Hi,
I tried that and I didn't like it.
The meaning of the degen. resistors is to balance better the LTP. In this schematic the LTP is deliberately preset in some imbalance. Better balancing the imbalance doesn't make sense to me
Additional penalty is the decreasing of the transistor transconductance (see Self for more).As for the filters - I guess you mean the diode-resistor-capacitor the way Avondale is doing that - I couldn't hear any improvement. In technical sense it's not a bad idea, although I would rather regulate the power supply for the whole amplifier and not try that. I have the feeling that it may be better if the input and the output see the same ripple. The filter will make very stable the front end and leave only the output to see the ripple and noise. According to Self this is better, according to me - may be, but not likely for this schematic (based on ears only!).
Belden 1583ENH Network Cable CAT5e Grey (1 Metre Length) | Rapid Online
If two runs of CAT 5 were used it should be OK, one as plus and one as ground/return. 7 x 0.51 mm is a reasonable NACA5 clone. 1 core could be tweeter. There are small differences if the tweeter sees the low impedance of the amplifier rather than share the crossover region with the bass unit. Of all the myths of hi fi biwiring holds some truth. If a SE valve amp I have my doubts as the output impedance can near that of the speaker. Here is an idea. If a better sound is sort build a chip amp for the tweeter. Set the gain to match that of the Naim clone. Draw off some power to have some class A output ( 240 R from output to -ve perhaps ). Make the input high impedance so as not to load down preamp ( 100 K ? ). Then bi-wire as usual except the tweeter has it's own amp that isn't shared. At low cost this might be a very reasonable upgrade. If the voltage rails are +/- 12 V it should be more than enough as 1 watt to a tweeter is rare. TDA2030/40/50 and similar. I dare say a 12 V motorcycle battery would be enough ( like +/- 6 V ). Use the tweeter crossover capacitor as DC blocking. 100 V polyester types being good enough. 4u7 250 V from Rapid electronics being a bargain ( Sun-tan brand, stated 5% and about 1.5 %). I just bought some cheap tweeters Monacor DT74/8. These are good enough to need this. I might include a 15 kHz treble boost and 25 kHz cut. Both first order. I run these with 3u3 almost as a super tweeter. I might use the bass unit as the heat sink.
DNM and Naim cable are now silly money. QED 79 is cheaper in real terms than the past if copper price taken into account and better copper grade. If split in two and twisted 2.5 turns per metre it meets the old Naim spec using this type of cable.
| RS Switchgear Cable 2.5 mm CSA 1000 V dc, 600 V ac Yellow PVC 4.2mm od , Maximum of +70 C 25m |
If two runs of CAT 5 were used it should be OK, one as plus and one as ground/return. 7 x 0.51 mm is a reasonable NACA5 clone. 1 core could be tweeter. There are small differences if the tweeter sees the low impedance of the amplifier rather than share the crossover region with the bass unit. Of all the myths of hi fi biwiring holds some truth. If a SE valve amp I have my doubts as the output impedance can near that of the speaker. Here is an idea. If a better sound is sort build a chip amp for the tweeter. Set the gain to match that of the Naim clone. Draw off some power to have some class A output ( 240 R from output to -ve perhaps ). Make the input high impedance so as not to load down preamp ( 100 K ? ). Then bi-wire as usual except the tweeter has it's own amp that isn't shared. At low cost this might be a very reasonable upgrade. If the voltage rails are +/- 12 V it should be more than enough as 1 watt to a tweeter is rare. TDA2030/40/50 and similar. I dare say a 12 V motorcycle battery would be enough ( like +/- 6 V ). Use the tweeter crossover capacitor as DC blocking. 100 V polyester types being good enough. 4u7 250 V from Rapid electronics being a bargain ( Sun-tan brand, stated 5% and about 1.5 %). I just bought some cheap tweeters Monacor DT74/8. These are good enough to need this. I might include a 15 kHz treble boost and 25 kHz cut. Both first order. I run these with 3u3 almost as a super tweeter. I might use the bass unit as the heat sink.
DNM and Naim cable are now silly money. QED 79 is cheaper in real terms than the past if copper price taken into account and better copper grade. If split in two and twisted 2.5 turns per metre it meets the old Naim spec using this type of cable.
| RS Switchgear Cable 2.5 mm CSA 1000 V dc, 600 V ac Yellow PVC 4.2mm od , Maximum of +70 C 25m |
AudioQuest G2 Speaker Cable - FutureShop.co.uk
I know Bill. So good to see he is still the gentleman he always was. This is very high spec for pennies.
I know Bill. So good to see he is still the gentleman he always was. This is very high spec for pennies.
With all these cheap cables the problem is the crappy and lossy PVC insulation.
(sorry for the Naim off-topic)
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[QUOTEAnd for sure it's not their perfection.
hallo ruwe
perfektky answered, thank you.
i finished now a tube amp that can drive elektrostatik loudspeaker and sound very good deep bass nice highes.
KT 88 PP Triode oder Pentode 36/70 Watt.
but after hearing the naim clone ,i feel the sound is not so much different.
so i need to go the same way like all the selfbuilders, tuning and changing parts ,and in the end go back like you to nearly original version.
i think, first, we love building, then hearing new sound, then getting boring ,so we build a new ones .
endless way .but i love it.
your shematik help me very much so i didnt have to change so much so long.
thank you again
hallo ruwe
perfektky answered, thank you.
i finished now a tube amp that can drive elektrostatik loudspeaker and sound very good deep bass nice highes.
KT 88 PP Triode oder Pentode 36/70 Watt.
but after hearing the naim clone ,i feel the sound is not so much different.
so i need to go the same way like all the selfbuilders, tuning and changing parts ,and in the end go back like you to nearly original version.
i think, first, we love building, then hearing new sound, then getting boring ,so we build a new ones .
endless way .but i love it.
your shematik help me very much so i didnt have to change so much so long.
thank you again
They should be plain copper.
Nothing in the description says anything about strand insulation, i.e. no strand insulation.
Except for Litz, I would expect all stranded cable to be uninsulated strands unless the description specifically says otherwise.
As far as I know NACA5 was PVC when introduced. Very little plasticiser used so as to be stiff, this was said to also eliminate the sound problems. NACA4 went black with time inside, A5 not. Seems to be something that turns cable black also kills the sound. My brother worked with plastics. He told me polypropylene is very cheap. No excuss for bad dielectics. The Audioquest should be like NACA5 in many ways. BTW NACA5 is nothing special although not obviously bad. It is ugly and difficult to use. The amounts of NACA5 I have cut and soldered run into miles. NACA4, not at all good. Linn version using polythene even worse ( dull, lumpy, harsh ). All were made by BICC as the early cable drums said so. I use a cable called Heywire ( Heybrook ). I think it is better. It looks to be telephone cable, perhaps OFC as that is cheap.
One 0.5 mm strand often sounds better than NACA5. People will say the chunky cable gives more bass. Actually it doesn't. The speakers needs re-engineering if that is to be made true. One speaker the Royd Minstrel would be better as it has no bass unit crossover. Thus there are gains to be had. For the Royd 7x CAT 5 strands bass and one treble might be ideal. Use two runs so as not to have capacitance issues. Dynaco A25 also. Alas time has caught up with A25, even so better bass is worth having.
One thing Naim buiders can do is think about Active. If the choke of the speaker they own is removed and that function taken to the amp more or tighter bass will be had. A single 0.5 mm cable and active EQ might give better bass and midband than NACA5 cable. If the pre amp is low impedance ( about 200 R ) and amp high a passive EQ will work. One resistor and one capacitor will replace a doubtful choke. If the cable resistance is calculated the output resistance might be dropped a tad. If the ratio on speaker to cable including output resistor is 15: 1 it is fine ( lower is still OK right down to 5 ). Lets say 0.22 R into 4R as worst case, that is 18. If the cable is 0R1 we could use 0R1 as the output resistor. If 8 R even 0R22 is OK, 8 R is often about 5R7. If a baffle speaker do not use low resistance cable as you actually want the speaker to be underdamped. My own have a QTs of 1.2 which is high Q and almost no damping from the amp ( 0.4 ohms total and 0.5 mm cable x 4 metres ). Even so I need active bass boost of about + 8 dB 30 Hz as the baffle is only 4 x 2 feet. The speakers hardly move but do make bass so real my ex wife thought someone was in the house. The sound comes from nowhere. On paper the speaker looks unlikely to work. It works without any problems. I tried the drive units most people have and 50 % of the time they are OK. The rest of the time the are unusable. Hi fi engineering has turned into a bit of a lie. Things the 1950's knew and could do are now thought to be past history. Not so. That past history was getting the wives to allow hi fi into the home. The wife test is not the sound test. It is an ex wife test. The funny thing is watching a film she said " these speakers are really good".
With KT 88 amp , try some EL 34 ( Ruby are OK and very cheap ). Adjust bias to suit ( about 24 watts dissipation or often 60 mA ). EL 34 has about double the distortion but nicer distortion curves ( on my tests ). KT 88 and I were born a few days apart. I popped out first. KT 88 started life in 1935 at Harries valve company and was bought by RCA to become 6L6 and 807 circa 1937. 6L6 became KT66 ( 6L6GC and like 5881 ). German tube generic Gu50 ( LS 50 ) might just be best of all except it has it's own valve base. On paper Gu50 looks to be like EL 34 with KT88 power. EL156 also interesting. They cost big money.
I am not sure Andrew. It will be found 3 metres into the cable. NACA5 not. The plastisier was blamed. I haven't seen it so bad with PVC clad flex. BICC are not unskilled. I suspect without being asked the boss at BICC thought being flexible mattered. I can not say as I have not seen this before to this extent. It looked very black.
In my company we uesd papper and cotton then PVC. A very good and cheap way. The cable company loved us as it was easier to make. I told my boss paper or cotton. He misheard. This is something other than speaker cables and only midly related. When I wanted paper cable one Yorkshire company says it puts the phone down if hi fi people. Crazy if they spend money . That cable is used with oil.
I tested some relays in oil. Do not believe all you read. Sparks in relays do not instantly dissapear if no air around. Oh sure there might be oxygen in the oil. Even so the change was trivial. Nice watching sparks in oil. It has a fish tank quality to it. I do have vacuum pumps. Maybe I should try that? We hid a mercury vacuum pump as it is the best. Not allowed under health and safety. On the rare occasion needed the risk is worth it. The cupboard has a false back I think I was told? Oliver Lodge worked there at one point. The Mercury pump can go to levels that vaccuum tubes need without using a getter ( even so you would ). Modern pumps are said to be as good. The man who hid the pump says not.
In my company we uesd papper and cotton then PVC. A very good and cheap way. The cable company loved us as it was easier to make. I told my boss paper or cotton. He misheard. This is something other than speaker cables and only midly related. When I wanted paper cable one Yorkshire company says it puts the phone down if hi fi people. Crazy if they spend money . That cable is used with oil.
I tested some relays in oil. Do not believe all you read. Sparks in relays do not instantly dissapear if no air around. Oh sure there might be oxygen in the oil. Even so the change was trivial. Nice watching sparks in oil. It has a fish tank quality to it. I do have vacuum pumps. Maybe I should try that? We hid a mercury vacuum pump as it is the best. Not allowed under health and safety. On the rare occasion needed the risk is worth it. The cupboard has a false back I think I was told? Oliver Lodge worked there at one point. The Mercury pump can go to levels that vaccuum tubes need without using a getter ( even so you would ). Modern pumps are said to be as good. The man who hid the pump says not.
more off-topic
Early super cables which used large amounts of cheap plasticiser for a high degree of flexibility, such as "Monster Cable" brand and its imitators, certainly did suffer corrosion of its multistrand plain copper wire. Through the clear sleeving, you could see green fluid at the ends and copper tarnishing effects within 5 years in our coastal climate. I have stripped many, much older PVC mains cables and only seen clean copper, so the problem was down to a heavily plasticised specification and relatively large air gaps between strands.
PVC is ordinarily quite rigid, almost as hard as plumbing and electrical fittings so originally, flexible PVC sheet, laminates and extrusions such as cables, were softened by adding liquid Di-Octyl Phthalate (DOP). Unfortunately, that substance slowly migrates out of the plastic again and reacts with the copper in moist air, which makes its way in via the space between the wire strands. More stable but expensive plasticisers were certainly available then but cheapness is more convincing to buyers who have no clue other than sales pitch and appearance.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
For the sake of others reading here though, particularly ESL folk, perhaps hoping to find ordered discussion and help on the kits, I think we should get back on-topic and keep focused, like the title says, on clone kit matters.
Early super cables which used large amounts of cheap plasticiser for a high degree of flexibility, such as "Monster Cable" brand and its imitators, certainly did suffer corrosion of its multistrand plain copper wire. Through the clear sleeving, you could see green fluid at the ends and copper tarnishing effects within 5 years in our coastal climate. I have stripped many, much older PVC mains cables and only seen clean copper, so the problem was down to a heavily plasticised specification and relatively large air gaps between strands.
PVC is ordinarily quite rigid, almost as hard as plumbing and electrical fittings so originally, flexible PVC sheet, laminates and extrusions such as cables, were softened by adding liquid Di-Octyl Phthalate (DOP). Unfortunately, that substance slowly migrates out of the plastic again and reacts with the copper in moist air, which makes its way in via the space between the wire strands. More stable but expensive plasticisers were certainly available then but cheapness is more convincing to buyers who have no clue other than sales pitch and appearance.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
For the sake of others reading here though, particularly ESL folk, perhaps hoping to find ordered discussion and help on the kits, I think we should get back on-topic and keep focused, like the title says, on clone kit matters.
I use Van Damme studio cable on my NCC200/Hackernaps, either the blue 2.5mm or I also have the "shotgun" 6mm twin axial cable. Nothing fancy but good quality cable. All of my NAP/NCC amps have the output inductor. Specs are here:
Van Damme - Specifications - Blue Series Studio Grade speaker cable
Van Damme - Specifications - Blue Series Studio Grade speaker cable
I have to say Ian the importance of the cable shifted gear. Most of my suggestions were nothing to do with Quad. I thought very early on that builders of these kits would be clueless about the cable types. If the kits follow a true Naim pattern the cable will be as important as the right type of oil for a car or lawn mower ( the later being more complex ). As I said Audioquest looks to be like NACA5 in the areas of doubt. QED not quite good enough in standard form. However if split and twisted to 2.5 turns per metre meets Naim 1976 specs. Naim hated QED cable. Mostly as people bought it without thinking.
Ian whatever you do don't see cable as " not very important ". In general it isn't. This is the exception. NACA5 was even said to be less than ideal if < 3.5 metres. 99% of what I said was nothing to do with Quad. I tell a lie, 100 %. I will be suggesting the Audioquest to the friend for the Quads as a coincidence. The main reason being that mains cable is not really cheaper and is ugly. Bill Low the boss of Audioquest is a very nice person who I suspect always tries to do the job at the best posible price when for the mass market. One of his cables used polypropylene farm type rope as dielectric. That is a very smart move.
CPC Farnell sell a brand called Pro Power. It is so cheap as to seem to be below market prices for copper. I bought some of their basic OFC mic cable for experiments. It costs about a Big Mac for 30 metres. As far as I know it is to broadcast standards and if cables have a sound, sounds better than most. It solders very well is the reason I suspect. It almost pulls the solder out of my hand. Dielectric is PVC which makes it more surprising. It is very thin ( circa 4 mm ) which means if stripped and sleeved will go into DIN plugs as true mono cables. A friend with Naim NAP 250 etc has some of these which to him outperforrm all others. That only started as he wanted a cheap cable for a tape deck. I use Rean Neutrik cheaper DIN which are the best audio connector I ever found regardless of price. Rean cheapest RCA also. They are much better than Neutrik Pro range. Thus for $5 a DIN/RCA connector that will never be beaten in reality. Reason is as few parts as possible sized to the best possible sizes. I would say any cable I have every used will not convince me it is better than the ones just described. I am the type who believes in cables. I have no belief they should be expensive. Capacitance is a question as is ideal types of conductor. Size alone in most cases is the key question. Keep it as small as you can in many cases. Although I have no proof I tend to find chunky cables sound bad. I think that is because no passion went into the product. I have bought HDMi cables at Poundland that please me more. They are crimped and either work or don't work. Mostly they work. I hate to think of the working conditions that encourage the price!
BTW DIN is best. Even XLR is not in itself as good. It is better as it is balanced. XLR is too chunky for ideal audio work. Now I can't prove that, but totally believe it. RCA is hopeless regardless of make or price. It was a cheap connector that became important. DIN is associated with cheap things. A shame because it is rather excellent.
Ian whatever you do don't see cable as " not very important ". In general it isn't. This is the exception. NACA5 was even said to be less than ideal if < 3.5 metres. 99% of what I said was nothing to do with Quad. I tell a lie, 100 %. I will be suggesting the Audioquest to the friend for the Quads as a coincidence. The main reason being that mains cable is not really cheaper and is ugly. Bill Low the boss of Audioquest is a very nice person who I suspect always tries to do the job at the best posible price when for the mass market. One of his cables used polypropylene farm type rope as dielectric. That is a very smart move.
CPC Farnell sell a brand called Pro Power. It is so cheap as to seem to be below market prices for copper. I bought some of their basic OFC mic cable for experiments. It costs about a Big Mac for 30 metres. As far as I know it is to broadcast standards and if cables have a sound, sounds better than most. It solders very well is the reason I suspect. It almost pulls the solder out of my hand. Dielectric is PVC which makes it more surprising. It is very thin ( circa 4 mm ) which means if stripped and sleeved will go into DIN plugs as true mono cables. A friend with Naim NAP 250 etc has some of these which to him outperforrm all others. That only started as he wanted a cheap cable for a tape deck. I use Rean Neutrik cheaper DIN which are the best audio connector I ever found regardless of price. Rean cheapest RCA also. They are much better than Neutrik Pro range. Thus for $5 a DIN/RCA connector that will never be beaten in reality. Reason is as few parts as possible sized to the best possible sizes. I would say any cable I have every used will not convince me it is better than the ones just described. I am the type who believes in cables. I have no belief they should be expensive. Capacitance is a question as is ideal types of conductor. Size alone in most cases is the key question. Keep it as small as you can in many cases. Although I have no proof I tend to find chunky cables sound bad. I think that is because no passion went into the product. I have bought HDMi cables at Poundland that please me more. They are crimped and either work or don't work. Mostly they work. I hate to think of the working conditions that encourage the price!
BTW DIN is best. Even XLR is not in itself as good. It is better as it is balanced. XLR is too chunky for ideal audio work. Now I can't prove that, but totally believe it. RCA is hopeless regardless of make or price. It was a cheap connector that became important. DIN is associated with cheap things. A shame because it is rather excellent.
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Nigel, you did ask a question in #1336 about what cable to recommend for a Quad 303/ESL57 system. Perhaps it was rhetorical musing, but that is what I was replying to.
Few here now, are saying they want to complete their clone as a Naim design anyway. Quite a few have commented that they see more value in The NCC200 direction. That is also claimed to sound better to the Naim fanatics at PFM forum. The modifications are minimal, inexpensive and the special cable issue should also be avoided, allowing the use of standard speaker cables.
It would be interesting to hear back from those who have followed the published NCC200 schematic or copied an Avondale clone directly in their Ebay clone build, to hear their conclusions.
Few here now, are saying they want to complete their clone as a Naim design anyway. Quite a few have commented that they see more value in The NCC200 direction. That is also claimed to sound better to the Naim fanatics at PFM forum. The modifications are minimal, inexpensive and the special cable issue should also be avoided, allowing the use of standard speaker cables.
It would be interesting to hear back from those who have followed the published NCC200 schematic or copied an Avondale clone directly in their Ebay clone build, to hear their conclusions.
Ian I understood that and wanted to be clear with people that the Naim sound is an odd- valid 1970's way of thinking. Almost what soup is to other food.
The very great shame is no one revisits the Sinclair Z30/50 that all these ideas came from and not the supurious RCA that in no way resembles the Naim. Where as the Lada Riva is a Fiat 124 the Naim is not a RCA. The Sinclair has a biasing system that given more thought might be the fastest way of shutting down the bases. If over biased class AB it should be fine. Douglas Self has taught people to reject this option. Shame. The mods to NAP 140 make it a new design. If one takes it too far one gets a Denon PMA 250.
The very great shame is no one revisits the Sinclair Z30/50 that all these ideas came from and not the supurious RCA that in no way resembles the Naim. Where as the Lada Riva is a Fiat 124 the Naim is not a RCA. The Sinclair has a biasing system that given more thought might be the fastest way of shutting down the bases. If over biased class AB it should be fine. Douglas Self has taught people to reject this option. Shame. The mods to NAP 140 make it a new design. If one takes it too far one gets a Denon PMA 250.
They can never be too big. The way Naim did it was that the whole case was the heat sink and not the bracket.
I have used 2 x 1 x 1/4 inch L shaped aluminium. Aluminium is often sold in inches. I suspect a heat sink of 0.5 degrees per watt would be about right. Naim used a thermal switch at about 75 C to switch the mains to the transformer off if too hot.
I have used 2 x 1 x 1/4 inch L shaped aluminium. Aluminium is often sold in inches. I suspect a heat sink of 0.5 degrees per watt would be about right. Naim used a thermal switch at about 75 C to switch the mains to the transformer off if too hot.