I have owned a HRDx for about 7.5 years now and recently acquired some new tubes both preamp and power amp, to replace all the stock tubes in the amp.
For the power tubes I bought a matched pair of Groove Tube 6L6 GE Reissues.
Swapping the tubes, along with re-biasing, was really straightforward even though it was the first time I have ever done this.
After some experimentation, I settled on a bias of 68. The bias range was 44 to 100. I had read that 68 was the sweet spot for this amp and I'm really pleased with how the amp sounds at this setting.
However, I noticed earlier today that the power tubes - visually at least - do not 'line up'. I had made the tube changes and did the biasing earlier this week.
What I mean by this is, for example. the GT logo and other markings on the tubes do not point in the same direction when looking at the rear of the amp straight on, and neither do the internal parts. It's like the tube in the V4 position has been twisted!
I know the new tubes went in to the sockets correctly and they appear to working just fine but why does it appear - when looking straight on at the rear of the amp - as if the power tube closest to the PI preamp tube in V3 is turned slightly to the right in the direction away from the power tube to the left (in V5)? Is this normal? It was only when I went to put the back panel on earlier today that I noticed.
It's been driving me nuts, can someone put me out of my misery here and tell me that this is perfectly normal? (or not if that's the case).
I don't see how the tubes can be put it wrong, it's not like the guide pins were missing or broken or anything like that.