Stuart,
A typo i think, you probably mean the NAD 3020.
Which was a NAD highlight, the 4020 was a tuner model afaik.
(3020-3020A-3020B-3020i)
I recall reading in those days about a NAD Integrated being hooked to Apogees, that must have been you.
Nice heatsink profile, volume were it is supposed to be.
(btw, i've just ordered a pair of aluminium fluid coolers for a Scuba Krell)
A typo i think, you probably mean the NAD 3020.
Which was a NAD highlight, the 4020 was a tuner model afaik.
(3020-3020A-3020B-3020i)
I recall reading in those days about a NAD Integrated being hooked to Apogees, that must have been you.
Nice heatsink profile, volume were it is supposed to be.
(btw, i've just ordered a pair of aluminium fluid coolers for a Scuba Krell)
Mark A. Gulbrandsen said:
Looks good! I just bought one like this from Steve and am about to slice it and dice it to make four heatsinks out of it; 2 for the KSA-50 and 2 for the KSA-100.
Do you need help with the group purchase for the ThermaFlo? Or are you still researching the best option? I could save this one for some other project.
hmm, musings/ramblings...
The heatsink looks ideal...
Jacco, you're probably right about the model number being wrong, though I still have the NAD piece, and it's definitely not the 3020, which, IIRC was an integrated amp, this is a reciever...4030 perhaps...
Oh well not important really...just don't trust those companies that use labels instead of transistors...but I'm obviously preaching to the choir here...as if any of you guys would consider skimping on transistors...
Intel makes very limited edition extreme edition processors for nut case game players, can we get on-semi to make their to3 parts in oxygen free copper cases? Silver/gold plated perhaps? is there a special grade of epoxy we ought to be asking for when we order to247 parts?
On a different note: How come the legs on a to3 stick out of the heat dissipating side of the case, if the idiots put them on the other side the heat transfer capabilities of the case would be enhanced, and it would be a million (approx.) times easier to mount as well...or is it just me?
Stuart
The heatsink looks ideal...
Jacco, you're probably right about the model number being wrong, though I still have the NAD piece, and it's definitely not the 3020, which, IIRC was an integrated amp, this is a reciever...4030 perhaps...
Oh well not important really...just don't trust those companies that use labels instead of transistors...but I'm obviously preaching to the choir here...as if any of you guys would consider skimping on transistors...
Intel makes very limited edition extreme edition processors for nut case game players, can we get on-semi to make their to3 parts in oxygen free copper cases? Silver/gold plated perhaps? is there a special grade of epoxy we ought to be asking for when we order to247 parts?
On a different note: How come the legs on a to3 stick out of the heat dissipating side of the case, if the idiots put them on the other side the heat transfer capabilities of the case would be enhanced, and it would be a million (approx.) times easier to mount as well...or is it just me?
Stuart
Hi Stuart,
How about making them out of this stuff?
500ºF Thermally Conductive Epoxies from:
http://cotronics.com/vo/cotr/ea_thermallyconductive.htm
"a million (approx.) times easier to mount as well...or is it just me?",
Nope, a few of us wonder the same thing.
How about making them out of this stuff?
500ºF Thermally Conductive Epoxies from:
http://cotronics.com/vo/cotr/ea_thermallyconductive.htm
"a million (approx.) times easier to mount as well...or is it just me?",
Nope, a few of us wonder the same thing.
heat conductive epoxy, now thats cool...
...literally and figuratively...
I'm done bolting transistors, I'm going to stick them on the heatsinks with solidifying heat conductive goop, just clamp them until the stuff sets and voila...I've always hated drilling and tapping aluminum, has anyone actually used this stuff, does it work as implied/advertised?
If they used this to encapsulate the transistors we could use heatsinks on both sides of the plastic packages, I'd guess it would help the overall thermal capacity of the package.
Stuart
...literally and figuratively...
I'm done bolting transistors, I'm going to stick them on the heatsinks with solidifying heat conductive goop, just clamp them until the stuff sets and voila...I've always hated drilling and tapping aluminum, has anyone actually used this stuff, does it work as implied/advertised?
If they used this to encapsulate the transistors we could use heatsinks on both sides of the plastic packages, I'd guess it would help the overall thermal capacity of the package.
Stuart
Zobel Network??? Went back through and could not find the values... The older 1983 schematic calls for 5.6 ohms and 1uf in series... does anyone know if this is correct for the MK-2 version of the amp. 1 uf seems a bit high to me..... What ever it is I will post it in the WIKI.
Thanks!
Mark
Thanks!
Mark
I've posted the zobel values twice on this thread so far: 100nF and 5R6.
Those wanting to imitate the original closely (for whatever reason), the resistor is a Dale 5W and the capacitor a Philips MKT (those orange ones) in the Mk1 and some green-looking thing (perhaps Mylar, it's enshrouded in heatshrink) in the Mk2.
Those wanting to imitate the original closely (for whatever reason), the resistor is a Dale 5W and the capacitor a Philips MKT (those orange ones) in the Mk1 and some green-looking thing (perhaps Mylar, it's enshrouded in heatshrink) in the Mk2.
AndrewT said:
Now that is truly funny, your sense of humor is spectacularly improving, Mr T.
Although the 2.8 W/C.m number of Duralco compound looks attractive, the 3-5 mills thickness is not if compared to mica and goop. I love epoxy, have used it since 1985 for everything from boatbuilding to potting toroids with thermal epoxy resin, but for semiconductor thermal transfer they'll have to do better.
The legs of TO3s having to go through the heatsink is a downside, but other than that they're still the superior package type imo. Fortunately there's a 2-bolt Jappon alternative.
Covering something that needs cooling with plastic on the top has little rationale, where's the full metal TO247 ? I sometimes miss the 2955/3055 and Hitachi TO3 days, the spreading of TO3 leads is so much nicer than the tight legging of flatpacks. Still think an output stage with TO3s and Al2O3 insulators is a sight for sore eyes, and still waiting for Magura to post some pics of his TO3 output stage with the TO3 aluminium oxyde insulators i sent him. I like drilling and tapping though, my dad paid me $0.50/hr for that when i was 8.
Scrooge alert !
I've heard a rumor that packages that can be heatsinked on both sides do exist.
(I had a 3020, first number that sprung to mind, find the NAD front looks very attractive up till today. And still a budget audiophile product IMB)
Mmm,
Me thinks they did that after some renegades came up with KSA100 plans. They ? Something Pink, i think.
Second thought :
The MJ15024/25 series was a giant leap forwards, at a time when a lot of Rod Elliots were (still) using MJ2955 TO3s. Take a look at a 2N3055 datasheet and compare that shocking one with the ones of Motorola MJ150** TO3s.
Compared to MJ15003/4, OnSemi's MJLs are just about the same evolutionary step size to perfection as the MJ15s were from Rod Elliot's relics from the graveyard.
Still, 20 years later and not a month goes by without some smuck anouncing he's about to make an amplifier with RCA TO3s.
Me thinks they did that after some renegades came up with KSA100 plans. They ? Something Pink, i think.
Second thought :
The MJ15024/25 series was a giant leap forwards, at a time when a lot of Rod Elliots were (still) using MJ2955 TO3s. Take a look at a 2N3055 datasheet and compare that shocking one with the ones of Motorola MJ150** TO3s.
Compared to MJ15003/4, OnSemi's MJLs are just about the same evolutionary step size to perfection as the MJ15s were from Rod Elliot's relics from the graveyard.
Still, 20 years later and not a month goes by without some smuck anouncing he's about to make an amplifier with RCA TO3s.
more to do with some excuse about screwing up the database when someone did a search. Seems their puny computer could not cope with VERY long threads AND searching. I believe the ksa50 thread is being held open pending some milestone.jacco vermeulen said:
Seems a shame I cannot contribute much to the 50 thread now that I am transferring my allegiance to the 100. Besides, I never built the 50! But I'll do what I can to give the Mods some work.
Sorry to confuse the issue, the 3-5 mils is not the thickness required for a bond. That's the amount that needs to squeeze out at the edge for lateral bond to the substrate. Some folks are known to use it like silicon seal around a bathtub by using the finger to smooth it to the edge.
A number of other makers of this space age stuff make even better temperature/non conductive/electrical conductive/ceramic filled and on and on types. You can even find the type that's used on our space shuttle. But the price...............?
Don't personally mind drilling the holes for TO3 since my jig works so well with the drill press.
HTH
Regards
A number of other makers of this space age stuff make even better temperature/non conductive/electrical conductive/ceramic filled and on and on types. You can even find the type that's used on our space shuttle. But the price...............?
Don't personally mind drilling the holes for TO3 since my jig works so well with the drill press.
HTH
Regards