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Post by PinkFloyd on Oct 11, 2010 15:33:16 GMT
Does the 5 watts give an advantage compared to 0.5 watt then? And would you rather use a 0.5watt carbon film than ie. a 2watt metal film, 3watt wirewound or 3 watt metal oxide. Its hard to make a qualified choice when the specifications are rather similar, but the construction ant material type is very different. To a novice mind more watts and size seems appealing and "better" but i suspect that isnt the case here? This may be a stupid answer but the reason I used the 5 watt resistors is because I had them. Some say that it is better to use high wattage resistors due to the increased surface area (sonically advantageous). You certainly don't want to use wirewound types as they are inductive... metal film resistors also have inductance and drift, and their sound is a little harsh.... the Kiwame resistors are non inductive and their silicone insulated body is reputed to be reason for their nice sound properties. The Kiwame's aren't too expensive either
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Post by Koolind on Oct 11, 2010 15:47:47 GMT
Does the 5 watts give an advantage compared to 0.5 watt then? And would you rather use a 0.5watt carbon film than ie. a 2watt metal film, 3watt wirewound or 3 watt metal oxide. Its hard to make a qualified choice when the specifications are rather similar, but the construction ant material type is very different. To a novice mind more watts and size seems appealing and "better" but i suspect that isnt the case here? My answer would be: I would prefer 0.5W metal or carbon film over wirewound as wirewound acts more like a coil then the film types. When you were to short the output of the amp and have a 68 Ohm resistor mounted and it would be putting out a continuous sinewave at maximum power the resistor would be dissipating 1.4 Watts. In practice with musical content and a headphone connected the dissipated power would always remain well below 0.5W. Your ears would be glowing before the resistors are with this power. With smaller resistor values of say 10 Ohms (recommend to experiment with those values as the Panda is quite capable of handling this) the recommended rating would be a 5W type for this one. Shorting the output in this vcase and playing it full power will burn out the 10 Ohm emitter resistors in the output stage and possibly overheat the power transistors. Keep in mind that when fitted you can literally destroy low ohmic headphones with it, not high Ohmic (above 300 Ohm) though. Thank you for clarifying.. My plan is to fit a 10 ohm resistor to begin with, and then make a swich or most likely an external adapter of some sort afterwards. In this case however i would have to get a 5w 10ohm resistor of some sort used at all times. For this i suppose that some of the very nice looking Kiwame carbon film resistors would be good, although they are a bit pricey (mostly due to shipping, as they only seem to be sold a few places) I wouldnt want to create a "bottle neck" at this point though by using a non-optimal resistor naturally
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Post by Koolind on Oct 11, 2010 15:56:31 GMT
Does the 5 watts give an advantage compared to 0.5 watt then? And would you rather use a 0.5watt carbon film than ie. a 2watt metal film, 3watt wirewound or 3 watt metal oxide. Its hard to make a qualified choice when the specifications are rather similar, but the construction ant material type is very different. To a novice mind more watts and size seems appealing and "better" but i suspect that isnt the case here? This may be a stupid answer but the reason I used the 5 watt resistors is because I had them. Some say that it is better to use high wattage resistors due to the increased surface area (sonically advantageous). You certainly don't want to use wirewound types as they are inductive... metal film resistors also have inductance and drift, and their sound is a little harsh.... the Kiwame resistors are non inductive and their silicone insulated body is reputed to be reason for their nice sound properties. The Kiwame's aren't too expensive either I will try and get some Kiwame's then Good that i found out by now at least, i was about to order wirewound ones
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Post by PinkFloyd on Oct 11, 2010 15:57:46 GMT
Mick, That is very nice work indeed I'll send those resistors over to you tomorrow and will see if I have another toggle switch kicking about.
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Post by Deleted on Oct 11, 2010 16:34:02 GMT
If you mean the little yellow ones Frans, i just followed the photo`s posted on here, they seemed to be mounted high, but will remember what you say next time i need to install them. PS. Just lowered them all down to the natural bend.
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Post by Deleted on Oct 11, 2010 16:38:46 GMT
Mick, That is very nice work indeed I'll send those resistors over to you tomorrow and will see if I have another toggle switch kicking about. Thanks Mike, done my best, just lowered the ceramic caps to the natural bend, so should be right now . Any joy with the toroid yet!! Mick.
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Post by Deleted on Oct 11, 2010 16:49:27 GMT
Yes ... I meant those yellow ones indeed. the natural bend is the correct position. These yellow ones are much more sturdy then the blue (Siemens) Sibatit ones that used to break when you heated them and tried to reposition them. These resistors: uk.farnell.com/tyco-electronics-cgs/mpc52100j/resistor-5w-10r/dp/1174266Are also extremely good. a bit fragile though... (the ceramic back and legs aren't the most bullitproof pieces of it)
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Post by bizzie on Oct 11, 2010 16:51:52 GMT
My kit arrived today and I've checked the contents already, everything's there and one extra transistor. The only thing I don't like is that the volume pot has the split end designed for a push on knob so doesn't work very well with an extension rod but I have a spare 50k pot with a straight shaft so I'll use that one instead. I'm not sure when I can get to put it together though as work is going to get in the way of fun
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Post by PinkFloyd on Oct 11, 2010 19:33:34 GMT
Hi folks, this is my 'cherry' post - so please be gentle with me! I've been lurking here for a while and must say you guys seem to be a great bunch and very knowledgable. I expect to pick up some great tips and get some education here and I've already learned alot (and spent a fortune ) - being a newbie to headfi. Anyhow, I've been following the Panda thread and have bought one - but I've been holding off building it until Mike has built Panda 3 - just so I don't damage any components or the board if any components need changing. So, in relation to changing components, if these Kiwame resistors are so good for audio use, why wouldn't one simply replace all the Panda resistors with like-for-like Kiwame equivalents? Would this be an even better sounding 'super-Panda'? I hope this isn't a blindingly stupid question!? Hi Dicky, Welcome to the forum. If they were standard metal film types then I'd possibly say yes, it may be beneficial to change them over to the Kiwame types. Thing is, the kit comes with Dale resistors which are very good quality 1% tolerance types, they also have non magnetic end caps and pure copper leads. The non magnetic end caps are good for high frequency response and low crosstalk.... in fact, there are no magnetic materials used in the construction of the Dale resistors which is very good for audio Hope this helps, Mike.
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Post by dicky on Oct 11, 2010 20:29:00 GMT
Thanks for the welcome Mike, so I guess the non-Dale resistors in the Panda design are not in the audio path? So, when you substitute capacitors - like in the X-CAN upgrades, what properties are important to the sound? I've heard of paper and oil; polyethylene and mica capacitors and-so-on. I've heard of specific 'audio' components costing £100's but I guess there's also a law of diminishing returns. Regards, Richard
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Post by Deleted on Oct 11, 2010 21:05:15 GMT
Does the 5 watts give an advantage compared to 0.5 watt then? And would you rather use a 0.5watt carbon film than ie. a 2watt metal film, 3watt wirewound or 3 watt metal oxide. Its hard to make a qualified choice when the specifications are rather similar, but the construction ant material type is very different. To a novice mind more watts and size seems appealing and "better" but i suspect that isnt the case here? My answer would be: I would prefer 0.5W metal film or carbon composite or carbon film over wirewound as wirewound acts more like a coil (unless we are talking about special wound, so called bifilar winding, wirewound resistors) then the film or composite types. When you were to short the output of the amp and have a 68 Ohm resistor mounted and it would be putting out a continuous sinewave at maximum power the resistor would be dissipating 1.4 Watts. In practice with musical content and a headphone connected the dissipated power would always remain well below 0.5W. Your ears would be glowing before the resistors are with this power. With smaller resistor values of say 10 Ohms (recommend to experiment with those values as the Panda is quite capable of handling this) the recommended rating would be a 5W type for this one. There are ceramic power resistors that can handle these power and have almost zero induction, just like carbon composite. Shorting the output in this vcase and playing it full power will burn out the 10 Ohm emitter resistors in the output stage and possibly overheat the power transistors. Keep in mind that when fitted you can literally destroy low ohmic headphones with it, not high Ohmic (above 300 Ohm) though. I agree with Frans on this one. Also,you are extremely unlikely to hear any difference between the expensive resistors and a normal metal film 1% resistor in this part of the circuit. That is not the case in the input and feedback areas of the design though. .5W emitter resistors are more likely, at least in my experience, to go open circuit in an overload situation which helps to protect the output devices . Alex
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Post by Koolind on Oct 11, 2010 21:47:09 GMT
My answer would be: I would prefer 0.5W metal film or carbon composite or carbon film over wirewound as wirewound acts more like a coil (unless we are talking about special wound, so called bifilar winding, wirewound resistors) then the film or composite types. When you were to short the output of the amp and have a 68 Ohm resistor mounted and it would be putting out a continuous sinewave at maximum power the resistor would be dissipating 1.4 Watts. In practice with musical content and a headphone connected the dissipated power would always remain well below 0.5W. Your ears would be glowing before the resistors are with this power. With smaller resistor values of say 10 Ohms (recommend to experiment with those values as the Panda is quite capable of handling this) the recommended rating would be a 5W type for this one. There are ceramic power resistors that can handle these power and have almost zero induction, just like carbon composite. Shorting the output in this vcase and playing it full power will burn out the 10 Ohm emitter resistors in the output stage and possibly overheat the power transistors. Keep in mind that when fitted you can literally destroy low ohmic headphones with it, not high Ohmic (above 300 Ohm) though. I agree with Frans on this one. Also,you are extremely unlikely to hear any difference between the expensive resistors and a normal metal film 1% resistor in this part of the circuit. That is not the case in the input and feedback areas of the design though. .5W emitter resistors are more likely, at least in my experience, to go open circuit in an overload situation which helps to protect the output devices . Alex Ok.. So its presumeably more of a theoretical issue than an actual sonic difference ? You propose that it could be an advantage that the resistors will fail at a too high load? Doesnt the resistance change to a certain extent when the temperature goes up, thus affecting the sound?
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Post by Deleted on Oct 11, 2010 21:56:24 GMT
I agree with Frans on this one. Also,you are extremely unlikely to hear any difference between the expensive resistors and a normal metal film 1% resistor in this part of the circuit. That is not the case in the input and feedback areas of the design though. .5W emitter resistors are more likely, at least in my experience, to go open circuit in an overload situation which helps to protect the output devices . Alex Ok.. So its presumeably more of a theoretical issue than an actual sonic difference ? You propose that it could be an advantage that the resistors will fail at a too high load? Doesnt the resistance change to a certain extent when the temperature goes up, thus affecting the sound? Not too any great extent, unless severely overloaded. I would rather replace a couple of resistors worth a few cents than a couple of output transistors. If you have a better than average resolution DMM, check the value of the resistors before soldering, and again after soldering in situ. You wil see a small but definte change in value. Depending on how long the soldering iron is held on during soldering, resistors that were reading exactly the same value before soldering , may no longer be a complete match. Alex
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Post by clausdk on Oct 11, 2010 22:23:37 GMT
Splendid work Mick, if only I had your skill and patience
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Post by PinkFloyd on Oct 11, 2010 22:40:03 GMT
Thanks for the welcome Mike, so I guess the non-Dale resistors in the Panda design are not in the audio path? You guess correct Low ESR caps (low resistance) electrolytics are generally better than general purpose types but not in "all" applications. There is no such thing as one brand of capacitor which is suitable for use "anywhere".... unfortunately people have been misled in this respect and believe that if they replace all of their capacitors with "Black Gate" types that some sort of magical sound will automatically appear. The truth is that if you fire in "boutique" caps holus bolus you are likely to end up with a "worse" sounding amp! Ever heard the one about black gate caps taking 6 months to "burn in"?.... another myth IMO, more likely that after 6 months your ears get used to the shitty sound Properties important to the sound? What I always look for is greater clarity, better bass extension, more midrange detail, a greater sense of space round instruments and an inky black silence between starts and stops. Unforunately, there is no defacto recipe for cap upgrades, it really is a case of trial and error.... after a while you will get used to the "house sound" of the various brands and will learn how to "mix and match" to achieve the presentation you are looking for. Basically..... "expensive" caps do not always mean "best" caps.... look at the SCHA, for example, quite a few of the builders agreed that the SunTan capacitors were the best in the PSU section and SunTan caps are probably the cheapest capacitor there is. Similarly, in the X-CAN amps, I have found that the Hitano 105C non polar caps perform better than any other I have tried and they are the cheapest you can buy! So, to try and answer your question, it's not so much the law of diminishing returns as a capacitor costing £100 may well sound inferior to a capacitor costing ten pence.... it's all about choosing the "right" capacitor for the job. The guys that fire black gates in like they are sweets have already been convinced that, in doing so, their amp will be improved dramatically..... they have a listen, find the sound a bit harsh, they are then informed that the black gates will take 6 months to "burn in"..... as I said, they either get used to the sound or are too embarrassed to admit that they have just wasted a couple of hundred quid making their amp sound worse. A capacitor that takes 6 months to form? absolute hogwash! pure BS but "BS" that a lot of audiophiles seemingly believe.... if a company told me that their capacitors take 6 months to burn in then I would steer WELL CLEAR of such a capacitor.... not your audiophile though, he will actually pay £25 "each" for them and sit there for 6 months waiting for the "magic" to happen Don't get me wrong, black gate caps are excellent IF used in the right places but to just fit them all over the shop is a total waste of money.
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Post by Deleted on Oct 11, 2010 23:00:01 GMT
A very welcome injection of fresh air and common sense !!!
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Post by Deleted on Oct 11, 2010 23:10:23 GMT
Here's a couple of ropey shots of my almost finished Panda. I'll get better ones tomorrow hopefully, when the wires are tidied up. I had a stepped attenuator so I thought I'd incorporate it. The LED mount is very much a temporary arrangement to judge the light output. I'm still just playing it from my PC/SPDIF/XDAC V8 but it sounds extremely detailed and musical into AKG701s which I don't use a lot. There is definitely a good detailed bass I don't recall from the 701s before. Syd
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Post by PinkFloyd on Oct 11, 2010 23:27:03 GMT
Here's a couple of ropey shots of my almost finished Panda. I'll get better ones tomorrow hopefully, when the wires are tidied up. I had a stepped attenuator so I thought I'd incorporate it. The LED mount is very much a temporary arrangement to judge the light output. I'm still just playing it from my PC/SPDIF/XDAC V8 but it sounds extremely detailed and musical into AKG701s which I don't use a lot. There is definitely a good detailed bass I don't recall from the 701s before. Syd Syd, That is far from "ropey", you have made a fantastic job of that.... very nice indeed! I'm going to fit a stepped attenuator on Panda three.... those coupling rods are a friggin' rip off @ £10 a set... I see you went for an encapsulated toriod and have heat sleeved the "kissing pairs" ( ) a lovely, tidy build.... well done
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Post by PinkFloyd on Oct 11, 2010 23:40:55 GMT
I have been in negotiations and should be able to provide the Panda kit amp to UK Rock Grotto members for £45 shipped or £60 shipped with a high quality toroidal transformer included. If you want the hook up wire, the silver loaded "future" solder, a headphone socket and a pair of phono sockets it will be £75 shipped....
Would anybody be interested?
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Post by Koolind on Oct 11, 2010 23:46:42 GMT
I have been in negotiations and should be able to provide the Panda kit amp to UK Rock Grotto members for £45 shipped or £60 shipped with a high quality toroidal transformer included. If you want the hook up wire, the silver loaded "future" solder, a headphone socket and a pair of phono sockets it will be £75 shipped.... Would anybody be interested? Thats cheap ! Because of the danish postal service and custom rules i am ending up paying about 75£ shipped for the kit only If i will need a second one, this would surely be a better alternative!
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Post by PinkFloyd on Oct 12, 2010 0:06:25 GMT
I have been in negotiations and should be able to provide the Panda kit amp to UK Rock Grotto members for £45 shipped or £60 shipped with a high quality toroidal transformer included. If you want the hook up wire, the silver loaded "future" solder, a headphone socket and a pair of phono sockets it will be £75 shipped.... Would anybody be interested? Thats cheap ! Because of the danish postal service and custom rules i am ending up paying about 75£ shipped for the kit only If i will need a second one, this would surely be a better alternative! Sorry but this offer is UK only The cost to ship abroad will add a fair bit more onto the price..... I will be buying in bulk and my margins will be very small.
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Post by Koolind on Oct 12, 2010 0:16:47 GMT
Ah yes, i were still thinking the mentioned price plus additional shipping (if you are willing to ship abroad, that is) Im not buying one more just yet. I havent even recieved my first yet However, for UK this is truely a bargain, and for other contries still very cheap even if you were to add the extra shipping i think.. I am in no doubt that your margins will be very small indeed. You wouldnt be able to buy it cheaper yourselfes anywhere else, so its a great deal ! *thumps up*
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Post by PinkFloyd on Oct 12, 2010 2:08:24 GMT
I have bought 100 Panda kits. I will secure more once the first batch arrive safely. I will aim to make this kit even "more" affordable to Rock grotto members.
Mike.
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Post by Deleted on Oct 12, 2010 5:14:22 GMT
Syd, Judging from the pictures it looks like you did not install any (series) output resistors. These output series resistors are NOT present on the board and thus have to be added between the output connector on the PCB and the output socket (Mikes pics shows them clearly) I strongly recommend you use at least 10 Ohms in series (but may end up between 50 and 100 Ohms after experimenting) You can drive HP's without any series resistors but ONLY high Ohmic cans (200 Ohms and up). If you also use low Ohmic HP's (the K701 being one of them with it's 60 Ohms) you should realise these amps can burn out the drivers when left on full power (accidentally ?). 32 Ohm cans might have a very short lifespan as the amp easily puts out 2 Watts in those when there are no series resistors mounted at full power. When you own low- & high-Ohmic headphones and look for 'universal' mount something inbetween 50 and 100 Ohms. Without output resistors the Panda can even drive speakers with it until the emitter resistors burn out (literally burn !) with 8 Ohm speakers you can get around 5W output power for a short period of time before the emitter resistors burn out.
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Post by Deleted on Oct 12, 2010 5:20:53 GMT
Yes, like a lighted match ! Been there,done that . (years ago, though.) Later type resistors may not be so flammable ? Hopefully !
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