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Best output devices for NCC200

cchean

cchean

pfm Member
Will be building a couple of Avondale NCC200 boards in the summer, the original output device is BUV20, now discontinued. As I"ve seen, current builders are using MJ15003G. Which one would you choose if you had the option? I plan to use the boards to build a pair of voyagers.

The BUV20 can still be found at a hefty price on ebay. Not sure if they are originals, but seller has a 100% feedback rating. MJ15003G is in back order and the "G-less" can still be found. ON SEMI is almost $8 here in US, but I also found Multicomp (Newark) and NTE.

Any advice? Thanks to all.
 
NCC220

G means lead free so non G will be NOS. On Semi was Motorola and the original manufacturer of this device and I'd go for those or Semelab. Avoid NTE!
 
I've always used On Semi. Not sure if you still can, but you used to be able to order small quantities of "free samples" from their website for a mere $15 postage
 
I've tried BUX20s in my NCC200s and much prefered them to MJ15003s. Unfortunately they too are hard to find. Price is the same with BUVs, starting around 20 euro/pair.
 
BUV20s were a significant improvement on the MJ15003. I still have a number of spares here. I must get round to making a proper transistor tester because a lot of them measure low hFE with a battery operated tester.
 
As stated above BUV20s are great, if found paralleled MJ15003s to be quite a big step up in performance over a single set but not compared directly to BUV20s. I’d not worry about it too much, some of the other mods make far more of a difference albeit for a little more effort investment.
 
I'd use MJ15003 in preference to BUV20 all day long but the part Russel links to above should indeed be better than either. To rephrase his fashion point.... it 's more a case of sod all the technical facts but what do other people believe to be the best parts based purely on rumours on the web... as ever!

There are literally hundreds of different devices which would work well in this application at the end of the day but only two get discussed simply because those are the ones everyone else is discussing:D
 
I've only ever used BUV20s on the NCC boards that we made the WH amps from. When we listened to a pair compared to the MJEs they had more presence. Same circuit, same bias. There are any number of high power TO3 devices that would work here, Arkless is right - we only talk about about these two because we do. You'd probably want to check stability with any other device though.
 
glenn jarrett said:
cpc has multicomp pro MJ15003 £2.05 plus vat
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May well be fine but with Multicomp and RS Pro they basically just supply a low priced generic component of whatever is the cheapest version they could get hold of and which they deem adequate at the price.

I needed a load of caps from RS a week or two back and after finding my usual Rubycon part was out of stock for 5 months and the best priced branded alternative was about £3.50 each as opposed to about £1.70 for the similarly specced Rubycon part I found an "RS Pro" part which according to the specs was well up to the job. They were only about £0.80 each! I guess I shouldn't have been surprised to get "Jackcon" Taiwanese caps! I believe some types are rebranded RS Pro but all RS Pro electrolytics are actually Jackcon, after a quick google. They are actually not at all bad and far better than some Chinese ones but "it doesn't look good" as it were.
 
martin clark said:
That's a nice part and suggestion; might get a few to play with / as potential spares for my Quad 306.
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I use the plastic version MJL21193 and it’s complement the MJL21194 in my COD405 current dumping amplifier. I have some of the metal parts ready for my baby Krell project.
 
TOR said:
found paralleled MJ15003s to be quite a big step up in performance over a single set
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Interesting! May I ask what driver transistors did you use for the parallel output devices? Would the usual MJE243/253 suffice?
 
jpk said:
Interesting! May I ask what driver transistors did you use for the parallel output devices? Would the usual MJE243/253 suffice?
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Same output devices with appropriate heat sinks but each output device has it’s own 0.22r.
 
Just to clarify for the NCC200 the existing driver transistors MJE15030 & MJE15031 can be used to drive 2 sets of output transistors, you just need 2 sets of output transistors, 2 x 100 ohm & 2 x 0.22 resistor and good common heatsinking for both sets of output transistors

Alan
 
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