-Fi, many of us see it as a diverse frontier for experimenting with the hobby. Once you've put the effort into the signal and antenna what do we have left to experiment with if your interest in radio goes beyond ragchewing?

Today there are so many different ways to achieve Hi-Fi from analog to digital that it allows people with different backgrounds to apply their knowledge in accomplishing the same goal. I'm somewhat amazed how a bunch of ones and zeros arranged in the correct order can now reproduce the same sound analog equipment has in the past. That opens the door for everyone from old school audiophiles to computer buffs to join in.

<blockquote data-quote="Shockwave" data-source="post: 505844" data-attributes="member: 10882">Direct injection is certainly one of the ways to achieve Hi-Fi and it can produce exceptional results. Although I&#039;ve noticed some major differences between &quot;outboard audio&quot; and changing the audio caps in the AF stages. Having run the outboard modulating equipment in several setups before, I have to ask have you not noticed extra attention was required to keep RFI feedback out of the external mic pre-amps? That can be a particularly stubborn problem with AM.The mic amp stages in CB radios almost always use discrete transistors that have their individual base to emitter junction RF bypassed with a ceramic cap. Most modern studio pre-amps and &quot;export&quot; radios use an IC chip as the pre-amp which presents a situation were you cannot bypass the many internal transistors used in high gain stages. You also have to be very careful about not creating any ground loops and providing the correct gain distribution between stages otherwise you get hum and inside noise.You will need an external compressor / limiter in order to keep the peaks from flat topping or reaching RF cutoff. Modifying the internal audio circuits allows you to repurpose the original AMC circuit in the CB. While we often notice aggressive compression even when the stock circuit has its potentiometer wide open, it&#039;s very easy to increase the point at which compression begins. That will make the AMC circuit a bit more desirable to leave intact.Perhaps the biggest difference is the fact that once you modify the internal AF stages you actually get to hear the improvement in your receiver where direct injection only allows you to transmit in Hi-Fi. For those who question others who have an interest in Hi-Fi, many of us see it as a diverse frontier for experimenting with the hobby. Once you&#039;ve put the effort into the signal and antenna what do we have left to experiment with if your interest in radio goes beyond ragchewing?Today there are so many different ways to achieve Hi-Fi from analog to digital that it allows people with different backgrounds to apply their knowledge in accomplishing the same goal. I&#039;m somewhat amazed how a bunch of ones and zeros arranged in the correct order can now reproduce the same sound analog equipment has in the past. That opens the door for everyone from old school audiophiles to computer buffs to join in.</blockquote>

[QUOTE="Shockwave, post: 505844, member: 10882"] Direct injection is certainly one of the ways to achieve Hi-Fi and it can produce exceptional results. Although I've noticed some major differences between "outboard audio" and changing the audio caps in the AF stages. Having run the outboard modulating equipment in several setups before, I have to ask have you not noticed extra attention was required to keep RFI feedback out of the external mic pre-amps? That can be a particularly stubborn problem with AM. The mic amp stages in CB radios almost always use discrete transistors that have their individual base to emitter junction RF bypassed with a ceramic cap. Most modern studio pre-amps and "export" radios use an IC chip as the pre-amp which presents a situation were you cannot bypass the many internal transistors used in high gain stages. You also have to be very careful about not creating any ground loops and providing the correct gain distribution between stages otherwise you get hum and inside noise. You will need an external compressor / limiter in order to keep the peaks from flat topping or reaching RF cutoff. Modifying the internal audio circuits allows you to repurpose the original AMC circuit in the CB. While we often notice aggressive compression even when the stock circuit has its potentiometer wide open, it's very easy to increase the point at which compression begins. That will make the AMC circuit a bit more desirable to leave intact. Perhaps the biggest difference is the fact that once you modify the internal AF stages you actually get to hear the improvement in your receiver where direct injection only allows you to transmit in Hi-Fi. For those who question others who have an interest in Hi-Fi, many of us see it as a diverse frontier for experimenting with the hobby. Once you've put the effort into the signal and antenna what do we have left to experiment with if your interest in radio goes beyond ragchewing? Today there are so many different ways to achieve Hi-Fi from analog to digital that it allows people with different backgrounds to apply their knowledge in accomplishing the same goal. I'm somewhat amazed how a bunch of ones and zeros arranged in the correct order can now reproduce the same sound analog equipment has in the past. That opens the door for everyone from old school audiophiles to computer buffs to join in. [/QUOTE]

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