Carbon-Composition was carbon granules (mixed with clay) pressed together. The individual granules were "in contact", a poor connection. Only the fact that there were billions of such contacts made them "OK".
Carbon-Film is fuel-gas soot spun onto bodies. The "particles" are far smaller, more contacts, and probably less contamination. Carbon-Film is very much better than Carbon-Composition.
Wire-Wound is wire. You smelt a ton of metal, skim the scum, then run through heavy rollers, mashing all the atoms INTIMATELY together. No "contacts". Roll to a bar, then draw through small and smaller dies to work it down to wire. Done with steel, this process raises 20kpsi rough steel to 200kpsi wire, showing how all "poor connections" are worked-out and melded-together. In resistors it approaches the theoretical limit of resistor noise-power.
("Wire" varies. Tungsten is not easily hot-rolled, too hard to soften. For lamps we traditionally used a sintering process, powder heated not all the way to the melting point and then smooshed. Incandescent lamps fail where the powder grains fail to adhere, "poor contact", local heating, hot-spots, evaporation, wire gets thin and blows-out. But we do not use this type tungsten in ordinary resistors; various NiChromes and similar do fine.)
Heatsink
Michael, are you using the 120mm or 180mm heatsink in post #2? I like your method of avoiding having to tap holes in the heatsink!
Michael, are you using the 120mm or 180mm heatsink in post #2? I like your method of avoiding having to tap holes in the heatsink!
Thank you for the quick response. I have 4 ohm speakers, so I was thinking of reducing the voltage and raising the current. Something like 15 volts and 3 amps. That would seem to generate around 45 watts as opposed to the 32 watts or so of 19 volts at 1.7 amps (about 40% warmer?). I could get closer to the 32 watts if I went with 12 volts or should I just get the bigger heat sink?
Good morning,
what is the preamp you are using with your mofo ? Tube or not? SS II, triode Korg? Another DIY?
Nice week end
what is the preamp you are using with your mofo ? Tube or not? SS II, triode Korg? Another DIY?
Nice week end
I used BA-3 pre which is a perfect match and also Korg which also worked really good (much better than expected).
Dear gentlemen,
thank you for all your answers concerning your Mofo best preamp match. I appreciate.
I have another question but technical:
I would like to integrated the MW switching power supply inside the the mofo enclosure ( certainly near the inductor). I do not like its PC laptop look. Do you think it’s ok, it will not bring any electromagnetic waves ?
Thank you in advance for your reaction and advice.
Musically yours
TYM
thank you for all your answers concerning your Mofo best preamp match. I appreciate.
I have another question but technical:
I would like to integrated the MW switching power supply inside the the mofo enclosure ( certainly near the inductor). I do not like its PC laptop look. Do you think it’s ok, it will not bring any electromagnetic waves ?
Thank you in advance for your reaction and advice.
Musically yours
TYM
Mate, is that MW LRS-350-24? does the cooling fan keep kicking in every 3-4 mins? Mine does and it's loud and annoying. Eventually I unplugged the fan and removed the top cover, now it's totally silent. Another good thing is it has a couple of seconds delay, which is a very favourable feature as I integrate my preamp in the same box as MoFo, no more pops when turn on.
Finally finished
Here are a few pics of my MOFOs. Again, many thanks to everyone here, especially Vunce for providing the unobtanium boards. I'm almost up to date with this thread, and I feel I've learned much reading through, but also peeked ahead into a huge field of experience to come.
I'm a total neophyte, except for those years taking EE courses so long ago. Oh, and that metal detector I assembled when I was ... 15, I think. I now have a nice Weller soldering iron and a cheapo DMM; fundamentals for learning fundamentals. For my next project, I'm thinking about a guitar amp for my son. Then a proper preamp for the MOFO, probably the AksaLender, as many have suggested.
My sonic impressions echo what others have said; I, too, feel like the MOFO has more bass response than I'm used to from other commercial amps (NAD and an old SONY).
Kind regards,
Drew
Here are a few pics of my MOFOs. Again, many thanks to everyone here, especially Vunce for providing the unobtanium boards. I'm almost up to date with this thread, and I feel I've learned much reading through, but also peeked ahead into a huge field of experience to come.
I'm a total neophyte, except for those years taking EE courses so long ago. Oh, and that metal detector I assembled when I was ... 15, I think. I now have a nice Weller soldering iron and a cheapo DMM; fundamentals for learning fundamentals. For my next project, I'm thinking about a guitar amp for my son. Then a proper preamp for the MOFO, probably the AksaLender, as many have suggested.
My sonic impressions echo what others have said; I, too, feel like the MOFO has more bass response than I'm used to from other commercial amps (NAD and an old SONY).
Kind regards,
Drew
