I need to add another example to the praise for Mikhail. I don't want to come across as a fanboy, but people considering buying a Singlepower amp should know about his customer service.
In May I upgraded my MPX3 to the Solen III and Black Gates (I previously had Solen I, Jensen Paper in Oil capacitors, and Goldpoint attenuator). After letting the amp burn in for 500 hours, I still did not like the sound. It was too dark. The mids were very recessed, and I listen with the RS-1s, which are more forward headphones. I spoke with Mikhail about my concerns, what I was looking for, and sent in the amp.
He first added a Solen 4.7uF bypass cap and spent some time listening to that. He wasn't satisfied, though, and added additional Teflon-Silver bypass couplers. He let these burn-in for a week straight and listened again. He thought the sound was just about there. Mids were much more prominent and the overall sound was more balanced. I was planning to get my amp yesterday or today.
He sent an email saying the amp will be delayed until Friday as he added more features than originally planned. He ended up adding Jupitor bee's wax capacitors to the interstage as well. Apparently, these keep the bass nice and tight, and let the full range really sing. He also modified the power supply regulator circuit as well to produce more current. He said he had trouble knowing when to stop with the tweaking, but the end result is to get the best sound.
How much did he charge for this? Nothing. He wanted to make sure I was happy with the amp after the upgrade. What great service! That is why I have decided it is worth seeking out small, "boutique" audio manufacturers like Singlepower, Ray Samuels, WooAudio, and others. It is here you get the best customer service and quality components.
