Avondale NCC300 amp project ..
- Thread starter laverda
- Start date
Chops54
pfm Member
I also like the idea of bolting a device to the heat sink but that BD237 looks naff with the legs crossed over. Is it the same for the NCC220?
laverda
pfm Member
Nice one Alan, I'm running 2.250 bias which equates to 35°at the heat sinks after a few hours yesterday. I'll clip on two meters today and see what their doing mA wise. I was going to leave them on overnight with this higher bias to put some more hours on them..but thought better of it. So will run them all day today and check periodically.
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337alant
Negatively Biased
Thanks Graham
With the type of heat sinking we have in the modushop cases I think you would be safe even at 2.3v the bias became stable
That said I think the figure you are using not is about right recon that would be about 150-160ma
I'm running mine 24/7 now
Be careful when checking the bias current to allow the cap banks to drain before disconnecting and connecting power rails
Alan
With the type of heat sinking we have in the modushop cases I think you would be safe even at 2.3v the bias became stable
That said I think the figure you are using not is about right recon that would be about 150-160ma
I'm running mine 24/7 now
Be careful when checking the bias current to allow the cap banks to drain before disconnecting and connecting power rails
Alan
S-Man
StrivingON
flashgo
DIY Practitioner
Naff? I thought it was an elegant dead bug.
The NCC220 has the wiring aligned for the BD237. Also, the NCC220 is through-holed while the NCC300 just has surface pads at the heat spreader.
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laverda
pfm Member
Oh dear.... I thought it was a very good bit of light engineering as a solution to a problem, there are other ways of doing it. (you pays your money you takes your choice) Christ I've dead bugged loads of circuits (they look shite)... but their still working a decade later...but no one ever sees them...
Chops54
pfm Member
Thanks Flash. I wasn’t complaining but if the tracks are aligned on the 220 why not on the 300? Anyway it’s nothing I can’t sort out
Once I’ve finished the 220s I’ll have to find time to crack on with the 300s.
flashgo
DIY Practitioner
The 220 is purpose-built to have the BD237 on the spreader while the 300 is designed for a 2N5551 on the PCB. It's then optional on the 300 to pull it out to the spreader, following some traces on the PCB. If you move the 2N5551, the tracks aren't crossed.
I like Les' suggestion of drilling a hole into the spreader and then just tucking the 2N5551 into the hole with some thermal paste. Then all of the legs line up with the traces. Job done. However, I hadn't thought of that, so I used the BD237, which has a hole for a mounting screw, but the legs aren't the same, so you end up crossing them in order to connect to the traces on the PCB. Hence, the dead but effective bug.
I like Les' suggestion of drilling a hole into the spreader and then just tucking the 2N5551 into the hole with some thermal paste. Then all of the legs line up with the traces. Job done. However, I hadn't thought of that, so I used the BD237, which has a hole for a mounting screw, but the legs aren't the same, so you end up crossing them in order to connect to the traces on the PCB. Hence, the dead but effective bug.
flashgo
DIY Practitioner
Can you check the power consumption? I'm running 2.20V bias, resulting in 25° heat spreaders at rest. A "Kill-a-Watt" meter says my entire rack, including the two 300 converted NAP135s consumes 55w at rest and 75w playing the Ramones.
It sounds terrific (without the watt meter inline), and I'm loathe to use a lot of electricity and generate a lot of heat.Can you check the power consumption? I'm running 2.20V bias, resulting in 25° heat spreaders at rest. A "Kill-a-Watt" meter says my entire rack, including the two 300 converted NAP135s consumes 55w at rest and 75w playing the Ramones.
That's close to nothing, my 9018 / NTD1 DAC consumes about the same.
That's very good news
Does anybody has the watt output at 4/8 Ohms ?
retseldrib
pfm Member
Just been alerted to this thread via the classifieds ref the NCC220 AMPS for sale.
Question (excuse my total ignorance) - can the M130s be upgraded to this new NCC300 module? I have three sets of Avondale built 130s in a Linn Aktiv Isobarik set up.
Many thanks
Question (excuse my total ignorance) - can the M130s be upgraded to this new NCC300 module? I have three sets of Avondale built 130s in a Linn Aktiv Isobarik set up.
Many thanks
divedeepdog
pfm Member
They won't fit, they're double width boards, think Voyager configuration with regulated front end + amplifier board.
The NCC220 is a straight swap for NCC200 though, and many have said how much better they are.
Chops54
pfm Member
Thank you for the explanation. For whatever reason I thought that both amps used BD237s.
retseldrib
pfm Member
Thanks
337alant
Negatively Biased
Mark I'm sure you won't be disappointed
My amps are sounding very good now I've knocked the Bias current back to 70ma and seems cleaner with better bass response to me
I have to say I am impressed, I am hearing individual instruments more clearly defined, some awesome bass and drum lines coming through I didn't hear with my voyages which were very good in their own right.
More to come I'm sure as wee keep tweaking this amp
Alan
My amps are sounding very good now I've knocked the Bias current back to 70ma and seems cleaner with better bass response to me
I have to say I am impressed, I am hearing individual instruments more clearly defined, some awesome bass and drum lines coming through I didn't hear with my voyages which were very good in their own right.
More to come I'm sure as wee keep tweaking this amp
Alan
Pete MB&D
Pete Maddex, the one and only!
Does anybody know what a NAP300 deals with for voltages before and after regulation.
And could a NAP300 be used as a basis to achieve similar results to this project - by playing with the voltages and bias as per the recommendations in this thread.
Or am I way off
I think you would be better off selling the NAP300 and buying a pair of NAP135s.
Pete