A Phono Preamp Upgrade for The Dynaco PAT-4 Preamp
I've been listening to records lately... Old records... analog records... and been enjoying every second of it! Like you, I've
got a PAT-4 Preamp, but I was never really satisfied with the Phono section. So I re-did it, and I think you'll agree that this upgrade
kit will make your PAT-4 much better than new.
How Did You Do It?
The improvements come from topology changes that are only available to you if you have installed the upgraded PATPWR power supply. It has
the negative 17.5 volt output that enables the magic to happen.
- The preamp noise is about 4 to 8 dB lower than the stock design. That puts its performance into seriously pricey territory.
- A better biasing scheme lets us take two electrolytic caps out of the signal path, decreasing distortion.
- Film caps now carry the signal from the phono preamp to the line stage. Film caps are well known for their superior sound qualitites.
- The input impedance is now constant down to the lowest frequencies. In the old design, the impedance decreased with decreasing frequency.
That made for non-optimal catridge loading, hurting the sound
- You can customize the gain to optimize overload and signal to noise ratio.
- You can even run more current in the phono preamp, increasing its capabilities in the face of extreme high frequency stresses.
- The tape head and special inputs go away, but in exchange, the PHONO LOW, TAPE HEAD, and SPECIAL inputs are all equalized for phono. You could
run 3 turntables on the PAT-4.
- The clunks and pops are gone. Remember the big juicy POP you'd get going in and out of phono? It's gone! Silent switching is the rule
The Best Components
You get the top quality components you've come to expect from Updatemydynaco.
- 1% metal film resistors for low noise and flawless repeatability
- new, low noise transistors, including a Darlington (like the DRD4 Distortion Reducer), used for optimizing noise and minimizng distortion
- Film caps for input and output coupling for lowest distortion and accurate setting of the bandwidth limits.
- We even give you new caps so you can replace C16 in the line amps. Owing to their position above R20, they often become leaky, leading
to scratchy bass control action. We don't want anything to get in the way of your great sound!
Assuring Your Success
You get the things that make doing even a challenging rebuild like this one possible, and even pleasurable.
- A carefully written and proofed assembly manual full of pictures, with step by step instructions.
- You get pre-printed wire labels that make it easy for you to get the preamp back together after the rebuild
- Thoughtful little goodies like keps nuts. They have built-in lockwashers, making reassembly easier.
- Email support when questions arise
And it sounds awesome! There's something special about the sound of vinyl, and this upgrade to the PAT-4 lets the greatness
in the grooves shine through.
This is an astounding improvement for just $24.00 plus shipping. When you make these upgrades, you'll have one of the best sounding,
smoothest operating PAT-4 Preamps ever made.
Just One More Thing
If you're going to do the work of installing the PAT4LP upgrade, it makes a lot of sense to install the Line State Distortion
Reduction kit (DRD4) at the same time. It reduces the distortion of the line stage by a factor of 10. At just $5.00, it has been
called the best value in audio.
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