The Fully Modified Amp
"The Shep-1"*
Here you see the fully modified amp. At least the top part.
* This amp is called the "Shep-1" named for an audiophile friend "Shep" in the South of France who has been encouraging me to modify this amp. He was wise to do so. =)
What's been done? Clockwise from the lower left:
New volume pot
New input signal connection point
New input caps
Rerouted input lines
Upgraded RCA connectors
Grounded copper shields around filter inductors
Larger tank caps
| The stock volume control was of unknown quality. I replaced it with a nice little Panasonic 50K pot. The front panel hole needed to be enlarged slightly. You might able to get a larger, better pot in here. See more on this page. |
| The input signal is now connected to the jumper pins. From here it goes to the input caps, then to the chip. See more on this page. |
| New input caps. The stock caps are inexpensive metalized foil types. A good start, but we can do better. I've used the inexpensive but good quality Jantzen 1.5uF caps. A perfect fit! Use whatever flavor cap you like. For reference, the Jantzens shown are 25mm x 13mm. You have a long series of hole into which you can solder, allowing you a range of sizes and styles. See here and here for a better view. |
| The input signal path was rerouted via shielded cable. I don't like the way the input traces on the board run so close to the noisy output filters. Learn more about that here. |
| The Stock RCA connectors are OK, but not great. I chose to replace them. You can easily desolder the center pin and unscrew the connectors. My replacement RCAs were a little fatter, so I needed to drill out the hole a tiny bit. The stock were 8mm, I think. That should help if you are shopping for new connectors. |
| Fancy hand made copper RFI shields. Aircore inductors have a nice top end and smooth sound, but they radiate RF like great little antennas. See more here. And here. |
| New, bigger power caps. These tank caps have a lot of influence on the sound of the amp. Big high qualify caps give the amp a fuller bass, more dynamics, better channel separation and a wider soundstage. See more here. And here. |
