They might be ceramic. Funny how the rest of the pF caps appear to be polystyrene.
Yes, transistors and all the resistors are from my side.
I like it
Pay attention on LEFT channel 560R @ CCS vs RIGHT 620R.
It cures fatigue on mid frequency action, very noticable, even on first start up. There is always penalty... loss of a littlebit of a dynamics... but they come always back and back more when naim heats up.
EDIT: it would be bad if i had to leave 560R both channels... i could have gotten many dislikes on that party.
Yes, transistors and all the resistors are from my side.
I like it
Pay attention on LEFT channel 560R @ CCS vs RIGHT 620R.
It cures fatigue on mid frequency action
, very noticable, even on first start up. There is always penalty... loss of a littlebit of a dynamics... but they come always back and back more when naim heats up.EDIT: it would be bad if i had to leave 560R both channels... i could have gotten many dislikes on that party.
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Here you go - all the fancy film capacitor types, including all the polystyrene film/foil range, that you could imagine. Tube Radio Capacitor Shopping Cart.
Expensive to buy? Yes, by the time you pay for minimum quantities and freight you could be up for some serious money but that's the only way small suppliers can survive.
Expensive to buy? Yes, by the time you pay for minimum quantities and freight you could be up for some serious money but that's the only way small suppliers can survive.
You might find it useful to have a few more values on hand so you can try different values for the Miller cap and check the sound and the bench measurements. Say, 47pF, 68pF and 100pF.
The smaller the value the less current is required from the input stage to charge the Miller cap up and down. This will improve linearity. However, as the Miller cap value decreases the circuit will become increasingly unstable. There is a trade off.
The smaller the value the less current is required from the input stage to charge the Miller cap up and down. This will improve linearity. However, as the Miller cap value decreases the circuit will become increasingly unstable. There is a trade off.
I must be able to find you that in my archives.Maybe someone here in Europe have 39pf polystyrene's for sale and then could ship them to me
give me a little time to find it and I send you a mp for your address
Okey, but if you are low in stock than pls dont do that, they are getting very hard to find parts.
I will wait for your pm. Thanks.
I got my final 1pcs 2SC5200 TOSHIBA, totalling 12pcs of original fresh 2sc5200's
I have to delay the resistor comparison for few weeks atleast, case will be finished this weekend.
47pf might be good idea. 68 and 100 would be waste of money on nap140 circuits imo...
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The need for a small Miller compensation cap in NAP designs is related to the unusually high (30pF) Cob of the VAS transistor(s). If you fit parts that are normally preferred for the duty, such as KSC3503/A1381 (3pF) for VAS transistors, this will certainly require a step up to the typical range of 70-100pF Cdom to restore stability. Unfortunately, that comes at the cost of the characteristic Naim sound quality.
The effect has been discussed here many times and Bigun last described it well enough in reference to his TGM-10 version of the NAP amplifier. I think we will find that by the time the capacitance has reached 50-70 pF, the sound quality will have become noticeably poor.
It's been amusing to note how many years it has taken the Chinese clone kit makers to wake up to this key NAP design element. After reading the comments praising builds of their kits that would actually have sounded awful, you realise how much internet opinion on sound quality is misinformation. At least we can now buy some kits that come with the appropriate semis for where it really matters and I'd like to think that has resulted from critical comments voiced in this thread.
The effect has been discussed here many times and Bigun last described it well enough in reference to his TGM-10 version of the NAP amplifier. I think we will find that by the time the capacitance has reached 50-70 pF, the sound quality will have become noticeably poor.
It's been amusing to note how many years it has taken the Chinese clone kit makers to wake up to this key NAP design element. After reading the comments praising builds of their kits that would actually have sounded awful, you realise how much internet opinion on sound quality is misinformation. At least we can now buy some kits that come with the appropriate semis for where it really matters and I'd like to think that has resulted from critical comments voiced in this thread.
it is a beautiful design work but I do not think you have understood the spirit of this scheme.
for example, ceramic capacitors operate but do not give the same result with polystyrene and tantalum capacitors.
Ditto for the heatsink, unless you chose the overbiassed, it is much too massive and the fans are useless.
now, I have no doubt that it should make music but not like a naim
for example, ceramic capacitors operate but do not give the same result with polystyrene and tantalum capacitors.
Ditto for the heatsink, unless you chose the overbiassed, it is much too massive and the fans are useless.
now, I have no doubt that it should make music but not like a naim
Hi,
I built the clone with an objective in mind to closely follow the original values per NAIM schematic. (except the now older transistors of course). I did however made a few changes so I could obtain clean results in sim, changes was 47pf for vas miller cap (39pf works fine though), 12pf for the feedback phase network (39pf original) in order to flatten the appearing gain bump at AC analysis. Idle current was set to 25ma (about 6.6mv) and I've read at the pink fish forum that ideal was 7.1mv across re. DC offset was at 2mv. Tantalum caps is quite hard to find here in my place but the input bandpass filter 330pf was a wima mkp and the 470pf at the driver bases are polystyrene caps.
While I have not auditioned a NAIM amp I could not claim that it sounds NAIM like, if you notice however the harmonics profile in sim, the extended harmonics could be the inherent dominant even harmonics character of the NAP amp. The fan seemed to be no longer needed per my actual test (heatsink barely gets warm), the only device that gets hot to the touch are the TO92M vas trannies but it looks though that they could survive for longer hours of playing music. The challenge here is to use substitute transistors without altering much of the original values like what I'm seeing from a lot of clones out there. Over all my schematic was more of a combination of NAIM and the Avondale mod.(?) The pcb is one is single sided like the original but I made it a lot more compacted. VBE multiplier was bent underneath with the flat face touching the heatsink for better thermal tracking, it looks stable never had "drifting" issues.
The amp is pretty silent and the sonic dynamics and soundstage was really nice though.
I built the clone with an objective in mind to closely follow the original values per NAIM schematic. (except the now older transistors of course). I did however made a few changes so I could obtain clean results in sim, changes was 47pf for vas miller cap (39pf works fine though), 12pf for the feedback phase network (39pf original) in order to flatten the appearing gain bump at AC analysis. Idle current was set to 25ma (about 6.6mv) and I've read at the pink fish forum that ideal was 7.1mv across re. DC offset was at 2mv. Tantalum caps is quite hard to find here in my place but the input bandpass filter 330pf was a wima mkp and the 470pf at the driver bases are polystyrene caps.
While I have not auditioned a NAIM amp I could not claim that it sounds NAIM like, if you notice however the harmonics profile in sim, the extended harmonics could be the inherent dominant even harmonics character of the NAP amp. The fan seemed to be no longer needed per my actual test (heatsink barely gets warm), the only device that gets hot to the touch are the TO92M vas trannies but it looks though that they could survive for longer hours of playing music. The challenge here is to use substitute transistors without altering much of the original values like what I'm seeing from a lot of clones out there. Over all my schematic was more of a combination of NAIM and the Avondale mod.(?) The pcb is one is single sided like the original but I made it a lot more compacted. VBE multiplier was bent underneath with the flat face touching the heatsink for better thermal tracking, it looks stable never had "drifting" issues.
The amp is pretty silent and the sonic dynamics and soundstage was really nice though.
I have experienced alot with that NCC200 schematic, absolutely nothing special compared to naim nap 140 clone.
Yes, dynamics might be even BETTER from start on, i agree. My LM1875 has better dynamics as well unfortunaly....
Soundstage, hmm... listening to nap 140 gives more realistic sense of instruments and they'r positions.
Final and the most important is the emotion that varies from material you play... some dont have it, some have it alot... you wont be able to detect it.
Yes, dynamics might be even BETTER from start on, i agree. My LM1875 has better dynamics as well unfortunaly....
Soundstage, hmm... listening to nap 140 gives more realistic sense of instruments and they'r positions.
Final and the most important is the emotion that varies from material you play... some dont have it, some have it alot... you wont be able to detect it.
If anyone is really trying to clone a Naim amp I would recommend borrowing one from someone and listening to it. Otherwise you are just guessing.
Also be aware that when you build a "clone" circuit without using the same matching of parts, part materials and layout and wiring and so on, it won't sound the same. for this reason I predict any two circuits you build will likely sound different. So you can end up with the left and right not sounding the same, which isn't good. This is a useful auditioning test, feed both channels the same signal and swap the speaker between them and see if you can hear a difference.
The NAP topology is very sensitive to these things.
Also be aware that when you build a "clone" circuit without using the same matching of parts, part materials and layout and wiring and so on, it won't sound the same. for this reason I predict any two circuits you build will likely sound different. So you can end up with the left and right not sounding the same, which isn't good. This is a useful auditioning test, feed both channels the same signal and swap the speaker between them and see if you can hear a difference.
The NAP topology is very sensitive to these things.
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in fact, that's what decided me to try the adventure of the "real clone"
I had some naim (nap and nait) to repair these last years and I liked.
until I remember I bought one of these kits about 8 or 9 years ago and I did not like it at all.
I documented, I read a lot and then I came across this thread that allowed me to mount my first nap 140.
now, I want to build a 90/110