I would like to start off by stating that this is no slight against you, it just is what it is. You have made an inaccurate assumption about the THD Type-O (the letter “O”, not the number “zero”). What you assume are cold solder joints, are nothing of the kind. We have been using lead-free, silver-tin solder since 1987, and silver-tin solder never makes shiny solder joints, no matter how perfect the joint is. If it were made with lead-tin solder, then your belief that the solder joints were cold, would be correct. Silver-tin solder joints are much lower-noise than those from lead-tin, and, even more importantly, it’s non-toxic, and is legal to import into other countries. When we started manufacturing in 1987, there was no electronics-grade lead-free solder available in the US, so we had to have it custom-made for us by Multicore. I even testified before Congress about the merits of lead-free solder, against the Electronic Industry Association, who wanted to keep the US from joining the rest of the world in banning lead-bearing solder. In the end, the EIA won, and we remain one of the few countries which allows companies to poison their employees, customers, and the environment, with lead. In the future, if you have any THD products on your bench for repair, please contact us first. We are easy to find, having been in business since 1987. Our knowledge, experience, and expertise, can save you hours of troubleshooting and misunderstanding, and thus save your client a lot of money, and give them a better-repaired product. Thanks!
Hi, thanks for your comment. I actually got in contact with Andy Marshall when I had this amp in. Great guy and very helpful. I appreciated the insight. I am aware of the difference between lead and silver solder. Aslo the pros and cons of both. I have worked on many amps with silver solder. I can certainly understand teh difference between the two. In this case this amp had many cold joints. In no way am I insuating this came out of the factory this way. It is not only possible but likely that someone had been in this amp before and tried touching up solder joints with lead on top of the silver solder causing the poor joints. Its not often I get a THD in for repair, so whatever yall are doing is likely just fine and I am sorry if the video portrayed the amp in a bad light. On a side note. I am obssesed with attenuators and I would love to try one of the hotplates out. Do you still manufacture them?
