By the way, I bought the Rivera TBR1SL used for US$600. I won it on an ebay bid. Si Rivera nagsabi ng US$5000 na iyan at hindi ako.
Just a background on the US$4,000 soldano SLO. I have a Soldano Hot Rod 50. It claims to emulate the lead channel of the SLO. So, I said to myself how far can the extra US$3,000 upcharge go? I was so shocked that the SLO sounded different and way way musical. This opened my mind to pursue to more expensive stuff and test their limits. Because at that point in time I did not feel that any amplifier for that matter would be worth more than US$2000. The SLO changed that. Being that the case, I will tell right off the bat if you are willing to spend US$4,000 on amp and at that point in time if the Diezel Herbert was available, I would have spent it on the Herbert.
Because of the experience with the SLO, I started to experiment and purchase stuff like Two Rock Cables, Mastodon Nuts, Titanium nuts, Paper in Oil Capacitors, cryogenically treated electronics etc.