The
12500-12750 and 12400-12500 numbers are the readings from a tube tester (in UMhos). The tubes have 2 plates in each and those are the numbers for each plate. Without looking up what the numbers should be these seem like well matched tubes. Each plate in each tube is the same. And the 2 tubes are close enough for me.
So I bought a Pro-ject Pre Box RS... (Valve suggestions?)
The Pre Box RS comes from the factory with
Electro Harmonix 6922, on the output stage.
All I have read about this pre has suggested a linear power supply upgrade and tube rolling gives
significantly better results, so the linear PSU is already done (19VDC from a HDPlex 200W).
I've already got some tubes I bought for my old old DAC (it's now 9 years old).
I have a pair of Amperex P.Q 6922 [VCM 163 tested], and a pair of
Phillips E88CC SQ [1109] with writing on the box [12500-12750 and 12400-12500 on the other box] What do those hand written numbers mean?
Anyway, which valves should I likely go with? (I am hoping for longevity as well as quality)
significantly better results, so the linear PSU is already done (19VDC from a HDPlex 200W).
I've already got some tubes I bought for my old old DAC (it's now 9 years old).
I have a pair of Amperex P.Q 6922 [VCM 163 tested], and a pair of
Phillips E88CC SQ [1109] with writing on the box [12500-12750 and 12400-12500 on the other box] What do those hand written numbers mean?
Anyway, which valves should I likely go with? (I am hoping for longevity as well as quality)