hilde45,
First of all go to Andy’s website and immerse yourself for an hour or two. Take note of his test equipment. That’s a collection by itself!
I’ve spoken with him at length about tubes and not only does he have a grasp on that subject, but he knows circuit design in detail.
I remember when I wanted to tube roll some 5687s in my ModWright Anniversary PreAmp. He started asking me some questions about the output circuit design (most of which I couldn’t answer). He then called Dan Wright directly to find out what he needed to know. He called me back and we had a discussion about the sound characteristics I was looking for. I was looking for some “vividness” without it being etched. I felt if the sound was overemphasized in the upper mids/lower treble, I could compensate downstream. I had the Amperex brand in mind and he completely agreed with me.
He recommended the Amperex 7119, D Getter, Pinched Waist (Late 1950s). They weren’t cheap but when I popped them in place, the sound absolutely glowed. No hiss, no hum, no microphonics, no unwanted sound at all. I’ve had them in place for a few years now with NO problems.
This man has seen it all when it comes to tubes. And he is willing to go the extra mile to make sure the tube is compatible (and optimal) with the circuit it is in.
I also bought two Amperex 6922, 1965 “USN”, White Label, Gold Pins for my ModWright modded Pioneer CD player.
These two components along the MOSFET powered Modwright KWA 100SE are a match made in Heaven!
If you speak directly
with Andy Bouwman, you will realize the
level of his expertise. He’s my tube guy for life!