Little Dot I+ mods

~ tubes in rotation ~

Amperex 5654
(The box does not say North American Philips.
The top of the tube has two seams like a typical Mullard from the UK.)
This is a noble tube - sweet nimble detail, human midrange. Nothing crude here.

Russian 6J1-P
Very fur coated midrange warmthy from the Novosibirsk Factory
The box

Mullard E91
Best of the bunch. Lots of punch with extension and delicacy.

Replaced the 470uF/25v brown caps /w Rubycon low impedance 1000uF/25v

~ opamps in rotation ~


stock MC33078P opamp.	OPA2604 /w .1uF stacked film cap on v+, v-	LM4562 /w Blackgate NX Hi-Q .1uF/50v

Click image to see details LM4562 /w .1uF stacked film caps to ground Detailed/neutral/open opamp goes great with warm tubes. Too much /w bright tubes.	OPA2228 /w .1uF stacked film caps to ground Warmer, slower sound goes good with bright tubes and makes warm tubes narcotic.	I keep trying to fix OPA827s to the adapter but burn out a channel setting the BlackGates. If only I could get this right.

- Jumper Settings for Tubes -

WE408A	1. K1 and K2 set to the side of the “WE408A” text 2. Make sure the jumper caps are removed from J1 and J2 (open circuit)
6JI, 6AK5, 5654, WE403A/B, etc	1. K1 and K2 set to the side of the “6JI” text 2. Make sure the jumper caps are removed from J1 and J2 (open circuit)
EF91, EF92, CV131, CV138, etc	1. K1 and K2 set to the side of the “6JI” text 2. Make sure the jumpers caps are in place over both J1 and J2 (short circuit)

- Jumper Settings for Gain -

~ Headphones in play ~
Grado SR-60 - Poppa bear, too warm
Sennheiser HD280 - Momma bear, too cold
Denon AH-D1001 - Baby bear, just right

1.24.2010