- Apr 3, 2022
- Reaction score
Oh, what a wonderful project you embarked on. Yes! Those Melos amps were a pain in the butt to get going without hassles. On certain days they operate fine and on other days they crap out. I can't even remember the number of times we sent these monoblocks to our techie to fix. Once we received all the required parts through our distributor in Thailand, our techie was able to get these beautiful amps going and wow did they really shine!Hello Woof
Let me tell you. Using these Melos was sometimes a nightmare. First. I had to draw the schematics because nobody has them in the world. The output sockets develop bad contacts so I had to change them. The circuit board heat so much so it blackened in some places. This means conductive carbon. With near 600 VDC on some board traces, I had arcing and redesigned the way high voltage goes to the tubes with teflon wires, repositioning fuses etc. These amps like most Melos gear had reliability problems and technical design which needed work to work correctly. Mark Porzolli, the designer of Melos gear was sick about using mosfet buffers between each tube stage. I stripped some and it helped a lot for the sound. Leaving for one weekend, I forgot to turn off y amps. When returning at home, I opened the house door an smelled a strong burnt odor. One amp was not working and had an OPT toasted !!!. Arcing again was the culprit before I decided to do the BIG job. I discovered the OPT in these amps are in reality push pull OPTs connected in single ended mode !!! Square waves in the bass was not good and guess why ?. A friend of mine had a monster pair od Audionote PP OPTs with 1.8 K primary. This is what I needed. They had exactly the same size and mounting bolts as the originals. As They were still PP OPTs, I saw in Glass Audio an article from Dave wolze wo made SE opt with PP big Hammonds OPTs. He used a hacksaw and made two gaps (cuts) in the armature to convert PP OPTs to SE OPTs. As I didn't had the patience to take 3 hours to do that per transformer, One of my friends did them with a band saw. I finished them by hand to take care of internal copper bobbin. Now, how it sounds ? MARVELLOUS, New amps, incredible, I saved my amps and they are hard to beat with good speakers. It is shame because many Melos gear is going in the garbage because nobody can repair them. I really thought being alone to use these SE-75, More about these amps driving .... the CLSII.
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As you correctly pointed out, once upto proper spec and in top working conditions, these particular amplifiers are SOTA!
Sadly many can't do work like this anymore or many techies aren't bothered because it takes a lot of time and effort. You'd have to take annual leave just to service these things. I had the Golden Triode version, I think it was called Gold 400's or something like that. They were Melos top of the line.
These days, very few companies offer tube gear like this, only a handful can compare. CJ, VAC, VTL, Destination Audio, Aries Cerat and Audio Note Ongaku or the Kogaru monoblocks are on par. That's the class of tube gear these amps are in. I guess it's like one of those rare thoroughbreds... on certain days they don't run but when they do decide to run, get ready for blistering speed!