NTP M510 and ZFT info - anyone?

Mlewis · Feb 28, 2006

did anyone ever have a look inside the NTP M510 VCA?

i'm looking at the 179-400 schematic and running through my mind some of the things people have said about NTP compressors ("it's one of my little secrets here at masterdisk" etc) and wondering how difficult it could be?

I know some people have looked at that ZFT input transformer/opamp oddity and i'm sure we could do a replacement with a lundahl and an opamp (maybe the M100), but i can't find anything about the VCA.

is it a lost cause getting info on this?

http://www.ntp-dag2000.dk/ doesn't seem to work anymore.

do you think the magic would be lost if the circuit was modified for a THATcorp VCA and the Lundahl/M100 bodge?

strangeandbouncy · Feb 28, 2006

My 177-400's have a 2151 and 5534 combination sub-board for the vca. I guess this was a later version of the M510. 177-400 is a limiter, and not the compressor that mastering facilities rave about. They would be fairly easy to clone, but for the FET that is un-available, as is any info about how to select them. I cannot recomend the 177-400 enough, as it is esential for me, but is a very different beast to the old discrete comps.

ANdyP

gyraf · Feb 28, 2006

We've discussed these briefly before:

http://www.groupdiy.com/index.php?topic=1142

Remains of NTP are now in the hands of DK-Audio (the meter manufacturer).

Andy - is there any chance of figuring out how the 2151/5534 combination sub-board is made? Would be nice info, now that NTP is completely out..

Jakob E.

strangeandbouncy · Feb 28, 2006

JAkob,

Hi! Long time no speak . . . Hope all is well with you! I will do what I can, but it will take some time since, a) NTP limiter is in Daily Use, nd b) I am totally crap at trying to work-out and back-engineer-drawing-type-stuff!

:green: ANdyP

[silent:arts] · Feb 28, 2006

I don't know the NTP M510 VCA,
but if you need M500 VCAs:
shamles bump: http://www.groupdiy.com/index.php?topic=11297

Mlewis · Mar 2, 2006

wow thanks for the info...

i'd love to know more about the 2151 and 5534 combination sub-board.

They would be fairly easy to clone, but for the FET that is un-available

which fet do you mean? is it the 2N 4393? i punched all of the transistor and fet codes listed on page 24 of the 179-160 service manual into google and found places selling them cheap.

it was the 179-170 (the stereo version of the 179-160) that the guy from masterdisk was raving about and it seems to me to be an M510 VCA comp (with the VCA located on the motherboard that the comp/limit/gate cards slot into) rather than the FET 179-120. i could be confusing things tho since i don't fully understand the circuit.

if we could cobble together the M510=2151+5534 VCA, we'd be in business for a 179-170 clone wouldn't we?