no Luke, its for the set, they are calling the 'item' the matched combined device, which is equivalent to a set of 8 resistors. its still pricey, but when you are asking for the highest matching they can muster and asking for a custom made laser trimmed device, in a form that is not anything in their catalogue, you would expect some additional expense.
Last edited:
The resistors - For a slightly different approach to these ....
I built some "home-made" non inductive, non capacitive Isotan and Manganin resistors for my headamp with excellent results (PIA to make!)
Following Patrick's advice to find the Futaba MPC74 resistors at "Buerklin", I noticed that they kept some of the Isabellenheutte SMD resistors, the Isoplan range, that are not only accurate, reasonably priced, are also 50ppm for the SMR 4723 and also the bigger PBH ones - they are made of the same Manganin material - they will need two "legs" to mount in the pcb to reach the heatsink, but no real problem.
Manganin, Isotan, Constantan, etc is readily available in the EU in 5metre lengths at ges.cz, buerklin, sos, conrad, etc. and definitely worth a try.
... highly recommended.
I built some "home-made" non inductive, non capacitive Isotan and Manganin resistors for my headamp with excellent results (PIA to make!)
Following Patrick's advice to find the Futaba MPC74 resistors at "Buerklin", I noticed that they kept some of the Isabellenheutte SMD resistors, the Isoplan range, that are not only accurate, reasonably priced, are also 50ppm for the SMR 4723 and also the bigger PBH ones - they are made of the same Manganin material - they will need two "legs" to mount in the pcb to reach the heatsink, but no real problem.
Manganin, Isotan, Constantan, etc is readily available in the EU in 5metre lengths at ges.cz, buerklin, sos, conrad, etc. and definitely worth a try.
... highly recommended.
huh? first time i've mentioned or even heard of them, ashaw got the quote on a custom job and laid down the details, but you seemed to have some trouble understanding, so I confirmed it, first time i've said anything about them
I dont mind dropping a butt load of cash on a nice case and so forth, but 365 bucks for 8 resistors? Is anyone here seriousyl considering this? If not lets get on with what people here will do.
If you are serious, accept my apology, carry on and I'll just find something sane to use.
Russellc
If you are serious, accept my apology, carry on and I'll just find something sane to use.
Russellc
depends on what I spend on my case, but no probably not straight away, I will get my head around the build as speced and probably find the best match I can from 20 or so caddock or perhaps ohmite to220 thin films (havent checked if they go that low). I only commented again due to the strange attitude from luke based on a figment.
I have been a good customer of theirs in the past, but have never dropped more than 125 on a quad of signal R's matched global and relative to 0.005%, that was pretty crazy and this is crazier money, so I would only do it if the amp wins my heart and I want to give back to it with a round of tweaks and parts upgrades ;D
so happy to get back to the scheduled program and leave this for a GB if it gets that far.
I have been a good customer of theirs in the past, but have never dropped more than 125 on a quad of signal R's matched global and relative to 0.005%, that was pretty crazy and this is crazier money, so I would only do it if the amp wins my heart and I want to give back to it with a round of tweaks and parts upgrades ;D
so happy to get back to the scheduled program and leave this for a GB if it gets that far.
Last edited:
I must say I follow this discussion with amusement.
But there is a better thread for this discussion -- the F5 impression thread from Bear. There I have seen most innovative ideas like separate power supply for input and output stages. So maybe you should consider to continue the discussion there. I am sure it will be a lot more fun.
Yes, Isabellenhuette makes good resistors, especially for measurement purposes where low TCR and inductance are important. You will find that they are even better than Caddock MP930s in those aspects. To use Isabellehuette, you don't need to go SMD, just use the PBH series which is available from Buerklin. The PCB will take it just by drilling bigger holes (DIY without saying), and you don't even need to heat sink. Free air rating is 3W, which is sufficient for this application.
Why do I know all these ? pPlease take a look at these two-legged TP247 devices in post #335. That was, as I said, 2004.
Patrick
But there is a better thread for this discussion -- the F5 impression thread from Bear. There I have seen most innovative ideas like separate power supply for input and output stages. So maybe you should consider to continue the discussion there. I am sure it will be a lot more fun.
Yes, Isabellenhuette makes good resistors, especially for measurement purposes where low TCR and inductance are important. You will find that they are even better than Caddock MP930s in those aspects. To use Isabellehuette, you don't need to go SMD, just use the PBH series which is available from Buerklin. The PCB will take it just by drilling bigger holes (DIY without saying), and you don't even need to heat sink. Free air rating is 3W, which is sufficient for this application.
Why do I know all these ? pPlease take a look at these two-legged TP247 devices in post #335. That was, as I said, 2004.
Patrick
Last edited:
I am sure the Vishay Z foils are excellent resistors, and I use them as well when their attributes are important, e.g. in IV conversion. In this particular application, the source resistor is used in combination with the MOSFET, so the two should be seen a one sub-component. Then you could ask yourself what would happen if the resistor has a higher TCR, or is slightly inductive. Does it makes things worst, or does it help to compensate for some of the not-so-welcomed characteristics of the MOSFETs ?
I guess no one here would say that the likes of Accuphase, Pass Labs and Ayre make bad sounding amplifiers. I see MPC78s in Accuphase brochures for years now, I see multiple PRP resistors used in parallel in Ayre products. The intelligent circuit designer does not have to (always) resort to exotic parts to make good sounding amplifiers, but rather intelligent choice of components, picking the right characteristics for the right application.
Patrick
I guess no one here would say that the likes of Accuphase, Pass Labs and Ayre make bad sounding amplifiers. I see MPC78s in Accuphase brochures for years now, I see multiple PRP resistors used in parallel in Ayre products. The intelligent circuit designer does not have to (always) resort to exotic parts to make good sounding amplifiers, but rather intelligent choice of components, picking the right characteristics for the right application.
Patrick
For those who wants to have good sounding, good looking amplifiers without spending a fortune, I tried to offer you a solution, my solution. The good news for those who wants to follow my example is that MPC74 is now available at Buerklin (with sales office in Germany, USA and Brazil), at a price which is even lower than what I paid for mine half a year ago. So this will not costs you more than 5 Euros.
For those who wants to test the limit, maybe the solution I am offering here is not the optimal solution for you after all. But we would be happy to, at special request, offer you our mini-tower monoblock design, custom made to your needs, has enough heat sink to make sure you will never go over 50°C, will also take Plitron low noise audio transformers, technically much more superior than dual-mono, and totally exclusive design not shared by another 50 guys around. That must be worth another 2 grand (Euros I meant) ?
And it goes without saying that the PCB is also not optimum for you, because it is way too big if you want to use TZ220 for the 50R feedback resistors, or Vishay VAR for the JFET source resistor, .... The no-compromise solution can only be a custom made, solid silver PCB laid specially to accommodate those exclusive parts. And I am sure there are no shortage of skill here to lay a PCB for such a simple circuit.
No, no, I am not being sarcastic. I would be the first to encourage you to try this out and report back to us all, and I shall be the first to congratulate you if you are trilled with your special solution. But my task here is to offer a (IMHO good) solution for the general membership to help them enjoy DIY without spending more than they are willing to. And I only hope that I can half way succeed in doing so.
If what I offer is not good enough for your critical demands, I am sure you also have the capability to find a tailored solution which meets all your expectations. And I look forward to seeing your special solution here before too long.
Best regards,
Patrick
For those who wants to test the limit, maybe the solution I am offering here is not the optimal solution for you after all. But we would be happy to, at special request, offer you our mini-tower monoblock design, custom made to your needs, has enough heat sink to make sure you will never go over 50°C, will also take Plitron low noise audio transformers, technically much more superior than dual-mono, and totally exclusive design not shared by another 50 guys around. That must be worth another 2 grand (Euros I meant) ?
And it goes without saying that the PCB is also not optimum for you, because it is way too big if you want to use TZ220 for the 50R feedback resistors, or Vishay VAR for the JFET source resistor, .... The no-compromise solution can only be a custom made, solid silver PCB laid specially to accommodate those exclusive parts. And I am sure there are no shortage of skill here to lay a PCB for such a simple circuit.
No, no, I am not being sarcastic. I would be the first to encourage you to try this out and report back to us all, and I shall be the first to congratulate you if you are trilled with your special solution. But my task here is to offer a (IMHO good) solution for the general membership to help them enjoy DIY without spending more than they are willing to. And I only hope that I can half way succeed in doing so.
If what I offer is not good enough for your critical demands, I am sure you also have the capability to find a tailored solution which meets all your expectations. And I look forward to seeing your special solution here before too long.
Best regards,
Patrick
Last edited:
Words carved in the stone
If MPC74/78 are good for Accuphase, they are good for Patrick.
If they are good for Patrick, they are excellent for me.
This is the thread I was referring to in post #452.
http://www.diyaudio.com/forums/pass-labs/155599-f5-listening-impressions-discussion.html
P.
http://www.diyaudio.com/forums/pass-labs/155599-f5-listening-impressions-discussion.html
P.
This one for those who want to wind their own resistors (excellent piece of work by John) :
IV resistor 500 Ohm
Patrick
IV resistor 500 Ohm
Patrick
Bahahaha, why do people always take it to the extreme when extreme parts choices are mentioned AS AN OPTION, I find the idea intriguing as I do dearly love the Zfoil material for line level and i've been looking for an excuse to use the power resistors for a while, but the custom built though I appreciate the effort that goes into them, is crazy expensive and I would need to be given good reason to do such a thing, but I will only take that step once the meat and potatoes is taken care of and after I know a bit more about the amplifier and maybe finished my speakers (now theres an idea). i'll try them out in the D1 IV instead where they dont cost 300 each.
Considering the vast majority of my builds to this point have been line level gear, their power supplies, or headphone amps (though some at silly voltages for the output) i'm not planning to make any radical departures as I clarified above. i'm quite happy to save some money so caddock is fine and I may or may not go with the case, not just on design, but if I can build something suitable cheaper that works as well for me, I probably will. great looking and well built cases are excellent and I love a great piece of industrial design as much as the next guy (maybe more having a graphic design and photographic imaging background), but just wondering why they dont fall into the same category when essentially you could strap a couple of conrad sinks to a wooden box and achieve mostly the same audible result? perhaps higher if that money saved goes towards other options. (this is hypothetical BTW)
the thing is, the source that this will be used with I have gone pretty crazy on parts choices, teflon substrate on the sabre dac etc as an attempt to stop myself from just building anything and everything I get my hands on. so I know myself at some point after the amp is built I will get an itch, so perhaps I may go the TX220Z, perhaps i'll do something else like change to one of the other output devices. I dont know, but the chances of it staying in stasis are next to none.
so i'll say again, happy to follow what goes on in here and happy to drop the zfoil convo, its really not at the forefront of my mind. guess i'm just excited, been putting off a speaker amp and speaker build for some time now, but this one grabbed me by the balls.
Considering the vast majority of my builds to this point have been line level gear, their power supplies, or headphone amps (though some at silly voltages for the output) i'm not planning to make any radical departures as I clarified above. i'm quite happy to save some money so caddock is fine and I may or may not go with the case, not just on design, but if I can build something suitable cheaper that works as well for me, I probably will. great looking and well built cases are excellent and I love a great piece of industrial design as much as the next guy (maybe more having a graphic design and photographic imaging background), but just wondering why they dont fall into the same category when essentially you could strap a couple of conrad sinks to a wooden box and achieve mostly the same audible result? perhaps higher if that money saved goes towards other options. (this is hypothetical BTW)
the thing is, the source that this will be used with I have gone pretty crazy on parts choices, teflon substrate on the sabre dac etc as an attempt to stop myself from just building anything and everything I get my hands on. so I know myself at some point after the amp is built I will get an itch, so perhaps I may go the TX220Z, perhaps i'll do something else like change to one of the other output devices. I dont know, but the chances of it staying in stasis are next to none.
so i'll say again, happy to follow what goes on in here and happy to drop the zfoil convo, its really not at the forefront of my mind. guess i'm just excited, been putting off a speaker amp and speaker build for some time now, but this one grabbed me by the balls.
Last edited:
> What are the benefits of balanced F5 over standard?
Constant current draw, better immunity to noise (if you balance all the way from source, e.g. CD, to speaker), super symmetry, much lower even order harmonic distortions, higher power, .......
Enough ?
Patrick
PS
There might still be people who prefer the SE f5, like some people prefer Aleph to Aleph-X.
They belong to the group of people who prefers second harmonics to third, and think that it is more musical.
Matter of taste.
My system is totally balanced. Would not want anything else.
.
Constant current draw, better immunity to noise (if you balance all the way from source, e.g. CD, to speaker), super symmetry, much lower even order harmonic distortions, higher power, .......
Enough ?
Patrick
PS
There might still be people who prefer the SE f5, like some people prefer Aleph to Aleph-X.
They belong to the group of people who prefers second harmonics to third, and think that it is more musical.
Matter of taste.
My system is totally balanced. Would not want anything else.
.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.