azazello wrote:
Congratulations!
I don't doubt that it sound is amazing!
I like this 3D wiring ! /what kind of output trany Hammond You use?/.
Later You can compare SE 300B and PP KT88 and SE GM70!
Thanks.
The optimal position for every wire was carefully calculated to minimize noise and induced interference and each was cut to precision within 1 mm before being carefully placed in their 3D configurations as shown above!
I wish. Actually this wire I bought is finely stranded and won't hold a bend, I need something with fewer strands or even solid that holds it's shape - lesson learned for my KT88.
The trannys are Hammond 1627SEA, 30 watt, 2500 ohms - 4/8/16 ohms. I would recommend a slightly higher primary impedance for a single 300B tube, although with the secondary taps on this one there is some flexibility in changing the reflected impedance of the secondary as seen by the primary. I was contemplating making or later modding this into a parallel dual tube SET which is the reason for the lower impedance and high wattage. It can handle the bias current for two 300Bs in parallel if I ever decide to go there.
The only thing I wish it had was more power. My speakers are not very efficient (91dB/1 meter), and I didn't expect it to be very loud, but it's about 4 to 6 dB lower in volume than I expected before it noticeably distorts. I need to put my scope on it and see what's going on to make sure it's properly biased. However, at low volume it
really sounds good. I think this might be the first amp I've ever even listened to in my entire life with no global feedback. I can't put the sound into words. It's different, but definitely in a good way. I need to get a pair of efficient speakers and listen a lot more.
I can say with confidence that the solder joints are all solid and it's "safe" in terms of solid chassis grounding, fusing, and insulation.
BTW, I plugged a guitar cabinet into it and tried it as a guitar amp. It distorts VERY NICELY on electric guitar. I don't know how good that is for my 300B tubes, but it really sounds nice. It very gently "breaks up" with a bluesy sound at first, and when you really drive it hard you get full blown sustaining distortion that sounds like a quality guitar amp.
Also, the blue glow is completely gone. I'm guessing the getter absorbed some gas that was in the tubes that was ionizing. I miss my blue glow.